Loss of cytosolic NADP-malic enzyme 2 in Arabidopsis thaliana is associated with enhanced susceptibility to Colletotrichum higginsianum

VOLL, L. M.; ZELL, M. B.; ENGELSDORF, T.; SAUR, A.; GERRARD WHEELER, M. C.; DRINCOVICH, M. F.; WEBER, A. P. M.; MAURINO, V. G.

NEW PHYTOLOGIST

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 p. 189 - 202

0028-646X

? While photosynthetic NADP-malic enzyme (NADP-ME) has a prominent role in the C4cycle, the biological function of nonphotosynthetic isoforms remains elusive. Here, we analysedthe link between Arabidopsis thaliana cytosolic NADP-ME2 and the plant defenceresponse.? Arabidopsis thaliana plants with wild-type and modified NADP-ME2 expression levels wereanalysed after elicitation with pathogen-associated molecular patterns (PAMPs) and duringthe interaction with the hemibiotrophic fungal pathogen Colletotrichum higginsianum.? Under normal growth conditions, the lack or gain of NADP-ME2 activity produced largechanges in plant metabolite pool sizes without any effect on morphology or development.Total NADP-ME activity and NADP-ME2 transcript level were enhanced after PAMP treatmentand pathogen infection. During infection with C. higginsianum, loss-of-function mutants ofNADP-ME2 (nadp-me2) showed enhanced susceptibility. Transient apoplastic reactive oxygenspecies (ROS) production after elicitation and callose papilla formation after infection weredampened in nadp-me2. Late salicylic acid (SA)-dependent and SA-independent defenceresponses were not affected.? Taken together, our results indicate that NADP-ME2 is an important player in plant basaldefence, where it appears to be involved in the generation of ROS. Moreover, NADP-ME2was found to be dispensable for later defence responses.