背景回顾：Plant flavonoids are valuable natural antioxidants. Sweet potato (Ipomoea batatas) leaves are rich in flavonoids, regenerate rapidly, and can adapt to harsh environments, making them an ideal material for flavonoid biofortification. 

主要发现：Here, we demonstrate that the B-box (BBX) family transcription factor IbBBX29 regulates the flavonoid contents and development of sweet potato leaves. 

结果1-表达模式：IbBBX29 was highly expressed in sweet potato leaves and significantly induced by auxin (IAA). 

结果2-基因功能：Overexpression of IbBBX29 contributed to a 21.37–70.94% increase in leaf biomass, a 12.08–21.85% increase in IAA levels, and a 31.33–63.03% increase in flavonoid accumulation in sweet potato, whereas silencing this gene produced opposite effects. Heterologous expression of IbBBX29 in Arabidopsis (Arabidopsis thaliana) led to a dwarfed phenotype, along with enhanced IAA and flavonoid accumulation.

结果3-下游靶基因：RNA-seq analysis revealed that IbBBX29 modulates the expression of genes involved in the auxin signaling and flavonoid biosynthesis pathways. ChIP-qPCR and EMSA indicated that IbBBX29 targets key genes of auxin signaling and flavonoid biosynthesis to activate their expression by binding to specific T/G-boxes in their promoters, especially those adjacent to the transcription start site. 

结果4-互作蛋白：Moreover, IbBBX29 physically interacted with developmental and phenylpropanoid biosynthesis-related proteins, such as MADS-box protein IbAGL21 and MYB308-like protein IbMYB308L. 

结果5-根中的作用：Finally, overexpressing IbBBX29 also increased flavonoid contents in sweet potato storage roots. 

结论：These findings indicate that IbBBX29 plays a pivotal role in regulating IAA-mediated leaf development and flavonoid biosynthesis in sweet potato and Arabidopsis, providing a candidate gene for flavonoid biofortification in plants.

植物黄酮类化合物是重要的天然抗氧化剂。甘薯叶片富含黄酮类化合物，并且再生迅速，能够适应恶劣的生存环境，因此是进行黄酮类化合物生物强化的理想材料。本文中，作者发现甘薯中BBX家族的转录因子IbBBX29调控叶片中的黄酮类化合物含量以及叶片发育。IbBBX29基因在甘薯叶片中高表达，并且受到生长素IAA的显著诱导。过表达IbBBX29基因会导致甘薯叶片生物量的提高（21.37–70.94%），IAA水平的提升（12.08–21.85%）以及类黄酮化合物含量的增加（31.33–63.03%），而沉默IbBBX29基因则会导致相反的表型。在拟南芥中异源表达甘薯的IbBBX29基因会导致矮化表型，同时IAA水平和黄酮类化合物积累增加。转录组测序显示，IbBBX29能够调控生长素信号转导基因和黄酮类化合物生物合成基因的表达。ChIP-qPCR和EMSA试验发现，IbBBX29能够靶向生长素信号转导和黄酮类化合物生物合成的关键基因，通过直接结合到这些基因启动子区域，尤其是在转录起始位点附近的T/G-boxes，从而激活这些基因的表达。此外，IbBBX29能够与发育和苯丙素类化合物生物合成相关蛋白发生物理互作，比如MADS-box蛋白IbAGL21和MYB308类蛋白IbMYB308L。最终，过表达IbBBX29会增加甘薯储藏根中的黄酮类化合物含量。本文的研究结果揭示了甘薯中IbBBX29在调控IAA介导叶片发育和黄酮类化合物生物合成方面的重要作用，为植物的黄酮类化合物生物强化提供了一个候选基因。

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