Abstract：
BACKGROUND: The utilization of heterosis based on three-line system is an effective strategy in crop breeding. However, cloning and mechanism elucidation of restorer genes for cytoplasmic male sterility (CMS) in upland cotton have yet been realized.
RESULTS: This research is based on CMS line 2074A with the cytoplasm from Gossypium harknessii (D2-2) and restorer line R186. The offspring of 2074A × R186 were used to conduct genetic analysis. The fertility mechanism of 2074A can be speculated to be governed by multiple genes, since neither the single gene model nor the double genes model could be used. The bulked segregant analysis (BSA) for (2074A × R186) F2 determined the genetic interval of restorer genes on a region of 4.30 Mb on chromosome D05 that contains 77 annotated genes. Four genes were identified as candidates for fertility restoration using the RNA-seq data of 2074A, 2074B, and R186. There are a number of large effect variants in the four genes between 2074A and R186 that could cause amino acid changes. Evolutionary analysis and identity analysis revealed that GH_D05G3183, GH_D05G3384, and GH_D05G3490 have high identity with their homologs in D2-2, respectively. Tissue differential expression analysis revealed that the genes GH_D05G3183, GH_D05G3384, and GH_D05G3490 were highly expressed in the buds of the line R186. The predicted results demonstrated that GH_D05G3183, GH_D05G3384 and GH_D05G3490 might interact with GH_A02G1295 to regulate orf610a in mitochondria.
CONCLUSIONS: Our study uncovered candidate genes for fertility restoration in the restorer line R186 and predicted the possible mechanism for restoring the male fertility in 2074A. This research provided valuable insight into the nucleoplasmic interactions.
RESULTS: This research is based on CMS line 2074A with the cytoplasm from Gossypium harknessii (D2-2) and restorer line R186. The offspring of 2074A × R186 were used to conduct genetic analysis. The fertility mechanism of 2074A can be speculated to be governed by multiple genes, since neither the single gene model nor the double genes model could be used. The bulked segregant analysis (BSA) for (2074A × R186) F2 determined the genetic interval of restorer genes on a region of 4.30 Mb on chromosome D05 that contains 77 annotated genes. Four genes were identified as candidates for fertility restoration using the RNA-seq data of 2074A, 2074B, and R186. There are a number of large effect variants in the four genes between 2074A and R186 that could cause amino acid changes. Evolutionary analysis and identity analysis revealed that GH_D05G3183, GH_D05G3384, and GH_D05G3490 have high identity with their homologs in D2-2, respectively. Tissue differential expression analysis revealed that the genes GH_D05G3183, GH_D05G3384, and GH_D05G3490 were highly expressed in the buds of the line R186. The predicted results demonstrated that GH_D05G3183, GH_D05G3384 and GH_D05G3490 might interact with GH_A02G1295 to regulate orf610a in mitochondria.
CONCLUSIONS: Our study uncovered candidate genes for fertility restoration in the restorer line R186 and predicted the possible mechanism for restoring the male fertility in 2074A. This research provided valuable insight into the nucleoplasmic interactions.
摘要：
背景：基于三系系统的杂种优势利用是作物育种的有效策略。然而,陆地棉细胞质雄性不育（CMS）恢复基因的克隆和机制阐明尚未实现。
结果：该研究基于CMS系2074A，其细胞质来自沙克氏棉属（D2-2）和恢复系R186。对2074A×R186的后代进行遗传分析。2074A的育性机制可以推测为受多个基因支配，因为单基因模型和双基因模型都不能使用。对（2074A×R186）F2的大量分离分析（BSA）确定了D05染色体上4.30Mb区域上恢复基因的遗传间隔，该区域包含77个注释基因。使用2074A的RNA-seq数据确定了四个基因作为生育力恢复的候选基因，2074B,R186在2074A和R186之间的四个基因中存在许多可引起氨基酸变化的大效应变体。进化分析和同一性分析表明，GH_D05G3183，GH_D05G3384和GH_D05G3490分别与D2-2中的同源物具有高度同一性。组织差异表达分析表明，GH_D05G3183，GH_D05G3384和GH_D05G3490基因在R186系的芽中高表达。预测结果表明，GH_D05G3183，GH_D05G3384和GH_D05G3490可能与GH_A02G1295相互作用以调节线粒体中的orf610a。
结论：我们的研究发现了恢复系R186中恢复生育力的候选基因，并预测了2074A中恢复男性生育力的可能机制。这项研究为核质相互作用提供了有价值的见解。
结果：该研究基于CMS系2074A，其细胞质来自沙克氏棉属（D2-2）和恢复系R186。对2074A×R186的后代进行遗传分析。2074A的育性机制可以推测为受多个基因支配，因为单基因模型和双基因模型都不能使用。对（2074A×R186）F2的大量分离分析（BSA）确定了D05染色体上4.30Mb区域上恢复基因的遗传间隔，该区域包含77个注释基因。使用2074A的RNA-seq数据确定了四个基因作为生育力恢复的候选基因，2074B,R186在2074A和R186之间的四个基因中存在许多可引起氨基酸变化的大效应变体。进化分析和同一性分析表明，GH_D05G3183，GH_D05G3384和GH_D05G3490分别与D2-2中的同源物具有高度同一性。组织差异表达分析表明，GH_D05G3183，GH_D05G3384和GH_D05G3490基因在R186系的芽中高表达。预测结果表明，GH_D05G3183，GH_D05G3384和GH_D05G3490可能与GH_A02G1295相互作用以调节线粒体中的orf610a。
结论：我们的研究发现了恢复系R186中恢复生育力的候选基因，并预测了2074A中恢复男性生育力的可能机制。这项研究为核质相互作用提供了有价值的见解。
