Programmed cell death (PCD) plays an essential role in plant development and response to environmental stimuli. However, the underlying molecular regulatory mechanisms are largely unknown. In this study, we investigated the roles of the SMS1 gene to dissect its molecular mechanisms in rice PCD. The SMS1 gene was characterized by map-based cloning. Functional prediction and verification of the SMS1 gene were further conducted through complementation tests, subcellular localization assays, tissue-specific gene expression using GUS staining, and overexpression analysis using real-time quantitative RT-PCR. The sms1 mutant showed constitutive PCD, defective cell wall structure, and reduced pollen sterility. SMS1 encodes a uridine diphosphate glucose pyrophosphorylase (UGPase). SMS1 is ubiquitously expressed in rice, and the SMS1 protein localizes to both the cytoplasm and nucleus, implying a fundamental and crucial role in various rice tissues. Taken together, we demonstrate that by modulating UDP-glucose metabolism, SMS1 contributes to the maintenance of cell wall organization and cell viability in rice, providing, for the first time, evidence that sugar homeostasis regulates plant PCD.

程序性细胞死亡 (PCD) 在植物发育和对环境刺激的反应中起着至关重要的作用。然而，潜在的分子调控机制在很大程度上是未知的。在这项研究中，我们研究了SMS1基因的作用，以剖析其在水稻 PCD 中的分子机制。在SMS1基因的特点是基于地图的克隆。SMS1基因的功能预测和验证通过互补测试、亚细胞定位分析、使用 GUS 染色的组织特异性基因表达和使用实时定量 RT-PCR 的过表达分析进一步进行。在SMS1突变体显示组成型PCD，有缺陷的细胞壁结构，和减少的花粉育。短信1编码尿苷二磷酸葡萄糖焦磷酸化酶 (UGPase)。SMS1在水稻中普遍表达，并且 SMS1 蛋白定位于细胞质和细胞核，这意味着在各种水稻组织中发挥着基本和关键的作用。总之，我们证明通过调节 UDP-葡萄糖代谢，SMS1 有助于维持水稻的细胞壁组织和细胞活力，首次提供了糖稳态调节植物 PCD 的证据。