The B-box transcription factor IbBBX29 regulates leaf development and flavonoid biosynthesis in sweet potato

• DOI: 10.1093/plphys/kiac516
• Publication Date: 2022-11-15T12:49:05Z
• Authors: Xiao-ru Gao; Huan Zhang; Xu Li; Yi-wei Bai; Kui Peng; Zhen Wang; Zhuo-ru Dai; Xiao-feng Bian; Qian Zhang; Li-cong Jia; Yan Li; Qing-chang Liu; Hong Zhai; Shao-pei Gao; Ning Zhao; Shao-zhen He
• Keywords: Flavonoid Biosynthesis; Phenylpropanoid; Ipomoea; Chromatin immunoprecipitation

Plant flavonoids are valuable natural antioxidants. Sweet potato (Ipomoea batatas) leaves rich in flavonoids, regenerate rapidly, and can adapt to harsh environments, making them an ideal material for flavonoid biofortification. Here, we demonstrate that the B-box (BBX) family transcription factor IbBBX29 regulates contents development of sweet leaves. was highly expressed significantly induced by auxin (IAA). Overexpression contributed a 21.37%-70.94% increase leaf biomass, 12.08%-21.85% IAA levels, 31.33%-63.03% accumulation potato, whereas silencing this gene produced opposite effects. Heterologous expression Arabidopsis (Arabidopsis thaliana) led dwarfed phenotype, along with enhanced accumulation. RNA-seq analysis revealed modulates genes involved signaling biosynthesis pathways. Chromatin immunoprecipitation-quantitative polymerase chain reaction electrophoretic mobility shift assay indicated targets key activate their binding specific T/G-boxes promoters, especially those adjacent start site. Moreover, physically interacted developmental phenylpropanoid biosynthesis-related proteins, such as AGAMOUS-LIKE 21 protein IbAGL21 MYB308-like IbMYB308L. Finally, overexpressing also increased storage roots. These findings indicate plays pivotal role regulating IAA-mediated Arabidopsis, providing candidate biofortification plants.