ROLE OF GASOTRANSMITTER HYDROGEN SULFIDE (H2S) IN PLANT IMMUNE RESPONSES

D'AMBROSIO, JUAN MARTÍN; DI FINO, LUCIANO M.; GARCÍA-MATA, CARLOS; SCUFFI, DENISE; LAXALT, ANA MARIA

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Abstract: As a member of the family of gasotransmitters, hydrogen sulfide (H2S) is endogenously synthesized and has specific molecular targets. In plants, H2S is produced by the enzyme L-cysteine desulfhydrase 1 (DES1) which degrades L-cysteine into H2S, piruvate and ammonia. H2S participates in several plant processes such as stomatal closure. Although the study of H2S in plants has increased in the last years still much remains to be discovered. Stomata are pores surrounded by a pair of cells, guard cells, through which plants regulate the gaseous exchange with the environment and the loss of water by evapotranspiration. Moreover, when open, stomatal pores are ?access points? for pathogens, therefore the regulation of stomatal closure is considered a first immunity barrier. So the stomatal pore regulation is a key process for carbon and water homeostasis and also for plant defense.In this work we study the role of H2S in pathogen-induced stomatal closure. We made use of mutant and silenced A. thaliana plants in specific genes as H2S-source DES1 and those that participate in immune-responses such as the NADPH oxidase RBOHD and the phosholipase C2 (PLC2). Experiments were performed in Arabidopsis isolated epidermal peels. Stomata were preincubated in opening buffer for 3 hours under light and subsequently incubated with the different treatments on the same buffer. Stomatal aperture assays show that bacterial elicitor flg22-dependent stomatal closure was partially blocked by 200 µM of H2S scavenger, Hypotaurine (Dunn´s;P