Methods and compositions for providing salicyclic acid-independent pathogen resistance in plants

1. A plant protecting composition comprising a diluent and/or carrier and a compound of general formula I:

or salt thereof, wherein:

R 1 is C, N or S;

R 2 and R 4 are each independently a hydrogen, sulfide, alkyl, hydroxyl, alkoxide, amino, mercapto, alkyl sulfide, thionyl, halo, cyano, nitro or carboxylate;

R 3 and R 9 can be a hydrogen, alkyl, halo or mercapto, wherein at least one of R 3 and R 9 is a halogen;

A 1 is selected from the group consisting of a carbon, nitrogen, oxygen and sulfur; and

A 2 is nitrogen or —NHR 8 wherein R 8 is —H, or an alkyl;

wherein when A 1 or A 2 is a nitrogen then R 5 , R 6 , R 7 or R 8 is a hydrogen;

wherein when A 1 is a carbon then A 1 is either —COOH or a carboxyalkyl;

wherein the composition comprises an effective amount or concentration of the compound so as to induce modulation of a resistance gene or a gene from Table I, or induce pathogen or disease resistance in a plant; and

wherein the diluent and/or carrier is suitable for application to plants and/or seeds of plants.

2. The composition of claim 1 , wherein at least one of R 3 or R 9 is a chloro-, iodo- or bromo-group.

3. The composition of claim 1 , wherein the compound comprises general formula II:

or a salt thereof, wherein:

R 1 is C or N;

R 3 and R 9 are each individually selected from chloro, bromo or iodo group;

A 1 is a —COOH or a carboxyalkyl; and

A 2 is —NHR 8 wherein R 8 is —H, or an alkyl.

4. The composition of claim 3 , wherein the compound comprises a compound of formula III:

or a salt thereof.

5. The composition of claim 1 , wherein the composition is formulated for foliar application, seed coating, and/or soil application.

6. The composition of claim 1 , wherein the composition further comprises salicylic acid.

7. A method of providing pathogen resistance in a plant comprising contacting the plant with the composition of claim 1 .

8. A method of inducing pathogen resistance in a plant comprising contacting the plant with a compound having the general formula I:

or salt thereof, wherein:

R 1 is C, N or S;

R 2 and R 4 are each independently a hydrogen, oxygen, sulfide, alkyl, hydroxyl, alkoxide, amino, mercapto, alkyl sulfide, thionyl, halo, cyano, nitro or carboxylate;

R 3 and R 9 can be a hydrogen, alkyl, oxygen, halo or mercapto, wherein at least one of R 3 and R 9 is a halogen;

A 1 is selected from the group consisting of carbon, nitrogen, oxygen and sulfur; and

A 2 is a nitrogen or —NHR 8 wherein R 8 is —H, or an alkyl;

wherein when A 1 or A 2 is a nitrogen, R 5 , R 6 , R 7 or R 8 is a hydrogen;

wherein when A 1 is a carbon then A 1 is either —COOH or a carboxyalkyl; and

wherein a structure of compound I induces modulation of a resistance gene or a gene from Table I, induces pathogen or disease resistance in a plant.

9. The method of claim 8 , wherein:

A 1 and A 2 are each independently carbon or nitrogen; and

at least one of R 3 or R 9 is a chloro-, iodo- or bromo-group.

10. The method of claim 8 , wherein the compound comprises general formula II:

or salt thereof, wherein:

R 1 is C or N;

R 3 and R 9 are each individually selected from chloro, bromo or iodo group;

A 1 is a —COOH or a carboxyalkyl; and

A 2 is —NHR 8 wherein R 8 is —H, or an alkyl.

11. The method of claim 10 , wherein the compound comprises a formula III:

or salt thereof,

wherein the agent increases the production or transcription of a resistance gene.

12. The method of claim 8 wherein the resistance gene comprises a LURP gene member.

13. The method of claim 8 wherein the compound causes an increase in expression of LURP genes and an SA-independent constitutive expression of PR genes.

14. The composition of claim 1 , wherein the compound has an effective concentration leading to half maximal response (“EC 50 ”) of less than 10 μM for inducing pathogen or disease resistance in a plant.

15. The composition of claim 1 , wherein the composition transiently induces pathogen or disease resistance in a plant from 1 hour up to 6 days after treatment.

16. The method of claim 8 , wherein the compound has an effective concentration leading to half maximal response (“EC 50 ”) of less than 10 μM for inducing pathogen or disease resistance in a plant.