Key message

Numbers of critical genes and pathways were found from the levels of transcriptome and metabolome, which were useful information for understanding of kenaf CMS mechanism.

Abstract

Cytoplasmic male sterility (CMS) is a maternally inherited trait in higher plants that leads to the inability to produce or release functional pollen. However, there is lack of comprehensive studies to reveal the molecular basis of CMS occurrence in kenaf. Herein, we performed transcriptome and UPLC-MS-based metabolome analyses in the anthers of a CMS (UG93A) and its maintainer (UG93B) to sort out essential genes and metabolites responding to CMS in kenaf. Transcriptome characterized 7769 differentially expressed genes (DEGs) between these two materials, and pathway enrichment analysis indicated that these DEGs were involved mainly in pentose and glucuronate interconversions, starch and sucrose metabolism, taurine and hypotaurine metabolism. In the metabolome assay, a total of 116 significantly different metabolites (SDMs) were identified between the CMS and its maintainer line, and these SDMs were involved in eight KEGG pathways, including flavone and flavonol biosynthesis, glycerophospholipid metabolism, flavonoid biosynthesis, glycosylphosphatidylinositol-anchor biosynthesi. Integrated analyses of transcriptome and metabolome showed that 50 genes had strong correlation coefficient values (R² > 0.9) with ten metabolites enriched in six pathways; notably, most genes and metabolites of flavonoid biosynthesis pathways and flavone and flavonol biosynthesis pathways involved in flavonoids biosynthetic pathways were downregulated in CMS compared to those in maintainer. Taken together, the decreased accumulation of flavonoids resulted from the compromised biosynthesis pathways coupled with energy deficiency in the anthers may contribute largely to CMS in UG93A of kenaf.

中文翻译：

---

全面整合转录组和代谢组分析，揭示红麻 CMS 中涉及的关键基因和基本代谢途径

关键信息

从转录组和代谢组水平发现了许多关键基因和途径，这对于理解红麻CMS机制是有用的信息。

抽象的

细胞质雄性不育（CMS）是高等植物中的一种母系遗传性状，导致无法产生或释放功能性花粉。然而，缺乏全面的研究来揭示红麻中 CMS 发生的分子基础。在此，我们在 CMS (UG93A) 及其维持者 (UG93B) 的花药中进行了转录组和基于 UPLC-MS 的代谢组分析，以筛选出响应红麻中 CMS 的必需基因和代谢物。转录组对这两种材料之间的7769个差异表达基因（DEGs）进行了表征，通路富集分析表明，这些DEGs主要参与戊糖和葡萄糖醛酸的相互转化、淀粉和蔗糖代谢、牛磺酸和亚牛磺酸代谢。在代谢组分析中，在CMS及其维持系之间共鉴定出116种显着不同的代谢物（SDM），这些SDM参与了8个KEGG途径，包括黄酮和黄酮醇生物合成、甘油磷脂代谢、类黄酮生物合成、糖基磷脂酰肌醇-锚生物合成。转录组和代谢组的综合分析表明，50个基因具有很强的相关系数值（R ²  > 0.9)，十种代谢物在六种途径中富集；值得注意的是，与维持剂相比，CMS 中黄酮类生物合成途径的大多数基因和代谢物以及黄酮类生物合成途径中涉及的黄酮和黄酮醇生物合成途径均下调。总之，由于生物合成途径受损以及花药中的能量缺乏导致黄酮类化合物的积累减少可能在很大程度上促成了红麻UG93A中的CMS。