PLC2 and RbohD: H2S partners in stomatal response to pathogens

DENISE SCUFFI; JUAN MARTÍN D'AMBROSSIO; ANA MARÍA LAXALT; CARLOS GARCIA-MATA

Glasgow

Workshop; 18 th International Workshop on Plant Membrane Biology; 2019

H2S is a small gas, member of the group of gasotransmitters. One of the main sources of H2S in plants is the cytosolic enzyme L-cysteine desulfhydrase 1 (DES1) which produces H2S during the passage of L-Cysteine to pyruvate and ammonia. H2S participates in diverse physiological processes in plants, among others germination, root growth, senescence and stomatal movement.Stomata are pores conformed by pairs of epidermal specialized cells, called guard cells, through which plants regulate CO2 uptake and transpirational water loss. In addition, stomatal pores are natural access routes for microorganisms representing a first physical barrier for plant immune response.H2S participates in several of the pathways that form the stomatal signaling network, including ABA, EtOH and Flagellin, interacting with other signal molecules like nitric oxide (NO), phosphatidic acid (PA) and hydrogen peroxide (H2O2). We have recently shown that H2S induces stomatal closure through NADPH oxidase (NOX) dependent ROS production. We reported that both guard cell expressed isoforms of NOX, RbohD and RbohF, are involved in H2S-dependent response. One of the members of the phosphoinositide-specific phospholipase C (PI-PLC), PLC2, is an early component of bacterial conserved peptide flg22 (flg22) induced response. We also demonstrated that PLC2 binds to RbohD to regulate flg22-induced ROS production.In this work we advanced on the knowledge of H2S participation in pathogen-dependent regulation of stomatal movement. Preliminary results indicate that DES1 is involved in flg22-dependent ROS production and stomatal closure. On the other hand, Arabidopsis PLC2-silenced plants do not close stomata under H2S donor treatments showing evidence about a possible interaction between H2S, RbohD-induced ROS production and PLC2 during pathogen triggered stomatal closure.