Advances in the transcriptional regulation of seed vigor and its application in molecular breeding for rice

Rice seed vigor is a life-cycle trait whose performance after sowing depends on physiological capacity established during seed development, preserved during storage, and reactivated during germination and seedling establishment. Rather than functioning as isolated stage-specific pathways, transcriptional networks coordinate a series of transitions between protection and growth. During seed development, transcription factors establish embryo competence, reserve organization, desiccation tolerance, and proteostasis, thereby creating the physiological capacity for subsequent performance. During storage, ABA- and auxin-associated bZIP networks, including the OsARF12-OsbZIP23 and OsbZIP23-PER1A modules and SAG9-associated regulation, maintain longevity through antioxidant and protective processes; emerging salicylic acid-associated signaling further extends this hormone-redox regulatory framework. After imbibition, ABA-GA balance, sugar and energy signaling, reserve mobilization, reactive oxygen species homeostasis, and cell expansion determine the timing and uniformity of germination, while related regulatory modules support establishment under salinity, chilling, water deficit, and oxygen limitation. Importantly, current evidence varies substantially in strength: some regulators are directly supported by germination, longevity, dormancy, or stress-vigor phenotypes, whereas others remain developmental candidates inferred mainly from grain composition or seed-development traits. Field-emergence validation and natural-storage evidence also remain limited. We therefore propose that rice seed-vigor improvement should prioritize stage-appropriate regulatory alleles and precise modulation of transcription-factor activity, while jointly considering storability, dormancy and pre-harvest sprouting resistance, field establishment, yield, and grain quality.