The apple transcription factor MdbHLH4 regulates plant morphology and fruit development by promoting cell enlargement.
The apple transcription factor MdbHLH4 regulates plant morphology and fruit development by promoting cell enlargement.
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DOI：
10.1016/j.plaphy.2023.108207
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发表时间：
2023-11
期刊：
影响因子：
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通讯作者：
Huayu Liu;Kangning Wang;Jie Yang;Xingfa Wang;Quanlin Mei;Lina Qiu;Fengwang Ma;Ke Mao
中科院分区：
文献类型：
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作者：
Huayu Liu;Kangning Wang;Jie Yang;Xingfa Wang;Quanlin Mei;Lina Qiu;Fengwang Ma;Ke Mao
The bHLH family, the second largest transcription factor (TF) family in plants, plays a crucial role in regulating plant growth and development processes. However, the biological functions and mechanisms of most bHLH proteins remain unknown, particularly in apples. In this study, we found thatMdbHLH4positively modulates plant growth and development by enhancing cell expansion. Overexpression (OE) ofMdbHLH4resulted in increased biomass, stem and root length, leaf area, and larger areas of pith, xylem, and cortex with greater cell size compared with wild-type apple plants. Conversely, RNA interference (RNAi)-mediated silencing ofMdbHLH4led to reduced xylem and phloem as well as smaller cell size compared to wild-type apple plants. Ectopic expression ofMdbHLH4in tomatoes resulted in enlarged fruits with impaired color appearance, decreased accumulation of soluble solids, and decreased flesh firmness along with larger seeds. Subsequent investigations have shown that MdbHLH4 directly binds to the promoters ofMdARF6bandMdPIF4b, enhancing their expression levels. These findings suggest that MdbHLH4 potentially regulates plant cell expansion through auxin and light signaling pathways. These study results not only provide new insights into the roles of bHLH transcription factors in regulating plant growth and development but also contribute to a deeper understanding of their underlying mechanisms.
