Early events following phosphorous deprivation involve modulation of nitric oxide

RAMOS ARTUSO F; SANTA MARÍA G; GALATRO A; BATTHYÁNY DIGHIERO C; LIMA A; SIMONTACCHI M

Corrientes

Congreso; XXXI Reunión Argentina de Fisiología Vegetal.; 2016

Sociedad Argentina de Fisiología Vegetal

Phosphorus (P) is a critical resource for plant growth being involved in cellular metabolism, energy conversion, signal transduction and protein activity regulation. Nitric oxide (NO) and reactive oxygen species (ROS) play important physiological roles in signaling and acclimation to several stress conditions. In order to evaluate whether early events following P restriction include an effect on NO levels and NO mediated responses, seven-day-old soybean plants were exposed up to 48 h to a medium lacking P. As expected, total P-concentration significantly decreased in roots and leaves after 48 h of P-deprivation. Chlorophyll content and quantum yield of photosystem II (PSII) did not change in the first pair of leaves during that period. However, stomatal conductance was significantly affected as a consequence of the stress condition. Confocal laser microscopy (employing specific probes) unveiled a high NO level and ROS generation in P-deprived leaves. Moreover, analysis of nitrotyrosines by two-dimensional PAGE/western blot/Mass spectrometry showed an increase in protein tyrosine nitration in leaves of P-deprived plants. Additionally, a differential protein expression pattern, analyzed by nLC-ion trap MS, was observed in the leaves upon 24 h of P restriction. The results suggest the modulation of NO levels in early events related to P scarcity.