Functional Analysis Of The Rice Di19 In The Regulation Of Drought Tolerance

With global climate change,drought is becoming the overriding factor that limits crop production.Rice(Oryza sativa)is particularly sensitive to drought,and how to improve drought tolerance has become an important object of rice research.Di19 is one of the drought-induced zinc finger transcription factors that widely exist in plants.The Di19 protein family members are highly conserved and have been found to play a positive role in plant response to drought stress.Here,our study investigated a new rice Di19 member and provided new cues in rice tolerance to drought stress.ZhongHual 1(ZH11)wild-type rice is employed for genetic background.First,qRT-PCR was used to verify the drought induction of the Dil9 gene in wild-type.To further study the function of OsDi19,the transgenic rice overexpressing OsDil9 was generated,and two lines Di190E6 and Di19OE10 with high expression levels were selected for subsequent research.The in soil water deprivation experiment found that the transgenic rice plants were more drought tolerant than the WT,which indicates that overexpressed rice strains were more tolerant to drought than wild-type rice,indicating that the rice Di19 plays a positive role in drought stress response.In addition,we observed the rice leaf after water loss treatment under ESM and found that the stomatal opening of transgenic rice was lower than that of the wild type,and the proportion of closed stomata was higher than the wild type,which is consistent with the water loss rates of the two lines.To make further study,we also conducted Yeast Two-Hybrid,Co-IP,and BiFC experiments and got two OsDi 19-interacting proteins:OsCCPK and OsNEK,which provide us some ideas in revealing the molecular mechanisms of OsDi 19 in drought tolerance.Moreover,to reveal the downstream signaling pathway regulated by OsDi 19,we also conducted transcriptome analysis and got 224 upregulated genes and 167 downregulated genes(log2(OE/WT)>1&p-Value<0.05),of which contain a lot of stress-related genes.Moreover,based on the transcriptome data,we also performed ChIP-PCR analysis and found five target genes that are directly regulated by OsDi 19,of which two are stress-regulated genes.These findings explained the drought regulation of OsDi 19 in some degrees.