EIN3-LIKE1, MYB1, and ETHYLENE RESPONSE FACTOR3 act in a regulatory loop that synergistically modulates ethylene biosynthesis and anthocyanin accumulation

First author: Jian-Ping An; Affiliations: Shandong Agricultural University (山东农业大学): Taian, China

Corresponding author: Yu-Jin Hao

Ethylene regulates climacteric (跃变型) fruit ripening, and EIN3-LIKE1 (EIL1) plays an important role in this process. In apple (Malus domestica), fruit coloration is accompanied by (伴随着) ethylene release during fruit ripening, but the molecular mechanism that underlies these two physiological processes is unknown. In this study, we found that ethylene treatment markedly induced fruit coloration as well as the expression of MdMYB1, a positive regulator of anthocyanin (花青素) biosynthesis and fruit coloration. In addition, we found that MdEIL1 directly bound to the promoter of MdMYB1 and transcriptionally activated its expression, which resulted in anthocyanin biosynthesis and fruit coloration. Furthermore, MdMYB1 interacted with the promoter of ETHYLENE RESPONSE FACTOR3 (MdERF3), a key regulator of ethylene biosynthesis, thereby providing a positive feedback for ethylene biosynthesis regulation. Overall, our findings provide insight into a mechanism involving the synergistic interaction (协同互作) of the ethylene signal with the MdMYB1 transcription factor to regulate ethylene biosynthesis and fruit coloration in apple.

乙烯调控呼吸跃变型的果实成熟，EIL1基因在该过程中扮演重要的作用。在苹果中，果实成熟期的果实着色伴随着乙烯的释放，然而这两个生理过程潜在的分子层面的联系还不清楚。本文，作者发现了乙烯处理能够显著诱导果实的着色以及一个花青素生物合成和果实着色正向调控的基因MdMYB1的表达。另外，作者还发现MdEIL1可以直接结合到MdMYB1基因的启动子区，转录激活MdMYB1基因的表达，进而导致了花青素的生物合成和果实着色。此外，MdMYB1能够与MdERF3基因启动子互作，而MdERF3基因是乙烯生物合成的一个关键调控子，因此构成了对乙烯生物合成的正向反馈调节。综上，本文的结果揭示了乙烯信号与MdMYB1转录因子的协同互作，共同调控苹果中的乙烯生物合成和果实着色。

通讯：郝玉金 (http://yyxy.sdau.edu.cn/2012/0528/c1457a15086/page.htm)

个人简介：1994年，山东农业大学，学士；1997年，山东农业大学，硕士；2000年，华中农业大学，博士；先后在北京大学、日本果树研究所（筑波）和美国加州大学河滨分校从事博士后研究。

研究方向：1、苹果果实品质形成：果实色泽和酸度等品质性状相关基因的分离和鉴定，探讨温度、光照和碳氮等信号途径影响果实品质形成的分子机理，解析品质形成的调控网络。2、苹果砧木抗性等研究：克隆鉴定苹果砧木抗性等重要性状的相关基因，揭示其作用机理，并用于砧木遗传改良。

doi: https://doi.org/10.1104/pp.18.00068

Journal: Plant Physiology

First Published: 20 June, 2018

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