A molecular framework of ethylene-mediated fruit growth and ripening processes in tomato

第一作者：Wei Huang

第一单位：南方科技大学

通讯作者：Hongwei Guo

 Abstarct 

背景回顾：Although the role of ethylene in tomato (Solanum lycopersicum) fruit ripening has been intensively studied, its role in tomato fruit growth remains poorly understood. In addition, the relationship between ethylene and the developmental factors NON-RIPENING (NOR) and RIPENING INHIBITOR (RIN) during ripening is under debate. 

尽管乙烯在番茄果实成熟过程中的作用已经被广泛研究，但是其在番茄果实生长方面的作用还不清楚。另外，乙烯和发育因子NOR和RIN在果实成熟过程中关联也存在争议。

主要研究：Here, we carried out comprehensive genetic analyses of genome-edited mutants of tomato ETHYLENE INSENSITIVE 2 (SlEIN2), four EIN3-like genes (SlEIL1–4), and three EIN3 BINDING F-box protein genes (SlEBF1–3). 

本文中，作者对由基因组编辑介导的番茄SlEIN2基因、4个EIN3-like基因（SlEIL1–4）、3个EIN3 BINDING F-box蛋白基因（SlEBF1–3）功能缺失突变体进行了遗传分析。

结果1-乙烯与果实发育：Both slein2-1 and the high-order sleil mutant (sleil1 sleil2 sleil3/SlEIL3 sleil4) showed reduced fruit size, mainly due to decreased auxin biosynthesis. During fruit maturation, slein2 mutants displayed the complete cessation of ripening, which was partially rescued by slebf1 but not slebf2 or slebf3. 

slein2-1突变体和sleil高阶突变体（sleil1 sleil2 sleil3/SlEIL3 sleil4）表现出了果实大小变小，而这主要是由于生长素生物合成的降低。在果实成熟过程中，slein2突变体会表现出成熟的完全停滞，该表型能够被slebf1突变部分恢复，但是不能被slebf2或者slebf3突变恢复。

结果2-乙烯与发育因子：We also discovered that ethylene directly activates the expression of the developmental genes NOR, RIN, and FRUITFULL1 (FUL1) via SlEIL proteins. Indeed, overexpressing these genes partially rescued the ripening defects of slein2-1. 

作者还发现乙烯能够通过SlEIL蛋白，直接激活发育基因NOR、RIN以及FUL1基因的表达。确实，过表达这些基因能够部分恢复slein2-1突变的果实成熟缺陷表型。

结果3-乙烯与果实成熟：Finally, the signal intensity of the ethylene burst during fruit maturation was intimately connected with the progression of full ripeness. 

最后，果实成熟过程中乙烯爆发的信号强度与完成成熟的进程密切相关。

结论：Collectively, our work uncovers a critical role of ethylene in fruit growth and supports a molecular framework of ripening control in which the developmental factors NOR, RIN, and FUL1 act downstream of ethylene signaling.

综上，本文的研究揭示了乙烯在果实生长中的重要作用，同时表明发育因子NOR、RIN以及FUL1作为乙烯信号的下游组分，参与番茄果实的成熟控制。

** 郭红卫 **

doi: https://doi.org/10.1093/plcell/koac146

Journal: The Plant Cell

Published date: May 23, 2022

CITE

Wei Huang, Nan Hu, Zhina Xiao, Yuping Qiu, Yan Yang, Jie Yang, Xin Mao, Yichuan Wang, Zhengguo Li, Hongwei Guo. A molecular framework of ethylene-mediated fruit growth and ripening processes in tomato. The Plant Cell, 2022. DOI: https://doi.org/10.1093/plcell/koac146