IDENTIFICATION OF PHOSPHOLIPASE C ISOFORMS INVOLVED IN THE NITRIC OXIDE SIGNALLING PATHWAY INDUCED BY THE FUNGAL ELICITOR XYLANASE

GONORAZKY, G; RAMIREZ, L; TEN HAVE, A; LAMATTINA L AND LAXALT, AM.

Congreso; SAFV; 2012

Plant perception of different pathogen-derived elicitors trigger the activation of phospholipase-C (PLC) signalling, which is involved in the induction of defence responses. Recently it was reported that the PLC gene family in tomato (Solanum lycopersicum) is composed of six members named SlPLC1 to SlPLC6. It was demonstrated that SlPLC4 and SlPLC6 are involved in the induction of plant defence responses. We have previously demonstrated that the fungal elicitor xylanase requires the second messenger nitric oxide (NO) to activate the PLC pathway and downstream defence responses. Nevertheless, which PLC isoforms are regulated by NO and required or involved in the induction of the xylanase induced response is still unknown. We studied the expression profile of the SlPLC family in tomato cell suspensions treated with xylanase. The results obtained indicate that SlPLC2 and SlPLC5 expression is increased upon xylanase treatment. This coincides with the induction of HSR203J, a hypersensitive response (HR) marker, and PR1a. Moreover, we show that NO production is required for the induction of SlPLC5, HSR203J and PR1a in xylanase treated tomato cells. This suggests that SlPLC5 is involved in the defence signalling pathway triggered by NO during xylanase perception. The physiological role of SlPLC2 and SlPLC5 during the activation of plant defence remains to be demonstrated.