The mode of action of remorin1 in regulating fruit ripening at transcriptional and post-transcriptional levels

First author: Jianghua Cai; Affiliations: Institute of Botany, The Chinese Academy of Sciences (中科院植物所): Beijing, China

Corresponding author: Shiping Tian (田世平)

Remorins are plant‐specific and plasma membrane‐associated proteins that display a variety of functions in plant growth, development, biotic and abiotic stresses, and signal transduction. However, little information is available for understanding their role in fruit ripening. Here, remorin 1 (SlREM1) is cloned from tomato and its localization is examined by co‐localization analysis and immunoblotting (免疫印迹). Functions of SlREM1 in fruit ripening are characterized based on gene expression, co‐immunoprecipitation (免疫共沉淀) coupled with mass spectroscopy (质谱分析) and split luciferase complementation imaging assays (荧光酶片段互补成像分析) in SlREM1 overexpression and RNA interference (RNAi) lines. The results indicate that SlREM1 is localized at the plasma membrane. Overexpression of SlREM1 in tomato stimulates fruit ripening with an increase in ethylene production and lycopene (番茄红素) accumulation as compared to the wild‐ ype. Consistently, these genes involved in ethylene and lycopene biosynthesis and ripening regulators also are upregulated in SlREM1 overexpression lines. SlREM1 can interact with ethylene biosynthesis proteins SAM1, ACO1 and ACS2 and is degraded by ubiquitin‐mediated proteolysis (蛋白水解). Our findings reveal that SlREM1 serves as a positive regulator of fruit ripening and provide novel cues for understanding of the molecular regulation network of fruit ripening.

Remorins蛋白是一类植物特有的质膜相关蛋白，在植物生长、发育、生物和非生物胁迫以及信号方面具有重要作用。然而，关于该类蛋白在果实成熟中的作用所知甚少。本文克隆了番茄remorin 1编码基因SlREM1，通过共定位分析和免疫印迹对其进行了定位。作者基于SlREM1过表达RNAi株系，通过基因表达、偶联质谱分析的免疫共沉淀及荧光酶片段互补成像试验分析了SlREM1基因在果实成熟过程中的功能。结果显示SlREM1定位于质膜。相比于野生型番茄，过表达SlREM1基因能够通过增加乙烯产量及番茄红素极累促进果实成熟。同时，在SlREM1过表达株系中，参与乙烯和番茄红素生物合成基因及成熟调控基因的表达量有明显上调。SlREM1能够与乙烯生物合成蛋白SAM1、ACO1和ACS2相互作用，并且被泛素所介导的蛋白水解途径所降解。本文的发现揭示了SlREM1作为植物果实成熟的正向调控子，对于理解果实成熟相关的分子调控网络提供了新的视角。

通讯：田世平 (http://sourcedb.ib.cas.cn/cn/expert/200904/t20090403_44967.html)

个人简介：1982年，四川农业大学，学士；1995年，意大利博洛尼亚大学，博士，方向：植物病理学；1996-1997年，意大利博洛尼亚大学，博士后。

研究方向：果实采后品质保持的生物化学基础及调控机制；病原菌毒素生物合成的分子调控机理及控制技术研究；病原菌分子致病机制及调控技术。

doi: https://doi.org/10.1111/nph.15264

Journal: New Phytologist

First Published: 06 July, 2018

（P.S. 原文下载：链接:https://pan.baidu.com/s/1qFiSsqwlF_7JjmGMbedfhQ  密码:dmu6）