Functional analysis of methyl jasmonate using the inducible JMT-overexpressing Arabidopsis

Abstract

Methyl jasmonate (MeJA) is a volatile plant cellular regulator that modulates expression of various genes involved in diverse developmental and defensive processes. A number of its biosynthetic intermediates, isomers, derivatives and metabolites of this pathway are also known to be powerful cellular regulator depending on biological system. Though JMT enzyme which is synthesizing MeJA from JA was cloned in previous study it was hard to distinguish MeJA and JA in biological roles. To know their real functions, three approaches were attempted in this study. First method was exogenous MeJA and JA treatment. This experiment shows different pattern of various genes expression respectively. Second was to control JMT gene expression. Controlling JMT expression would be one of essential experiment toward resolving the complexity of jasmonate-mediating plant responses. To obtain more accurate data than constitutive JMTexpressing palnt inducible-JMT plant, using pER8 plant inducible vector, was generated and used. Third was using the peroxisomal-targeting JMT expression. JMT enzyme is in cytoplasm, and JA is synthesized and accumulated in peroxisome. To overcome this limitation of contact, peroxisomaltargeting JMT (pER-PeJMT) was generated, and tested in JA-response. These three approaches made us understood that MeJA and JA have the unique and common signal pathways which are overlapped and separate in some parts, and only MeJA can increase JA-response throughout the active self-regulation pathway. Moreover, these result suggest that MeJA should be a long distance signal molecule, and related to secondary metabolites.