Overexpression of OsDT11, which encodes a novel cysteine-rich peptide, enhances drought tolerance and increases ABA concentration in rice

Short-chain peptides play important roles in plant development and responses to abiotic and biotic stresses. Here, we characterized a gene of unknown function termed OsDT11, which encodes an 88 amino acid short-chain peptide and belongs to the cysteine-rich peptide family. It was found that the expression of OsDT11 can be activated by polyethylene glycol (PEG) treatment. Compared with wild-type lines, the OsDT11-overexpression lines displayed dramatically enhanced tolerance to drought and had reduced water loss, reduced stomatal density, and an increased the concentration of abscisic acid (ABA). The suppression of OsDT11 expression resulted in an increased sensitivity to drought compared to wild-type expression. Several drought-related genes, including genes encoding abscisic acid (ABA) signaling markers, were also strongly induced in the OsDT11-overexpressing lines. Moreover, the expression of OsDT11 was repressed in ABA-insensitive mutant Osbzip23 and Os2H16 RNAi lines. These results suggest that OsDT11-mediated drought tolerance may be dependent on the ABA signaling pathway.