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Article|10 Mar 2021|OPEN
PbEIL1 acts upstream of PbCysp1 to regulate ovule senescence in seedless pear
Huibin Wan1, Haiqi Zhang1, Fangfang Liang1, Liu Cong1, Linyan Song1, Xieyu Li1, Rui Zhai1, Chengquan Yang1, Fengwang Ma1, Zhigang Wang1, & Lingfei Xu1,
1College of Horticulture, Northwest A&F University, Yangling, Shaanxi Province, China

Horticulture Research 8,
Article number: 59 (2021)
doi: 10.1038/hortres.2021.59
Views: 332

Received: 07 Oct 2020
Revised: 26 Dec 2020
Accepted: 29 Dec 2020
Published online: 10 Mar 2021

Abstract

Numerous environmental and endogenous signals control the highly orchestrated and intricate process of plant senescence. Ethylene, a well-known inducer of senescence, has long been considered a key endogenous regulator of leaf and flower senescence, but the molecular mechanism of ethylene-induced ovule senescence has not yet been elucidated. In this study, we found that blockage of fertilization caused ovule abortion in the pear cultivar ‘1913’. According to transcriptome and phytohormone content data, ethylene biosynthesis was activated by pollination. At the same time, ethylene overaccumulated in ovules, where cells were sensitive to ethylene signals in the absence of fertilization. We identified a transcription factor in the ethylene signal response, ethylene-insensitive 3-like (EIL1), as a likely participant in ovule senescence. Overexpression of PbEIL1 in tomato caused precocious onset of ovule senescence. We further found that EIL1 could directly bind to the promoter of the SENESCENCE-ASSOCIATED CYSTEINE PROTEINASE 1 (PbCysp1) gene and act upstream of senescence. Yeast one-hybrid and dual-luciferase assays revealed the interaction of the transcription factor and the promoter DNA sequence and demonstrated that PbEIL1 enhanced the action of PbCysp1. Collectively, our results provide new insights into how ethylene promotes the progression of unfertilized ovule senescence.