Hao Suxiao, Lu Yanfen, Peng Zhen, Wang Enying, Chao Linke, Zhong Silin, Yao Yuncong
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beijing, 102206, China.
Beijing Bei Nong Enterprise Management Co. Ltd, Beijing, 102206, China.
Hortic Res. 2021 Aug 1;8(1):182. doi: 10.1038/s41438-021-00620-0.
Temperature changes affect apple development and production. Phenylpropanoid metabolism and hormone signaling play a crucial role in regulating apple growth and development in response to temperature changes. Here, we found that McMYB4 is induced by treatment at 28 °C and 18 °C, and McMYB4 overexpression results in flavonol and lignin accumulation in apple leaves. Yeast one-hybrid (Y1H) assays and electrophoretic mobility shift assays (EMSAs) further revealed that McMYB4 targets the promoters of the flavonol biosynthesis genes CHS and FLS and the lignin biosynthesis genes CAD and F5H. McMYB4 expression resulted in higher levels of flavonol and lignin biosynthesis in apple during growth at 28 °C and 18 °C than during growth at 23 °C. At 28 °C and 18 °C, McMYB4 also binds to the AUX/ARF and BRI/BIN promoters to activate gene expression, resulting in acceleration of the auxin and brassinolide signaling pathways. Taken together, our results demonstrate that McMYB4 promotes flavonol biosynthesis and brassinolide signaling, which decreases ROS contents to improve plant resistance and promotes lignin biosynthesis and auxin signaling to regulate plant growth. This study suggests that McMYB4 participates in the abiotic resistance and growth of apple in response to temperature changes by regulating phenylpropanoid metabolism and hormone signaling.
温度变化影响苹果的发育和产量。苯丙烷类代谢和激素信号传导在响应温度变化调节苹果生长发育过程中发挥关键作用。在此，我们发现McMYB4在28°C和18°C处理下被诱导，并且McMYB4过表达导致苹果叶片中黄酮醇和木质素积累。酵母单杂交（Y1H）试验和电泳迁移率变动分析（EMSA）进一步表明，McMYB4靶向黄酮醇生物合成基因CHS和FLS以及木质素生物合成基因CAD和F5H的启动子。在28°C和18°C生长期间，McMYB4的表达导致苹果中黄酮醇和木质素生物合成水平高于在23°C生长期间。在28°C和18°C时，McMYB4还与AUX/ARF和BRI/BIN启动子结合以激活基因表达，从而加速生长素和油菜素内酯信号通路。综上所述，我们的结果表明，McMYB4促进黄酮醇生物合成和油菜素内酯信号传导，降低活性氧含量以提高植物抗性，并促进木质素生物合成和生长素信号传导以调节植物生长。本研究表明，McMYB4通过调节苯丙烷类代谢和激素信号传导参与苹果对温度变化的非生物抗性和生长。
