OsWRKY76 positively regulates drought stress via OsbHLH148-mediated jasmonate signaling in rice

Abstract

Drought stress is a major environmental threat that limits plant growth and crop productivity. Therefore, it is necessary to uncover the molecular mechanisms behind drought tolerance in crops. Here, OsWRKY76 positively regulated drought stress in rice. OsWRKY76 expression was induced by PEG treatment, dehydration stress, and exogenous MeJA rather than by no treatment. Notably, OsWRKY76 knockout weakened drought tolerance at the seedling stage and decreased MeJA sensitivity. OsJAZ12 was significantly induced by drought stress, and its expression was significantly higher in OsWRKY76-knockout mutants than in wild-type ZH11 under drought stress. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that OsWRKY76 interacted with OsJAZ12. OsWRKY76 weakened the interaction between OsbHLH148 and OsJAZ12 in yeast cells. The OsJAZ12 protein repressed the transactivation activity of OsbHLH148, and this repression was partly restored by OsWRKY76 in rice protoplasts. Moreover, OsDREB1E expression was lower in OsWRKY76-knockout mutants than in wild-type ZH11 under drought stress, but it was upregulated under normal growth conditions. Yeast one-hybrid, electrophoretic mobility shift, and dual-luciferase assays showed that OsWRKY76 and OsbHLH148 bound directly to the OsDREB1E promoter and activated OsDREB1E expression in response to drought stress. These results suggest that OsWRKY76 confers drought tolerance through OsbHLH148-mediated jasmonate signaling in rice, offering a new clue to uncover the mechanisms behind drought tolerance.

RIP5 Interacts with REL1 and Negatively Regulates Drought Tolerance in Rice

“…Finally, in RNA-sequencing most of the DEGs are related to stress responses, and rip5-ko might affect the content of ascorbate to enhance drought tolerance ( Figure 8 A–C). Our results also demonstrated that OsWRKY76 , OsbHLH148 , POX22.3 , and OsMYB2 genes, functioning as positive regulators in the drought response [ 26 , 27 , 28 , 29 ], were significantly up-regulated in rip5-ko plants ( Figure 9 A–D). Taken together, these results indicate that RIP5 negatively regulates drought-stress tolerance in rice.…”

Transcriptomics and Metabolomics Analysis Revealed the Ability of Microbacterium ginsengiterrae S4 to Enhance the Saline-Alkali Tolerance of Rice (Oryza sativa L.) Seedlings

“…The research has found that OsWRKY76 is widely involved in abiotic stress processes in rice. OsWRKY76 interacts with OsbHLH148 to trans-activate the expression of OsDREB1B, enhancing the cold tolerance of rice [57]; in addition, OsWRKY76 can also mediate the positive regulation of drought stress in rice jasmonic acid signaling transduction [58]. OsWRKY76, as an important transcription factor involved in abiotic stress in rice, may regulate the involvement of OsSTAR2 in salt and alkali stress resistance in rice.…”