Cooperation and functional diversification of two closely related galactolipase genes for jasmonate biosynthesis = Jasmonic acid생합성에 관련된 두가지 유사 Galactolipase유전자들의 협동과 기능적 다양성

Abstract

Jasmonic acid (JA) plays pivotal roles in diverse plant biological processes, including wound response. Chloroplast lipid hydrolysis is a critical step for JA biosynthesis, but the mechanism of this process remains elusive. We report here that DONGLE (DGL), a homolog of DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1), encodes a chloroplast-targeted lipase with strong galactolipase and weak phospholipase A1 activity. DGL is expressed in the leaves and has a specific role in maintaining basal JA content under normal conditions, and this expression regulates vegetative growth and is required for a rapid JA burst after wounding. During wounding, DGL and DAD1 have partially redundant functions for JA production, but they show different induction kinetics, indicating temporally separated roles: DGL plays a role in the early phase of JA production, and DAD1 plays a role in the late phase of JA production. Whereas DGL and DAD1 are necessary and sufficient for JA production, phospholipase D appears to modulate wound response by stimulating DGL and DAD1 expression.