State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, 455000, China.
Xinjiang Qianhai Seed Industry Limited Liability Company, Tumsuk, 843901, China.
Planta. 2021 Jun 17;254(1):7. doi: 10.1007/s00425-021-03597-1.
Flavonoids are involved in axillary bud development in upland cotton. The phenylpropanoid and flavonoid biosynthesis pathways regulate axillary bud growth by promoting the transport of auxin in upland cotton. In cotton production, simplified cultivation and mechanical harvesting are emerging trends that depend on whether the cotton plant type meets production requirements. The axillary bud is an important index of cotton plant-type traits, and the molecular mechanism of axillary bud development in upland cotton has not yet been completely studied. Here, a combined investigation of transcriptome and metabolome analyses in G. hirsutum CCRI 117 at the fourth week (stage 1), fifth week (stage 2) and sixth week (stage 3) after seedling emergence was performed. The metabolome results showed that the total lipid, amino acid and organic acid contents in the first stalk node decreased during axillary bud development. The abundance of 71 metabolites was altered between stage 2 and stage 1, and 32 metabolites exhibited significantly altered abundance between stage 3 and stage 2. According to the correlation analysis of metabolome and transcriptome profiles, we found that phenylpropanoid and flavonoid biosynthesis pathways exhibit high enrichment degrees of both differential metabolites and differential genes in three stages. Based on the verification of hormone, soluble sugar and flavonoid detection, we propose a model for flavonoid-mediated regulation of axillary bud development in upland cotton, revealing that the decrease in secondary metabolites of phenylpropanoid and flavonoid biosynthesis is an essential factor to promote the transport of auxin and subsequently promote the growth of axillary buds. Our findings provide novel insights into the regulation of phenylpropanoid and flavonoid biosynthesis in axillary bud development and could prove useful for cultivating machine-harvested cotton varieties with low axillary buds.
类黄酮参与陆地棉腋芽发育。苯丙烷和类黄酮生物合成途径通过促进陆地棉中生长素的运输来调节腋芽生长。在棉花生产中，简化栽培和机械收获是新兴趋势，这取决于棉花株型是否符合生产要求。腋芽是棉花株型特征的重要指标，陆地棉腋芽发育的分子机制尚未完全研究。在这里，对出苗后第 4 周（第 1 期）、第 5 周（第 2 期）和第 6 周（第 3 期）的 G. hirsutum CCRI 117 进行了转录组和代谢组联合分析。代谢组结果表明，在腋芽发育过程中，第一茎节中的总脂质、氨基酸和有机酸含量降低。在第 2 期和第 1 期之间，有 71 种代谢物的丰度发生变化，在第 3 期和第 2 期之间，有 32 种代谢物的丰度发生显著变化。根据代谢组和转录组谱的相关分析，我们发现苯丙烷和类黄酮生物合成途径在三个阶段均表现出高的差异代谢物和差异基因的富集度。基于激素、可溶性糖和类黄酮检测的验证，我们提出了一个黄酮类物质介导的陆地棉腋芽发育调控模型，揭示了苯丙烷和类黄酮生物合成的次生代谢物减少是促进生长素运输并进而促进腋芽生长的重要因素。我们的研究结果为腋芽发育中苯丙烷和类黄酮生物合成的调控提供了新的见解，并可能有助于培育低腋芽的机械收获棉花品种。
