PLANT NATRIURETIC PEPTIDES IMPROVE PLANTRESISTANCE DURING BIOTIC STRESS

FICARRA F; OTTADO J; GARAVAGLIA B; GRANDELLIS C; GOTTIG N

Congreso; 52 th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

Plant natriuretic peptides (PNPs) are extracellular, systemically mobile molecules that are involved in the modulation of salt and water homeostasis and AtPNPA from Arabidopsis thaliana has been extensively studied. Distinctively, the bacterial pathogen of citrus plants, Xanthomonas citri subsp.Citri (Xcc) contains a PNP-like gene (XacPNP). Both peptides, AtPNPA and XacPNP induce similar physiological responses when applied on plant tissue, including stomatal opening and photosynthetic efficiency improvement. A. thaliana-Pseudomonassyringae pv. Tomato (Pst) patho system and its genetic resources allowed us to analyze the role of XacPNP and AtPNPA in A. thaliana during infection. To this aim, A. thaliana transgenic lines were generated overexpressing XacPNP and AtPNPA, and RNA interference lines silencing endogenous AtPNPA were also obtained. Overexpressing PNPs lines showed enhanced resistance to Pst, while PNP-deficient plants were more susceptible. Moreover, pretreatment of A. thaliana leaves with XacPNP before Pst infection resulted in increased resistance evidenced by higher remnant chlorophyll, lower pathogen survival and induction of defense associated genes. Our results state a role for PNPs during plant biotic stress improving plant performance under stressful conditions