The behaviour of the opr3 tomato mutant points to a role of OPDA in plant defense

Abstract: Previous work on basal and induced resistance by different pathogens like B. cinerea and P. syringae point to an important role of OPDA in plant defense responses. To check the role that OPDA has in defense of tomato plant against pathogens, we silenced the 12-oxophytodienoate reductase3 (opr3) in Lycopersicon esculentum cv Monney Maker plants. The analysis of gene expression as well as the hormone levels in opr3 mutants infected with B. cinerea demonstrates that the mutant undergoes severe alterations in OPR3 gene expression. Furthermore, the susceptibility of these mutants to B. cinerea was accompanied by a decrease in the levels of OPDA and in an almost abolished production of JA-Ile.