Overexpression of BdRHP1 improves drought tolerance and reduces yield loss in rice

Abstract

Drought is a major factor decreasing the growth, development, and productivity of rice in about one-third of the world area. The characterization of genes imparting tolerance to drought in rice, is an attractive strategy for genetic engineering to improve drought tolerance. It is demonstrated that ectopic overexpression of Brachypodium distachyon RING-H2 finger gene (designated as BdRHP1) enhances drought tolerance in rice at both the vegetative and reproductive stages. When subjected to drought, positive transgenic lines showed delayed wilting, and improved recovery after rewatering. However, the transgenic plants exhibited more significant germination delay and shoot and root growth arrest than WT under 5 μM abscisic acid (ABA) treatment. When they were subjected to drought at the reproductive stage, the transgenic plants lost water more slowly compared to WT and they had higher leaf relative water content. After 28 d of slow progressive soil drying, transgenic plants recovered better after rewatering and flowered earlier than WT plants. The yield of water-stressed transgenic plants was higher than that of WT plants. Together, the data suggest that BdRHP1 has a specific function in positive modulation of improving drought tolerance in rice.