Transcriptional profiling analysis of OsDT11 -mediated ABA-dependent signal pathway for drought tolerance in rice

Small cysteine-rich peptides (CRPs) are important in plant responses to biotic and abiotic stresses. OsDT11, encoding an 88 amino acid CRP-type protein, has been reported to enhance tolerance to drought in rice (Oryza sativa L.) without negatively affecting other agronomic traits. However, the molecular mechanisms of OsDT11-mediated drought tolerance are still unclear. Here, we performed RNA-Seq analysis to compare the transcriptome profiles between wild-type (WT) and OsDT11-overexpressing (OE) rice lines under drought stress or under control (non-drought) conditions. A total of 1570 and 1421 differentially expressed genes were identified in the OE lines and the WT under drought treatment, respectively, compared to non-drought conditions. Gene ontology analysis indicated that the 430 up-regulated genes in common to both OE and the WT lines were induced for functions related to responses to water deprivation and to abscisic acid (ABA). More than half of these genes had higher expression in the OE than in the WT under drought stress. In the OE, but not in the WT, 294 genes were specifically up-regulated under drought stress and were functionally enriched in starch and sucrose biosynthetic processes and in response to stress. This implies that OsDT11 not only triggers strongly response to drought stress, but also alters several metabolic processes to enhance drought tolerance. Gene expression profiling suggests that OsDT11 confers drought tolerance by mediating an enhanced response to drought stress in an ABA-dependent signaling pathways.