BACKGROUND Rice (Oryza sativa) is one of the main crops in the world, and more than 3.9 billion people will consume rice by 2025. Sterility significantly affects rice production and leads to yield defects. The undeveloped anthers or abnormal pollen represent serious defects in rice male sterility. Therefore, understanding the mechanism of male sterility is an important task. Here, we investigated a rice sterile mutant according to its developmental morphology and transcriptional profiles. RESULTS An untagged T-DNA insertional mutant showed defective pollen and abnormal anthers as compared with its semi-sterile mutant (sstl) progeny segregates. Transcriptomic analysis of sterile sstl-s revealed several biosynthesis pathways, such as downregulated cell wall, lipids, secondary metabolism, and starch synthesis. This downregulation is consistent with the morphological characterization of sstl-s anthers with irregular exine, absence of intine, no starch accumulation in pollen grains and no accumulated flavonoids in anthers. Moreover, defective microsporangia development led to abnormal anther locule and aborted microspores. The downregulated lipids, starch, and cell wall synthesis-related genes resulted in loss of fertility. CONCLUSIONS We illustrate the importance of microsporangia in the development of anthers and functional microspores. Abnormal development of pollen grains, pollen wall, anther locule, etc. result in severe yield reduction.

中文翻译：

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TRIM收集的水稻不育突变体sstl的研究。

背景技术稻米（Oryza sativa）是世界上的主要农作物之一，到2025年将有39亿人食用大米。不育会极大地影响稻米生产并导致单产下降。花药未发育或花粉异常代表水稻雄性不育的严重缺陷。因此，了解男性不育的机理是一项重要的任务。在这里，我们根据其发育形态和转录谱研究了水稻不育突变体。结果与半不育突变体（sstl）后代分离相比，未标记的T-DNA插入突变体显示出花粉缺陷和花药异常。无菌sstl-s的转录组学分析显示了几种生物合成途径，例如下调细胞壁，脂质，次级代谢和淀粉合成。这种下调与外来不规则的sstl-s花药的形态学特征一致，外花不存在intine，花粉粒中没有淀粉积累，而花药中没有黄酮类化合物。此外，有缺陷的小孢子囊发育导致花药室异常和小孢子流产。脂质，淀粉和细胞壁合成相关基因的下调导致生育力的丧失。结论我们阐明了小孢子囊在花药和功能性小孢子发育中的重要性。花粉粒，花粉壁，花药室等的异常发育导致严重的减产。小孢子囊发育不良导致花药室异常和小孢子流产。脂质，淀粉和细胞壁合成相关基因的下调导致生育力的丧失。结论我们阐明了小孢子囊在花药和功能性小孢子发育中的重要性。花粉粒，花粉壁，花药室等的异常发育导致严重的减产。小孢子囊发育不良导致花药室异常和小孢子流产。脂质，淀粉和细胞壁合成相关基因的下调导致生育力的丧失。结论我们阐明了小孢子囊在花药和功能性小孢子发育中的重要性。花粉粒，花粉壁，花药室等的异常发育导致严重的减产。