GB2224209A

GB2224209A - Preventing or inhibiting plant virus diseases

Info

Publication number: GB2224209A
Application number: GB8924527A
Authority: GB
Inventors: Jun Hiraki; Hiroshi Morita; Masahiro Fujii
Original assignee: Chisso Corp
Current assignee: JNC Corp
Priority date: 1988-10-31
Filing date: 1989-10-31
Publication date: 1990-05-02
Also published as: GB2224209B; FR2638324B1; DE3934761A1; GB8923367D0; GB8924527D0; JPH02121903A; FR2638324A1

Description

2224O -9 1 M&C FOLIO: 230P59617 WANGDOC: 09171 Method and Composition for

Preventing or Inhibiting Plant Virus Diseases The present invention relates to a method and composition for preventing or inhibiting plant virus diseases.

Usually, when a plant is infected with a virus disease. the whole plant is infected and dies readily. Also. the infected plant communicates the disease to other healthy plants one after the other. by contact or entomophilous contagion and as a result a great deal of damage is done to the plants. before the plants are cropped or removed. Examples of viruses of these plant pathogens include the tobacco mosaic viruses, the potato viruses and the cucumber mosaic viruses, which infect the eggplant. cucumber and rape families.

Methods which have been suggested for preventing these virus diseases include, for example. for entomophilous infection. such as the cucumber mosaic diseases caused by cucumber mosaic viruses. the extermination of intermediate insects. a change of planting time to avoid the insect generating time. cultivation of specially bred plants and so on. However. these methods do not generally give a good control effect. For preventing the spread of virus diseases. infected plants have been pulled out. However. it is difficult to prevent infected insects flying in from other fields, so that this attempt at prevention is not effective.

2 On the other hand. the tobacco mosaic virus disease, which do not infect by entomophily. but by contact contagion. infects crops by contact of the viruses with agricultural machines or by mixing into the soil. For preventing these diseases. agricultural machines, the soil. working clothes, fingers. etc. are subjected to disinfection. including high cost and labour. However, such methods are insufficient to prevent these virus diseases from occurring.

As described above. physical elimination or agronomic control are only considered as a counterplan for preventing plant virus diseases under existing circumstances. However. the control effect is small and extensive damage is done to crops by plant virus diseases is an important subject for agriculture.

For research purposes into prevention agents for plant virus diseases. many antiviral activates prepared from many natural products or synthetic compounds have been investigated. As a result. some materials having antiviral activity have been found. Firstly. a so-called multiplication control agent which controls virus multiplication control agent which controls virus multiplication in plant bodies. materials similar to nucleic acids such as 2-thiouracil, 8-azaguanine and 5-fluorouracil. etc have been found. However. some of these materials generate mutants and inhibit metabolism of nucleic acids or proteins in the hosts and give rise to damage. These materials are generally expensive and have little actual control effect in the field, so that these materials are not used in practice.

As an agent for blocking contact contagion. sodium alginate has been used. However, its application is limited to the tobacco mosaic viruses and the control effect is limited. The agent is ineffective with an 3 entomophilous contagion virus, such as the cucumber mosaic viruses, which is carried by plant lice such as aphids.

We have previously found that polylysine has the effect of preventing plant virus diseases. We have found that alkyldiethylenetriaminoacetic acids (or their salts) have the effect of preventing or inhibiting plant virus diseases.

Accordingly. one embodiment of the invention provides a method for the prevention or inhibition of plant virus diseases in plants which comprises applying to the plants alkyldiethylenaminoacetic acids or salts thereof.

A second embodiment of the invention provides a composition for the prevention or inhibition of plant virus diseases which comprises an alkyldiethylene-. triaminoacetic acid or salt thereof in association with a carrier or diluent thereof.

The alkyldiethylenetriaminoacetic acids are ampholytic surface active agents which may, for example be monoalkyldiethylenetriaminoacetic acids of the formula R (NH-CH -Ch)-NH-CH -COOH 1 2 2 2 2 or dialkyldiethylenetriaminoacetic acids of the formula R,-NH-CH 2 -CH 2 R,-NH-CH 2 -CH 2 N-CH 2 -COOH (wherein R is a higher alcohol group).

Alkydiethylenetriaminoacetic acids (and their salts) are widely sued as a sterilizing agent in disinfectants which are stable to.protein and electrolytes. However, their antiviral actions were not known.

4 entomophilous contagion virus, such as the cucumber mosaic viruses, which is carried by plant lice such as aphids.

Accordingly, one embodiment of the invention provides a method for the prevention or inhibition of plant virus diseases in plants which comprises applying to the plants alkyldiethylenaminoacetic acids or salts thereof.

A second embodiment of the invention provides a composition for the prevention or inhibition of plant virus diseases which comprises an alkyldiethylenetriaminoacetic acid or salt thereof in association with a carrier or diluent thereof.

The alkyldiethylenetriaminoacetic acids are ampholytic surface active agents which may. for example be monoalkyldiethylenetriaminoacetic acids of the formula R (NH-CH -Ch)--NH-CH -COOH 1 2 2 2 2 or dialkyldiethylenetriaminoacetic acids of the formula R,-NH-CH 2 -CH 2 R,-NH-CH 2-CH2 N-CH 2 -COOH 1 (wherein R 1 is a higher alcohol group).

Alkydiethylenetriaminoacetic acids (and their salts) are widely sued as a sterilizing agent in disinfectants which are stable,to protein and electrolytes. However, their antiviral actions were not known.

7-Monooctyldi ' ethylenetriaminoacetic acid whose alkyl group is an octyl group can be produced by the following process, for instance. Four moles of diethylenetriamine NH2-CH2-CH2-NH-CH2-CH2-NH2 is heated to 1800C and one moles of octyl chloride C8H17C1 is added for four hours. After cooling, the produced diethylenetriamine hydrochloride is removed, the liquid reaction product is distilled under reduced pressure and the distillate fraction is obtained at 150-200"C (15mmHg). The fraction compound is monoocty1diethylenetriamine C8Hl7-NH- ' CH2-CH2-NH-CH2-CH2-NH2. The obtained fraction is heated and reacted with an equivalent solution of monochloroacetic acid at 100C for a half hours. The desired hydrochloride of monooctyldiethylenetriamino- acetic acid C8Hl7(NH-CH2-CH2)2-NH-CH2-COOH.HC1 is obtained. The compound can be used with further purification or it can be used after dissolving in water.

Diocty1diethylenetriaminoacetic acid can be prepared by the following process, for instance. 1.125 moles of diethylenetriamine is boiled while back-flow stirring and 0.75 moles of octylchloride is added for four hours. After cooling, the produced crystalline diethylenetria mine hydrochloride is separated from the liquid phase.

After removal of the compound, the liquid is distilled under reduced pressure at 20 mmHg, a forerun having the boiling points below 200C is cut off and 72 grammes of the distilled fractiori having the boiling points of 2002500C (200 mmHg) is collected. The main fraction compound is dioctyldiethylenetriamine. 35 grammes of the main fraction and 100 ml of 1N monochloroacetic acid solution are heated with stirring for 45 hours on a boiled water bath to obtain the desired aqueous solution of hydrochloride of diocty1diethylenetriaminoacetic acid:

6 C8H17-NH-CH2_Ck N-CH2-COOH'HC" C8Hl7-NH-CH2-CH2 Needless to say, the methods for producing the alky1diethylenetriaminoacetic acids (salts) which are used in the present invention are not limited to the above processes.

Alkyldiethylenetriaminoacetic acid (salt) used in the present invention acts neutrally in a neutral phase by salt-forming of an intramolecular group as if it were an amino acid. Further, it acts in an acid phase by salt-forming of an amino group as if it were a cation surface active agent, while it acts in an alkali phase by producing a carboxylate as it were an anion surface active agent. The aqueous solutions of the alkyldiethylenetriaminoacetic acids (salts) are transparent and scarcely toxic and can be dissolved in water and alcohol.

The alkyl groups of the alky1diethylenetriaminoacetic acids (salts) may have four or more carbon atoms, preferably higher 8-18 carbon atoms.

The purpose of the present invention is attainable with either the above monoalkyldiethylenetriaminoacetic acids (salts) or dialkyldiethylenetriamino acetic acids (salts).

Methods for preventing plant virus diseases by using the alky1diethylenetriaminoacetic acids (salts) according to the present invention are as follows. - 1) 10 to 500 ppm of aqueous solutions of alkyl- diethylenetriaminoacetic acids (salts) are applied or sprayed on plants to be prevented. I 2) While working by polling the tops, nipping out buds, binding props etc. , workers disinfect agricultural tools such as shears and their fingers, using 100-500 of aqueous alky1diethylenetriaminoacetic acid (salt) 1 i 7 solution, whenever they treat a few crops.

3) Before sowing is carried out, seeds are dipped into a 100-500 ppm of alkyldiethylenetriaminoacetic acid (salt) solution for a definite time.

As virus diseases which can be prevented by using the alky1diethylenetriaminoacetic acids (salts) according to the present invention as a preventing agent, in addition to the above tobacco mosaic viruses and potato viruses, cucumber mosaic viruses, pumpkin mosaic viruses, turnip mosaic viruses and cauliflower mosaic viruses can be mentioned by way of example.

When the plant virus diseases caused by these viruses are prevented and exterminated, the preventive effect can be enhanced by (1) simultaneous use of a spreader for an agricultural medicament and the preventing agent of the present invention, or (2) simultaneous use of a preventing agent for plant lice, such as aphids, and the preventing agent of the present invention. The simultaneous use or preparation can exceed the simple use of the compounds of the present invention in its preventive effect.

When the alky1diethylenetriaminoacetic acids (salts) of the present invention are used as a preventing agent for plant virus diseases, its main advantage is enhanced safety and the heightened preventive effect obtained. For example, when 7-dodecyldiethylenetriamino-l-acetic acid is administered in the abdominal cavity of mice, the acute toxicity LDSO is about 1.7 g/kg. The primary test in which eye mucous membranes of rabbits are stimulated gives little stimulative action.

As described above, the preventing agent plant virus diseases of the present invention, in which alkyldiethylenetriaminoacetic acids (salts) is used, shows a better preventive than that of conventional preventing 1 8 agents, so that the virus damage of useful plants can be prevented. Efficiency can also be heightened while carry ing out agricultural work. Thus, the agent of the present invention can produce practical results.

The following Examples illustrate the present inven tion more specifically.

-Example 1

Sodium 7-monolauryldiethylenetriamino-l-acetate aqueous solutions adjusted to concentrations of.3.0, 1.Or 0.3, 0.1 and 0.03 mg/ml were equally sprayed on every leaf of potted tobaccos (Samsun NC breed) at the period of 10 leaves, respectively. Two hours after spraying, sap of leaves was inoculated with previously prepared tobacco mosaic virus-OM (1 1.ig/ml) in the usual way by means of carborundum. Four days after-the inoculation, local lesions were examined and the virus infection inhibition rates were calculated by the following equation. The other hand, as a control group, distilled water was sprayed on control leaves.

Concentration of sodium 7monolauryldiethylenetriamino -1-acetate aqueous solution rate virus infection inhibition rate = C - T - X 100% C C: the number of local lesions of the control group T: the number of local lesions of the treated group The examined results are shown in Table 1. Table 1 Infectin Medical damage inhibition 0.3 1.0 0.3 0.1 0.03 mg 1 M1 i 98 93 79 60 28 Nothing Nothing Nothing Nothing Nothing 1 9 0.0 (control-group) 0 Nothing Example 2

By dissolving 300 ppm of hydrochloride of dioctyldiethylenetriaminoacetic acid in water, a solution prepared.

The aqueous solution of hydrochloride of dioctyldiethylenetriaminoacetic acid prepared as described above was equally sprayed on each leaf of potted tobaccos (Samsun NC breed) at the period of 10 leaves, respectively. One hour after spraying, sap of leaves was inoculated with previously prepared potatot virus (5 1,g/ml) in the usual way by means of carborundum.

Four days after the inoculation, local lesions were examined and the potato virus infection inhibition rates were calculated by using the same method in Example 1.

The other hand, as a control group, distilled water was sprayed on control leaves.

The examined results are shown in Table 2.

Table 2

Agent used Concentration Infection Medical (Ppm) inhibition damage rate (%) Hydrochloride of dioctyl- 300 diethylenetriaminoacetic acid 77.6 Nothing 0 Non-treatment 0 0 Nothing (Control group) 1 Example 3

A solution prepared by dissolving 1,500 ppm of sodium 7-monolauryldiethylenetriamino-l-aceticacetate in water was equally sprayed on seed leaves of potted cucumber (Syogoin Fushinari cucumber breed) of five days after germinating. One hour after spraying, sap of leaves was inoculated with previously prepared cucumber mosaic virus in the usual way by means-of carborundum. 14 days after inoculating, the number of roots having mosaic local lesions on the cucumber seed leaves was examined and the virus infection inhibition rates (%) were calculated by the following equation. The other hand, as a control group, distilled water was sprayed on control leaves.

Ten roots per group were used in a test in a green house and the test was repeated twice. N - T Infection inhibition rate - X 100% N N: the number of mosaic roots in a non-treated group T: the number of mosaic roots in a treated group The examined results are shown in Table 3. Table 3 Acueous solution of sodium 1500 7-monolauryldiethylenetriamino-l-acetate Non-treated group Agent used Concentration Infection Medical (Ppm) inhibition damage rate (%) Nothing 0 Nothing Example 4

Green peppers were cultivated and over-wintered in a house where green peppers had caught a toba,cco mosaic disease at the last planting. The green peppers had been set out at the begining of October in the house. 1000 ppm sodium 7- monolauryldiethylenetriamino-l-acetate acueous solution was repeatedly sprinkled on the green peppers in z the proportion of 20 litre per are every seven days from one week after the green peppers had been set out. After sprinkling the solution, inducement work was conducted and the green peppers were harvested by a plucking method. The solution was sprinkled 20 times up to March and the generating rate of disease roots was finally 33%. on the other hand. the generating rate of disease roots was 100% at a non-sprinkled area. The harvesting rate of the sprinkled area increased by 37% in comparison with 10 the non-sprinkled area.

The results are shown in Table 4. Table 4 Test area Generating rate Harvest Medical damage of disease roots (kg) Medical-sprinkled 33 area 20 Non-sprinkled 5.5 Nothing 4.0 Nothinl Notice Harvest: harvest of one area per seven roots.

1 It 12

Claims

Claims:

(1) An agent for ireventinq plant virus diseases, characterized in thatthe agent contains at least one kind of compounds selected from the group consisting of.alkyldiethylenetriamino acetic acids and the salts of alky1diethylenetriaminoacetic acids as an active component.

(2) An agent as claimed in claim 1, wherein'the alky1diethylenetriaminoacetic acids are 7-alkyldiethylenetriamino-1acetic acid.

(3) An agent as claimed in claim 1, wherein the alky1diethylenetriaminoacetic acids are selected from the group consisting of monoalkyldiethylenetriaminoacetic acids and dialkyldiethylenetriamino acetic acids.

(4) An agent as claimed in claim 1, wherein the alkyl groups of the alky1diethylenetriaminoacetic acids are higher alkyl groups having four or more carbon atoms.

(5) An agent as claimed in claim 1, wherein the alkyl groups of the alky1diethylenetriaminoacetic acids are selected from the group consisting of octyl, decyl and lauryl.

(6) An agent as claimed in any one of claims 1 to 5, wherein the salts of the alky1diethylenetriaminoacetic acids are present in the form of alkaline metal salts or alkaline earth metal salts.

(7) An agent as claimed in any one of claim 1 to wherein the alky1diethylenetriaminoacetic acids are present in the form of hydrochlorides of the alky1diethylenetriaminoacetic acids.

A 4 13 8. A method of preventing or inhibiting plant virus diseases which comprises applying to the plants an alkyldiethylenetriamino aceticacid or a salt thereof.

9. A method as claimed in claim 8. wherein the alkyldiethylenetriaminoacetic acid is a 7-alkyldiethylenetriamino-iacetic acid.

10. A method as claimed in claim 8. wherein the alkyldiethylenetriaminoacetic acid is a monoalkyldiethylenetriaminoacetic acid or a dialkyldiethylenetriamino acetic acid.

11. A method as claimed in any one of claims 8 - 10 wherein the alkyl group(s) of the alkyldiethylene triaminoacetic acid contains four or more carbon atoms.

12. A method as claimed in claim 8. wherein the alkyl group(s) of the alkyldiethylenetriaminoacetic acid are octyl. decyl or lauryl groups.

13. A method as claimed in any one of claims 8 - 12 wherein the salt of the alkyldiethylene-triaminoacetic acid is an alkali metal salt or an alkaline earth metal salt.

14. A method as claimed in any one of claims 8 to 12 wherein the alkyldiethylenetriaminoacetic acid is present in the form of a hydrochloride.

15. A method as claimed in claim 8 substantially as hereinbefore described with reference to the Examples.

14 16. A composition for the preparation or inhibition of plant virus diseases which comprise an alkyldiethylenetriaminoacetic acid, or salt thereof. in association with a carrier or diluent.

17. A composition as claimed in claim 16 in which the alkyldiethylenetriaminoacetic acid is as defined in any one of claims 914.

1 z Published 1990 atThe Patent Office. State House, W71 High Holborn. IoondonWCIR4TP- Further copiesmaybe obtained from The Patent Office. Sales Branch, St Mary Cray, Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1187