OsGATA16, a GATA Transcription Factor, Confers Cold Tolerance by Repressing OsWRKY45-1 at the Seedling Stage in Rice

Abstract

\n BackgroundCold stress in rice is a major abiotic stress that adversely affects growth and substantially reduces rice yield. Identification of cold-related functional rice genes is important for breeding programs aimed at increasing resilience and yield in rice crops. GATA-family transcription factors involve diverse function in rice, however, their roles in the response to low-temperature stress remain unclear.ResultsA GATA-type zinc finger transcription factor, OsGATA16, that increases cold tolerance in rice. OsGATA16 is an OsGATA subfamily-II protein and contains eleven putative phosphorylation sites, NLS, and several conserved domains. Overexpression of OsGATA16 increased tolerance to cold stress at seedling stage. Transcriptional analysis showed that OsGATA16 was induced by cold and ABA treatments, but was repressed by drought, cytokinin, and JA. OsGATA16 was expressed in all plant tissues, with highest expression in panicles. Subcellular localization and transcriptional analysis indicated that OsGATA16 acted as a nuclear-targeted transcriptional suppressor. Four cold-related genes (OsWRKY45-1, OsSRFP1, OsCYL4, and OsMYB30) were repressed in OsGATA16-overexpression lines compared with wild type after low-temperature exposure. Yeast one-hybrid and Dual-luciferase reporter assays showed that OsGATA16 bound to the promoter of OsWRKY45-1 and repressed its expression. Eleven SNPs within OsGATA16 were identified and haplotype analysis showed a polarization between Japonica and Indicia subspecies. A non-synonymous SNP was identified that explained differences in cold tolerance among the 137 rice accessions.ConclusionA novel GATA transcription factor, OsGATA16, plays a positive role in cold tolerance at the seedling stage in rice by direct repression of OsWRKY45-1 expression. One SNP was identified that explained cold tolerance differences among rice accessions. These results support future breeding programs to improve cold tolerance in commercial rice crops.