Integrated transcriptomic, transcriptional factors, and protein interaction reveal the regulatory mechanisms of flowering time in rice (Oryza sativa L.).

Appropriate flowering time is important for rice regional adaptation and optimum rice production, but little is known about the omics of heading date in rice. Here, we studied omics including transcriptome, proteome and transcriptional factors to identify regulatory genes related to flowering time. A total of 1402 differentially expressed genes (DEGs, 721 up-regulated and 681 down-regulated) were detected in wild and mutant. These transcripts are classified according to biological processes, cellular components, and molecular functions. Among these differentially expressed genes, many transcription factor genes demonstrated multiple regulatory pathways involved in flowering time. Gene expression analysis showed that Os03g0122600 (OsMADS50), Os08g0105000 (Ehd3), Os06g0275000 (Hd1) were expressed higher and Os06g0199500 (OsHAL3), Os06g0498800 (OsMFT1), Os08g0105000 (Ehd3), Os06g0157700 (Hd3a), and Os02g0731700 (Ghd2), were expressed lower in wild compared to mutant, which are the key genes that regulate the flowering in rice. In addition, Ghd7 interacted with Os10g30860 and Os12g08260 using yeast two-hybrid assay. We identified 28 potential Ghd7 transcriptional regulators using the transcription factor-centered yeast one hybrid (TF-Centered Y1H) assay. Taken together, this study developed a new set of genomic resources to identify and characterize genes, proteins, and motifs associated with flowering time.