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Abstract：
BACKGROUND: Cytoplasmic male sterility (CMS) has greatly improved the utilization of heterosis in crops due to the absence of functional male gametophyte. The newly developed sporophytic D1 type CMS (CMS-D1) rice exhibits unique characteristics compared to the well-known sporophytic CMS-WA line, making it a valuable resource for rice breeding.
RESULTS: In this research, a novel CMS-D1 line named Xingye A (XYA) was established, characterized by small, transparent, and shriveled anthers. Histological and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays conducted on anthers from XYA and its maintainer line XYB revealed that male sterility in XYA is a result of delayed degradation of tapetal cells and abnormal programmed cell death (PCD) of microspores. Transcriptome analysis of young panicles revealed that differentially expressed genes (DEGs) in XYA, compared to XYB, were significantly enriched in processes related to chromatin structure and nucleosomes during the microspore mother cell (MMC) stage. Conversely, processes associated with sporopollenin biosynthesis, pollen exine formation, chitinase activity, and pollen wall assembly were enriched during the meiosis stage. Metabolome analysis identified 176 specific differentially accumulated metabolites (DAMs) during the meiosis stage, enriched in pathways such as α-linoleic acid metabolism, flavone and flavonol biosynthesis, and linolenic acid metabolism. Integration of transcriptomic and metabolomic data underscored the jasmonic acid (JA) biosynthesis pathway was significant enriched in XYA during the meiosis stage compared to XYB. Furthermore, levels of JA, MeJA, OPC4, OPDA, and JA-Ile were all higher in XYA than in XYB at the meiosis stage.
CONCLUSIONS: These findings emphasize the involvement of the JA biosynthetic pathway in pollen development in the CMS-D1 line, providing a foundation for further exploration of the molecular mechanisms involved in CMS-D1 sterility.
RESULTS: In this research, a novel CMS-D1 line named Xingye A (XYA) was established, characterized by small, transparent, and shriveled anthers. Histological and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays conducted on anthers from XYA and its maintainer line XYB revealed that male sterility in XYA is a result of delayed degradation of tapetal cells and abnormal programmed cell death (PCD) of microspores. Transcriptome analysis of young panicles revealed that differentially expressed genes (DEGs) in XYA, compared to XYB, were significantly enriched in processes related to chromatin structure and nucleosomes during the microspore mother cell (MMC) stage. Conversely, processes associated with sporopollenin biosynthesis, pollen exine formation, chitinase activity, and pollen wall assembly were enriched during the meiosis stage. Metabolome analysis identified 176 specific differentially accumulated metabolites (DAMs) during the meiosis stage, enriched in pathways such as α-linoleic acid metabolism, flavone and flavonol biosynthesis, and linolenic acid metabolism. Integration of transcriptomic and metabolomic data underscored the jasmonic acid (JA) biosynthesis pathway was significant enriched in XYA during the meiosis stage compared to XYB. Furthermore, levels of JA, MeJA, OPC4, OPDA, and JA-Ile were all higher in XYA than in XYB at the meiosis stage.
CONCLUSIONS: These findings emphasize the involvement of the JA biosynthetic pathway in pollen development in the CMS-D1 line, providing a foundation for further exploration of the molecular mechanisms involved in CMS-D1 sterility.
摘要：
背景：由于缺乏功能性雄配子体，细胞质雄性不育（CMS）大大提高了作物杂种优势的利用。与著名的孢子体CMS-WA系相比，新开发的孢子体D1型CMS(CMS-D1)水稻表现出独特的特性，使其成为水稻育种的宝贵资源。
结果：在这项研究中，建立了一个名为XYA（XYA）的新CMS-D1系，特点是小,透明,和枯萎的花药。对XYA及其保持系XYB的花药进行的组织学和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）测定表明，XYA中的雄性不育是绒毡层细胞延迟降解和异常程序性细胞死亡（PCD）的结果小孢子。对幼穗的转录组分析表明，XYA中的差异表达基因（DEGs），与XYB相比，在小孢子母细胞（MMC）阶段，与染色质结构和核小体相关的过程显着富集。相反，与孢子囊蛋白生物合成相关的过程，花粉外壁的形成,几丁质酶活性，在减数分裂阶段富集了花粉壁组装。代谢组分析确定了减数分裂阶段176个特定的差异积累代谢物（DAMs），富含α-亚油酸代谢等途径，黄酮和黄酮醇的生物合成，和亚麻酸代谢。转录组和代谢组数据的整合强调,与XYB相比,在减数分裂阶段,茉莉酸(JA)生物合成途径在XYA中显著富集。此外，JA的水平，MeJA,OPC4,OPDA,在减数分裂阶段，XYA和JA-Ile均高于XYB。
结论：这些发现强调了JA生物合成途径参与CMS-D1系花粉发育，为进一步探索CMS-D1不育的分子机制奠定了基础。
结果：在这项研究中，建立了一个名为XYA（XYA）的新CMS-D1系，特点是小,透明,和枯萎的花药。对XYA及其保持系XYB的花药进行的组织学和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）测定表明，XYA中的雄性不育是绒毡层细胞延迟降解和异常程序性细胞死亡（PCD）的结果小孢子。对幼穗的转录组分析表明，XYA中的差异表达基因（DEGs），与XYB相比，在小孢子母细胞（MMC）阶段，与染色质结构和核小体相关的过程显着富集。相反，与孢子囊蛋白生物合成相关的过程，花粉外壁的形成,几丁质酶活性，在减数分裂阶段富集了花粉壁组装。代谢组分析确定了减数分裂阶段176个特定的差异积累代谢物（DAMs），富含α-亚油酸代谢等途径，黄酮和黄酮醇的生物合成，和亚麻酸代谢。转录组和代谢组数据的整合强调,与XYB相比,在减数分裂阶段,茉莉酸(JA)生物合成途径在XYA中显著富集。此外，JA的水平，MeJA,OPC4,OPDA,在减数分裂阶段，XYA和JA-Ile均高于XYB。
结论：这些发现强调了JA生物合成途径参与CMS-D1系花粉发育，为进一步探索CMS-D1不育的分子机制奠定了基础。
