Overexpression of OsPIN5b Alters Plant Architecture and Impairs Cold Tolerance in Rice (Oryza sativa L.)

作者：Xiaoyu Fu, Guo Chen, Xinya Ruan, Guozhang Kang, Dianyun Hou, Huawei Xu · 发表于：Plants · 年份：2025 · DOI：10.3390/plants14071026 · 被引用次数：8 · 研究领域：Plant Stress Responses and Tolerance、Plant Molecular Biology Research、Plant responses to water stress

Auxin plays a versatile role in regulating plant growth and development. The auxin efflux carrier PIN-FORMED (PIN) proteins dictate the distribution and maximum of auxin within various tissues. Despite extensive research on OsPINs in recent years, their functions in abiotic stress resistance, particularly cold tolerance, remain poorly understood. Here, we investigated the role of OsPIN5b in rice (Oryza sativa L.) growth and development, as well as its contribution to cold tolerance using overexpression technology. Overexpression of OsPIN5b (OE) resulted in reduced shoot height and a lower number of adventitious roots at the seedling stage. Transgenic rice plants exhibited an earlier heading date, stunted growth, and compromised agronomic traits, including shortened panicle length, decreased grain number per panicle, reduced seed size, and lower seed setting rate during the reproductive stage. Auxin content in the transgenic lines was significantly elevated, as indicated by the upregulation of the auxin-responsive gene OsIAA20 and increased auxin levels quantified using a newly developed method. Compared with wild-type plants, the cold tolerance of OE plants was markedly reduced, as evidenced by lower survival rates, higher levels of electrolyte leakage, and increased malondialdehyde (MDA) production following cold treatment. In line with this, the transgenic lines produced less soluble sugar and proline, while accumulating more hydrogen peroxide (H2O2) and superoxide anion ra...