BACKGROUND Cytoplasmic male sterility (CMS) plays a crucial role in the utilization of heterosis and various types of CMS often have different abortion mechanisms. Therefore, it is important to understand the molecular mechanisms related to anther abortion in wheat, which remain unclear at present. RESULTS In this study, five isonuclear alloplasmic male sterile lines (IAMSLs) and their maintainer were investigated. Cytological analysis indicated that the abortion type was identical in IAMSLs, typical and stainable abortion, and the key abortive period was in the binucleate stage. Most of the 1,281 core shared differentially expressed genes identified by transcriptome sequencing compared with the maintainer in the vital abortive stage were involved in the metabolism of sugars, oxidative phosphorylation, phenylpropane biosynthesis, and phosphatidylinositol signaling, and they were downregulated in the IAMSLs. Key candidate genes encoding chalcone--flavonone isomerase, pectinesterase, and UDP-glucose pyrophosphorylase were screened and identified. Moreover, further verification elucidated that due to the impact of downregulated genes in these pathways, the male sterile anthers were deficient in sugar and energy, with excessive accumulations of ROS, blocked sporopollenin synthesis, and abnormal tapetum degradation. CONCLUSIONS Through comparative transcriptome analysis, an intriguing core transcriptome-mediated male-sterility network was proposed and constructed for wheat and inferred that the downregulation of genes in important pathways may ultimately stunt the formation of the pollen outer wall in IAMSLs. These findings provide insights for predicting the functions of the candidate genes, and the comprehensive analysis of our results was helpful for studying the abortive interaction mechanism in CMS wheat.

中文翻译：

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比较转录组分析表明，核心转录网络介导了小麦（Triticum aestivum L.）的同核异质雄性不育。

背景技术细胞质雄性不育（CMS）在杂种优势的利用中起着至关重要的作用，各种类型的CMS通常具有不同的流产机制。因此，重要的是了解与小麦花药流产有关的分子机制，目前尚不清楚。结果在这项研究中，研究了五个同核异质雄性不育系（IAMSL）及其维持者。细胞学分析表明，IAMSLs的流产类型相同，典型流产和可染色流产，关键流产期处于双核阶段。通过转录组测序鉴定的1,281个核心共有差异表达基因中的大多数与生命流产阶段的维持者相比，涉及糖的代谢，氧化磷酸化，苯丙烷的生物合成，和磷脂酰肌醇信号，它们在IAMSL中被下调。筛选并鉴定了编码查尔酮-黄酮酮异构酶，果胶酯酶和UDP-葡萄糖焦磷酸化酶的关键候选基因。此外，进一步的验证表明，由于这些途径中下调的基因的影响，雄性不育花药的糖和能量不足，ROS过多积聚，孢子粉合成受阻，绒毡层降解异常。结论通过比较转录组分析，提出并构建了一个有趣的小麦核心转录组介导的雄性不育网络，并推断重要途径中基因的下调可能最终阻碍了IAMSLs花粉外壁的形成。