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

Abstract

• While photosynthetic NADP-malic enzyme (NADP-ME) has a prominent role in the C(4) cycle, the biological function of nonphotosynthetic isoforms remains elusive. Here, we analysed the link between Arabidopsis thaliana cytosolic NADP-ME2 and the plant defence response. • Arabidopsis thaliana plants with wild-type and modified NADP-ME2 expression levels were analysed after elicitation with pathogen-associated molecular patterns (PAMPs) and during the interaction with the hemibiotrophic fungal pathogen Colletotrichum higginsianum. • Under normal growth conditions, the lack or gain of NADP-ME2 activity produced large changes 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 treatment and pathogen infection. During infection with C. higginsianum, loss-of-function mutants of NADP-ME2 (nadp-me2) showed enhanced susceptibility. Transient apoplastic reactive oxygen species (ROS) production after elicitation and callose papilla formation after infection were dampened in nadp-me2. Late salicylic acid (SA)-dependent and SA-independent defence responses were not affected. • Taken together, our results indicate that NADP-ME2 is an important player in plant basal defence, where it appears to be involved in the generation of ROS. Moreover, NADP-ME2 was found to be dispensable for later defence responses.

• Authors: Lars M Voll, Martina B Zell, Timo Engelsdorf, Alexandra Saur, Mariel Gerrard Wheeler, Maria F Drincovich, Andreas P M Weber, Veronica G Maurino
• Journal: The New phytologist (New Phytol) Vol. 195 Issue 1 Pg. 189-202 (Jul 2012) ISSN: 1469-8137 [Electronic] England
• PMID: 22497207 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Chemical References

• Arabidopsis Proteins
• Glucans
• Indoles
• Reactive Oxygen Species
• Thiazoles
• camalexin
• callose
• Malate Dehydrogenase
• malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+)
• Salicylic Acid

Topics

• Arabidopsis (enzymology, microbiology)
• Arabidopsis Proteins (genetics, metabolism)
• Colletotrichum (pathogenicity)
• Cytosol (metabolism)
• Disease Susceptibility
• Gene Expression Regulation, Plant
• Genetic Association Studies
• Genetic Complementation Test
• Glucans (metabolism)
• Indoles (metabolism)
• Malate Dehydrogenase (genetics, metabolism)
• Mutation
• Plant Diseases (microbiology)
• Plant Leaves (enzymology, microbiology)
• Reactive Oxygen Species (metabolism)
• Salicylic Acid (metabolism)
• Thiazoles (metabolism)