Transcriptome-Based Identification of Novel Transcription Factors Regulating Seed Storage Proteins in Rice

Seed storage proteins (SSPs) play a pivotal role in determining the development, quality, and nutritional value of rice seeds. In this study, we conducted a transcriptome-based correlation analysis to identify novel transcription factors (TFs) potentially involved in the biosynthesis and accumulation of SSPs. Our analysis revealed nine TFs—OsGATA8, OsMIF1, OsMIF2, OsGZF1, OsbZIP58, OsS1Fa1, OsS1Fa2, OsICE2, and OsMYB24—that exhibit strong co-expression with key SSP genes, including those encoding glutelin and prolamin. Gene expression profiling using quantitative RT-PCR and GUS reporter assays revealed that these TFs are predominantly expressed during seed development, with peak expression observed at 10 days after flowering (DAF). Promoter analysis further demonstrated an enrichment of seed-specific and hormone-responsive cis-regulatory elements, reinforcing the seed-preferential expression patterns of these TFs. Collectively, our findings identify a set of candidate TFs likely involved in SSP regulation and seed maturation, providing a foundation for the genetic enhancement of rice seed quality and nutritional content through targeted breeding and biotechnological approaches.