Arsenic stress induces changes in lipid signalling and evokes the stomata closure in soybean

ANA L. ARMENDARIZ; MELINA A. TALANO; ANA L. VILLASUSO; CLAUDIA TRAVAGLIA; GRACIELA E. RACAGNI; HERMINDA REINOSO; ELIZABETH AGOSTINI

PLANT PHYSIOLOGY AND BIOCHEMISTRY

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2016 vol. 103 p. 45 - 52

0981-9428

Soybean (Glycine max) is often exposed to high arsenic (As) level in soils or through irrigation withgroundwater. In previous studies on As-treated soybean seedlings we showed deleterious effect ongrowth, structural alterations mainly in root vascular system and induction of antioxidant enzymes.However, there are not reports concerning signal transduction pathways triggered by the metalloid inorder to develop adaptive mechanisms. Phosphatidic acid (PA), a key messenger in plants, can begenerated via phospholipase D (PLD) or via phospholipase C (PLC) coupled to diacylglycerol kinase(DGK). Thus, changes in PA and in an enzyme involved in its metabolism (PLD) were analysed in soybeanseedlings treated with 25 mM AsV or AsIII. The present study demonstrated that As triggers the PA signalby PLD and also via PLC/DGK mainly after 48 h of As treatment. DGPP, other lipid messenger produced byphosphorylation of PA by PAK increased in As treated roots. Arsenic also induced rapid and significantstomatal closure after 1.5 h of treatment, mainly with AsIII, probably as an adaptive response to themetalloid to reduce water loss by transpiration. This report constitute the first evidence that shows theeffects of As on lipid signalling events in soybean seedlings which would be crucial in adaptation andsurvival of soybean seedlings under As stress.