WO2005012507A1

WO2005012507A1 - Production of plant secondary metabolites using adsorption and elicitation in cell suspension culture

Info

Publication number: WO2005012507A1
Application number: PCT/AU2004/000991
Authority: WO
Inventors: Wei Zhang; Christopher Milton Mathew Franco
Original assignee: Flinders University of South Australia; Albright and Wilson Australia Ltd; Commonwealth Scientific and Industrial Research Organization CSIRO; University of Melbourne; Tridan Ltd
Current assignee: Albright and Wilson Australia Ltd; Commonwealth Scientific and Industrial Research Organization CSIRO; University of Melbourne; Tridan Ltd; Flinders University
Priority date: 2003-07-25
Filing date: 2004-07-23
Publication date: 2005-02-10
Anticipated expiration: 2006-01-25
Also published as: AU2003903909A0

Abstract

The invention discloses a method of producing a plant secondary metabolite of interest,comprising: (a) cultivating by suspension culture in a suitable nutrient medium plant cells that produce the secondary metabolite; (b) including within the suspension culture an amount of adsorbent and one or more elicitor agents suitable to increase production of the secondary metabolite; (c)recovering the secondary metabolite from the suspension culture. In a preferred emobidment the invention discloses a method of producing a stilbene plant secondary metabolite of interest, comprising: (a) cultivating by suspension culture in a suitable nutrient medium plant cells that produce a stilbene secondary metabolite; (b) including within the suspension culture an amount of adsorbent and one or more elicitor agents suitable to increase production of the stilbene; (c) recovering the stilbene from the suspension culture.

Description

Production of plant secondary metabolites using adsorption and elicitation in cell suspension culture

FIELD OF THE INVENTION

5 The present invention relates to methods of producing plant secondary metabolites, such as stilbenes, alkaloids, terpenoids, isoprenoids, phenylpropanoids, glucosinolates, steroids and pyretlirin compounds, by cell suspension culture of plant derived cells. The invention also relates to the plant secondary metabolite compounds produced by the methods of the invention. In a particularly preferred embodiment the invention relates to methods of 10 production of the stilbene compound resveratrol, and to the resveratrol so produced.

BACKGROUND OF THE INVENTION

Plants produce a wide range of "secondary metabolite compounds", which while having no

15 apparent function in the plant's primary metabolism, may have a secondary role. For example secondary metabolites may function as pollinater attractants, may be produced in response to environmental stresses or may serve as chemical defences against microorganisms, insects and higher predators or even other plants. Common classes of secondary metabolites are compounds derived from glucose and acetyl-CoA which are

20 Icnown as isoprenoids as well as compounds derived from amino acids such as alkaloids, phenylpropanoids and glucosinolates. Many plant secondary metabolites have been identified to have commercially valuable activities in products such as insecticides, pharmaceuticals, fragrances, UV protectants, flavours and dyes. Some well known and commercially important plant secondary metabolite compounds include nicotine, the

25 pyrethrins and rotenone, which are used in limited quantities in pesticides, and certain steroids and alkaloids that are used in pharmaceutical manufacture. Other secondary metabolites, such as the diterpene esters (among which are phorbol derivatives) from the latices of various species of Euphorbia are potent irritants and carcinogens that are useful in the study of chemical carcinogenesis. However, many plant secondary metabolite 0 compounds are complex organic species, which are unsuitable for production by chemical synthesis. A family of plant secondary metabolite compounds of particular interest to the present inventors is the stilbenes, which, as shown in the examples of stilbene structures depicted in figure 1, are characterised by the presence of two aromatic rings connected by a two carbon bridge. Of the stilbenes, resveratrol is of particular importance as not only has it been demonstrated to have important pharmacological activity in the treatment of human conditions such as cancers, cardiovascular degenerative diseases, skin aging, diabetes, neurological diseases, eczema, acne, psoriasis, menopause and microbial and viral infections, but it may also be used as the basic skeleton for synthesis of a number of other stilbene compounds. As shown in figure 2, which outlines the biosynthetic pathway of resveratrol, resveratrol is directly biosynthesised from p-coumaroyl CoA and malonyl CoA.

Resveratrol has been identified in at least 72 plant species. However, the most important dietary source is in the skins of red grapes such as Vitis vinifera, Vitis labrusca and Vitis muscadine, which are used to make wine. They are the most abundant natural sources of resveratrol with a content of 50-100 μg/g, based upon fresh weight of the grape skins, and about 1-3 mg/L, within red wine. As it is believed that a biologically effective daily allowance of resveratrol is in the range of 50-500 mg, it is not possible to derive such a dose simply from consumption of grapes or grape-derived products.

Resveratrol and a number of the other stilbene compounds are considered to be phytoalexin compounds. Phytoalexins are a diverse group of fungitoxic, lipophilic, low molecular weight, secondary metabolites produced and accumulated in grape vines and other plants in non-selective response to various kinds of stresses, such as attack by fungal pathogens or exposure to ultraviolet radiation. Phytoalexins are supposedly synthesised and packaged into lipid vesicles to be transported to the sites of infection where they restrict pathogen growth. They are therefore induced in antifungal plants, such that they are not present in the healthy plants but are synthesised in response to pathogenic attack or stress. Perhaps unlike some of the other phytoalexin compounds, resveratrol rapidly accumulates in healthy tissues immediately surrounding the site of pathogen infection; in the case of resveratrol, infection by Botrytis cinerea. Resveratrol is generally stored in the form of glycosides within the cells in which it is produced (as outlined in Teguo P. W. et al. (1996) The accumulation of stilbene glycosides in Vitis vinifera cell suspension cultures. J. Nat. Prod. 59: 1189-1191), with the result that if enough resveratrol is produced in the vicinity of the infection, the spread of fungal infection will be halted.

Despite the pharmacological benefits of resveratrol outlined above, and the more recently demonstrated cancer chemo-preventative activity of resveratrol, which results from the apparent inhibition of cyclooxygenase-1 (COX-1), there is still yet to be developed an efficient and low cost method of production. In this regard, a number of possibilities have to date been investigated, including solvent extraction from resveratrol-producing plants, increasing plant production of resveratrol by genetic manipulation to increase expression of the critical enzyme (stilbene synthase), and suspension cell culture with and without the use of natural elicitors that mimic pathogen infection or environmental stimuli for resveratrol production. Unfortunately, resveratrol production levels in genetically unmodified plants are so low as to preclude the commercial viability of chemical extraction as a production method, and although genetic manipulations have offered some promise there is, at least to date, a strong public concern in relation to the commercial adoption of genetically modified organisms. While the use of suspension cell culture systems involving elicitor agents such as jasmonic acid, salicylic acid, 3 -methyl-salicylic acid, betaine, /5-glucan, methyl-/3-cyclodextrin, chitosan and ethylene have demonstrated some success in increasing plant secondary metabolite (including resveratrol) production levels in suspension cell culture, the use of elicitation techniques has at best been effective to increase secondary metabolite production by several to a hundred fold. While this may sound impressive, due to the very low base level of production of resveratrol and other plant secondary metabolites, a hundred fold increase in production is generally not sufficient for commercial production purposes.

It is with this background in mind that the present inventors have investigated the use of adsorbent materials in suspension cell culture as a means for improving yield of plant secondary metabolites. Although adsorbent materials such as AMBERLITE® XAD-7 have been applied to other plant cell culture systems, their use in the past has generally resulted in an enhanced production yield of several fold to several ten-fold, whereas the present inventors have been able to demonstrate increased yields in the order of one thousand to several thousand-fold.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention there is provided a method of producing a plant secondary metabolite of interest, comprising: (a) cultivating by suspension culture in a suitable nutrient medium plant cells that produce the secondary metabolite; (b) including within the suspension culture an amount of adsorbent and one or more elicitor agents suitable to increase production of the secondary metabolite; (c) recovering the secondary metabolite from the suspension culture.

The cells may be derived from regularly sub-cultured callus culture and/or suspension cell culture. The cells or those from which they are derived may have been subjected to genetic manipulation. Preferably the callus culture will have been established in a solidified callus induction medium from plant explants of a species that produces the secondary metabolite.

In a preferred embodiment of the invention the cells are derived from one or more of the following plant species:

Atropa bella donna, Erythrina flabelliformis, Ipomoea tricolor, Erythrina crista, Celosia cristata, Gallium spurium, Lauras nobilis, Vitis labrusca, Vitis vinifera, Gratiola officinalis, Symphitum officinalis, Hosta fortunei, Cassia hebecarpa, Thalictrum flavum, Scutellaria altissima, Portulacca oleracea, Scutellaria certicola, Physalis sp., Geum fauriei, Gentiana tibetica, Linum hirsutum, Aconitum napellus, Podophyllum emodii, Thymus cretaceus, Carlina acaulis, Chamaecrista fasciculata, Pinus pinea, Peganum harmala, Tamarindus indica, Carica papaya, Cistus incanus, Capparis spinosa, Cupressus lusitanica, Diospyros kaki, Eryngium campestre, Aesculus woerlitzensis, Aesculus hippocastanum, Cupressus sempervirens, Celtis occidentalis, Polygonum cuspidatum, Elaeagnus angustifolia, Elaeagnus commutata, Gentiana macrophylla, Brassica rapa, Sesbania exaltata, Sesbania speciosa, Spartina potentifiora, Brassica juncea, Helianthus annuus, Poinsettia sp., Pelargonium zonale, Synapsis sp., Leontopodium alpinum, Lupinus luteus, Buxus microphylla var. japonica, Liatris spicata, Primula japonica, Betula nigra, Filipendula vulgrais, Lobelia siphilitica, Grevillea robusta, Reseda luteola, Gentiana littoralia, Campanula carpatica, Ageratum conizoides, Psidium guajava, Ailanthus altissima, Hydrocotyle asiatica, Brugmansia suaveolens, Thymus pulegioides, Thymus lema-barona, Thymus serphyllum (wild), Gaultheria procumbens, Thymus camosus, Thymus tliracicus, Calycanthus floridus, Zin giber officinalis, Lamium dulcis, Thymus praecox "arcticus ", Thymus speciosa, Thymus pseudolamginosus, Thymus vulgraris, Ficus religiosa, Forsythia suspensa, Chelidonium majus, Thymus wooly, Thymus portugalense, Nicotiana tabacum, Thymus cytriodorus "aureus ", Cactus officinailis, Lablab purpurea, Juglans regia, Actinidia chinensis, Hemerocallis sp., Betula pendula, Gardenia jasminoides, Taxodium distichum, Magnolia loebherii, Crataegus praegophyrum, Larix decidua, Thuja orientalis, Thuja ociden talis, Cupressocyparis leylandii, Pseudotsuga menziesii, Abies firma, Parthenocissus quinquefolia, Allium cemuum, Juniperus "blue pacific", Taraxacum officinalis, Yucca sp., Tsuga canadensis, Ilex aquifolium, Ilex comuta, Taxus hiksii, Taxus media, Metasequoia glyptostroboides, Pinus bungi ana, Buxus sempervirens, Stewartia koreana, Prunus sp., Betula dahurica, Plantago minor Acer palmatum, Acer campestre, Cotinus coggygria, Quercus robur, Acer truncatum, Achyranthes bidentata, Allium japonicum, Carum cap sicum, Agastache mexicana, Prunella vulgaris, Tagetes minuta, Nepeta cataria, Ratibida columnaris, Aster novae angliae, Myrica cerifera, Pittosporam tobira, Plantago major, Pinus sylvestris, Acoras canadensis, Pieris japonica, Pinus strobus, Trifolium pratense, Prunus serotina, Datura stramonium, Geranium maculatum, Hydrocotyle asiatica, Astragalus sinicus, Centaurea maculata, Ruschia indurata, Myrthus communis, Platanus occidentalis, Licium barba turn, Lavandula officinalis, Grevillea robusta, Hypophae rhamnoides, Filipendula ulmaria, Betula pendula, Polygonum odoratum, Brugmansia graveolens, Rhus toxi codenta, Armoracia rasticana, Ficus benjaminii, Sufflera sp., Baikiaea recurvata, Asimina triloba, Lippia dulcis, Epilobium augustifolium, Brugmansia suaveolens, Xanthosoma sagittifolium, Monstera deliciosa., Aglaonema commutatus, Dieffenbachia leopoldii, Anthurium andreanum, Syngonium podophyllum, Dracaena fragrans, Ananas comosus, Strelitzia reginae, Dieffenbachia segiune, Syngonium auritum, Dracaena sp., Haemanthus katharinae, Anthurium altersianum, Spathiphyllum grandifioram, Spathiphyllum cochle arispatum, Monstera pertusa, Anthurium magnificum, Anthurium hookeri, Anthurium elegans, Calathea zebrina, Yucca elephantipes, Bromelia balansae, Musa textilis, Myrthus communis, Olea oleaster, Olea europaea, Nerium oleander, Cocculus laurifolius, Microsorium punctatum, Sanseviera sp., Adansonia digitata, Boelimeria biloba, Piper nigrum, Phymatosorus scolopendria, Tumera ulmifolia, Nicodemia diversifolia, Tapeinochilos spectabilis, Rauwolfia tetraphylla, Ficus elastica, Cycas circinalis, Caryota urens, Cynnamomum zeylonicum, Aechmea luddemanniana, Phoenix zeylonica, Ficus benjamina, Ficuspumila, Murraya exotica, Trevesia sundaica, Clerodendrum speciosissimum, Actinidia kolomikta, Paeonia lactifiora, Paeonia suffraticosa, Quercus imbricaria, Iris pallida, Portulacca olleracea, Polygonum aviculare, Iris pseudocarpus, Ailium nutans, Ailium fistulosum, Anthericum ramosum, Veratram nigrum, Polygonum lapathifolium, Hosta lancifolia, Hosta sieboldii, Echinops sphaerocephalus, Paeonia dahurica, Inula helenium, Crambe pontica, Digitalis lutea, Baptisia australis, Aristolochia australis, Hyssopus seravschanicus, Teucrium chamaedrys, Sedum album, Heracleum pubes cens, Origanum vulgare, Cachrys alpina, Laser trilobum, Matteuccia strathiopteris, Sedum telephium, Bocconia cordata, Ajuga reptans, Thalictram minus, Anemone japonica, Clematis rectae, Alchemilla officinalis, Potentilla alba, Poterium sangiusorba, Menispermum dauricum, Oxybaphus nyctagineus, Armoracia rasticana, Crambe cordifolia, Agrimonia eupatoria. Anchusa officinalis, Polemonium caeruleum, Valeriana officinalis, Pulmonaria molissima, Stachys lanata, Coronilla varia, Platycarya grandiflora, Lavandula officinalis, Vincetoxicum officinale, Acalypha hispida, Gnetum gnemon, Psychotria nigropunctata, Psychotria metbac teriodomasica, Codiaeum variegatum, Phyllanthus grandifolius, Pterigota alata, Pachyra affinis, Sterculia data, Philodendron speciosum, Pithecellobium unguis-cati, Sanchezia nobilis, Oreopanax capitatus, Ficus triangularis, Kigelia pinnata, Piper cubeba, Lauras nobilis, Erythrina caJfra, Metrosideros excelsa, Osmanthus fragrans, Cupres sussempervirens, Jacobinia sp., Senecio platyphylloides, Livistona chinensis, Tetraclinis articulata, Eucalyptus radis, Podocarpus spinulosus, Eriobotrya japonica, Gingko biloba, Rhododendron sp., Thuja occidentalis, Fagopyrum sufraticosum, Geum macrophyllum, Magnolia kobus, Vinca minor Convallaria majalis, Corylus avellana, Berberis sp., Rosa multifiora, Ostrya carpinifolia, Ostrya connogea, Quercus rabra, Liriodendron tulipifera, Sorbus aucuparia, Betula nigra, Castanea sativa, Bergenia crassifolia, Artemisia dracunculus, Ruta graveolens, Quercus nigra, Schisandra chinensis, Betula alba, Sambucus nigra, Gentiana cruciata, Encephalartos horridus, Phlebodium aureum, Microlepia platyphylla, Ceratozamia mexicana, Stenochlaena tenuifolia, Adiantum trapeziforme, Adiantum raddianum, Lygodium japonicum, Pessopteris crassifolia, Asplenium australasicum, Agathis robusta, Osmunda regaus, Osmundastram claytonianum, Phyllitis scolopendrium, Polystichum braunii, Cyrtomium fortunei, Dryopteris flux mas, Equisetum variegatum, Athyrium nipponicum, Athyrium filix-femina, Parthenocissus tricuspidata, Ligusticum vulgare, Chamaecy parispisifera, Rosa canina, Cotinus coggygria, Celtis occidentalis, Picea schrenkiana, Cydonia oblonga, Ulmus pumila, Euonymus verrucosus, Deutzia scabra, Mespilus germanica, Quercus castaneifolia, Euonymus europea, Securinega sufruticosa, Koelreuteria paniculata, Syringa josikaea, Zelkova carpinifolia, Abies cephalonica, Taxus baccata, Taxus cuspidata, Salix babylonica, Thuja occidentalis, Actinidia colomicta, Mahonia aquifo hum, Aralia mandschurica, Juglans nigra, Euonymus data, Prinsepia sinensis, Forsythia europaea, Sorbocotoneaster pozdnjakovii, Moras alba, Crataegus macrophyllum, Eucommia ulmifolia, Sorbus commixta, Philodendron amu rense, Cornus mas, Kerria japonica, Parrotia persica, Jasminum fruticans, Swidasan guinea, Pentaphylloides fruticosa, Sibiraea altaiensis, Cerasus japonica, Kolkwitzia amabilis, Amigdalus nana, Acer mandschurica, Salix tama risifolia, Amelanchier spicata, Cerasus mahaleb, Prunus cerasifera, Corylus avellana, Acer tataricum, Viburnum opulus, Syringa vulgaris, Fraxinus exelsior, Quercus trojana, Chaenomeles superba, Pinus salinifolia, Berberis vulgaris, Cotoneaster horisontalis, Cotoneaster fangianus, Fagus sylvatica, Pinuspumila, Pinus sylvestris, Berberis thunbergii, Ajuga forrestii, Anisodus acutangulus, Chinchona ledgerina, Valeriana officinalis, Peganum harmala, Chrysanthemum cineraliaefolium, Tagetes patula, Scopolia japonica, Rauwolfia serpentine, Papaver somniferam, Capsicum fratescens, Fumaria capreolata L., Datura stramonium, Tinospora rumphii, Triptorygium wilfordii, Coptis japonica, Salvia officinalis, Colleus blumei, Catharanthus roseus, Morinda citrofolia, Lithospermum erythrorhizon, Dioscorea deltoidea, Mueune pruriens, Mirabilis Jalapa, Boerhavia diffusa, Camptotheca acuminate, Nothapodytes foetida, Moras nigra, Symphoricarpus albus and Ophiorrhiza pumila.

In one embodiment of the invention the cells may be derived from leaves, fruit, shoots, buds, flowers, bark, roots, branches, stems, seeds, cones, needles or cambium tissue of the plant. In a particularly preferred embodiment of the invention the cells are derived from meristematic plant tissue.

In a preferred embodiment of the invention the secondary metabolite is a stilbene compound. Examples of stilbene compounds encompassed by the invention include trans- resveratrol, cis-resveratrol, trans-piceid, cis-piceid, trans-resveratrol dehydrodimers, cis- resveratrol dehydrodimers, trans-pterostilbenes, cis-pterostilbenes, viniferins, trans- piceatannol, (3,5,5N,4N-tetrahydroxystilbene) 3-O- -glucoside (trans-astringin).

Preferably the secondary metabolite produced is trans-resveratrol or cis-resveratrol.

In another embodiment of the invention the secondary metabolite is an alkaloid compound, a terpenoid compound, an isoprenoid compound, a phenylpropanoid compound, a glucosinolate compound or a pyrethrin compound. Examples of such compounds that may be produced by methods of the invention include taxol, podophyllotoxin, indole alkaloids, β-carboline alkaloids, 10-hydroxy-N(alpha)-demethyl- 19,20-dehydroraumacline, terpenoid indole alkaloids, strictosidine, vallesamine, O-acetylvallesamine and voaphylline, campothecin, 3-oxo-rhazinilam, 10-hydroxycampothecin, maytansine, tripdiolide, harringtonine, homoharringtonine, isoharringtonine, braceantin, ellipticine, thalicarpine, indicine-N-oxide, baccharin, hyoscyamine, scopolamine, vinblastine, vincristine, catharanthine, vindoline, sanguinarine, norsanguinarine, valepotriates, atropine, quinidine,

9-dihydrobaccatin III derivatives, rhazinilam, tubotaiwine, phenanthrofuran derivatives, ajuforrestine A, resperpine, codeine, thebaine, cryptopine, berberine, saponins, sapogenins, ginsenoside, rosmarimic acid, arbutin, ajmalicine, anthraquinones, artemesin, forskolin, shikonin, anthocyanins, diosgenin, ubiquinone- 10, serpentine, L-DOPA, pyrethrin, thiophene, 6-hydroxytaumacline, capsaicin, mine, serotonin.

According to a further embodiment of the invention the sub-culturing mentioned above may be conducted weekly, fortnightly or monthly.

In another embodiment, the method of production is conducted in a batch process. For example, the cultivating step may be between about two days and about several months in duration, preferably between about six days and about twenty days in duration and more preferably between about eight days and about sixteen days in duration.

In another embodiment of the invention the production method is conducted in a semi- continuous or continuous process. For example, the semi-continuous process may be operated in a fed-batch or a repeated-batch mode in which the cultivation duration may be between about two days to about several months, preferably between about six days and about twenty days in duration. The continuous process can be operated in a two-phase system in which the plant cells may be growing in a bioreactor system in either suspension or immobilization, and the medium is circulated between the bioreactor and an absorbant reservoir or resin column for secondary metabolite adsorption.

According to a preferred embodiment of the invention the elicitor agents are selected from one or more of biotic elicitors, microbial fractions or products derived from biotic elicitors, and abiotic elicitors.

Examples of suitable elicitor agents include biotic elicitors such as: Botrytis cinerea Phytophthora megasperma, Pinellas stripticum, Oligosporas sp., Pythium mamiallatum, Pythium sylvaticum, Verticillium dahliae, Verticillium sp., Penicillium minioluteum, Phytophthora lateralis, Cytospora cincta, Cytospora leucostoma, Alternaria brassicicola, Alternaria solani, Alternaria cucumerina, Botrytis squamosa, Cochliobolus heterostrophus, Colletotrichum trifolii, Colletotrichum orbiculum, Colletotrichum graminicola, Colletotrichum gloeosporioides, Cylindrocladium floridanum, Fusarium crookwellense, Fusarium heterosporium, Fusarium oxysporam f. sp. conglutinans, Fusarium oxysporam f. sp. lycopersici, Fusarium oxysporam f. sp. pisi, Gibberella zeae, Gaeumaimomyces graminis var. tritici, Geotrichum sp., Leptosphaeria torrae, Nectria haematococca MPVI, Mycosphaerella pinodes, Ophiostoma ulmi, Phoma lingam, Phoma pinodella, Phytophthora infestans, Pythium aristosporum, Pythium graminicola, Pythium ultimum, Rhizoctonia solani, Sclerotinia sp., S. nodoram D-45, Trametes versicolor, Ustilago maydis, Venturia inequalis; microbial fractions or products derived from biotic elicitors such as: Chitosan, Lichenan, Glucomannan, Pleuran, Glucan, Carboxymethylglucan, Hydroxymethylglucan, Sulfoethylglucan, Mannan, Xylan, Mannobiose, Mannotriose, Mannopentaose, Mannotetraose, Cellulysin, Multifect XL, Multifect CL, Resinase, Pulpxyme, SP431, Pectinol, Rapidase, Klerzyme, Chitinase; or abiotic elicitors such as: Arachidonic acid, Elaidic acid, Cyclic AMP, Dibutyrl Cyclic AMP, Methyl Jasmone, Cis-Jasmone, Jasmonic acid, /3-glucan, Miconazol, Ferulic acid, AMO-1618, Triton X-100, Benzoic acid, Salicylic acid, Propyl gallate, Sesamol, Chlorocholine chloride, 3,4-dichlorophenoxy triethyl-, (amine), Chloroethylphosphonic acid, Diethyldithiocarbamic acid, Nordihydroguairetic acid, Dithiothreitol, Sodium metabisulfite, Potassium metabisulfite, d-amino-DL-Phenylalanine, Vanadyl sulfate, Uniconazol, Paclobutrazol, Spermine, Spermidine, Putrescine, Cadavarine, Protamine Sulfate, SKF-7997, MER 29, Ancymidol, Triadimefon, Phosphon D, Thiourea, Dextran Sulfate, Hydroquinone, Chitosan glutamate, Fenpropemorph, Prochloraz, Naptifine, EDU, HTA, MPTA, Glutathione, EGTA, Gibberellins, Abscisic Acid, 1,3-Diphenyl urea, Diazolidenyl urea, Phloroglucinol, Sodium alginate, Carrageenan, Aluminium chloride, Ethylene, Acetylsalicylic acid, Sodium chloride, Acetic acid. In a preferred embodiment of the invention the elicitors will be provided within the suspension culture in a concentration of from about 0.01 μM to about 1 M, preferably in a concentration from about 1 μM to about 500 mM, more preferably in a concentration of between about 10 μM to about 200 mM and most preferably in a concentration of between about 50 μM and about 50 mM.

In another preferred embodiment of the invention the elicitors will be added to the suspension culture at a time from the inoculation time to any time during the culture duration, preferably at a time from the early exponential growth phase to the stationary phase, depending on the natures of the metabolites and the cell line of particular plant species.

In another preferred embodiment of the invention there is a second or multiple addition of the elicitors into the suspension culture, conducted between about six hours to about a month in duration after the previous elicitation, more preferably between about twelve hours to about two weeks in duration after the previous elicitation, and most preferably between about twelve hours to about seven days in duration after the previous elicitation.

In another preferred embodiment of the invention the adsorbent is included in the suspension culture in an amount of between about 1 g/L and about 500 g/L, preferably in an amount between about 20 g/L and about 300 g/L, more preferably in an amount of between about 50 g/L and 200 g/L.

In another prefen'ed embodiment of the invention the adsorbent is added to the suspension culture between the inoculation to any time during the culture duration, preferably between the inoculation to the end of the exponential growth phase.

In another preferred embodiment of the invention the adsorbent is added in the suspension culture, in conjunction with one or a combination of elicitor agents at the same time or a different time during the cultivation, depending on the natures of the metabolites and the cell line of particular plant species. In another preferred embodiment of the invention the nutrient medium comprises one or more of a carbon source, an organic nitrogen source, and inorganic nitrogen source, a macrosalt, a microsalt, a rare trace element, a vitamin, an organic supplement, a plant hormone, a hormone substitute or derivative, a hormone inhibitor, a synthetic growth regulator, a biosynthetic precursor, a metabolic inhibitor, a non-metabolic inhibitor, a stimulant, an activator, an anti-browning agent, an anti-oxidant, a stabiliser, an enhancer, a radical, a scavenger, a conditioner and a reducing agent.

In one embodiment of the invention the adsorbent material is a macroporous non-ionic cross-linked polymeric material.

In a preferred embodiment of the invention the adsorbent is selected from one or more of Amberlite^® XAD7, Amberlite^® XAD2, Amberlite^® XAD7HP, Amberlite^® XAD4, Amberlite^® XAD16, Amberlite^® XAD1600, AMBERLITE®. AMBERLITE FP®, Purasorb^® AP-250, Purasorb^® AP-400; Dowex^® L493, Dowex^® V493, Dowex^® L323, Diaion^® HP20, Diaion^® HP21, SEPABEADS^® SP207, SEPABEADS^® SP70, SEPABEADS^® SP700, SEPABEADS^® SP825, SEPABEADS^® SP850, Diaion^® HP2MG; SERDOLIT^® PAD I, SERDOLIT^® PAD II, SERDOLIT^® PAD III, SERDOLIT^® PAD IV, RP-8 (Merck), Charcoal, activated charcoal, Supelpak^®-2, Supelρak^®-2B, Supelite^® DAX-8, Duolite^® XAD761, Dowex^®, Optipore^® L493, Poly(styrene-co-divinylbenzene), AMBERSORB^® 572, AMBERSORB^® 348F, Dimethylaminomethyl-polystyrene, Poly(4- ethylstyrene-co-divinylbenzene), Florisil^®, Ferric hydroxide oxide, Sepiolite, Mimetic Green 1 Ligand Affinity Adsorbent, Mimetic Yellow 2 Ligand Affinity Adsorbent, Mimetic Red 2 Ligand Affinity Adsorbent, Mimetic Orange 2 Ligand Affinity Adsorbent, Mimetic Blue 1 Ligand Affinity Adsorbent, Mimetic Blue SA Ligand Affinity Adsorbent, Mimetic Blue 2 Ligand Affinity Adsorbent, Mimetic Orange 3 Ligand Affinity Adsorbent, Mimetic Red 3 Ligand Affinity Adsorbent , Mimetic Blue AP Ligand Affinity Adsorbent, Mimetic Orange 1 Ligand Affinity Adsorbent, Mimetic Yellow 1 Ligand Affinity Adsorbent, Tenax™ TA, AMBERCHROM™ , AMBERJET®, AMBERLYST® , DUOLITE® , MAC™ HP , Acrylic anion resins, XAD polymeric adsorbents, Phenol- formaldehyde resin , Nuclear grade resins.

Preferred adsorbents include aliphatic adsorbents such as HP2MG and XAD-7, which are particularly preferred.

In another embodiment the adsorbent is in the form of an immiscible liquid phase adsorbent. Examples of immiscible liquid phase adsorbents include, but are not limited to dimethyl siloxane polymer (Silicone antifoam A), polymethoxy silanes (also known as silicone oils), long chain or branched (eg. having at least 8 and preferably having 12 to 20 carbon atoms) alkane adsorbents such as hexadecane and glycol or polyol adsorbents such as Myglyol.

In a particularly preferred embodiment of the invention the secondary metabolite is recovered in an amount at least 800-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture. In a particularly preferred embodiment of the invention the recovery of the secondary metabolite is increased at least 1000-fold, more preferably at least 1200-fold and more preferably at least 1500-fold and particularly preferably at least 3000-fold.

Preferably the stilbene is trans-resveratrol, cis-resveratrol, trans-piceid, cis-piceid, trans- resveratrol dehydrodimers, cis-resveratrol dehydrodimers, trans-pterostilbenes, cis- pterostilbenes, viniferins, trans-piceatannol, (3,5,5N,4N-tetrahydroxystilbene) 3-0-/3- glucoside (trans-astringin).

Preferably the recovery of the secondary metabolite from the suspension culture is achieved by isolating the secondary metabolite from the cells, the adsorbent and the nutrient medium utilising solvent extraction with a suitable solvent.

According to a still further embodiment the present invention relates to the secondary metabolite product produced by the methods outlined above. According to a further embodiment of the present invention there is provided a method of producing a stilbene plant secondary metabolite of interest, comprising:

(a) Cultivating by suspension culture in a suitable nutrient medium plant cells that produce a stilbene secondary metabolite; (b) including within the suspension culture an amount of adsorbent and one or more elicitor agents suitable to increase production of the stilbene; (c) recovering the stilbene from the suspension culture.

Preferably the plant cells are derived from Vitis vinifera or Polygonum cuspidatum. Preferably the adsorbent included within the suspension culture is AMBERLITE® XAD-7, preferably provided in an amount of between about 1 g/L to about 500 g/L, more preferably between about 20 g/L to about 300g/L, particularly preferably between about 50 g/L and about 200 g/L.

Preferably the one or more elicitor agents is/are selected from jasmonic acid, salicylic acid, chitosan and /5-glucan.

DESCRIPTION OF THE FIGURES

Figure 1 shows chemical structures of trans/cis-resveratrol and several other stilbene phytoalexins.

Figure 2 shows the biosynthetic pathway of resveratrol.

Figure 3 shows an HPLC chromatogram of lOOx concentrated medium extract, the arrow indicates the resveratrol peak and the insert indicates the UV/Vis spectrum of resveratrol.

Figure 4 shows the effect of various amounts of XAD-7 added into the medium at day 0, on the production of resveratrol in the culture at day 7. Figure 5 shows the effect of 10 g/L XAD-7 added into the medium at day 0 on the cell growth of Vitis vinifera cell culture.

Figure 6 shows an HPLC chromatogram for XAD-7 experiment, red is extract from cells and XAD-7, blue is extract from XAD-7 alone.

Figure 7 shows the kinetics of resveratrol production in the culture where the V. vinifera cells grew with 10 g/L XAD-7 added to the medium.

Figure 8 shows the effect of various elicitors and elicitor combinations on intracellular resveratrol production. Treatments tested include: (1) None (control 1 without the addition of elicitors and solvents); (2) EtOH + H₂O (solvent control for jasmonic acid elicitation); (3) 10 JA+H₂O (10 μM Jasmonic acid in solvent); (4) 20 JA+H₂O (20 μM Jasmonic acid in solvent); (5) 1 GLU+EtOH50 (1 mg/L β-glucan in solvent); (6) 1 GLU+10 JA (1 mg/L β-glucan + 10 μM jasmonic acid); (7) 1 GLU+20 JA (1 mg/L β-glucan + 20 μM jasmonic acid); (8) CH₃COOH (solvent control for Chitosan); (9) 5 Chitosan (5 mg/L Chitosan);

(10) EtOH 100 + EtOH50 (solvent control for the combined elicitors of JA and GLU);

(11) 100 SA +10 JA (100 μM salicylic acid + 10 μM Jasmonic acid).

Figure 9 shows the effect of various elicitors and elicitor combinations on extracellular resveratrol production in the medium on day 7 and day 10. Treatments tested include: (1) None (control 1 without the addition of elicitors and solvents); (2) EtOH (solvent control); (3) 1 μg/ml GLU (1 mg/L β-glucan in solvent); (4) lOμM JA (10 μM jasmonic acid); (5) 20μM JA (20 μM jasmonic acid; (6) I μg/ml GLU +10 JA (1 mg/L β-glucan + 10 μM Jasmonic acid); (7) lμg/ml GLU +20 JA (1 mg/L β-glucan + 20 μM Jasmonic acid).

Figure 10 shows the effect of various amounts of XAD-7 added into the medium at day 0, on the production of resveratrol in the culture (extracted from the XAD-7 beads) at day 7. Figure 11 shows the effect of the combined treatments of XAD-7 and elicitors on cell growth on day 4, 7 and 10. Treatments tested include: (1) 20XAD-7 (20 g/L XAD-7); (2) 20XAD-7 + GLU+JA (20 g/L XAD-7 + 1 mg/L β-glucan + 10 μM jasmonic acid); (3) 20CTRL (20 g/L XAD-7 + solvents); (4) 200XAD-7 (200 g/L XAD-7); (5) 200XAD-7 + GLU+JA(200 g/L XAD-7 + 1 mg/L β-glucan + 10 μM jasmonic acid); (6) 200CTRL (200 g/L XAD-7 + solvents).

Figure 12 shows the effect of the combined treatments of XAD-7 and elicitors on resveratrol content per gram of fresh cells + XAD-7 adsorbent on day 4, 7 and 10. Treatments tested include: (1) CTRL (control 1 without the addition of elicitors and solvents); (2) 10 JA (10 μM jasmonic acid); (3) 20 JA (20 μM jasmonic acid; (4) GLU (1 mg/L β-glucan in solvent); (5) GLU +10 JA (1 mg/L β-glucan + 10 μM Jasmonic acid); (6) GLU +20 JA (1 mg/L β-glucan + 20 μM Jasmonic acid); (7) 20XAD-7 (20 g/L XAD- 7); (8) 20XAD-7 + GLU+JA(20 g/L XAD-7 + 1 mg/L β-glucan + 10 μM jasmonic acid); (9) 20CTRL (20 g/L XAD-7 + solvents); (10) 200XAD-7 (200 g/L XAD-7); (11) 200XAD-7 + GLU+JA(200 g/L XAD-7 + 1 mg/L β-glucan + 10 μM jasmonic acid); (12) 200CTRL (200 g/L XAD-7 + solvents).

Figure 13 shows the effect of the combined treatments of XAD-7 and elicitors on resveratrol yield on day 4, 7 and 10. All treatments tested as described in Figure 12.

Figure 14 shows an HPLC chromatogram for the extracts from both cells and XAD-7 beads in the experiment of combined treatments of 20 g/L XAD-7, and 1 mg/L β-glucan and 10 μM jasmonic acid and the inserts indicate the UV / Vis spectrum for the resveratrol peak.

Figure 15 shows a bar graph of resveratrol production (mg/L) in FU-04 cell culture using one of several different adsorbent materials, where resveratrol was extracted from the adsorbent resin on the basis of a first extraction only and where samples were taken from the cell culture at 7 days (lightly shaded) and 10 days (darkly shaded). Figure 16 shows a bar graph of resveratrol production (mg/L) in FU-04 cell culture using one of several different adsorbent materials, where resveratrol was extracted from the adsorbent resin on the basis of a first extraction only and where samples were taken from the cell culture at 7 days (lightly shaded) and 10 days (darkly shaded).

Figure 17 shows a bar graph of phenolic compound production (mg/L) in FU-04 cell culture using one of several different elicitor treatments at day 4, where samples were taken from the cell culture at 7 days (lightly shaded) and 10 days (darkly shaded).

Figure 18 shows a bar graph of resveratrol production (mg/L) in FU-04 cell culture using one of several different elicitor treatments at day 4, where samples were taken from the cell culture at 7 days (lightly shaded) and 10 days (darkly shaded).

Figure 19 shows a bar graph of cell growth (dry cell weight) in Vitis vinifera FU-04 cell culture using XAD-7 as adsorbent and one of several different elicitor treatments as described in Table 11, where samples were taken from the cell culture at 4 days (lightly shaded - control), 7 days (darkly shaded) and 10 days (unshaded).

Figure 20 shows a bar graph of total phenolic compound production (mg/L) in Vitis vinifera FU-04 cell culture using XAD-7 as adsorbent and one of several different elicitor treatments as described in Table 11, where samples were taken from the cell culture at 4 days (lightly shaded - control), 7 days (darkly shaded) and 10 days (unshaded).

Figure 21 shows a bar graph of resveratrol production (mg/L) in Vitis vinifera FU-04 cell culture using XAD-7 as adsorbent and one of several different elicitor treatments as described in Table 11, where samples were taken from the cell culture at 4 days (lightly shaded - control), 7 days (darkly shaded) and 10 days (unshaded). DETAILED DESCRIPTION OF THE INVENTION

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The present invention provides methods of producing plant secondary metabolites of interest. Generally these compounds of interest will be secondary metabolite compounds that are known to be produced within plants and which, as a result of their identified properties, are of commercial value, for example as pharmaceutical agents, fragrances, food or beverage ingredients, precursors for chemical synthesis, ingredients in industrial products such as pesticides, herbicides, fungicides, anti-bacterial or anti-viral agents, or the like. As discussed above, plant secondary metabolites are compounds produced in plant cells that have no apparent function in the plant's primary metabolism, but may have a secondary activity.

Examples of classes of chemical compounds that fall under the banner of secondary metabolites include stilbene compounds, such as trans-resveratrol, cis-resveratrol, trans- piceid, cis-piceid, trans-resveratrol dehydrodimers, cis-resveratrol dehydrodimers, trans- pterostilbenes, cis-ptero stilbenes, viniferins, trans-piceatannol, (3,5,5N,4N- tetrahydroxystilbene) 3-O-/5-glucoside (trans-astringin); and alkaloid compounds, terpenoid compounds, isoprenoid compounds, phenylpropanoid compounds, glucosinolate compounds and pyrethrin compounds, such as taxol, podophyllotoxin, indole alkaloids, β- carboline alkaloids, 10-hydroxy-N(alpha)-demethyl-19,20-dehydroraumacline, terpenoid indole alkaloids, strictosidine, vallesamine, O-acetylvallesamine and voaphylline, campothecin, 3-oxo-rhazinilam, 10-hydroxycampothecin, maytansine, tripdiolide, harringtonine, homoharringtonine, isoharringtonine, braceantin, ellipticine, thalicarpine, indicine-N-oxide, baccharin, hyoscyamine, scopolamine, vinblastine, vincristine, catharanthine, vindoline, sanguinarine, norsanguinarine, valepotriates, atropine, quinidine, 9-dihydrobaccatin III derivatives, rhazinilam, tubotaiwine, phenanthrofuran derivatives, ajuforrestine A, resperpine, codeine, thebaine, cryptopine, berberine, saponins, sapogenins, ginsenoside, rosmarimic acid, arbutin, ajmalicine, anthraquinones, artemesin, forskolin, shikonin, anthocyanins, diosgenin, ubiquinone- 10, serpentine, L-DOPA, pyrethrin, thiophene, 6-hydroxytaumacline, capsaicin, mine, serotonin.

The production method will be established by cultivating a suspension cell culture of plant cells either derived from a plant known to produce the secondary metabolite of interest or from plant cells that have been genetically manipulated in order to produce the secondary metabolite of interest. The plant cells may be derived from a wide variety of plant species such as those listed above, although not limited to those listed species. An appropriate plant cell line may be established by initiating a callus culture from plant explants in a suitable solidified medium, followed by somoclonal selection. In the case of Vitis vinifera cv. Gamay Freaux (FU-1) callus culture may for example be initiated using young berries. A suitable medium such as a modified B5 medium [O.L. Gamborg, R.A. Miller, K. Ojima, (1968) Nutrient requirements of suspension cultures of soybean root cells. Exp. Cell. Res., 50 151-156.] supplemented for example with 30 g/L sucrose, 250 mg/L casein hydrolysate, 0J mg/L α-naphthaleneacetic acid (NAA), 0.2 mg/L kinetin (K) and 0.5% agar, may be utilised. The initial pH of the medium is preferably adjusted to 5.7-5.8 using 0J N KOH before autoclaving. The surface of the plant material (e.g. young berries) may be sterilised, for example by brief immersion in 70%) ethanol followed by immersion in 1.5% sodium hypochlorite for 20 minutes. The sterilized plant material may be chopped into suitable sized pieces (for example 4-6 pieces in the case of young berries) and placed upon solidified callus induction medium. Callus may be established by around 2 months after initiation.

To establish suspension cultures, portions of established callus may be placed in the above mentioned appropriate liquid medium (e.g. liquid modified B5 medium) without agar. The suspension culture is preferably subcultured weekly in the dark, for example in 250 ml Erlenmeyer flasks enclosed with aluminum foil containing approximately 50 ml of the medium. The inoculum size may be approximately 2.5 g wet cells per 50 ml medium prepared by filtering pre-cultured 7-day old suspension cells with a 50 μm stainless steel mesh (for example, Endecotts Ltd., London, England). The subcultures may be maintained on a reciprocating shaker (100 strokes/min) at 27±1°C in a temperature-controlled incubator.

The plant explants that are used to establish the cell line may be derived from a wide variety of plant tissue including, but not limited to, leaves, fruit, shoots, buds, flowers, bark, roots, branches, stems, seeds, cones, needles or cambium tissue of the plant. The most preferred explant material that may be utilised for establishment of a plant cell line may be derived from meristematic plant tissue (characterised by high levels of the metabolite of interest), which encompasses regions of plant tissue characterised by rapid cellular division and growth.

In the case of a cell line where cells are derived from those previously subjected to genetic manipulation, such manipulation may involve cellular transfection with one or more suitable vectors that incorporates a nucleic acid sequence encoding a protein or peptide of interest, such as for example an enzyme involved in secondary metabolite production. As will be well understood by a person skilled in the art, nucleic acid sequences encoding peptides or proteins of interest may be manipulated and incorporated within cells in accordance with conventional molecular biology techniques, such as for example outlined in Sambrook and Russell, Molecular Cloning: A Laboratory Manual, Third Edition, Cold Spring Harbour Laboratory Press, Cold Spring Harbour, New York.

To prevent contamination of the culture, the plant tissue should be surface-sterilised prior to introduction into the callus induction medium. Conventional sterilisation techniques such as the use of 70%o ethanol, 15% sodium hypochlorite and "Chlorox" (a trade mark owned by the Chlorox company for bleach) treatment would be effective. In addition, antimicrobial agents such as cefoxitin, benlate, cloxacillin, ampicillin, gentamycin sulphate and phosphomycin may be used for surface sterilisation of plant material.

The explants taken from the plant may be utilised to establish a callus culture. The term "callus" is used to describe a mass of cultured plant cells that is structurally undifferentiated, and is cultured on a solidified medium. Cells derived from a callus culture may be utilised to establish a suspension culture. "Suspension culture" is used to describe structurally undifferentiated cells that are dispersed in a liquid nutrient medium. It is understood that suspension cultures comprise cells in various stages of aggregation. A range of aggregate sizes are encountered in the suspensions described in this invention, with sizes ranging from tens of microns in diameter (single cells or few-aggregated cells) to aggregates many millimetres in diameter, consisting of many thousands of cells.

Callus cultures will typically exhibit variability in growth morphology, productivity, product profiles and other characteristics. Since individual cell lines vary in their preferences for growth medium constituents, many different growth media may be used for induction and proliferation of the callus. The appropriate medium composition varies depending upon the species being cultured. Examples of media that may be suitable are listed in Table 1. Growth hormones or regulators may additionally be incorporated within the callus culture medium, for example in an amoimt between about 1 ppb to 10 ppm, preferably between about 2 ppb to about 1 ppm. Amounts of other medium ingredients can be varied from the levels outlined in Table 1 ; for example from one tenth concentration to three times the concentrations indicated in the table.

Plant suspension cultures are capable of rapid growth rates and high cell densities. However, optimal conditions vary from one cell line to another, and accordingly, methods leading towards rapid optimisation for any given cell line must be considered. The initial cultures of various species may be sub-cultured by transfer into suitable suspension culture nutrient medium. Examples of media suitable for culture of Vitis species cells are provided in Tables 2 to 5, with reference to the B5 stock solutions outlined in Table 6 and the MS microsalt and SM macrosalt solutions outlined in Tables 7A and 7B, respectively. Such media will contain macro and micro nutrients, organic salts and growth hormones. The amount of the ingredients included within the suspension culture nutrient medium will generally be within one tenth concentration to three times the concentration of the exemplary concentrations provided in Table 2. The nutrient medium selected may include one or more of a carbon source, an organic nitrogen source, an inorganic nitrogen source, a macrosalt, a microsalt, a rare trace element, a vitamin, an organic supplement, a plant hormone, a hormone substitute or derivative, a hormone inhibitor, a synthetic growth regulator, a biosynthetic precursor, a metabolic inhibitor, a non-metabolic inhibitor, a stimulant, an activator, an anti-browning agent, an anti-oxidant, a stabiliser, an enhancer, a radical or scavenger, a conditioner and a reducing agent.

Certain classes of additives in the nutrient medium are referred to by special names in this invention, and are defined here. As used herein, the term "anti-browning agents" refer to components that are added to the nutrient medium to prevent the formation of pigments during cell cultivation. These pigments include phenolics and related compounds that are generally observed to have a deleterious effect on cell growth, viability, and production formation. As used herein, the term "biosynthetic precursors" are used to describe compounds added to the nutrient medium that are metabolised and incorporated by the cells into the metabolites of interest (for example resveratrol). As used herein, the term "metabolic inhibitors" is used to describe compounds added to the nutrient medium that interfere with specific biosynthetic pathways. For example, a metabolic inhibitor may be used to enhance biosynthesis by blocking a different pathway that competes with secondary metabolite for an early biosynthetic precursor. As used herein, the term stimulator or activator is used to describe compounds added to the nutrient medium that stimulate or activate specific biosynthetic pathways, for example those leading to biosynthesis. It is understood that the mechanism of action of the additives described herein may not be completely understood.

It is understood that modifications may be made in the medium such as substitution of other conventional salt compositions (such as organics, vitamins, amino acids, precursors, activators and inhibitors), addition or deletion of various components, growth regulators or alteration of proportions.

In addition to non-volatile dissolved nutrients, gaseous components, primarily oxygen, carbon dioxide, and ethylene (a plant hormone), play critical roles in growth and product formulation. Two parameters are important. The dissolved gas concentrations favouring growth and secondary metabolite formation are obviously important since they dictate reactor operating conditions. In addition, the rates of consumption or production need to be incorporated into reactor design, so that the optimum specified concentrations can be maintained.

Besides this importance in respiration, oxygen can also dramatically affect the rate of secondary biosynthesis. A high saturation constant for an oxygen-requiring step on a secondary biosythetic pathway may require cells to be subjected to high oxygen levels in the reactor. The importance of CO₂ supplementation in maintaining high growth rates has also been documented. Ethylene, a plant hormone, plays pleiotropic roles in all aspects of plant growth and development, including secondary metabolism.

Biosynthesis of secondary metabolites may also be stimulated by medium exchange, perhaps due to removal of the product to thereby prevent feedback inhibition and product degradation. The periodic removal of spent medium incorporates production yield advantages, and additionally, may serve to depress secondary biosynthesis by removing other, non-desired secondary metabolites which exhibit an inhibitory activity. The replenishment of fresh medium to cells undergoing active biosynthesis may also enhance production by providing essential nutrients that have been depleted. It is to be recognised that the amount of medium exchange, the frequency of exchange, and the composition of the medium being replenished may be varied, depending upon the specific circumstances. For example, medium may be exchanged on a continuous or periodic basis, such as for example hourly, daily, on alternate days or weekly.

The liquid cultures are exposed to air and preferably shaken and otherwise gently moved to introduce air into the medium, or air may be introduced through tubing into the culture vessel. The cultures are maintained under appropriate growth conditions at a temperature preferably between about 10°C to 40°C, more preferably between about 15°C to 30°C. The pH may be from between about 3 to about 7.5 and preferably between about 4 to about 6. The culture may be grown under light conditions ranging from total darkness to total light (narrow band and/or broad spectrum) for various periods of time. The culture conditions will of course be varied depending upon the plant cell species being cultured and upon the secondary metabolite or metabolites of interest. For example, in relation to production of some secondary metabolites in particular plant species production yields may be improved by lower or higher pH, lower or higher temperature or conditions of light or darkness. For example in the case of production of resveratrol in Vitis vinifera species derived cells it is preferred for the nutrient medium to be adjusted to a pH of between about 5 and about 6.5, preferably about 5.7 or 5.8, and for the cultures to be incubated at a temperature of between about 24°C and about 28°C, preferably at about 26°C. It is preferred for light to be excluded.

In order to maintain culture growth it is preferred for callus and/or suspension cultures to be regularly sub-cultured, for example on a weekly, fortnightly or monthly basis.

A key aspect of the present invention, which results in significant increases in secondary metabolite yield, relative to plant cell suspension cultures without this feature, is the incorporation or inclusion within the suspension culture of an adsorbent, in conjunction with the addition of one or more elicitor agents. In the context of the present invention the adsorbent agents generally adopted may be in the solid form or may take the form of an immiscible liquid. Adsorbent agents are well known and readily commercially available and are characterised by the taking up of a substance or substances on their surface (or at the interface between liquids in the case of immiscible liquid adsorbents), for example by ionic, dipole-dipole interactions, hydrogen bonding or physical interactions, for example. The adsorbent agents adopted in the present invention are preferably those that demonstrate adsorption of the secondary metabolite compound of interest. The adsorbent agent or agents included within the suspension culture will be selected on the basis of the nature of the secondary metabolite of interest and the arrangement of the culture system. Adsorbent agents vary widely in their characteristics, such as size, binding characteristics and pore diameter (if any). Examples of preferred adsorbent agents include, but are not limited to, the following: Amberlite^® XAD7, Amberlite^® XAD2, Amberlite^® XAD7HP, Amberlite^® XAD4, Amberlite^® XAD16, Amberlite^® XAD1600, AMBERLITE®. AMBERLITE FP®, Purasorb^® AP-250, Purasorb^® AP-400, Dowex^® L493, Dowex^® V493, Dowex^® L323, Diaion^® HP20, Diaion^® HP21, SEPABEADS^® SP207, SEPABEADS^® SP70, SEPABEADS^® SP700, SEPABEADS^® SP825, SEPABEADS^® SP850, Diaion^® HP2MG; SERDOLIT^® PAD I, SERDOLIT^® PAD II, SERDOLIT^® PAD III, SERDOLIT^® PAD IV, RP-8 (Merck), Charcoal, activated charcoal, Supelpak^®-2, Supelpak^®-2B, Supelite^® DAX-8, Duolite^® XAD761, Dowex^® Optipore^® L493, Poly(styrene-co- divinylbenzene). AMBERSORB^® 572, AMBERSORB^® 348F, Dimethylaminomethyl- polystyrene, Poly(4-ethylstyrene-co-divinylbenzene), Florisil^®, Ferric hydroxide oxide, Sepiolite, Mimetic Green 1 Ligand Affinity Adsorbent, Mimetic Yellow 2 Ligand Affinity Adsorbent, Mimetic Red 2 Ligand Affinity Adsorbent, Mimetic Orange 2 Ligand Affinity Adsorbent, Mimetic Blue 1 Ligand Affinity Adsorbent, Mimetic Blue SA Ligand Affinity Adsorbent, Mimetic Blue 2 Ligand Affinity Adsorbent, Mimetic Orange 3 Ligand Affinity Adsorbent, Mimetic Red 3 Ligand Affinity Adsorbent , Mimetic Blue AP Ligand Affinity Adsorbent, Mimetic Orange 1 Ligand Affinity Adsorbent, Mimetic Yellow 1 Ligand Affinity Adsorbent, Tenax™ TA, AMBERCHROM™ , AMBERJET®, AMBERLYST® , DUOLITE® , IMAC™ HP , Acrylic anion resins, XAD polymeric adsorbents, Phenol- formaldehyde resin , Nuclear grade resins. In relation to the production of resveratrol in a Vitis vinifera suspension cell culture system a particularly preferred adsorbent agent is AMBERLITE® XAD-7, which is a non-ionic polymeric adsorbent with surface area of 450 m²/g and average pore diameter of 90 A, which is commercially available from Sigma- Aldrich.

In general preferred adsorbents include aliphatic adsorbents and particularly preferrred aliphatic adsorbents are HP2MG and XAD-7. , Diaion^® HP2MG is a highly porous methylacrylate based adsorption resin with a pore volume of 1.2 ml/g and a surface area of 470 meters² per gram, and is obtained from Mitsubishi Chemical Company.

Examples of immiscible liquid phase adsorbents include, but are not limited to dimethyl siloxane polymer (Silicone antifoam A), polymethoxy silanes (also known as silicone oils), long chain or branched (eg. having at least 8 and preferably having 12 to 20 carbon atoms) alkane adsorbents such as hexadecane and glycol or polyol adsorbents such as Myglyol. For example, the adsorbent material may be provided in an amount of between about 1 g/L to about 500 g/L, preferably between about 20 g/L to about 300 g/L, and particularly preferably between about 50 g/L and about 200 g/L. These amounts are particularly suitable for AMBERLITE® XAD-7 (which is often referred to herein as simply "XAD-7") and dimethyl siloxane polymer. The amount of adsorbent agent included within the suspension culture will depend upon the secondary metabolite of interest and will most usually be selected on the basis of maximum secondary metabolite production. The inventors have found that upon increasing amounts of adsorbent a threshold amount will be reached, above which yield of the secondary metabolite does not significantly further increase. The optimum type and amount of adsorbent and elicitor agent can readily be determined by conducting trial cultures, as for example outlined in examples 1 and 2. Preferably the amount and type of adsorbent and elicitor incorporated in the suspension culture will result in an at least 800-fold increase in secondary metabolite yield relative to a comparable suspension culture which does not include adsorbent and elicitor. Preferably the yield is increased at least 1, 000-fold, more preferably at least 1, 200-fold and particularly preferably at least 1, 500-fold.

By reference to inclusion of the adsorbent within the suspension culture it is intended to convey that the medium is in some way in communication with the adsorbent material. For example the adsorbent may be included directly in the culture. Alternatively, it may be included in a column, membrane or other physical or chemical barrier that is immersed within the culture or is in liquid communication with medium extracted from the culture. Preferably there is some form of barrier present, which substantially excludes accumulation of cells in or about the adsorbent, to thereby allow maximal interaction between the adsorbent and the medium. Similarly, reference to recovery of the secondary metabolite from the suspension culture is intended to mean that the secondary metabolite is substantially removed from the cells and preferably from other components of the culture such as the adsorbent, elicitor and other culture additives. Preferably the recovery step or steps results in secondary metabolite or secondary metabolites as a suspension, precipitate, solute, oil, crystalline or amorphous form substantially isolated from other culture components and with a level of purity of preferably at least 5%, more preferably at least 20%, particularly preferably at least 50%, more preferably at least 70%, 80%, 90% or 95% and most preferably at least 98%. Purity can readily be assessed by routine methods.

As outlined above the yield of the secondary metabolite produced according to the suspension cell culture method is also increased by including within the suspension culture one or more elicitors. As used herein, the term "elicitor" encompasses compounds of biological and non-biological origin that cause an increase in secondary metabolite production when applied to plants or plant-cell cultures. Many different and diverse compounds can act as elicitors, depending upon their nature of origin and their mode of action with cellular metabolism. Generally, elicitors may be characterised into classes of biotic elicitors, which for example include the following: Botrytis cinerea Phytophthora megasperma, Pinellas stripticum, Oligosporas sp., Pythium mamiallatum, Pythium sylvaticum, Verticillium dahliae, Verticillium sp., Penicillium minioluteum, Phytophthora lateralis, Cytospora cincta, Cytospora leucostoma, Alternaria brassicicola, Alternaria solani, Alternaria cucumerina, Botrytis squamosa, Cochliobolus heterostrophus, Colletotrichum trifolii, Colletotrichum orbiculum, Colletotrichum graminicola, Colletotrichum gloeosporioides, Cylindrocladium floridanum, Fusarium crookwellense, Fusarium heterosporium, Fusarium oxysporam f. sp. conglutinans, Fusarium oxysporam f. sp. lycopersici, Fusarium oxysporam f. sp. pisi, Gibberella zeae, Gaeumannomyces graminis var. tritici, Geotrichum sp., Leptosphaeria torrae, Nectria haematococca MPVI, Mycosphaerella pinodes, Ophiostoma ulmi, Phoma lingam, Phoma pinodella, Phytophthora infestans, Pythium aristosporam, Pythium graminicola, Pythium ultimum, Rhizoctonia solani, Sclerotinia sp., S. nodorum D-45, Trametes versicolor, Ustilago maydis, Venturia inequalis; microbial fractions or products derived from biotic elicitors:: Chitosan, Lichenan, Glucomannan, Pleuran, Glucan, Carboxymethylglucan, Hydroxymethylglucan, Sulfoethylglucan, Mannan, Xylan, Mannobiose, Mannotriose, Mannopentaose, Mannotetraose, Cellulysin, Multifect XL, Multifect CL, Resinase, Pulpxyme, SP431, Pectinol, Rapidase, Klerzyme, Chitinase; and abiotic elicitors: Arachidonic acid, Elaidic acid, Cyclic AMP, Dibutyrl Cyclic AMP, Methyl Jasmone, Cis-Jasmone, Miconazol, Feralic acid, AMO-1618, Triton X-100, Benzoic acid, Salicylic acid, Propyl gallate, Sesamol, Chlorocholine chloride, 3,4-dichlorophenoxy triethyl-, (amine), Chloroethylphosphonic acid, Diethyldithiocarbamic acid, Nordihydroguairetic acid, Dithiothreitol, Sodium metabisulfite, Potassium metabisulfite, d-amino-DL-Phenylalanine, Vanadyl sulfate, Uniconazol, Paclobutrazol, Speπriine, Spermidine, Putrescine, Cadavarine, Protamine Sulfate, SKF-7997, MER 29, Ancymidol, Triadimefon, Phosphon D, Thiourea, Dextran Sulfate, Hydroquinone, Chitosan glutamate, Fenpropemorph, Prochloraz, Naptifine, EDU, HTA, MPTA, Glutathione, EGTA, Gibberellins, Abscisic Acid, 1,3- Diphenyl urea, Diazolidenyl urea, Phloroglucinol, Sodium alginate, Carrageenan, aluminum chloride, ethylene, acetosalicylic acid, sodium chloride, acetic acid.

It is to be understood that the elicitors mentioned above have been mentioned by way of example only, and are not intended to be limiting upon the scope of the invention. Particularly preferred elicitors include jasmonic acid, salicylic acid, chitosan and /3-glucan.

Elicitors may be provided within the suspension culture in a concentration of from about 0.01 μM to about 1 M, preferably in a concentration from about 1 μM to about 500 mM, more preferably in a concentration of between about 10 μM to about 200 mM and most preferably in a concentration of between about 50 μM and about 50 mM, depending on the nature of the metabolite of interest and the cell line of the particular plant species adopted. Elicitors interact with dissolved gasses in many ways. Oxygen requirements may change upon elicitation. Increases in respiration rate as a wound response is commonly observed in plant cell culture. Importantly, elicitors may mediate their action via ethylene. In such cases, it may be desirable to substitute a microbial elicitor preparation with ethylene, and perhaps prevent toxicity associated with other microbial components in the elicitor preparation. Elicitors and metabolic stress agents may be utilised according to the invention to maximise secondary metabolite production and secretion in cell suspension culture by assessing elicitor specificity and concentration, timing, and duration, as a function of culture age and media composition.

It may be appropriate to add/or replenish elicitors on a continuous and/or periodic basis. For example, a second or subsequent addition of the elicitor/s into the suspension culture may be made at a time from about six hours to about a month in duration after the previous elicitation, more preferably at a time from about twelve hours to about two weeks in duration after the previous elicitation, and most preferably at a time from about 12 hours to about 7 days in duration after the previous elicitation. It may also be appropriate to initially add an elicitor some time after the suspension culture has been established, for example a matter of one to several hours later or 1 , 2, 4 or 6 days after suspension culture cultivation has commenced.

The operating mode for a plant cell culture process refers to the way that nutrients, cells and products are added or removed with respect to time. When all the nutrients are supplied initially, and the culture contents comprising cells and product are harvested at the end of the culture period, the operating mode is termed a "one-stage batch process". When a batch process is divided into two sequential phases, a growth and production phase, with the medium being exchanged in between the two phases, the operating mode is termed a "two-stage batch process".

hi a "FED-batch" operation, particular medium additives and nutrients are supplied either periodically or continuously through the course of a one-stage or a two-stage batch culture. When a substantial portion, but not all, of the contents of a batch culture is harvested, with additional fresh medium for continued cell growth and production, the process resembles a "repeated draw and fill" operation, and is termed a "semi-continuous process".

When fresh medium is continuously supplied, and effluent medium is continuously removed, the process is termed "continuous". If cells are retained within the reactor, the process is termed a "perfusion mode". If cells are continuously removed with the effluent medium, the continuous process is termed a "chemostat".

It is to be recognised that these various modes of process operation are compatible with the secondary metabolite production methods described herein.

Assuming a batch type process is adopted the suspension culture will be allowed to cultivate for an appropriate period of time, such as for example between about 2 days and several months in duration, preferably between about 6 days and about 1 month in duration and more preferably between about 7 days and about 16 days. After an appropriate cultivation period, when a batch process is adopted, which will be determined depending upon the nature of the secondary metabolite and the cell line concerned, the secondary metabolite will be recovered from the suspension culture. The cells and adsorbent may be harvested from the nutrient medium by removal of the medium, such as for example by filtration and the cell layer and adsorbent are separated. It may be appropriate to wash the adsorbent material with water to remove unwanted cellular material and medium components and a drying step may also be adopted. To remove the secondary metabolite product from the adsorbent material a solvent extraction process may be adopted, in a suitable solvent material selected on the basis of the nature of the adsorbent and secondary metabolite. For example, in the case of resveratrol production using an XAD-7 adsorbent, the solvent is preferably an organic solvent such as methanol, methanoic acid, ethanol, acetic acid, ethyl acetate, acetone, methyl acetate. A preferred extraction solvent is methanol. Extraction of the secondary metabolite may be conducted using conventional methods and over an appropriate period of time, such as between about 10 minutes and 24 hours, preferably between about 30 minutes and about 12 hours, more preferably for between about 1 hour to 6 hours, in between about 5 and about 50 volumes, preferably between about 10 and about 30 volumes, and more preferably in about 20 volumes of solvent relative to the volume of the cells and adsorbent. Second or multiple extraction may be required depending on the nature of the metabolites of interest and the concentration of the metabolites within the cells and adsorbents.

As indicated above, there will preferably be some form of barrier provided to avoid excessive direct interaction between the adsorbent and the cells, especially in the case where a continuous process is adopted. This could take the form of a fine grating, filter or membrane between the cells and the adsorbent, or even a "tea bag" type of arrangement where the adsorbent is located within a substantially cell impermeable but medium permeable material located in the culture. In another arrangement the adsorbent is retained in a separate receptacle into and through which medium is pumped and optionally then returned to the culture vessel. In this arrangement a barrier or filter would be provided to prevent ingress of cells into the adsorbent receptacle and to prevent egress of adsorbent back to the culture vessel.

In the case of an immiscible liquid adsorbent it is also possible to retain a reservoir of the adsorbent separate from the culture. From the reservoir the adsorbent can be pumped into and out of the culture vessel, preferably with a cell impermeable but medium permeable barrier provided to separate the adsorbent within the culture vessel from the cells. The adsorbent may then be withdrawn on a continuous or intermittent basis from the adsorbent reservoir for extraction of the secondary metabolite, by routine means. For example extraction may be achieved using a suitable solvent (eg. alcohol) wash, possibly by adopting a counter-current packed bed arrangement. An advantage of an immiscible liquid adsorbent is that it will preferably float on the surface of the culture, and although it may be agitated through the culture to maximise efficiency of secondary metabolite removal, it can form as a discrete phase. This allows ready removal of the adsorbent from the culture. Another advantage is that immiscible liquids are readily amenable to sterilisation, such as for example by autoclaving. If secondary metabolite formation in a suspension culture takes place concurrently with growth, the metabolite is termed growth-associated, and a single medium formulation may be sufficient to achieve good growth and high level production. In many other systems, it has been found that rapid growth and high product formation do not take place concurrently, hi such cases, growth and production phases are separated and a medium for each phase is developed independently. However, it is understood that a single growth/production medium may be formulated. The production media developed not only increase total secondary metabolite formation, but also direct cellular biosynthesis towards secondary metabolite production. The production media developed also promote prolonged cell viability and biosynthesis, and in addition, cause significant levels of product to be secreted into the extracellular medium. These characteristics may be important in the operation of an efficient commercial scale process for secondary metabolite production.

The present invention will now be described further with reference to the following non- limiting examples.

EXAMPLES Example 1 Hyper-production of resveratrol in Vitis vinifera cell suspension culture

Results and Discussion

The use of an adsorbent agent in a plant cell/tissue culture-based bioprocess for the hyper- production of natural resveratrol was investigated using a grape (Vitis vinifera) cell suspension culture system. The major stilbene present in the suspension culture system has been identified as tr-.«._-resveratrol-β-glucoside, which is otherwise known as tr-ws-piceid.

This compound is stored intracellularly, as verified by medium extraction with ethyl acetate and HPLC analysis. 7r-z«-?-resveratrol is present in the suspension cell culture only at very low levels, both intracellularly and in the culture medium. Figure 3 shows HPLC chromatogram from a 7-day old culture medium extracted with ethyl acetate and concentrated 100 times. The peak indicated by an arrow corresponds to Rt for an authentic tr- ,y-resveratrol standard, and exhibits characteristic UV / Vis spectra (as shown). The calculated concentration of tr «-?-resveratrol in day-7 medium is 40μg/l, which is minimal.

AMBERLITE® XAD-7 is a polymeric adsorbent resin that has been applied to plant cell culture systems where secondary metabolites are exported into the culture medium. In these circumstances it has generally demonstrated an enhanced effect (several fold to several ten-fold) on the production of secondary metabolites. We were interested to see the effect of XAD-7 in systems where there is little metabolite export from the cells. Experiments were performed where varying amounts of XAD-7 (5-50 g/L) were added to the culture medium. The results were surprising as increases in trans-resveratrol production of several thousand- fold were shown selectively in the medium. The increase in the level of trans-resveratrol in the medium is proportional to the level of XAD-7 added into the media (from 5-50g/L). These results are presented in Figure 4.

As shown in Figure 4, the addition of 5, 10, 20 and 50 g/L XAD-7 in the medium increased the level of trans-resveratrol production from 800 to 5000-fold in comparison with the control without XAD-7 (40 μg/L). However it is also surprising that the biomass growth was not significantly affected by the addition of XAD-7, as exemplified in Figure 5.

Figure 6 shows an example of HPLC analysis from the experiment with 10 g/L XAD-7, where an extract from cells + XAD-7 (before sugar-density separation) contains both trα«_.-piceid and trα/zs-resveratrol peaks and an extract from XAD-7 alone shows a trans- resveratrol peak along with other minor peaks.

Figure 7 shows an example of the kinetics of resveratrol production in the medium with the addition of 10 g/L XAD-7, based on HPLC analysis from XAD-7 extracts. By day 10 the calculated resveratrol concentration (against standard curve) reached 47mg/L. This represents approximately a 1000-fold increase compared with resveratrol concentrations found in culture medium in the control culture. Materials

Chemicals. AMBERLITE® XAD-7 is a nonionic polymeric adsorbent with surface area

450 m²/g and average pore diameter of 90 A, purchased from Sigma- Aldrich.

Plant cell culture. A Vitis vinifera cv. Gamay Freaux suspension cell line, FU-1, has been maintained by weekly subculturing in our laboratory since July 2000, according to the following method. This cell line, capable of anthocyanin accumulation in the dark, was originally a gift from Dr. Francois Cormier's group (Cormier et al. (1994) Anthocyanin production in selected cell lines of grape (Vitis vinifera) In Vitro Cell Develop. - Plant, 30: 171-177). Suspension cultures were subcultured weekly in the dark in 250-ml Erlenmeyer flasks enclosed with aluminum foil containing 50 ml B5 medium (Gamborg et al. (1968) Nutrient requirements of suspension cultures of soybean root cells. Exp. Cell Res.50: 151- 156) supplemented with 30g/l sucrose, 250 mg/1 casein hydrolysate, 0.1 mg/1 - naphthaleneacetic acid (NAA) and 0.2 mg/1 kinetin (K). The initial pH of the medium was adjusted to 5.7-5.8 using 0.1 M KOH before autoclaving. The inoculum size was approximately 2.5 g wet cells per 50 ml medium prepared by filtering pre-cultured 7-day- old suspension cells with a 50 μm stainless steel mesh (Endecotts Ltd., London, UK). The subcultures were maintained on a reciprocating shaker (100 strokes/min) at 27±1 °C in a temperature-controlled incubator. Calli originating from the same material as FU-1 were subcultured fortnightly onto solid GC-2 medium - which is B5 (Gamborg et al. 1968) supplemented with 6 g agar/1, 30 g sucrose/1, 250 mg casein hydrolysate/1, 0.1 mg α- naphthaleneacetic acid/1 and 0.2 mg kinetin/1. The initial pH was adjusted to 5.7-5.8 using 0.1 M KOH before autoclaving. Cultures were incubated in the dark at 26±1°C.

Methods

5, 10, 20 and 50 g/L of XAD-7 beads were added to the culture medium. The experiments were repeated 2-3 times. The medium was prepared by cleaning 15g XAD-7 for 30 minutes in 50mL MeOH and then washing 3x with MQ water on filter unit, then allowing to dry. The appropriate amount of beads was weighed and placed in 500mL flasks and then lOOmL GC-2 medium (broth) was added and autoclaved. Sampling and analysis on day zero was conducted by taking a representative sample (3ml) for each condition from each replicate flask and the samples were then pooled (total 3 samples), before conducting regular analysis (eg. fresh cell weight (FCW) and dry cell weight (DCW).

XAD-7 analysis was conducted by repeating the sampling as above (total 3 samples). Sample volumes were then recorded and samples were transferred into Eppendorf tubes. 3x 15mL falcon tubes each containing lOmL of 20%> sucrose solution were then prepared. The samples were filter dried and weighed before being transferred to 20% sucrose solution and being gently stirred at the top of the liquid to promote bead separation. Once separation was achieved the cell layer was removed and the beads were filter dried and washed thoroughly with water, before being transferred to Eppendorf tubes and weighed. 20x volume of MeOH was then added and allowed to extract for 1 hour, before collecting the supernatant and storing at -20°C. The sampling schedule adopted was to take 2x 3mL samples from each flask at day 4, day 7 and day 10, which were analysed as above.

Example 2 Synergistic enhancement of extracellular trans-resveratrol production in V. vinifera cell suspension culture by combined use of elicitation and XAD-7 adsorbent.

The effect of combined treatments of a range of elicitors and XAD-7 adsorbent on the resveratrol production in V. vinifera cell cultures was investigated. While resveratrol production reaches a plateau of 300-400 mg/L with the XAD-7 treatments alone, a significant synergistic enhancement was found when the XAD-7 treatments were combined with a range of elicitors, resulting in a yield of about 2000 mg/L of resveratrol. This yield is about 40,000-fold that of the control culture (40-50 μg/L). In addition, significant amounts of other stilbenes including viniferin and trans-resveratrol- dehydrodimer, were identified in the extracts from the cell suspension culture exposed to XAD-7 and elicitors. Materials and Methods

Plant cell culture conducted and the adsorbent used were identical to those reported in example 1.

Elicitors and their preparation. Jasmonic acid, chitosan, β-glucan and salicylic acid, purchased from Sigma-Aldrich, were used as elicitors in the experiments described in this report. The jasmonic acid and salicylic acid solutions were prepared by dissolving them in ethanohwater (12:13) to give a 100 mM stock solution. This solution was diluted appropriately to give a desired concentration in the culture medium. The β-glucan and chitosan solutions were prepared by dissolving in 100%> ethanol and 1M acetic acid, respectively to give a 1 mg/mL stock solution. This stock solution was added directly to the culture medium to give the final concentrations adopted in the experiments. Both elicitor solutions were sterilized using a 0.22 μm filter.

Elicitor screening. Preliminary screening to select the effective elicitors and the optimal elicitor concentrations was done in 100 ml shake flasks. In each flask, 1.0 g wet cells were inoculated into 20 ml fresh medium and 20 μl of the appropriate dilution of the stock solution of each elicitor and their combinations was added at 4 days after inoculation to obtain final concentrations indicated in the results. For the control cultures, 20 μl blank ethanohwater (12:13) solution or 100% ethanol solution was added on day 4. Three flasks were used for each sample per treatment. Cultures from the whole flask were collected for analysis on day 4, 7 and 10 during the cultures.

Elicitations. For elicitation experiments, 7-day-old cells were filtered through a 50 μm stainless steel mesh and about 1 g wet cells of Vitis vinifera were inoculated into 20 ml of fresh liquid medium in 100 ml flasks. Elicitation was performed by adding 20 μl elicitor solution at various defined concentrations, and at day 4 during the culture cycle. Control culture flasks received 20 μl of sterile filtered ethanol: water (12:13) solution or 100% ethanol solution. The final concentration of ethanol in JA-treated and control cultures was less than 0.05%). The cultures were harvested at day 4, 7 and 10 to determine cell growth and stilbene content. Triplicate flasks were ran for each treatment and control. Independent controls were performed for each experiment due to the variability of the cell line in various subcultures. All the cultures were incubated at 27°C on a reciprocating shaker at 100 strokes/min under darkness.

For the treatments with XAD-7 adsorbent, a specific concentration of XAD-7 beads up to 200 g/L was added in culture medium at day 0 during the inoculation. The XAD-7 beads were pretreated according to the protocol reported in example 1.

For the combined treatments with both XAD-7 and elicitors, a specific concentration of XAD-7 beads was added at day 0 and a specific concentration of the elicitors was added at day 4 after inoculation.

Sampling and analysis. Samples taken from 3 replicate flasks at each sampling time were analyzed separately, following the protocol below: • Harvest the cell culture from the whole flask and record the volume

• Filter-dry the cells and/or XAD-7 beads where applicable from the whole flask

• Obtain the fresh cell weight (+XAD-7 where applicable), calculate the FCW (Fresh cell weight),

• Take a portion of samples, dry at 80°C overnight and obtain the DCW (Dry cell weight)

• Take ca. 0.5g samples and add 20x volume of MeOH and extract for 1 hour, then collect supernatant and store at -20°C for HPLC analysis of stilbenes from both cells and XAD-7 when applicable.

For analysis of stilbenes from XAD-7 beads alone, the following protocol was applied to isolate the XAD-7 from the cells.

• Prepare 3x 50 mL falcon tubes each containing 30mL of 20% sucrose solution

• Transfer the rest of the filter-dried samples (cells+XAD-7 beads) above into 20% sucrose solution and gently stir sample at top of liquid to promote bead separation • Once separation is achieved remove cell layer, then filter-dry beads.

• Wash thoroughly with water, transfer beads to 100 mL flasks and weigh • Add 20x volume of MeOH and extract for 1 hour, then collect supernatant and store at -20°C for HPLC analysis of stilbenes.

Results Screening of elicitors that stimulate resveratrol production. To screen the efficient elicitors, a range of elicitors and elicitor combinations were tested. Figure 8 shows one example of results from one screening study on intracellular resveratrol production.

It was found that 1 mg/L β-glucan, 5 mg/L Chitosan, and 100 μM salicylic acid +10 μM Jasmonic acid stimulated the intracellular resveratrol production significantly, by 3-5-fold.

Figure 9 shows one example of results of the extracellular resveratrol production.

It was found that the combination of 1 mg/L β-glucan with 10 μM and 20 μM Jasmonic acid stimulate the production of extracellular resveratrol by 3-fold on day 10.

Effects of the concentration of XAD-7 beads. Further tests with the addition of XAD-7 beads have extended the concentration up to 200 g/L. The results are shown in Figure 10.

A linear increase in resveratrol production extracellularly was observed up to 50 g/L beads, which reached a plateau at the concentration of XAD-7 from 100 to 200 g/L. The maximum extracellular resveratrol production is approximately 330 mg/L in the presence of 200 g/L XAD-7. This is about an 8000-fold increase, compared with that in the control. There was no significant effect on cell growth even at the highest concentration of 200 g/L XAD-7.

Effects of the combined treatment of XAD-7 and elicitation. The results show that the addition of XAD-7 adsorbent and elicitors alone can both stimulate resveratrol production. In order to investigate if a synergistic effect can be achieved with a combined treatment of both XAD-7 and elicitation, further experiments were conducted. Figure 11 shows an example of the effect of the combined treatments on cell growth. As shown in Figure 11, no obvious effect on cell growth was observed with the addition of XAD-7 beads from 20 g/L to 200 g/L. However the combination of XAD-7 and elicitors reduced the cell growth by 50%), which may reflect the growth inhibition effect of the elicitors used.

Figure 12 shows the effect of combined treatments on the resveratrol content per gram of fresh cells + XAD-7 beads, where an extract from cells + XAD-7 was extracted and analyzed by HPLC. As shown in Figure 12, the elicitor treatments alone gave a several- fold increase in resveratrol content and the XAD-7 treatments surprisingly gave a few thousands-fold increase. The combination of XAD-7 and elicitors showed a synergistic effect, reaching a resveratrol content of more than 5000 ug/g-FCW (+XAD-7 beads) when 200 g/L XAD-7 was added on day 0 in the culture which was further elicited by 1 mg/L β- glucan and 10 μM jasmonic acid on day 4.

Similar trends were observed for the total resveratrol production as shown in Figure 13. Figure 13 indicated that the highest resveratrol production of 1932 mg/L could be obtained on day 10 of the culture when 200 g/L XAD-7 was added on day 0 in the culture which was further elicited by 1 mg/L β-glucan and 10 μM jasmonic acid on day 4. This value is approximately a 41000-fold increase compared to resveratrol concentrations found in culture medium in the control culture (47 μg/L).

Significant levels of other stilbenes from the culture, which have been tentatively identified as two types of viniferin and trans-resveratrol dehydrodimer (shown in Figure 14), have been demonstrated. Example 3

Comparison of single and double elicitation, adsorbent bead type and elicitor type

Materials and Methods

These materials and methods relate to experiments A to E of example 3, as discussed below. Medium preparation

Resin beads (e.g., XAD-7, HP2MG) were cleaned using MeOH, then washed with MilliQ water in vacuum filtration unit. 2 g of selected resin beads were placed in each lOOmL flask, then lOmL GC-2 medium was added. Each flask was covered with aluminum foil and autoclaved.

Adsorbent resin beads

The adsorbent resin beads used were from Mitsubishi Chemical Co: (Diaion series) HP2MG , HP20, HP 20SS, HP21 and (Sepabead series) SP207, SP70, SP700, SP825, SP850 and from Rohm & Haas Chemical Co: Amberlite series: XAD-4, XAD-7, XAD-16.

The resin beads were added at 200 g/1 of culture in Experiment C.

Experimental setup For each cell line, plant cell culture inoculum was prepared by taking wet cell material, from a 7-day old pre-culture grown in GC-2 medium and making the volume up with GC- 2 medium to give 1 g cell material per 10 ml GC-2 medium. Each flask was inoculated with 10ml of this suspension inoculum. Flasks were placed on a reciprocating shaker at 25±l°C set at lOO rpm.

Elicitation at Day 4

For Jasmonic acid (JA) treatment, 20 μL of a stock solution of lOmM JA in 50% ethanol was added to each flask to give a final concentration of 10 μM Jasmonic Acid. For β- glucan treatment, 80 μL of a stock solution of 0.25 mg β-glucan /ml in 5.7% ethanol was added to each flask to give final concentration of 1 mg β-glucan /L. For Salicylic acid (SA) treatments, 50 μL amounts of stock solutions of 200, 400 and 800 mM SA was added to each flask to give final concentrations of 500uM, ImM and 2mM of SA, respectively. For control flasks, 80 μL of 5.7% ethanol and 20 μL of 50% ethanol were added to the flask to give the same volume of solvent as the treatment flasks for JA and β-glucan. For control flasks for SA treatments, 50uL of 100% ethanol was used. Blanks of 80 μL of 5.7% ethanol or 20 μL of 50%> ethanol, or 50uL of 100%) ethanol were also added to treatment flasks as necessary. Sampling and analysis (Whole Flasks were Sampled)

Sample volume - For Day 0 samples, inoculum sample volume was measured in a 15 ml Falcon tube. For later samples, the whole of the contents of the 100 ml flask was transferred to a 50 ml Falcon tube and the volume measured.

Extracellular fermentation broth sample - When cells were settled, 1-1.5 ml of the cell-free medium was transferred to an eppendorf tube and stored at -20°C (Labelled M). At a later time the samples were thawed and analyzed for total phenolics by processing as cell-free samples using the phenolics analysis method described below.

Cell growth analysis - Cells + Resin beads were vacuum filtered and placed on pre- weighed pre-heated foil and weight of total fresh cells + Resin beads (from whole flask) was recorded. About 0.5g (exact weight was recorded) fresh cells + Resin beads was transferred to a 15 ml Falcon tube for anthocyanin extraction. About 0.5g (exact weight was recorded) fresh cells + Resin beads was transferred to a 15 ml Falcon tube for phenolics extraction. About 2 g (exact weight was recorded) fresh cells + Resin beads was transferred to a 50 mL falcon tube for Resin beads extraction. Remainder of fresh cells + Resin beads, in the pre-weighed foil, was placed in drying oven and weighed when dry.

Phenolics analysis

Phenolics analysis was conducted using Folin-Ciocalteu technique of Singleton & Rossi (1965); modified Zhang (2002), Zhang & Kupke 2003. For phenolics extraction the fresh cells + Resin beads in 15 ml Falcon tube were used and a 20-times volume of ethanol containing 0.P/o HC1 was added. The sample was homogenized for 1 minute, then placed horizontally on a shaker for 1 hour. 1-1.5 ml of extract was collected and centrifuged in Minifuge for 10 minutes at maximum rpm. The supernatant was transferred into a fresh Eppendorf vial, and stored at -20°C (Label P). Within 8 days the samples were analyzed for total phenolics using the phenolics analysis method described as follows:

The sample was diluted with MQ water as appropriate to give a 1.2 ml sample. 50 μl Folin-Ciocalteu reagent was added, the tube vortexed and allowed to stand for 7 minutes at room temperature. 290 μl of 20%> Na₂CO was added, the tube vortexed and allowed to stand for 1 hour at room temperature to allow reaction to complete. Absorbance was measured at 760nm (against empty cuvette). Total phenolics concentration was calculated from a gallic acid standard curve.

Analysis of resveratrol and stilbene compounds from Resin beads

About 20 mL of 20% sucrose solution was added to the 50 mL falcon tube containing the

Resin beads and the sample gently stirred to promote bead separation. Once beads were separated, the cell layer was removed and discarded using transfer pipette. Sucrose separation was repeated if necessary. Beads in sucrose were vacuum filter dried, using water to wash beads, then transferred to 100 ml flask and weighed. 20x volume of MeOH was added, the flask was covered with a double layer of cling wrap to reduce evaporation of solvent, and extracted overnight or longer on shaker. Extractant was poured off beads and the volume was measured. A 1-1.5 ml sample of extractant was collected and stored at -20°C (Label XI). A secondary extraction was carried out by adding the same volume of fresh MeOH and again extracting overnight or longer on shaker. Extractant was again poured off beads and the volume was measured. A 1-1.5 ml sample of extractant was collected and stored at -20°C (Label X2). At a later time the samples were analyzed for stilbenes using HPLC analysis.

Experiment A - Comparison of resveratrol and phenolics production and cell growth for single and double elicitation

The two conditions used in experiment A were as follows: Treatment ■ 200 g/L XAD-7 (added during medium preparation) + 1 mg/L β-glucan (added at Day 4 and again at Day 7) + 10 μM Jasmonic Acid (added at Day 4 and again at Day 7) Control • 200 g/L XAD-7 (added during medium preparation) ■ + 1 mg/L β-glucan (added at Day 4) + 10 μM Jasmonic Acid (added at Day 4) + same volumes elicitor solvents were added at Day 7 The number of replicates used for each condition was three.

Results Resveratrol production

Total resveratrol yield at day 10 (from both extractions from XAD-7) was almost 3.5 g/L for flasks elicited on both days 4 & 7, compared to almost 2.7 g/L for flasks elicited at only day 4.

Phenolics production

Extra-cellular phenolics (in medium) was 13mg/L in double elicited flasks, compared to 9.5mg/L in single elicited flasks. Phenolics in combined cells and XAD-7 was 3.76g/L in double elicited flasks, compared to 3.38g/L in single elicited flasks. Total phenolics (medium + cells + XAD-7) was 3.77g/L in double elicited flasks, compared to 3.39g/L in single elicited flasks.

Cell growth

Fresh cell weight was similar for both double (248g/L) and single (254g/L) elicited treatments.

Experiment B: Comparison of Types of Adsorbent Resin beads

Results Resveratrol production

Concentrations of resveratrol produced in Vitis vinifera FU-04 cell culture using various types of adsorbent resin beads, where samples were taken at 7 and 10 days, are shown in

Table 8 and Fig. 15. It can be seen that use of the aliphatic resins HP2MG and XAD-7 gave rise to the highest levels of resveratrol production at both 7 and 10 days. Experiment C: Comparison of Types of Adsorbent Resin beads

Results

Resveratrol production Resveratrol production results obtained from FU-04 cell culture when using one of a variety of different adsorbent materials are shown in Table 9 and Fig. 16.

Experiment D: Elicitation in combination with Salycylic acid

Results Phenolic compound production

Phenolic compound production results obtained from FU-04 cell culture when using one of a variety of the following elicitor treatments carried out at day 4 are provided in Fig. 17:

Jasmonic acid (JA) at 1 OμM Jasmonic acid (JA) at lOμM +β-glucan at lmg/L, Jasmonic acid (JA) at lOμM + β-glucan at lmg/L + Salicylic acid (SA) at 500 μM Jasmonic acid (JA) at lOμM + Salicylic acid (SA) at 10 mM Jasmonic acid (JA) at lOμM + Salicylic acid (SA) at 5 mM Salicylic acid (SA) at 500μM. Ethanol controls

Resveratrol production

Resveratrol production results obtained from FU-04 cell culture when using one of the elicitor treatments described above are shown in Table 10 and Fig. 18.

Experiment E: Elicitation with JA, β-glucan and Salicylic acid

Results Cell Growth Cell growth results (measured as dry cell weight) obtained from FU-04 cell culture when using one of the elicitation conditions described in Table 11 are provided in Fig. 19.

Phenolic compound production

Phenolic compound production results obtained from FU-04 cell culture when using one of the elicitation conditions described in Table 11 are provided in Fig. 20. Resveratrol production

Resveratrol production results obtained from FU-04 cell culture when using one of the elicitation conditions described in Table 11 are provided in Table 12 and Fig. 21.

It is to be understood that the present invention has been described by way of example only and is intended to encompass modifications and/or alterations that would be obvious to a person skilled in the art, based upon the disclosure herein.

Table 1 - Media for Plant Tissue and Cell Cultures (mg/L) Components Murashige ''White Gamborg Nitsch Heller Schenk - Nitsch- Kohlenbach - Knop -Skoog 1(1963 1(1968) (1951) '(1953) Hildebrand ι Nitsch , Schmidt (1865) _ (1962) _' , (1972) (1967) ι (1975) (NH₄)₂SO₄ - ^{' *}~^"~ ~>r~~~ ^"""134^" .— ^™ — - _^— -

MgS0_4x 7H₂0 370 J" — ^- - ,_^,-- - _,___ _{25Q 40Q} - ^ - 135" 250

Na₂S0₄ - _ ^" '200_^ , - - - - - __ - ^

KC1 - 65 -_ 1,500 750 - -

CaCl_2x 2H₂0 440 ^" '150 25 75 200 _ - '166

NaN0₃ - - .600 - j - _ _ -__

KNO3 ¹'⁹⁰⁰_ _? S3, 000 2,000 - 2,500 125 950 250

Ca(N0₃)_2x 4H₂0 - _j__!___. ~ - - - 500^" ~ ^S- 1,000

NH₄N0₃ ^X' _______ I ~ ^" " ^" 1__° r

NaH₂P0_4x H₂0_ -_ ^*" Ϊ_ -£T_ 150 250 125 - - ^"" _ - ^"

NH₄H₂P0₄ -_ ^""__ __„r~^" _ ι_- - .- 300 X ~ ^"-_

KH₂ ^*P0₄ '170 .'- _ I - - _ - ^"~ 1125 68^* 250 ____ ___⁷*? " " V __X⁸⁵ __ ²⁷.⁸⁵ _.^"""_^" _?7-.³ " _ ²_⁾ ___?__ -²-:⁵ r⁵⁷*²⁵ "

'7^{" "} .10 ~ (13 0.1 10 ^{" ~""}~ 25 ^{" "}'25 - __ -__- _ _ - *_?°i _ _ _

ZnS0_4x 7H₂0 8.6 — 3 2 0.5 1 — ^* 0.1 _™ 1,0 10 - ^' ϊ

o m o o o 'S m f- 1 © © o o i I o ro o H H 5¹ ' I o o m o m H H o o o O H I t . H

Table 2 GC-1 Medium ingredients

Chemical Amount (per Litre) Sucrose 20 g SM macrosalts (lOx) (see table 7B) 100 ml MS micrOSaltS (lOOOx) (see table 7A) 1 ml B5 vitamins (lOOx) 10 ml FeEDTA (7.34 g/L) 5 ml NOA (0.2 mg/ml) 5 ml BAP (0.2 mg/ml) 5 ml pH to 5.7-5.8

Solidified medium is prepared by adding 5g/ agar.

Table 3 GC-2 Medium ingredients

Chemical Amount (per Litre) B5(a) lOOOx 1 ml B5(b) lOOx 10 ml B5(c) lOOOx 1 ml B5(d) lOOOx 1 ml B5(e) lOOx 10 ml Sucrose 30 g Caesin Hydrolysate 250 mg Kinetin (0.2 mg/ml) 1 ml NAA (0.2 mg/ml) 0.5 ml pH to 5.7-5.8 -

Solidified medium is prepared by adding 8g/ agar.

Table 4 GC-3 Medium ingredients

Chemical Amount (per Litre)

B5(a) lOOOx 1 ml

B5(b) lOOOx 1 ml

B5(c) lOOOx 1 ml

B5(d) lOOOx 1 ml

B5(e) lOOx 10 ml

Glucose 50 g

Caesin Hydrolysate 250 mg

Kinetin (OJ mg/ml) 2 ml

NAA (0.1 mg/ml) 1 ml pH to 5.7-5.8 -

Solidified medium is prepared by adding 8g/L agar.

Table 5 GC-4 Medium ingredients

Chemical Amount (per Litre)

B5(a) lOOOx 1 ml

B5(b) lOOOx 1 ml

B5(c) lOOOx 1 ml

B5(d) lOOOx 1 ml

B5(e) lOOx 10 ml

Sucrose 80 g

Caesin Hydrolysate 250 mg

Kinetin (0.1 mg/ml) 2 ml

NAA (OJ mg/ml) 1 ml pH to 5.7-5.8 -

Solidified medium is prepared by adding 8g/L agar.

Table 6 B5 stock solutions ingredients

Stock code Chemical Concentration (g/L stock)

B5(a) (lOOOx) H₃BO₃ 3.0 MnSO₄JH₂O 13.2 ZnSO₄.7H₂O 2.0 NaMoO₄.2H₂O 0.25 CoCl₂.6H₂O 0.025 CuSO₄.5H₂O 0.025

B5(b) (lOOOx) myo-Inositol 100.0 Thi amine 10.0 Nicotinic acid 1.0 Pyridoxine 1.0

B5(c) (lOOOx) CaCl₂.H₂O 150.0

B5(d) (lOOOx) KI 0.75

B5(e) (100x) KNO₃ 250.0 MgSO₄.7H₂O 25.0 Na₂EDTA 3.73 FeSO₄.7H₂O 2.78 NaH₂PO₄.2H₂O 17.0 (NH₄)₂SO₄ 13.4

Tables 7 (A & B)

GC-1 medium stock solution ingredients

A. Ingredients for one litre of MS microsalts (lOOOx stock)

B. Ingredients for one litre of SM macrosalts (lOx stock)

Table 8

Comparison of Resveratrol Production by Vitis vinifera cell culture with different adsorbents (based on 1st extraction) Type of Resin Beads Resveratrol yield (mg/L culture) (X1 Sample extraction day only) HP2MG HP20 HP20SS HP21 PXAD-7 XAD-16 XAD-7 7 Average 1385 378 38 475 1123 389 1115 StdDev 40 35 7 44 118 40 103 10 Average 2627 550 114 604 2090 624 2174 StdDev 87 93 5 67 84 9 192

Table 9

Comparison of Resveratrol Production between FU-04 cultures with different adsorbents (based on 1st extraction) Type of Resin Beads Resveratrol yield (mg/L culture) (X1 Sample extraction day only) PXAD-7 SP207 SP70 SP700 SP825 SP850 XAD-4 XAD-7 7 Average 1583 6 341 202 375 349 470 1755 StdDev 117 1 43 3 13 17 5 9 10 Average 2310 15 695 532 761 967 818 2368 StdDev 185 11 25 63 137 87 72 88

Table 10

Comparison of Resveratrol Production between FU-04 cultures with different elicitor treatments 10uM JA+ Total yield 10uM JA + 1 mg/L resveratrol 1 mg/L 10uM JA+ beta- Sample extracted (mg/L beta- 10uM JA + 100ul 10uM JA+ glucan+ 10uM Ja+ day culture) glucan 500uM SA EtOH 10mM SA 500uM SA 5mM SA 500uM SA 60ul 7 Average 844 1068 681 8 10 162 StdDev 46 83 20 1 1 13 10 Average 2271 2869 1904 41 2972 211 291 StdDev 117 106 191 31 205 288 56

Table 11

Table 12

Comparison of Resveratrol production between FU-04 cultures with XAD-7, elicited in different ways. Yield of Resveratrol in mg/l culture

Claims

CLAIMS:

1. A method of producing a plant secondary metabolite of interest, comprising: (a) cultivating by suspension culture in a suitable nutrient medium plant cells that produce the secondary metabolite; (b) including within the suspension culture an amount of adsorbent and one or more elicitor agents suitable to increase production of the secondary metabolite; (c) recovering the secondary metabolite from the suspension culture.

2. The method according to claim 1 wherein the cells are derived from regularly sub- cultured callus culture.

3. The method according to claim 1 wherein the cells are derived from suspension cell culture.

4. The method according to claim 1 wherein the cells or those from which they are derived have been subjected to genetic manipulation.

5. The method according to claim 2 wherein the callus culture has been established in a solidified callus induction medium from plant explants of a species that produces the secondary metabolite.

6. The method according to any one of claims 1 to 5 wherein the cells are derived from one or more of the following plant species:

Atropa bella donna, Erythrina flabelliformis, Ipomoea tricolor, Erythrina crista, Celosia cristata, Gallium spurium, Laurus nobilis, Nitis labrusca, Nitis vinifera, Gratiola officinalis, Symphitum officinalis, Hosta fortunei, Cassia hebecaipa, Thalictrum flavum, Scutellaria altissima, Portulacca oleracea, Scutellaria certicola, Physalis sp., Geum fauriei, Gentiana tibetica, Linum hirsutum, Aconitum napellus, Podophyllum emodii, Thymus cretaceus, Carlina acaulis, Chamaecrista fasciculata, Pinus pinea, Peganum harmala, Tamarindus indica, Carica papaya, Cistus incanus, Capparis spinosa, Cupressus lusitanica, Diospyros kaki, Eryngium campestre, Aesculus woerlitzensis, Aesculus hippocastanum, Cupressus sempervirens, Celtis occidentalis, Polygonum cuspidatum, Elaeagnus angustifolia, Elaeagnus commutata, Gentiana macrophylla, Brassica rapa, Sesbania exaltata, Sesbania speciosa, Spartina potentifiora, Brassica juncea, Helianthus annuus, Poinsettia sp., Pelargonium zonale, Synapsis sp., Leontopodium alpinum, Lupinus luteus, Buxus microphylla var. japonica, Liatris spicata, Primula japonica, Betula nigra, Filipendula vulgrais, Lobelia siphilitica, Grevillea robusta, Reseda luteola, Gentiana littoralia, Campanula carpatica, Ageratum conizoides, Psidium guajava, Ailanthus altissima, Hydrocotyle asiatica, Brugmansia suaveolens, Thymus pulegioides, Thymus lema-barona, Thymus serphyllum (wild), Gaultheria procumbens, Thymus camosus, Thymus thracicus, Calycanthus floridus, Zin giber officinalis, Lamium dulcis, Thymus praecox "arcticus ", Thymus speciosa, Thymus pseudolamginosus, Thymus vulgraris, Ficus religiosa, Forsythia suspensa, Chelidonium majus, Thymus wooly, Thymus portugalense, Nicotiana tabacum, Thymus cytriodorus "aureus ", Cactus officinailis, Lablab purpurea, Juglans regia, Actinidia chinensis, Hemerocallis sp., Betula pendula, Gardenia jasminoides, Taxodium distichum, Magnolia loebherii, Crataegus praegophyrum, Larix decidua, Thuja orientalis, Thuja ociden talis, Cupressocyparis leylandii, Pseudotsuga menziesii, Abies fiπna, Parthenocissus quinquefolia, Allium cemuum, Juniperus "blue pacific", Taraxacum officinalis, Yucca sp., Tsuga canadensis, Ilex aquifolium, Ilex comuta, Taxus hiksii, Taxus media, Metasequoia glyptostroboides, Pinus bungi ana, Buxus sempervirens, Stewartia koreana, Prunus sp., Betula dahurica, Plantago minor Acer palmatum, Acer campestre, Cotinus coggygria, Quercus robur, Acer truncatum, Achyranthes bidentata, Allium japonicum, Carum cap sicum, Agastache mexicana, Prunella vulgaris, Tagetes minuta, Nepeta cataria, Ratibida columnaris, Aster novae angliae, Myrica cerifera, Pittosporam tobira, Plantago major, Pinus sylvestris, Acoras canadensis, Pieris japonica, Pinus strobus, Trifolium pratense, Prunus serotina, Datura stramonium, Geranium maculatum, Hydrocotyle asiatica, Astragalus sinicus, Centaurea maculata, Ruschia indurata, Myrthus communis, Platanus occidentalis, Licium barba turn, Lavandula officinalis, Grevillea robusta, Hypophae rhamnoides, Filipendula ulmaria, Betula pendula, Polygonum odoratum, Brugmansia graveolens, Rhus toxi codenta, Armoracia rusticana, Ficus benjaminii, Sufflera sp., Baikiaea recurvata, Asimina triloba, Lippia dulcis, Epilobium augustifolium, Brugmansia suaveolens, Xanthosoma sagittifolium, Monstera deliciosa., Aglaonema commutatus, Dieffenbachia leopoldii, Anthurium andreanum, Syngonium podophyllum, Dracaena fragrans, Ananas comosus, Strelitzia reginae, Dieffenbachia segiune, Syngonium auritum, Dracaena sp., Haemanthus katharinae, Anthurium altersianum, Spathiphyllum grandifiorum, Spathiphyllum cochle arispatum, Monstera pertusa, Anthurium magnificum, Anthurium hookeri, Anthurium elegans, Calathea zebrina, Yucca elephantipes, Bromelia balansae, Musa textilis, Myrthus communis, Olea oleaster, Olea europaea, Nerium oleander, Cocculus laurifolius, Microsorium punctatum, Sanseviera sp., Adansonia digitata, Boehmeria biloba, Piper nigrum, Phymatosoras scolopendria, Tumera ulmifolia, Nicodemia diversifolia, Tapeinochilos spectabilis, Rauwolfia tetraphylla, Ficus elastica, Cycas circinalis, Caryota urens, Cynnamomum zeylonicum, Aechmea luddemanniana, Phoenix zeylonica, Ficus benjamina, Ficuspumila, Murraya exotica, Trevesia sundaica, Clerodendrum speciosissimum, Actinidia kolomikta, Paeonia lactifiora, Paeonia suffruticosa, Quercus imbricaria, Iris pallida, Portulacca olleracea, Polygonum aviculare, Iris pseudocarpus, Ailium nutans, Ailium fistulosum, Anthericum ramosum, Neratram nigrum, Polygonum lapathifohum, Hosta lancifolia, Hosta sieboldii, Echinops sphaerocephalus, Paeonia dahurica, Inula helenium, Crambe pontica, Digitalis lutea, Baptisia australis, Aristolochia australis, Hyssopus seravschanicus, Teucrium chamaedrys, Sedum album, Heracleum pubes cens, Origanum vulgare, Cachrys alpina, Laser trilobum, Matteuccia strathiopteris, Sedum telephium, Bocconia cordata, Ajuga reptans, Thalictrum minus, Anemone japonica, Clematis rectae, Alchemilla officinalis, Potentilla alba, Poterium sangiusorba, Menispermum dauricum, Oxybaphus nyctagineus, Armoracia rusticana, Crambe cordifolia, Agrimonia eupatoria, Anchusa officinalis, Polemonium caeruleum, Naleriana officinalis, Pulmonaria molissima, Stachys lanata, Coronilla varia, Platycarya grandiflora, Lavandula officinalis, Vincetoxicum officinale, Acalypha hispida, Gnetum gnemon, Psychotria nigropunctata, Psychotria metbac teriodomasica, Codiaeum variegatum, Phyllanthus grandifolius, Pterigota alata, Pachyra affinis, Sterculia data, Philodendron speciosum, Pithecellobium unguis-cati, Sanchezia nobilis, Oreopanax capitatus, Ficus triangularis, Kigelia pinnata, Piper cubeba, Lauras nobilis, Erythrina caJfra, Metrosideros excelsa, Osmanthus fragrans, Cupres sussempervirens, Jacobinia sp., Senecio platyphylloides, Livistona chinensis, Tetraclinis articulata, Eucalyptus rudis, Podocarpus spinulosus, Eriobotrya japonica, Gingko biloba, Rhododendron sp., Thuja occidentalis, Fagopyrum sufraticosum, Geum macrophyllum, Magnolia kobus, Ninca minor Convallaria majalis, Corylus avellana, Berberis sp., Rosa multifiora, Ostrya carpinifolia, Ostrya connogea, Quercus rubra, Liriodendron tulipifera, Sorbus aucuparia, Betula nigra, Castanea sativa, Bergenia crassifolia, Artemisia dracunculus, Ruta graveolens, Quercus nigra, Schisandra chinensis, Betula alba, Sambucus nigra, Gentiana craciata, Encephalartos horridus, Phlebodium aureum, Microlepia platyphylla, Ceratozamia mexicana, Stenochlaena tenuifolia, Adiantum trapeziforme, Adiantum raddianum, Lygodium japonicum, Pessopteris crassifolia, Asplenium australasicum, Agathis robusta, Osmunda regaus, Osmundastrum claytonianum, Phyllitis scolopendrium, Polystichum braunii, Cyrtomium fortunei, Dryopteris flux mas, Equisetum variegatum, Athyrium nipponicum, Athyrium filix-femina, Parthenocissus tricuspidata, Ligusticum vulgare, Chamaecy parispisifera, Rosa canina, Cotinus coggygria, Celtis occidentalis, Picea schrenkiana, Cydonia oblonga, Ulmus pumila, Euonymus verracosus, Deutzia scabra, Mespilus germanica, Quercus castaneifoha, Euonymus europea, Securinega sufraticosa, Koelreuteria paniculata, Syringa josikaea, Zelkova carpinifolia, Abies cephalonica, Taxus baccata, Taxus cuspidata, Salix babylonica, Thuja occidentalis, Actinidia colomicta, Mahonia aquifo hum, Aralia mandschurica, Juglans nigra, Euonymus data, Prinsepia sinensis, Forsythia europaea, Sorbocotoneaster pozdnjakovii, Moras alba, Crataegus macrophyllum, Eucommia ulmifolia, Sorbus commixta, Philodendron amu rense, Cornus mas, Kerria japonica, Parrotia persica, Jasminum fruticans, Swidasan guinea, Pentaphylloides fruticosa, Sibiraea altaiensis, Cerasus japonica, Kolkwitzia amabilis, Amigdalus nana, Acer mandschurica, Salix tama risifolia, Amelanchier spicata, Cerasus mahaleb, Prunus cerasifera, Corylus avellana, Acer tataricum, Viburnum opulus, Syringa vulgaris, Fraxinus exelsior, Quercus trojana, Chaenomeles superba, Pinus salinifolia, Berberis vulgaris, Cotoneaster horisontalis, Cotoneaster fangianus, Fagus sylvatica, Pinuspumila, Pinus sylvestris, Berberis thunbergii, Ajuga forrestii, Anisodus acutangulus, Chinchona ledgerina, Naleriana officinalis, Peganum harmala, Chrysanthemum cineraliaefolium, Tagetes patula, Scopolia japonica, Rauwolfia serpentine, Papaver somniferam, Capsicum frutescens, Fumaria capreolata L., Datura stramonium, Tinospora rumphii, Triptorygium wilfordii, Coptis japonica, Salvia officinalis, Colleus blumei, Catharanthus roseus, Morinda citrofolia, Lithospermum erythrorhizon, Dioscorea deltoidea, Mueune prariens, Mirabilis Jalapa, Boerhavia diffusa, Camptotheca acuminate, Νothapodytes foetida, Moras nigra, Symphoricarpus albus and Ophiorrhiza pumila.

7. The method according to any one of claims 1 to 6 wherein the cells are derived from leaves, fruit, shoots, buds, flowers, bark, roots, branches, stems, seeds, cones, needles or cambium tissue of the plant.

8. The method according to any one of claims 1 to 6 wherein the cells are derived from meristematic plant tissue.

9. The method according to any one of claims 1 to 8 wherein the secondary metabolite is a stilbene compound.

10. The method according to claim 9 wherein the stilbene compound is trans-resveratrol, cis-resveratrol, trans-piceid, cis-piceid, a trans-resveratrol dehydrodimer, a cis-resveratrol dehydrodimer, a trans-pterostilbene, a cis-pterostilbene, a viniferin, trans-piceatannol or (3,5,5Ν,4Ν-tetrahydroxystilbene) 3-O-/5-glucoside (trans-astringin).

11. The method according to any one of claims 1 to 8 wherein the secondary metabolite produced is trans-resveratrol or cis-resveratrol.

12. The method according to any one of claims 1 to 8 wherein the secondary metabolite is an alkaloid compound, a terpenoid compound, an isoprenoid compound, a phenylpropanoid compound, a glucosinolate compound or a pyrefhrin compound.

13. The method according to claim 12 wherein the plant secondary metabolite is taxol, podophyllotoxin, an indole alkaloid, a β-carboline alkaloid, lO-hydroxy-N(alpha)- demethyl-19,20-dehydroraumacline, a terpenoid indole alkaloid, strictosidine, vallesamine, O-acetylvallesamine, voaphylline, campothecin, 3-oxo-rhazinilam, 10- hydroxycampothecin, maytansine, tripdiolide, harringtonine, homoharringtonine, isoharringtonine, braceantin, ellipticine, thalicarpine, indicine-N-oxide, baccharin, hyoscyamine, scopolamine, vinblastine, vincristine, catharanthine, vindoline, sanguinarine, norsanguinarine, a valepotriate, atropine, quinidine, a 9-dihydrobaccatin III derivative, rhazinilam, tubotaiwine, a phenanthrofliran derivative, ajuforrestine A, resperpine, codeine, thebaine, cryptopine, berberine, a saponin, a sapogenin, ginsenoside, rosmarimic acid, arbutin, ajmalicine, an anthraquinone, artemesin, forskolin, shikonin, an anthocyanin, diosgenin, ubiquinone- 10, serpentine, L-DOPA, pyrethrin, thiophene, 6- hydroxytaumacline, capsaicin, mine or serotonin.

14. The method according to claim 2 wherein the sub-culturing is conducted weekly, fortnightly or monthly.

15. The method according to any one of claims 1 to 14, which is conducted a batch process.

16. The method according to any one of claims 1 to 14, which is conducted in a semi- continuous or continuous process.

17. The method according to claim 16 wherein the semi-continuous process is operated in a fed-batch or a repeated-batch mode.

18. The method according to any one of claims 1 to 17 wherein the elicitor agents are selected from one or more of biotic elicitors, microbial fractions or products derived from biotic elicitors, and abiotic elicitors.

19. The method according to claim 18 wherein the biotic elicitors are selected from one or more of: Botrytis cinerea Phytophthora megasperma, Pinellas stripticum, Oligosporas sp., Pythium mamiallatum, Pythium sylvaticum, Verticillium dahliae, Verticillium sp., Penicillium minioluteum, Phytophthora lateralis, Cytospora cincta, Cytospora leucostoma, Alternaria brassicicola, Alternaria solani, Alternaria cucumerina, Botrytis squamosa, Cochliobolus heterostrophus, Colletotrichum trifolii, Colletotrichum orbiculum, Colletotrichum graminicola, Colletotrichum gloeosporioides, Cylindrocladium floridanum, Fusarium crookwellense, Fusarium heterosporium, Fusarium oxysporam f. sp. conglutinans, Fusarium oxysporam f. sp. lycopersici, Fusarium oxysporam f. sp. pisi, Gibberella zeae, Gaeumannomyces graminis var. tritici, Geotrichum sp., Leptosphaeria torrae, Nectria haematococca MPVI, Mycosphaerella pinodes, Ophiostoma ulmi, Phoma lingam, Phoma pinodella, Phytophthora infestans, Pythium aristosporum, Pythium graminicola, Pythium ultimum, Rhizoctonia solani, Sclerotinia sp., S. nodoram D-45, Trametes versicolor, Ustilago maydis, Venturia inequalis.

20. The method according to claim 18 wherein the microbial fractions or products derived from biotic elicitors are selected from one or more of: Chitosan, Lichenan, Glucomannan, Pleuran, Glucan, Carboxymethylglucan, Hydroxymethylglucan, Sulfoethylglucan, Mannan, Xylan, Mannobiose, Mannotriose, Mannopentaose, Mannotetraose, Cellulysin, Multifect XL, Multifect CL, Resinase, Pulpxyme, SP431, Pectinol, Rapidase, Klerzyme, Chitinase.

21. The method according to claim 18 wherein the abiotic elicitors are selected from one or more of: Arachidonic acid, Elaidic acid, Cyclic AMP, Dibutyrl Cyclic AMP, Methyl Jasmone, Cis-Jasmone, Jasmonic acid, jS-glucan, Miconazol, Feralic acid, AMO-1618, Triton X-100, Benzoic acid, Salicylic acid, Propyl gallate, Sesamol, Chlorocholine chloride, 3,4-dichlorophenoxy tri ethyl-, (amine), Chloroethylphosphonic acid, Diethyldithiocarbamic acid, Nordihydroguairetic acid, Dithiothreitol, Sodium metabisulfite, Potassium metabisulfite, d-amino-DL-Phenylalanine, Vanadyl sulfate, Uniconazol, Paclobutrazol, Spermine, Spermidine, Putrescine, Cadavarine, Protamine Sulfate, SKF-7997, MER 29, Ancymidol, Triadimefon, Phosphon D, Thiourea, Dextran Sulfate, Hydroquinone, Chitosan glutamate, Fenpropemorph, Prochloraz, Naptifme, EDU, HTA, MPTA, Glutathione, EGTA, Gibberellins, Abscisic Acid, 1,3-Diphenyl urea, Diazolidenyl urea, Phloroglucinol, Sodium alginate, Carrageenan, Aluminium chloride, Ethylene, Acetylsalicylic acid, Sodium chloride, Acetic acid.

22. The method according to any one of claims 1 to 21 wherein the elicitors are provided within the suspension culture in a concentration of from about 0.01 μM to about 1 M.

23. The method according to any one of claims 1 to 21 wherein the elicitors are provided in a concentration from about 1 μM to about 500 mM.

24. The method according to any one of claims 1 to 21 wherein the elicitors are provided in a concentration of between about 10 μM to about 200 mM.

25. The method according to any one of claims 1 to 21 wherein the elicitors are provided in a concentration of between about 50 μM and about 50 mM.

26. The method according to any one of claims 1 to 25 wherein the elicitors are added to the suspension culture at a time from the inoculation time to any time during the culture duration.

27. The method according to claim 26 wherein the elicitors are added to the suspension culture at a time from the early exponential growth phase to the stationary phase.

28. The method according to either claim 26 or claim 27 wherein there is a second or multiple addition of the elicitors into the suspension culture, conducted between about six hours to about a month in duration after the previous elicitation.

29. The method according to claim 28 wherein the second or multiple addition of elicitors is conducted between about twelve hours to about two weeks in duration after the previous elicitation

30. The method according to claim 28 wherein the second or multiple addition of elicitors is conducted between about twelve hours to about seven days in duration after the previous elicitation.

31. The method according to any one of claims 1 to 30 wherein the adsorbent is included in the suspension culture in an amount of between about 1 g/L and about 500 g/L.

32. The method according to any one of claims 1 to 30 wherein the adsorbent is included in the suspension culture in an amount of between 20 g/L and about 300 g/L.

33. The method according to any one of claims 1 to 30 wherein the adsorbent is included in the suspension culture in an amount of between about 50 g/L and about 200 g/L.

34. The method according to any one of claims 1 to 33 wherein the adsorbent is added to the suspension culture between the inoculation to any time during the culture duration.

35. The method according to any one of claims 1 to 33 wherein the adsorbent is added to the suspension culture between the inoculation to the end of the exponential growth phase.

36. The method according to any one of claims 1 to 35 wherein the adsorbent is added in the suspension culture in conjunction with one or a combination of elicitor agents at the same time during the cultivation.

37. The method according to any one of claims 1 to 35 wherein the adsorbent is added in the suspension culture in conjunction with one or a combination of elicitor agents at a different time during the cultivation.

38. The method according to any one of claims 1 to 35 wherein the nutrient medium comprises one or more of a carbon source, an organic nitrogen source, and inorganic nitrogen source, a macrosalt, a microsalt, a rare trace element, a vitamin, an organic supplement, a plant hormone, a hormone substitute or derivative, a hormone inhibitor, a synthetic growth regulator, a biosynthetic precursor, a metabolic inhibitor, a non-metabolic inhibitor, a stimulant, an activator, an anti-browning agent, an anti-oxidant, a stabiliser, an enhancer, a radical, a scavenger, a conditioner and a reducing agent.

39. The method according to any one of claims 1 to 38 wherein the adsorbent material is a macroporous non-ionic cross-linked polymeric material.

40. The method according to any one of claims 1 to 38 wherein the adsorbent is selected from one or more of Amberlite^® XAD7, Amberlite^® XAD2, Amberlite^® XAD7HP, Amberlite^® XAD4, Amberlite^® XAD 16, Amberlite^® XAD 1600, AMBERLITE®. AMBERLITE FP®, Purasorb^® AP-250, Purasorb^® AP-400; Dowex^® L493, Dowex^® V493, Dowex^® L323, Diaion^® HP20, Diaion^® HP21, SEPABEADS^® SP207, SEPABEADS^® SP70, SEPABEADS^® SP700, SEPABEADS^® SP825, SEPABEADS^® SP850, Diaion^® HP2MG; SERDOLIT^® PAD I, SERDOLIT^® PAD II, SERDOLIT^® PAD III, SERDOLIT^® PAD IV, RP-8 (Merck), Charcoal, activated charcoal, Suρelpak^®-2, Supelpak^®-2B, Supelite^® DAX-8, Duolite^® XAD761, Dowex^®, Optipore^® L493, Poly(styrene-co- divinylbenzene), AMBERSORB^® 572, AMBERSORB^® 348F, Dimethylaminomethyl- polystyrene, Poly(4-ethylstyrene-co-divinylbenzene), Florisil^®, Ferric hydroxide oxide, Sepiolite, Mimetic Green 1 Ligand Affinity Adsorbent, Mimetic Yellow 2 Ligand Affinity Adsorbent, Mimetic Red 2 Ligand Affinity Adsorbent, Mimetic Orange 2 Ligand Affinity Adsorbent, Mimetic Blue 1 Ligand Affinity Adsorbent, Mimetic Blue SA Ligand Affinity Adsorbent, Mimetic Blue 2 Ligand Affinity Adsorbent, Mimetic Orange 3 Ligand Affinity Adsorbent, Mimetic Red 3 Ligand Affinity Adsorbent , Mimetic Blue AP Ligand Affinity Adsorbent, Mimetic Orange 1 Ligand Affinity Adsorbent, Mimetic Yellow 1 Ligand Affinity Adsorbent, Tenax™ TA, AMBERCHROM™ , AMBERJET®, AMBERLYST® , DUOLITE® , JJViAC™ HP , Acrylic anion resins, XAD polymeric adsorbents, Phenol- formaldehyde resin , Nuclear grade resins.

41. The method according to any one of claims 1 to 38 wherein the adsorbent is in the form of an immiscible liquid phase adsorbent.

42. The method according to claim 41 wherein the immiscible liquid phase adsorbent is selected from one or more of dimethyl siloxane polymer (Silicone antifoam A), polymethoxy silanes, long chain or branched alkane adsorbents and glycol or polyol adsorbents.

43. The method according to any one of claims 1 to 42 wherein the secondary metabolite is recovered in an amount at least 800-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

44. The method according to any one of claims 1 to 42 wherein the secondary metabolite is recovered in an amount at least 1000-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

45. The method according to any one of claims 1 to 42 wherein the secondary metabolite is recovered in an amount at least 1200-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

46. The method according to any one of claims 1 to 42 wherein the secondary metabolite is recovered in an amount at least 1500-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

47. The method according to any one of claims 1 to 46 wherein the recovery of the secondary metabolite from the suspension culture is achieved by isolating the secondary metabolite from the cells, the adsorbent and the nutrient medium utilising solvent extraction with a suitable solvent.

48. A secondary metabolite product produced by the method according to any one of claims 1 to 47.

49. A method of producing a stilbene plant secondary metabolite of interest, comprising:

50. The method according to claim 49 wherein the cells are derived from regularly sub- cultured callus culture.

51. The method according to claim 49 wherein the cells are derived from suspension cell culture.

52. The method according to claim 49 wherein the cells or those from which they are derived have been subjected to genetic manipulation.

53. The method according to claim 50 wherein the callus culture has been established in a solidified callus induction medium from plant explants of a species that produces the secondary metabolite.

54. The method according to any one of claims 49 to 53 wherein the cells are derived from one or more of the following plant species:

Atropa bella donna, Erythrina flabelliformis, Ipomoea tricolor, Erythrina crista, Celosia cristata, Gallium spurium, Lauras nobilis, Vitis labrasca, Vitis vinifera, Gratiola officinalis, Symphitum officinalis, Hosta fortunei, Cassia hebecaipa, Thalictrum flavum, Scutellaria altissima, Portulacca oleracea, Scutellaria certicola, Physalis sp., Geum fauriei, Gentiana tibetica, Linum hirsutum, Aconitum napellus, Podophyllum emodii, Thymus cretaceus, Carlina acaulis, Chamaecrista fasciculata, Pinus pinea, Peganum harmala, Tamarindus indica, Carica papaya, Cistus incanus, Capparis spinosa, Cupressus lusitanica, Diospyros kaki, Eryngium campestre, Aesculus woerlitzensis, Aesculus hippocastanum, Cupressus sempervirens, Celtis occidentalis, Polygonum cuspidatum, Elaeagnus angustifolia, Elaeagnus commutata, Gentiana macrophylla, Brassica rapa, Sesbania exaltata, Sesbania speciosa, Spartina potentifiora, Brassica juncea, Helianthus annuus, Poinsettia sp., Pelargonium zonale, Synapsis sp., Leontopodium alpinum, Lupinus luteus, Buxus microphylla var. japonica, Liatris spicata, Primula japonica, Betula nigra, Filipendula vulgrais, Lobelia siphihtica, Grevillea robusta, Reseda luteola, Gentiana littoralia, Campanula carpatica, Ageratum conizoides, Psidium guajava, Ailanthus altissima, Hydrocotyle asiatica, Brugmansia suaveolens, Thymus pulegioides, Thymus lema-barona, Thymus serphyllum (wild), Gaultheria procumbens, Thymus camosus, Thymus thracicus, Calycanthus floridus, Zin giber officinalis, Lamium dulcis, Thymus praecox "arcticus ", Thymus speciosa, Thymus pseudolamginosus, Thymus vulgraris, Ficus religiosa, Forsythia suspensa, Chelidonium majus, Thymus wooly, Thymus portugalense, Nicotiana tabacum, Thymus cytriodoras "aureus ", Cactus officinailis, Lablab purpurea, Juglans regia, Actinidia chinensis, Hemerocallis sp., Betula pendula, Gardenia jasminoides, Taxodium distichum, Magnolia loebherii, Crataegus praegophyram, Larix decidua, Thuja orientalis, Thuja ociden talis, Cupressocyparis leylandii, Pseudotsuga menziesii, Abies firma, Parthenocissus quinquefolia, Allium cemuum, Juniperus "blue pacific", Taraxacum officinalis, Yucca sp., Tsuga canadensis, Ilex aquifolium, Ilex comuta, Taxus hiksii, Taxus media, Metasequoia glyptostroboides, Pinus bungi ana, Buxus sempervirens, Stewartia koreana, Prunus sp., Betula dahurica, Plantago minor Acer palmatum, Acer campestre, Cotinus coggygria, Quercus robur, Acer truncatum, Achyranthes bidentata, Allium japonicum, Carum cap sicum, Agastache mexicana, Prunella vulgaris, Tagetes minuta, Nepeta cataria, Ratibida columnaris, Aster novae angliae, Myrica cerifera, Pittosporam tobira, Plantago major, Pinus sylvestris, Acoras canadensis, Pieris japonica, Pinus strobus, Trifolium pratense, Prunus serotina, Datura stramonium, Geranium maculatum, Hydrocotyle asiatica, Astragalus sinicus, Centaurea maculata, Ruschia indurata, Myrthus communis, Platanus occidentalis, Licium barba turn, Lavandula officinalis, Grevillea robusta, Hypophae rhamnoides, Filipendula ulmaria, Betula pendula, Polygonum odoratum, Brugmansia graveolens, Rhus toxi codenta, Armoracia rusticana, Ficus benjaminii, Sufflera sp., Baikiaea recurvata, Asimina triloba, Lippia dulcis, Epilobium augustifohum, Bragmansia suaveolens, Xanthosoma sagittifolium, Monstera deliciosa., Aglaonema commutatus, Dieffenbachia leopoldii, Anthurium andreanum, Syngonium podophyllum, Dracaena fragrans, Ananas comosus, Strelitzia reginae, Dieffenbachia segiune, Syngonium auritum, Dracaena sp., Haemanthus katharinae, Anthurium altersianum, Spathiphyllum grandifioram, Spathiphyllum cochle arispatum, Monstera pertusa, Anthurium magnificum, Anthurium hookeri, Anthurium elegans, Calathea zebrina, Yucca elephantipes, Bromelia balansae, Musa textilis, Myrthus communis, Olea oleaster, Olea europaea, Nerium oleander, Cocculus laurifolius, Microsorium punctatum, Sanseviera sp., Adansonia digitata, Boehmeria biloba, Piper nigrum, Phymatosoras scolopendria, Tumera ulmifolia, Nicodemia diversifolia, Tapeinochilos spectabihs, Rauwolfia tetraphylla, Ficus elastica, Cycas circinalis, Caryota urens, Cynnamomum zeylonicum, Aechmea luddemanniana, Phoenix zeylonica, Ficus benjamina, Ficuspumila, Murraya exotica, Trevesia sundaica, Clerodendrum speciosissimum, Actinidia kolomikta, Paeonia lactifiora, Paeonia suffruticosa, Quercus imbricaria, Iris pallida, Portulacca olleracea, Polygonum aviculare, Iris pseudocarpus, Ailium nutans, Ailium fistulosum, Anthericum ramosum, Veratram nigrum, Polygonum lapathifohum, Hosta lancifolia, Hosta sieboldii, Echinops sphaerocephalus, Paeonia dahurica, Inula helenium, Crambe pontica, Digitalis lutea, Baptisia australis, Aristolochia australis, Hyssopus seravschanicus, Teucrium chamaedrys, Sedum album, Heracleum pubes cens, Origanum vulgare, Cachrys alpina, Laser trilobum, Matteuccia strathiopteris, Sedum telephium, Bocconia cordata, Ajuga reptans, Thalictram minus, Anemone japonica, Clematis rectae, Alchemilla officinalis, Potentilla alba, Poterium sangiusorba, Menispermum dauricum, Oxybaphus nyctagineus, Armoracia rusticana, Crambe cordifolia, Agrimonia eupatoria, Anchusa officinalis, Polemonium caeraleum, Valeriana officinalis, Pulmonaria molissima, Stachys lanata, Coronilla varia, Platycarya grandiflora, Lavandula officinalis, Vincetoxicum officinale, Acalypha hispida, Gnetum gnemon, Psychotria nigropunctata, Psychotria metbac teriodomasica, Codiaeum variegatum, Phyllanthus grandifolius, Pterigota alata, Pachyra affinis, Sterculia data, Philodendron speciosum, Pithecellobium unguis-cati, Sanchezia nobilis, Oreopanax capitatus, Ficus triangularis, Kigelia pinnata, Piper cubeba, Lauras nobilis, Erythrina caJfra, Metrosideros excelsa, Osmanthus fragrans, Cupres sussempervirens, Jacobinia sp., Senecio platyphylloides, Livistona chinensis, Tetraclinis articulata, Eucalyptus radis, Podocarpus spinulosus, Eriobotrya japonica, Gingko biloba, Rhododendron sp., Thuja occidentalis, Fagopyrum sufraticosum, Geum macrophyllum, Magnolia kobus, Vinca minor Convallaria majalis, Corylus avellana, Berberis sp., Rosa multifiora, Ostrya carpinifolia, Ostrya connogea, Quercus rubra, Liriodendron tulipifera, Sorbus aucuparia, Betula nigra, Castanea sativa, Bergenia crassifolia, Artemisia dracunculus, Ruta graveolens, Quercus nigra, Schisandra chinensis, Betula alba, Sambucus nigra, Gentiana cruciata, Encephalartos horridus, Phlebodium aureum, Microlepia platyphylla, Ceratozamia mexicana, Stenochlaena tenuifolia, Adiantum trapeziforme, Adiantum raddianum, Lygodium japonicum, Pessopteris crassifolia, Asplenium australasicum, Agathis robusta, Osmunda regaus, Osmundastrum claytonianum, Phyllitis scolopendrium, Polystichum braunii, Cyrtomium fortunei, Dryopteris flux mas, Equisetum variegatum, Athyrium nipponicum, Athyrium filix-femina, Parthenocissus tricuspidata, Ligusticum vulgare, Chamaecy parispisifera, Rosa canina, Cotinus coggygria, Celtis occidentalis, Picea schrenkiana, Cydonia oblonga, Ulmus pumila, Euonymus verracosus, Deutzia scabra, Mespilus germanica, Quercus castaneifoha, Euonymus europea, Securinega sufraticosa, Koelreuteria paniculata, Syringa josikaea, Zelkova carpinifolia, Abies cephalonica, Taxus baccata, Taxus cuspidata, Salix babylonica, Thuja occidentalis, Actinidia colomicta, Mahonia aquifo hum, Aralia mandschurica, Juglans nigra, Euonymus data, Prinsepia sinensis, Forsythia europaea, Sorbocotoneaster pozdnjakovii, Moras alba, Crataegus macrophyllum, Eucommia ulmifolia, Sorbus commixta, Philodendron amu rense, Cornus mas, Kerria japonica, Parrotia persica, Jasminum fraticans, Swidasan guinea, Pentaphylloides fruticosa, Sibiraea altaiensis, Cerasus japonica, Kolkwitzia amabilis, Amigdalus nana, Acer mandschurica, Salix tama risifolia, Amelanchier spicata, Cerasus mahaleb, Prunus cerasifera, Corylus avellana, Acer tataricum, Viburnum opulus, Syringa vulgaris, Fraxinus exelsior, Quercus trojana, Chaenomeles superba, Pinus salinifolia, Berberis vulgaris, Cotoneaster horisontalis, Cotoneaster fangianus, Fagus sylvatica, Pinuspumila, Pinus sylvestris, Berberis thunbergii, Ajuga forrestii, Anisodus acutangulus, Chinchona ledgerina, Valeriana officinalis, Peganum harmala, Chrysanthemum cineraliaefolium, Tagetes patula, Scopolia japonica, Rauwolfia serpentine, Papaver somniferam, Capsicum frutescens, Fumaria capreolata L., Datura stramonium, Tinospora rumphii, Triptorygium wilfordii, Coptis japonica, Salvia officinalis, Colleus blumei, Catharanthus roseus, Morinda citrofolia, Lithospermum erythrorhizon, Dioscorea deltoidea, Mueune prariens, Mirabilis Jalapa, Boerhavia diffusa, Camptotheca acuminate, Nothapodytes foetida, Moras nigra, Symphoricarpus albus and Ophiorrhiza pumila.

55. The method according to any one of claims 49 to 53 wherein the plant cells are derived from Vitis vinifera or Polygonum cuspidatum.

56. The method according to any one of claims 49 to 55 wherein the cells are derived from leaves, fruit, shoots, buds, flowers, bark, roots, branches, stems, seeds, cones, needles or cambium tissue of the plant.

57. The method according to any one of claims 49 to 55 wherein the cells are derived from meristematic plant tissue.

58. The method according to claim any one of claims 49 to 57 wherein the stilbene compound is trans-resveratrol, cis-resveratrol, trans-piceid, cis-piceid, a trans-resveratrol dehydrodimer, a cis-resveratrol dehydrodimer, a trans-pterostilbene, a cis-pterostilbene, a viniferin, trans-piceatannol or (3,5,5N,4N-tetrahydroxystilbene) 3-O- -glucoside (trans- astringin).

59. The method according to any one of claims 49 to 57 wherein the secondary metabolite produced is trans-resveratrol or cis-resveratrol.

60. The method according to claim 50 wherein the sub-culturing is conducted weekly, fortnightly or monthly.

61. The method according to any one of claims 49 to 60, which is conducted a batch process.

62. The method according to any one of claims 49 to 60, which is conducted in a semi- continuous or continuous process.

63. The method according to claim 62 wherein the semi-continuous process is operated in a fed-batch or a repeated-batch mode.

64. The method according to any one of claims 49 to 63 wherein the elicitor agents are selected from one or more of biotic elicitors, microbial fractions or products derived from biotic elicitors, and abiotic elicitors.

65. The method according to claim 64 wherein the biotic elicitors are selected from one or more of: Botrytis cinerea Phytophthora megasperma, Pinellas stripticum, Oligosporus sp., Pythium mamiallatum, Pythium sylvaticum, Verticillium dahliae, Verticillium sp., Penicillium minioluteum, Phytophthora lateralis, Cytospora cincta, Cytospora leucostoma, Alternaria brassicicola, Alternaria solani, Alternaria cucumerina, Botrytis squamosa, Cochliobolus heterostrophus, Colletotrichum trifolii, Colletotrichum orbiculum, Colletotrichum graminicola, Colletotrichum gloeosporioides, Cylindrocladium floridanum, Fusarium crookwellense, Fusarium heterosporium, Fusarium oxysporam f. sp. conglutinans, Fusarium oxysporam f. sp. lycopersici, Fusarium oxysporam f. sp. pisi, Gibberella zeae, Gaeumannomyces graminis var. tritici, Geotrichum sp., Leptosphaeria torrae, Nectria haematococca MPVI, Mycosphaerella pinodes, Ophiostoma ulmi, Phoma lingam, Phoma pinodella, Phytophthora infestans, Pythium aristosporam, Pythium graminicola, Pythium ultimum, Rhizoctonia solani, Sclerotinia sp., S. nodoram D-45, Trametes versicolor, Ustilago maydis, Venturia inequalis.

66. The method according to claim 64 wherein the microbial fractions or products derived from biotic elicitors are selected from one or more of: Chitosan, Lichenan, Glucomannan, Pleuran, Glucan, Carboxymethylglucan, Hydroxymethylglucan, Sulfoethylglucan, Mannan, Xylan, Mannobiose, Mannotriose, Mannopentaose, Mam otetraose, Cellulysin, Multifect XL, Multifect CL, Resinase, Pulpxyme, SP431, Pectinol, Rapidase, Klerzyme, Chitinase.

67. The method according to claim 64 wherein the abiotic elicitors are selected from one or more of: Arachidonic acid, Elaidic acid, Cyclic AMP, Dibutyrl Cyclic AMP, Methyl Jasmone, Cis-Jasmone, Jasmonic acid, /3-glucan, Miconazol, Ferulic acid, AMO-1618, Triton X-100, Benzoic acid, Salicylic acid, Propyl gallate, Sesamol, Chlorocholine chloride, 3,4-dichlorophenoxy triethyl-, (amine), Chloroethylphosphonic acid, Diethyldithiocarbamic acid, Nordihydroguairetic acid, Dithiothreitol, Sodium metabisulfite, Potassium metabisulfite, d-amino-DL-Phenylalanine, Vanadyl sulfate, Uniconazol, Paclobutrazol, Spermine, Spermidine, Putrescine, Cadavarine, Protamine Sulfate, SKF-7997, MER 29, Ancymidol, Triadimefon, Phosphon D, Thiourea, Dextran Sulfate, Hydroquinone, Chitosan glutamate, Fenpropemorph, Prochloraz, Naptifme, EDU, HTA, MPTA, Glutathione, EGTA, Gibberellins, Abscisic Acid, 1,3-Diphenyl urea, Diazolidenyl urea, Phloroglucinol, Sodium alginate, Carrageenan, Aluminium chloride, Ethylene, Acetylsalicylic acid, Sodium chloride, Acetic acid.

68. The method according to any one of claims 49 to 67 wherein the elicitors are provided within the suspension culture in a concentration of from about 0.01 μM to about 1 M.

69. The method according to any one of claims 49 to 67 wherein the elicitors are provided in a concentration from about 1 μM to about 500 mM.

70. The method according to any one of claims 49 to 67 wherein the elicitors are provided in a concentration of between about 10 μM to about 200 mM.

71. The method according to any one of claims 49 to 67 wherein the elicitors are provided in a concentration of between about 50 μM and about 50 mM.

72. The method according to any one of claims 49 to 71 wherein the elicitors are added to the suspension culture at a time from the inoculation time to any time during the culture duration.

73. The method according to claim 72 wherein the elicitors are added to the suspension culture at a time from the early exponential growth phase to the stationary phase.

74. The method according to either claim 72 or claim 73 wherein there is a second or multiple addition of the elicitors into the suspension culture, conducted between about six hours to about a month in duration after the previous elicitation.

75. The method according to claim 74 wherein the second or multiple addition of elicitors is conducted between about twelve hours to about two weeks in duration after the previous elicitation

76. The method according to claim 74 wherein the second or multiple addition of elicitors is conducted between about twelve hours to about seven days in duration after the previous elicitation.

77. The method according to any one of claims 49 to 76 wherein the adsorbent is included in the suspension culture in an amount of between about 1 g/L and about 500 g/L.

78. The method according to any one of claims 49 to 76 wherein the adsorbent is included in the suspension culture in an amount of between 20 g/L and about 300 g/L.

79. The method according to any one of claims 49 to 76 wherein the adsorbent is included in the suspension culture in an amount of between about 50 g/L and about 200 g/L.

80. The method according to any one of claims 49 to 79 wherein the adsorbent is added to the suspension culture between the inoculation to any time during the culture duration.

81. The method according to any one of claims 49 to 79 wherein the adsorbent is added to the suspension culture between the inoculation to the end of the exponential growth phase.

82. The method according to any one of claims 49 to 81 wherein the adsorbent is added in the suspension culture in conjunction with one or a combination of elicitor agents at the same time during the cultivation.

83. The method according to any one of claims 49 to 81 wherein the adsorbent is added in the suspension culture in conjunction with one or a combination of elicitor agents at a different time during the cultivation.

84. The method according to any one of claims 49 to 83 wherein the nutrient medium comprises one or more of a carbon source, an organic nitrogen source, and inorganic nitrogen source, a macrosalt, a microsalt, a rare trace element, a vitamin, an organic supplement, a plant hormone, a hormone substitute or derivative, a hormone inhibitor, a synthetic growth regulator, a biosynthetic precursor, a metabolic inhibitor, a non-metabolic inhibitor, a stimulant, an activator, an anti-browning agent, an anti-oxidant, a stabiliser, an enhancer, a radical, a scavenger, a conditioner and a reducing agent.

85. The method according to any one of claims 49 to 84 wherein the adsorbent material is a macroporous non-ionic cross-linked polymeric material.

86. The method according to any one of claims 49 to 84 wherein the adsorbent is selected from one or more of Amberlite^® XAD7, Amberlite^® XAD2, Amberlite^® XAD7HP, Amberlite^® XAD4, Amberlite^® XAD 16, Amberlite^® XAD 1600, AMBERLITE®. AMBERLITE FP®, Purasorb^® AP-250, Purasorb^® AP-400; Dowex^® L493, Dowex^® V493, Dowex^® L323, Diaion^® HP20, Diaion^® HP21, SEPABEADS^® SP207, SEPABEADS^® SP70, SEPABEADS^® SP700, SEPABEADS^® SP825, SEPABEADS^® SP850, Diaion^® HP2MG; SERDOLIT^® PAD I, SERDOLIT^® PAD II, SERDOLIT^® PAD III, SERDOLIT^® PAD IV, RP-8 (Merck), Charcoal, activated charcoal, Supelpak^®-2, Supelpak^®-2B, Supelite^® DAX-8, Duolite^® XAD761, Dowex^®, Optipore^® L493, Poly(styrene-co- divinylbenzene), AMBERSORB^® 572, AMBERSORB^® 348F, Dimethylaminomethyl- polystyrene, Poly(4-ethylstyrene-co-divinylbenzene), Florisil^®, Ferric hydroxide oxide, Sepiolite, Mimetic Green 1 Ligand Affinity Adsorbent, Mimetic Yellow 2 Ligand Affinity Adsorbent, Mimetic Red 2 Ligand Affinity Adsorbent, Mimetic Orange 2 Ligand Affinity Adsorbent, Mimetic Blue 1 Ligand Affinity Adsorbent, Mimetic Blue SA Ligand Affinity Adsorbent, Mimetic Blue 2 Ligand Affinity Adsorbent, Mimetic Orange 3 Ligand Affinity Adsorbent, Mimetic Red 3 Ligand Affinity Adsorbent , Mimetic Blue AP Ligand Affinity Adsorbent, Mimetic Orange 1 Ligand Affinity Adsorbent, Mimetic Yellow 1 Ligand Affinity Adsorbent, Tenax™ TA, AMBERCHROM™ , AMBERJET®, AMBERLYST® , DUOLITE® , MAC™ HP , Acrylic anion resins, XAD polymeric adsorbents, Phenol- formaldehyde resin , Nuclear grade resins.

87. The method according to any one of claims 49 to 84 wherein the adsorbent is in the form of an immiscible liquid phase adsorbent.

88. The method according to claim 87 wherein the immiscible liquid phase adsorbent is selected from one or more of dimethyl siloxane polymer (Silicone antifoam A), polymethoxy silanes, long chain or branched alkane adsorbents and glycol or polyol adsorbents.

89. The method according to any one of claims 49 to 88 wherein the secondary metabolite is recovered in an amount at least 800-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

90. The method according to any one of claims 49 to 88 wherein the secondary metabolite is recovered in an amount at least 1000-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

91. The method according to any one of claims 49 to 88 wherein the secondary metabolite is recovered in an amount at least 1200-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

92. The method according to any one of claims 49 to 88 wherein the secondary metabolite is recovered in an amount at least 1500-fold increased relative to a comparable method of production where adsorbent and elicitor are not included in the suspension culture.

93. The method according to any one of claims 49 to 92 wherein the recovery of the secondary metabolite from the suspension culture is achieved by isolating the secondary metabolite from the cells, the adsorbent and the nutrient medium utilising solvent extraction with a suitable solvent.

94. The method according to claim 1 wherein the adsorbent included within the suspension culture is an aliphatic adsorbent.

95. The method according to claim 49 wherein the adsorbent included within the suspension culture is an aliphatic adsorbent

96. The method according to claim 49 wherein the adsorbent included within the suspension culture is AMBERLITE® XAD-7.

97. The method according to claim 49 wherein the adsorbent included within the suspension culture is Diaion® HP2MG.

98. The method according to claim 49 wherein the one or more elicitor agents is/are selected from jasmonic acid, salicylic acid, chitosan and /3-glucan

99. A stilbene plant secondary metabolite produced by the method according to any one of claims 49 to 96.