H2S as a regulator of ion channels in plants

MARIA PAPANTSIOU; DENISE SCUFFI; LORENZO LAMATTINA; MICHAEL R. BLATT; CARLOS GARCIA-MATA

Santiago del Estero

Congreso; XLIV Reunión Anual Sociedad Argentina de Biofísica; 2015

Plants perform gas exchange with the atmosphere through small pores called stomata that pierce the epidermis of the aerial part of land plants. This is a crucial physiological process for plants, as it involves CO2 uptake for photosynthesis and regulation of evapotranspirational water loss. The stomata are surrounded by pairs of specialized cells called guard cells, which regulate the pore size through changes in cell volume. These volume changes are commanded by a massive relocation of solutes and charges, in particular K+ and Cl-. The hormone abscisic acid (ABA) is the master regulator of pore size in response to environmental stresses, and it does so through a complex signaling network with a single read out which is the reduction of the stomatal pore size. ABA triggers the activation of anion and Ca2+ channels. This produces membrane depolarization which in turn, inactivates inward rectifying K+ (IK+in) channel and activates outward rectifying K+ channels (IKOUT). This solute rearrangement drives water out of the cell with the consequent closure of the pore. Although guard cells are a model system for the study of plant signal transduction, new components are still emerging; such is the case of hydrogen sulfide (H2S). This small gas is a proved regulator of an ion channel in animal systems. In this work we present evidence showing that H2S is also involved in the regulation of ion channels in guard cells. In addition, evidence suggests that the effect of H2S on IKIN could be independent of ABA.Afiliaciones(1) Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, Escocia(2) IIB-CONICET, Cs. Exactas y Naturales, Universidad Nacional de Mar del Plata. Mar del Plata, ArgentinaAfiliaciones1,4 - Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, Escocia2,3,5 - IIB-CONICET, Cs. Exactas y Naturales, Universidad Nacional de Mar del Plata. Mar del Plata, Argentina