Involvement of phospholipase D in wound-induced accumulation of jasmonic acid in Arabidopsis

Multiple forms of phospholipase D (PLD) were activated in response to wounding, and the expressions of PLD alpha, PLD beta, and PLD gamma differed in wounded Arabidopsis leaves. Antisense abrogation of the common plant PLD, PLD alpha, decreased the wound induction of phosphatidic acid, jasmonic acid (JA), and a Jig-regulated gene for vegetative storage protein. Examination of the genes involved in the initial steps of oxylipin synthesis revealed that abrogation of the PLD alpha attenuated the wound-induced expression of lipoxygenase 2 (LOX2) but had no effect on allene oxide synthase (AOS) or hydroperoxide lyase in wounded leaves. The systemic induction of LOX2, AOS, and vegetative storage protein was lower in the PLD alpha -suppressed plants than in wild-type plants, with AOS exhibiting a distinct pattern. These results indicate that activation of PLD mediates wound induction of JA and that LOX2 is probably a downstream target through which PLD promotes the production of JA.