Cytosolic invertase (CIN) in plants hydrolyzes sucrose into fructose and glucose, influencing flowering time and organ development. However, the underlying molecular mechanisms remain elusive. Through expressional, genetic, and histological analyses, we identified a substantially role of SlCIN2 (localized in mitochondria) in regulating flowering and pollen development in tomato (Solanum lycopersicum). The overexpression of SlCIN2 resulted in increased hexose accumulation and decreased sucrose and starch content. Our findings indicated that SlCIN2 interacts with Sucrose transporter2 (SlSUT2) to inhibit the sucrose transport activity of SlSUT2, thereby suppressing sucrose content in flower buds and delaying flowering. We found that higher levels of glucose in SlCIN2-overexpressing anthers result in the accumulation of abscisic acid (ABA) and reactive oxygen species (ROS), thereby disrupting programmed cell death (PCD) in anthers and delaying the end of tapetal degradation. Exogenous sucrose partially restored fertility in SlCIN2-overexpressing plants. This study revealed the mechanism by which SlCIN2 regulates pollen development and demonstrated a strategy for creating sugar-regulated gene male sterility lines for tomato hybrid seed production.

中文翻译：

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胞质INVERTASE2调节番茄开花和活性氧触发的程序性细胞死亡


植物中的胞质转化酶 （CIN） 将蔗糖水解成果糖和葡萄糖，影响开花时间和器官发育。然而，潜在的分子机制仍然难以捉摸。通过表达、遗传和组织学分析，我们确定了 SlCIN2 （位于线粒体中）在调节番茄 （Solanum lycopersicum） 开花和花粉发育中的重要作用。SlCIN2 的过表达导致己糖积累增加，蔗糖和淀粉含量降低。我们的研究结果表明，SlCIN2 与蔗糖转运蛋白 2 （SlSUT2） 相互作用，抑制 SlSUT2 的蔗糖转运活性，从而抑制花芽中的蔗糖含量并延迟开花。我们发现，SlCIN2 过表达花药中较高水平的葡萄糖导致脱落酸 （ABA） 和活性氧 （ROS） 的积累，从而破坏花药中的程序性细胞死亡 （PCD） 并延迟绒毡层降解的结束。外源蔗糖部分恢复了 SlCIN2 过表达植物的生育能力。本研究揭示了 SlCIN2 调节花粉发育的机制，并展示了一种为番茄杂交种子生产创建糖调节基因雄性不育系的策略。