To elucidate the molecular mechanisms underlying salt tolerance in rice (Oryza sativa L.), this study investigated differential transcriptional responses during the tillering stage. Salt-tolerant (N14) and salt-sensitive (N6) varieties were subjected to 0.3% and 0.6% NaCl treatments for 72 h, and their transcriptomes were analyzed via RNA-Seq. The results revealed distinct response strategies: 372 differentially expressed genes (DEGs) were identified in N14 and 393 in N6, with only 17 genes responding similarly. Gene Ontology (GO) analysis showed the tolerant N14 activated protein phosphorylation and lipid transport, primarily in the membrane and extracellular regions (e.g., ATP binding), whereas the sensitive N6 activated photosynthesis and protein folding, localized to chloroplasts and peroxisomes. KEGG analysis highlighted the activation of “Plant-pathogen interaction” in N14 versus “Metabolic pathways” in N6. Differential transcription factor activation was also observed, with N14 mobilizing 52 TFs (mainly WRKY and MYB) and N6 mobilizing 36 TFs (mainly MYB and b-ZIP). This study demonstrates that N14 and N6 utilize significantly different molecular pathways to cope with salinity, providing a crucial theoretical foundation for identifying novel salt tolerance genes and developing molecular breeding strategies.

Rice, a staple food for billions around the globe, is cultivated in numerous forms. Among them, soft rice is well known, which is characterized by its tender, creamy consistency and desirable texture. In this study, we examined the physicochemical properties and fine structure of starch from two soft rice varieties, Jinong Xiangruan 1 and DGR1, cultivated in different regions in China (Baodi District, Tianjin City; Liaoning Province; and Fengyang City, Anhui Province). The aim was to understand how amylopectin content (AC) influences rice quality. This research aims to bridge the knowledge gap regarding the role of amylopectin in determining rice’s adhesive consistency and viscosity. Significant regional differences were observed in yield components such as the number of grains per panicle, seed setting rates and 1000-grain weight, with Liaoning generally showing higher performance metrics compared to other regions. Physicochemical analysis highlighted that though glue consistency and taste values showed little regional variation, AC significantly influenced rice hardness and viscosity. Rapid Visco Analyzer (RVA) profile analysis further demonstrated distinct differences in viscosity characteristics, underscoring the regional impacts on starch behavior. Additionally, molecular weight distribution and amylopectin chain length analysis, conducted via SEC-MALLS-RI and ICS ion chromatography, revealed notable differences in starch composition across varieties and locations. The findings suggest that environmental conditions play a crucial role in defining starch characteristics and, consequently, the eating quality of rice. This provides valuable insights for breeding high-quality japonica rice with broad adaptability.