Biobras-16 foliar spraying enhances rice (Oryza sativa L.) young plant growth under NaCL treatment

Abstract

Salinity is one of the most pressing stresses today and brassinosteroids are compounds which, not only stimulate plant growth but also improve plant tolerance to salt stress. In this paper, the effect of foliar spraying with a brassinosteroid analogue (Biobras-16, BB-16) on rice seedlings under this kind of stress was evaluated. For this purpose, rice young plants cv. J-104 were sprayed with BB-16 (0; 0,01; 0,1; 1 μmol L-1), half of them was treated with NaCl (100 mmol L-1) for seven days and later, these plants were transferred to nutrient solution to assess recovery during fourteen days. The growth evaluations (shoot and root length and dry mass) were made at the beginning and the end of saline treatment and seven and fourteen days after the recovery. From the results of this experiment, the best BB-16 concentration was chosen and a second experiment, following the same methodology, was performed and, where, the growth indicators and some biochemical indicators such as malondialdehyde, proline, chlorophylls and the activities of peroxidase and catalase enzymes were determined. Results demonstrated, in general, that the foliar spraying with BB-16 0,1 μmol L-1 increased the length of rice seedlings under saline conditions what appears to be associated with increased antioxidant defenses as well as an increase of the concentration of chlorophylls, chlorophyll a fundamentally.