Derivados de trealose no sistema antioxidante e fotossintético de plantas de milho expostas ao déficit hídrico

Abstract

In agriculture one of the limiting factors of plant development that directly affects the final production result is water availability. With the constant climate changes, it is necessary to carry out studies to discover new technologies to minimize water stress caused on plants, especially in the germination and growth, flowering and fruit filling phase. This work aimed to analyze the application of new trehalose-derived disaccharides in maize plants by checking the drought tolerance induction capacity. The experiment was carried out in a greenhouse using BRS 1030 hybrid corn sensitive to water deficit. Water stress was applied when the plants reached vegetative stage V6 and was imposed for 12 days, with foliar application of the mixture of derivatives (30mM) on the first and tenth day of water deficit imposition. The photosynthetic efficiency analyzes of chlorophyll a (ETRmax, Ik and α) were performed on the first and last day of water deficit imposition and 12 hours after rehydration, obtaining fast light curves through a fluorimeter. Leaf collections for biochemical analysis were performed at the beginning and end of water deficit and 12 hours after plant rehydration. Lipid peroxidation through MDA contents and antioxidant enzymatic activity SOD, APX, CAT and POD were evaluated. At the end of the experiment the leaves and roots were collected to analyze the concentrations of reducing sugars, total soluble sugars, starch, protein, proline and phenolic compounds. It was concluded that the exogenous application of the trehalose derivatives mixture proved to be efficient in mitigating damage caused by water deficit through the activation of antioxidant enzymes (SOD, APX and POD), besides promoting the accumulation of sugars, proline and phenolic compounds and improving photosynthetic efficiency in the BRS 1030 maize hybrid