Graduate School of Chinese Academy of Agricultural Science, Beijing 100081, China.
Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
Int J Mol Sci. 2020 Apr 1;21(7):2445. doi: 10.3390/ijms21072445.
-CMS (cytoplasmic male sterility) is the only male sterile system in tobacco breeding, but the mechanism of abortion is unclear. Cytological characteristics show that abortion in the -CMS line msZY occurs before the differentiation of sporogenous cells. In this study, a comparative transcriptomic analysis was conducted on flower buds at the abortion stage of msZY and its male fertile control ZY. A total of 462 differentially expressed genes were identified in msZY and ZY, which were enriched via protein processing in the endoplasmic reticulum (ER), oxidative phosphorylation, photosynthesis, and circadian rhythm-plant by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Most genes were downregulated in the ER stress pathway, heat-shock protein family, F1F0-ATPase encoding by the mitochondrial genome, and differentiation of stamens. Genes in the programmed cell death (PCD) pathway were upregulated in msZY. The transcriptome results were consistent with those of qRT-PCR. Ultrastructural and physiological analyses indicted active vacuole PCD and low ATP content in msZY young flower buds. We speculated that PCD and a deficiency in ATP synthesis are essential for the abortion of -CMS. This study reveals the potential mechanism of abortion of tobacco -CMS.
-CMS（细胞质雄性不育）是烟草育种中唯一的雄性不育系统，但败育机制尚不清楚。细胞学特征表明，msZY 不育系中的败育发生在小孢子母细胞分化之前。在这项研究中，对 msZY 及其雄性可育对照 ZY 的败育期花蕾进行了比较转录组分析。在 msZY 和 ZY 中共鉴定出 462 个差异表达基因，通过京都基因与基因组百科全书（KEGG）通路分析，这些基因富集于内质网（ER）蛋白加工、氧化磷酸化、光合作用和昼夜节律-植物途径。大多数基因在 ER 应激途径、热休克蛋白家族、线粒体基因组编码的 F1F0-ATP 酶和雄蕊分化中下调。msZY 中程序性细胞死亡（PCD）途径的基因上调。转录组结果与 qRT-PCR 一致。超微结构和生理分析表明，msZY 幼花蕾中存在活跃的液泡 PCD 和低 ATP 含量。我们推测 PCD 和 ATP 合成不足是 -CMS 败育的关键。本研究揭示了烟草 -CMS 败育的潜在机制。
