FR2808969A1 - Cationic lignosulfonates useful as plant growth stimulants, comprises chelating and auxin-protecting action - Google Patents

Abstract

Plant growth activator acting on rhizogenesis, flowering, and plant development, derived from cationic lignosulfonates, especially (I), have an auxin-protecting activity independent of the nature of the accompanying cation. Plant growth activator acting on rhizogenesis, flowering, and plant development, derived from cationic lignosulfonates, especially of formula (I) have an auxin-protecting activity independent of the nature of the accompanying cation.

Description

The present invention relates to an activator product for the growth and development of plants derived from cationic lignosulfonates.

Lignosulfonates are by-products of the paper industry. The action of lignosulfonates to promote plant growth is known.

No. 3,721,2803 discloses a composition for this purpose comprising a mixture of fish meal with a salt of lignosulfonic acid, for example calcium salt, the mixture being subjected to an acid hydrolysis which would have the effect of solubilizing at least two thirds proteins and being treated in an oxidizing medium between 20 and 80 C for a period of 2 hours to 6 days.

The plants are treated by spraying or dusting.

Patent FR 2 422 331 describes a plant growth regulating composition which may comprise lignosulphonates as dispersing agents.

The documents of the prior art are limited to the statement of a finding, that the beneficial effect on the growth of lignosulfonate plants without however being able to explain the mechanism and to isolate the active compounds for this purpose.

The present invention goes further than the simple unexplained or arguable findings of the prior art in that through the study of the action of lignosulfonates on plants, it has been possible to determine the characteristics of the active principle in the development and growth of the plant thus making it possible to achieve the characteristics of the plant growth and development activator according to the invention and to characterize a process for obtaining said activator from lignosulphonates.

For this purpose, the plant growth and development activator derived from the cationic lignosulfonates according to the invention is essentially characterized in that it comprises a protective function of the auxin of the plant, independent of the accompanying cation, this auxin being the hormone capable of promoting rhizogenesis and radial growth of the stems, as well as flowering and fruiting.

According to another characteristic, the activator according to the invention is defined by the possession of a chelating function and a auxin protective function.

Le procédé d'obtention de l'activateur de croissance selon l'invention à partir lignosulfonates se caractérise en ce qu'il est fait usage d'un fractionnement au méthanol pour obtenir une fraction soluble dans le méthanol comportant 75 % de matière sèche 77,5 du fer originaire composée de molécules de masse moléculaire les plus faibles 1500, contenant le ou les agents protecteurs des auxines et le ou les chélates que, cette fraction soluble au méthanol est soumise à une dialyse sur une membrane possédant MWCO de 1000, l'eau de dialyse comportant 93 % de matière sèche et 95 % du fer et contenant les molécules à faible masse moléculaire, que cette eau de dialyse est elle- même fractionnée par une dialyse sur une membrane MWCO 500, l'eau de dialyse obtenue contenant 91 % de la matière sèche et 98 % du fer ; et que l'eau de dialyse obtenue est filtrée sur un gel de SEPHADEX (marque déposée), ou tout type de tamis moléculaire. According to another characteristic of the invention, the molecular weight of the growth promoter is less than 3,000, preferably the molecular weight is still a further characteristic, the growth promoter according to the invention has a structure of the type

The process for obtaining the growth promoter according to the invention from lignosulphonates is characterized in that a fractionation with methanol is used to obtain a fraction soluble in methanol comprising 75% of dry matter 77, Of the original iron composed of molecules of the lowest molecular weight 1500, containing the auxin protective agent (s) and the chelate (s), which this methanol-soluble fraction is dialyzed on a membrane having MWCO of 1000, dialysis water containing 93% of dry matter and 95% of iron and containing the low molecular weight molecules, this dialysis water is itself fractionated by dialysis on a membrane MWCO 500, the dialysis water obtained containing % of dry matter and 98% of iron; and that the dialysis water obtained is filtered on a gel of SEPHADEX (registered trademark), or any type of molecular sieve.

According to yet another characteristic, the extraction process makes use of a fractionation using ultrafiltration membranes of adequate cut-off threshold, namely a cut-off ultrafiltration membrane of 1000 and which will be recovered. activator growth in the permeate obtained by this operation.

Lignosulfonate application tests on the growth and development of plants were conducted using iron lignosulphonates (LSFe) and calcium lignosulfonates (LSCa), the plant material consisting of monocotyledonous dicotyledons such as Tomatoes Peppers, Beans, But.

On observe une croissance supérieure pour les plants cultivés en présence de LSCa. On observe de même un chevelu racinaire beaucoup plus développé. Depending on the case, iron lignosulfonate (35 mg .L "1) was added in order to obtain a final concentration of 50 NM iron or calcium lignosulfonates at a concentration of 35 mg L-1. Growth Table I represent hydroponic cultures of peppers in the presence of LSCa, and without intake of LSCa.

Higher growth is observed for plants grown in the presence of LSCa. We also observe a much more developed root hair.

Table 2 illustrates different comparative parameters established on hydroponic corn crops in the presence of DE LSCa or in the absence of LSCa.

LSCa <SEP> + <SEP> LSCa <SEP> Increase <SEP> of
<tb> measured <SEP> parameter
<tb> Weight <SEP> total <SEP> of <SEP> 28g <SEP> 5.26g <SEP><B> +23% </ B>
<tb> plants <SEP> +/- 0.25 <SEP> + I-0.37
<tb> Weight <SEP> of <SEP> roots <SEP> 1,65g <SEP> 1,98g <SEP> + 20%
<tb> +/- 0.1 <SEP> +/- 0.14
<tb> Weight <SEP> of <SEP> the <SEP> part <SEP> 2,63 <SEP>! <SEP> 3.27g <SEP> + 24.3%
<tb> aerial <SEP> +/- 0.21 <SEP> +/- 0.3
<tb> Diameter <SEP> of <SEP> stem <SEP> 31 <SEP> mm <SEP> 5.38mm <SEP><B> + 27% </ B>
<tb> +/- 0.34 <SEP><B> +/- 0.33 </ B>
<tb> Diameter <SEP> of <SEP> the <SEP> 1,18mm <SEP> 1,5mm <SEP> +24,8
<tb> root <SEP> main <SEP> + I-0,18 <SEP><B> +/- 0.1 </ B> The total weight of the plants is increased by 23%.

Table 3 is a comparative table of dry matter weight of maize plants with or without LSCa.

-LSCa <SEP> + LSCa
<tb> Weight <SEP> total <SEP> of <SEP><B> 319.93 <SEP> 370.13 </ B>
<tb> plants <SEP> +/- 15 <SEP> +/- 29
<tb> Weight <SEP> of <SEP><B> 105.91 <SEP> 112.78 </ B>
<tb> roots <SEP> + I-2,8 <SEP> +/- 8
<tb> Weight <SEP> of <SEP><SEP><B> 2 </ B> 1 <B> 4.02 <SEP> 257.35 </ B>
<tb> part <SEP> aerial <SEP> +/- 13 <SEP> +/- 21 Table 4 is a comparative table showing the dry matter weight of the aerial and root parts of the maize plan.

-LSCa <SEP> + LSCa
<tb> Roots <SEP><B> 33.15% <SEP> 30.48% </ B>
<tb> +/- 1.25 <SEP> +/- 066
<tb> Part <SEP> aerial <SEP> 66,84% <SEP> 69,53%
<tb> + I-1.25 <SEP> +/- 065 The total weight of the plants is 15.7% higher in the presence of LSCa, and significantly. It is the same for the weight of dry matter of the aerial part. as regards the dry mass of the roots, it is more important in shots grown in the presence of LSCa, but this difference is not significant.

proportion of roots and aerial parts relative to the dry mass the plant varies here significantly. In untreated plants, the roots represent 33.15% whereas in the treated plants the dry mass of the roots does not represent 30.5%. These results are not contradictory with the results previously exposed on the fresh material. Indeed, plants treated with LSCa have a larger root hair. The peculiarity of this root system is to be composed of many young, non-serrated roots, whose cells being multiplied contain a high proportion of water. It is this variation in tissue differentiation that can explain the results obtained on the weighings of fresh matter and dry matter.

Significant results were also observed in the case of open-field maize cultivation with longer, heavier ears with a lower apical abortion rate, including total weight of the ear and weight. grains are larger with the addition of LSCa.

The examples mentioned are not limiting. The invention is applicable to all types of plants and in particular in silviculture, arboriculture, for vines or for walnuts.

It has been shown that lignosulphonates, whatever the nature of the chelated metal, promote plant growth and fruiting.

characteristics at the level of observed effects show an action of lignosulphonates on the regulation of auxins, which are the hormones involved in rhizogenesis, stem growth, flowering and fruiting.

This action of the phenolitic compounds of the lignosulfonates is carried on the AIA (indole-3-acetic acid) of the cell by delaying their degradation by peroxidase, the lignosulfonates and their phenolic compounds acting as protector of the endogenous AIA against degradation by AIA oxidase being preferentially oxidized by this enzyme.

Protectors are electron donors easily oxidized by peroxidase. The growth and development activator according to the invention is defined as comprising a protective function of auxin independent of the accompanying cation. In fact, the growth promoter according to the invention has both a chelating function and a protective function of auxin.

The growth activator acting as auxin protector and thus stimulating the formation of a dense root hair, promotes another physiological process, flowering.

Flowering is dependent on the presence of plant hormones, cytokinins, synthesized in the apex (extremities) of the roots. The growth promoter by increasing the number of secondary roots leads to an increase in the number of apices which gives the plant a higher cytokinin synthesis potential.

The growth promoter indirectly promotes the synthesis of cytokinins essential for the initiation of flower buds.

The growth promoter also promotes the next step of flower bud differentiation requiring high levels of AIA.

Cet isolement a été effectué en laboratoire par fractionnement au méthanol pour obtenir - Une fraction méthanol soluble qui représente 75 % de la matière sèche 77,5 % du fer (dans le cas de LS Fe) . The invention has sought to isolate the growth promoter according to the invention from lignosulphonates to arrive at a definition of a compound having a molecular mass below <B> 1000 </ B> and of a structure of the type

This isolation was performed in the laboratory by fractionation with methanol to obtain a soluble methanol fraction which represents 75% of the dry matter 77.5% of iron (in the case of LS Fe).

- It is this fraction which is responsible for all the protective effects of lignosulfonates on the degradation of AIA-OXIDASE.

An insoluble methanol fraction which represents 25% of the crude lignosulfonates and 22.5% of the total iron.

- This fraction has no effect on the degradation of AIA.

The soluble methanol fraction contains both the auxin protecting agents and the iron chelates.

The insoluble methanol fraction has no auxin protective effect and does not contain the chelate (s).

By gel filtration, for example SEPHADEX gel or any other molecular sieve, a molecular weight group of less than or equal to 1500 which contains most of the iron is obtained.

Dialysis of this soluble methanol fraction, for example on a membrane whose cut-off point (MWCO) is 1000, makes it possible to obtain a dialysis water comprising 93% of dry matter and 95% of iron and containing the molecules of low mass. . This dialysis water is again dialyzed on a cut-off membrane 500, the dialysis water obtained containing 91 dry matter and 98% iron.

The ultimate filtration of Sephadex gel 10 - (MWCO 500) dialysis water allows purification of a compound of molecular weight close to 400 and which has both the properties of chelating agent and auxin protector.

To this method of production can be substituted any other known method such as the filtration technique, tangential membrane filtration, electrofiltration, dialysis, reverse osmosis or the use of molecular sieve or any other method for separating molecules according to their molecular mass.

The lignosulfonate protecting compound may, according to the chosen technique, have a molecular mass of between 3000 and 400.

Claims (1)

1 - Growth activator involved in the rhizogenesis, flowering and development of plants derived from cationic lignosulfonates, characterized in that it comprises a protective function of auxin independent of the accompanying cation. 2 - growth activator according to claim 1 characterized in that it has both a chelating function and a auxin protective function. Growth promoter according to claim 1, characterized in that it has a molecular mass of between 3,000 and 400. Growth promoter according to claim 1 and any one of the preceding claims, characterized in that it has a structure like     5 - Process for obtaining the growth promoter according to claim 1 from lignosulfonates, characterized in that a fractionation with methanol is used to obtain a fraction soluble in methanol containing 76.5% of material. and 77.5 of the original iron composed of the lowest molecular weight molecules A500, containing the auxin protective agent (s) and the chelate (s), that this methanol-soluble fraction is dialyzed on a MWCO membrane. of 1000, the dialysis water comprising 93% of dry matter and 95% of iron and containing the low molecular weight molecules, this dialysis water is itself fractionated by dialysis on a membrane of MWCO 500, the water dialysis obtained containing 91% of the dry matter and 98% of iron; and that the dialysis water obtained is filtered on a gel of SI-IEPADEX. Process for obtaining the growth promoter according to Claim 1 from lignosulphonates, characterized in that fractionation using cut-off ultrafiltration membranes, namely an ultrafiltration membrane, is used. cutoff threshold of 3000 to 400 and that will recover the growth promoter in the permeate obtained by this operation. 7- Process for obtaining the growth promoter according to claim 1 from lignosulfonates, characterized in that it uses filtration techniques such as tangential membrane filtration, electrofiltration, electrodialysis, dialysis, reverse osmosis, the use of molecular sieves or any other method to separate molecules based on their molecular weight.