Transcriptomics analyses reveal that OsMIOX improves rice drought tolerance by regulating the expression of plant hormone and sugar related genes

Drought stress, as a key negative factor, could result in the reduction of yield and quality in rice. Myo-inositol oxygenase (MIOX), a unique monooxygenase, exerts an essential role in plant drought resistance. To investigate the function of the OsMIOX gene in drought process, a transcriptomic profile between OsMIOX-overexpressing (OE) plants and wild-type (WT) was performed by RNA-sequencing in rice. Under drought stress, a total of 23 million high-quality reads, assembled into 28,552 unigenes, were generated and 743 genes (534 up-regulated and 209 down-regulated) were significantly differentially expressed between OE plants and WT. These detected genes were mainly associated with plant hormones transduction and sugar metabolism. Interestingly, several transcription factors (TFs) were prominently identified in OE lines. A significant positive correlation between RNA-Seq data and qRT-PCR results was identified. In all, our results could partially provide relatively valuable clues in identifying candidate genes involved in drought-stress resistance and elucidating basis theory underlying the role of OsMIOX in drought resistance.