A mixture of trehalose derivatives stimulates the antioxidant system and improves photosynthetic efficiency in maize under water deficit

Hitherto studies on the synthesis of trehalose derivatives and their effects on plants have not been explored. Therefore, the purpose of this study was to perform a foliar application of trehalose and its derivatives and assess their role in mitigating drought effects in maize plants. The experiment was conducted in a greenhouse, using BRS 1030, a maize hybrid sensitive to water deficit. Water deficit was imposed for 12 days and the foliar application of the trehalose or a mixture of trehalose derivatives (28 mM) was performed on the first and fifth days of stress. The activity of antioxidant enzymes and the photosynthetic efficiency of Photosystem II were evaluated at 12 days of water deficit (WD), and 12 h after rehydration (RH). Reducing sugars, total soluble sugars, starch, and proline content were assessed at the end of the water deficit. Both trehalose and the mixture of trehalose derivatives influenced physiological responses in maize. The observed effects and their possible causes were hereby explored. Increased levels of soluble sugars, proline, and enzymatic antioxidant activity were observed in maize leaves under water deficit upon application of trehalose and its derivatives. Trehalose derivatives led to a more efficient response regarding proline accumulation and antioxidant activity than trehalose per se, and thus a higher photosynthetic efficiency. The foliar application of trehalose and its derivatives promoted biochemical responses in maize plants under water deficit. Henceforward, trehalose derivatives showed potential as biostimulants. Nevertheless, further studies should be performed to verify the effects of the new trehalose derivatives on the field.