Seed Storage Protein Identification and Transcriptome Analysis Reveal the Molecular Mechanisms of Wheat Quality Formation

High-quality wheat cultivars are essential for flour-based food processing. Xinong511 (XN511), a widely cultivated common wheat variety in the Yellow and Huai River Valley region of China, exhibits superior flour quality despite having a seed storage protein (SSP) composition similar to its male parent, Shaanmai159 (SM159). To investigate the molecular basis of this trait, we analyzed the SSP composition and transcriptome profiles of XN511 and its parental lines. At 13 days postanthesis (DPA), XN511 displayed a significantly higher expression of glutenin-related genes than its parents, leading to increased glutenin and glutenin macropolymer (GMP) accumulation and improved flour quality. Gene regulatory network analysis identified NAC transcription factors (TFs) as key regulators of SSP synthesis and accumulation in high-gluten wheat. Specifically, TaNAC19 and homologues of OsNAC20 were highly expressed, positively influencing XN511's quality traits. These findings provide insights into the genetic basis of superior flour quality and offer valuable guidance for wheat breeding programs aimed at enhancing grain quality.