The regulatory module MdPUB29-MdbHLH3 connects ethylene biosynthesis with fruit quality in apple
The regulatory module MdPUB29-MdbHLH3 connects ethylene biosynthesis with fruit quality in apple
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调控模块 MdPUB29-MdbHLH3 将乙烯生物合成与苹果的果实品质联系起来
DOI：
10.1111/nph.15511
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发表时间：
2019-03-01
期刊：
影响因子：
9.4
通讯作者：
Hao, Yu-Jin
中科院分区：
文献类型：
--
作者：
Hu, Da-Gang;Yu, Jian-Qiang;Hao, Yu-Jin
植物激素乙烯对跃变型果实的成熟至关重要，而葡萄糖和花青素决定了跃变型果实（如苹果）的品质。了解这一过程的确切分子机制对于阐明乙烯与果实品质的相互关系具有重要意义。苹果MdbHLH 3基因（花青素相关的碱性螺旋-环-螺旋转录因子（bHLH TF）基因）的过表达促进乙烯的产生，转基因苹果植株和树表现出与乙烯相关的根发育异常、叶片早衰和果实成熟。生物化学分析表明，MdbHLH 3结合到三个基因的启动子，参与乙烯生物合成，包括MdACO 1，MdACS 1，和MdACS 5A，激活它们的转录表达，从而促进乙烯生物合成。高糖抑制的U-box-type E3泛素连接酶MdPUB 29是拟南芥AtPUB 29在苹果中的直向同源物，它通过直接泛素化MdbHLH 3蛋白来影响乙烯生物合成基因的表达和乙烯的产生。我们的研究结果为葡萄糖抑制的泛素E3连接酶MdPUB 29在乙烯生物合成调控中对MdbHLH 3的泛素化提供了新的见解，并表明调控模块MdPUB 29-MdbHLH 3将乙烯生物合成与苹果果实品质联系起来。
The plant hormone ethylene is critical for climacteric fruit ripening, while glucose and anthocyanins determine the fruit quality of climacteric fruits such as apple. Understanding the exact molecular mechanism for this process is important for elucidating the interconnection of ethylene and fruit quality. Overexpression of apple MdbHLH3 gene, an anthocyanin-related basic helix-loop-helix transcription factor (bHLH TF) gene, promotes ethylene production, and transgenic apple plantlets and trees exhibit ethylene-related root developmental abnormalities, premature leaf senescence, and fruit ripening. Biochemical analyses demonstrate that MdbHLH3 binds to the promoters of three genes that are involved in ethylene biosynthesis, including MdACO1, MdACS1, and MdACS5A, activating their transcriptional expression, thereby promoting ethylene biosynthesis. High glucose-inhibited U-box-type E3 ubiquitin ligase MdPUB29, the ortholog of Arabidopsis AtPUB29 in apple, influences the expression of ethylene biosynthetic genes and ethylene production by direct ubiquitination of the MdbHLH3 protein. Our findings provide new insights into the ubiquitination of MdbHLH3 by glucose-inhibited ubiquitin E3 ligase MdPUB29 in the regulation of ethylene biosynthesis as well as indicate that the regulatory module MdPUB29-MdbHLH3 connects ethylene biosynthesis with fruit quality in apple.