The Role of 1-Methylcyclopropene in the regulation of ethylene biosynthesis and ethylene receptor gene expression in Mangifera indica L. (Mango Fruit).

Li Li,Guoming Liu,Liang Shuai,Ping Yi,Dongning Ling,Zhugui Zhou,Yayuan Tang,Fengjin Zheng,Jinfeng Sheng,Zhichun Li,Kin‐Weng Kong,Changbao Li,Jian Sun,Ming Xin,Jiemin Li,Xuemei He

doi:10.1002/fsn3.1417

Abstract

Mango (Mangifera indica L.) is respiratory climacteric fruit that ripens and decomposes quickly following their harvest. 1‐methylcyclopropene (1‐MCP) is known to affect the ripening of fruit, delaying the decay of mango stored under ambient conditions. The objective of this study was to clarify the role of 1‐MCP in the regulation of ethylene biosynthesis and ethylene receptor gene expression in mango. 1‐MCP significantly inhibited the 1‐aminocyclopropane‐1‐carboxylic acid (ACC) content. The activity of ACC oxidase (ACO) increased on days 6, 8, and 10 of storage, whereas delayed ACC synthase (ACS) activity increased after day 4. The two homologous ethylene receptor genes, ETR1 and ERS1 (i.e., MiETR1 and MiERS1), were obtained and deposited in GenBank® (National Center for Biotechnology Information‐National Institutes of Health [NCBI‐NIH]) (KY002681 and KY002682). The MiETR1 coding sequence was 2,220 bp and encoded 739 amino acids (aa). The MiERS1 coding sequence was 1,890 bp and encoded 629 aa, similar to ERS1 in other fruit. The tertiary structures of MiETR1 and MiERS1 were also predicted. MiERS1 lacks a receiver domain and shares a low homology with MiETR1 (44%). The expression of MiETR1 and MiERS1 mRNA was upregulated as the storage duration extended and reached the peak expression on day 6. Treatment with 1‐MCP significantly reduced the expression of MiETR1 on days 4, 6, and 10 and inhibited the expression of MiETR1 on days 2, 4, 6, and 10. These results indicated that MiETR1 and MiERS1 had important functions in ethylene signal transduction. Treatment with 1‐MCP might effectively prevent the biosynthesis of ethylene, as well as ethylene‐induced ripening and senescence. This study presents an innovative method for prolonging the storage life of mango after their harvest through the regulation of MiETR1 and MiERS1 expression.

Highlights

Ethylene is a gaseous plant hormone that is involved in plant growth and development, including fruit ripening, fruit abscission, leaf senescence, seed germination, and organogenesis (Bleecker & Kende, 2000; Trujillo-Moya & Gisbert, 2012)
Amornputti, Ketsa, and Doorn (2016) reported that 1-MCP inhibited the production of ethylene in fruit, which was correlated with the ACC content and the activity of ACC oxidase (ACO) and ACC synthase (ACS)
Treatment with 1-MCP was effective in delaying the evolution of mango postharvest ripening, including firmness, total soluble solid (TSS) and titratable acidity (TA). 1-MCP treatment inhibited the production of ethylene in fruit, which was correlated with the ACC content and the activity of ACO and ACS

Summary

Introduction

Ethylene is a gaseous plant hormone that is involved in plant growth and development, including fruit ripening, fruit abscission, leaf senescence, seed germination, and organogenesis (Bleecker & Kende, 2000; Trujillo-Moya & Gisbert, 2012) It regulates various stress responses in plants, including water deficits, mechanical wounds, and pathogen attacks (Jiang & Fu, 2000; Martínez, Gómez, & Gómez-Lim, 2001). In a two-hybrid in vitro binding experiment, the C-terminal regions of both ETR1 and ERS1 were shown to interact with the rapidly accelerated fibrosarcoma kinase-like protein known as constitutive triple response 1 (CTR1) and to negatively regulate the transduction pathway of ethylene (Kuroda, Hirose, Shiraishi, Davies, & Abe, 2004)

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