SEASONALITY AND Cr(VI) AFFECT STARCH-SUCROSE PARTITIONING AND RELATED ENZYMES IN FLOATING LEAVES OF Salvinia minima

ROSA, MARIANA; PRADO, CAROLINA; CHOCOBAR PONCE, SILVANA; PAGANO, EDUARDO; PRADO, FERNANDO

Congreso; XXII Reunion de la Sociedad Española de Fisiología Vegetal; 2017

Sociedad Española de Fisiología Vegetal

The effect of both seasonality and increasing concentrations of Cr(VI) on starch-sucrose partitioning and enzyme activities involved in starch and sucrose metabolism were analyzed in fronds of Salvinia minima. Carbohydrate contents and enzyme activities of Cr-exposed fronds show different patterns inwinter and summer seasons. Total soluble sugars, starch, glucose and fructose were higher in winter fronds, whereas sucrose concentration showed aseasonal inverse pattern with the higher content in summer fronds. Carbohydrates, except glucose, increased under increasing Cr(VI) concentrations in winter fronds, while in summer ones only sucrose increased under Cr(VI) exposure. In summer fronds the contents of starch, total soluble sugars, fructose and glucose practically stayed without changes in all assayed Cr(VI) concentrations. Most of enzyme activities (e.g. ADPGase, SPS, SS and AI) related to starch and sucrose metabolisms were higher in winter than in summer, whereas only amylase and cFBPase activities were higher in this last. Except ADPGase activity, Cr(VI) treatment increased enzyme activities in both winter and summer fronds, but a no clear pattern was observed. Data of this study show clearly that carbohydrate metabolism is differently perturbed by both seasonality and Cr(VI) stress, which affects the carbon partitioning of fronds interms of SLA.