Abstract：
The fleshy fruit of tomato (Solanum lycopersicum) are climacteric and, as such, ethylene plays a pivotal role in their ripening and quality traits. In this study, a basic helix-loop-helix transcription factor, EMB1444-like, was found to induce the expression of YELLOW-FRUITED TOMATO 1 (YFT1), which encodes the SlEIN2 protein, a key element in the ethylene signaling pathway. Yeast one-hybrid and EMSA analyses revealed that EMB1444-like binds to the E-box motif (CACTTG, -1295 bp to -1290 bp upstream of the ATG start codon) of the YFT1 promoter (pYFT1). Suppression of EMB1444-like expression in tomato lines (sledl) using RNAi reduced ethylene production by lowering the expression of 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 2/4 (ACS2/4) and ACC OXIDASE1 (ACO1) in a positive feedback loop. sledl tomato also showed differences in numerous quality traits related to fruit ripening, compared with the wild type, such as delayed chromoplast differentiation, a decrease in carotenoid accumulation, and delayed fruit ripening in an ethylene-independent manner, or at least upstream of ripening mediated by YFT1/SlEIN2. This study elucidates the regulatory framework of fruit ripening in tomato, providing information that may be used to breed tomato hybrid cultivars with an optimal balance of shelf-life, durability, and high quality.
摘要：
番茄的肉质果实（Solanumlycopersicum）是更年期的，因此，乙烯在其成熟和品质性状中起着举足轻重的作用。在这项研究中,一个基本的螺旋-环-螺旋转录因子，EMB1444-like,发现诱导黄花果番茄1（YFT1）的表达，它编码SlEIN2蛋白，乙烯信号通路中的一个关键因素.酵母单杂交和EMSA分析显示EMB1444样与E盒基序结合(CACTTG，在YFT1启动子（pYFT1）的ATG起始密码子上游-1295bp至-1290bp。使用RNAi抑制番茄品系（sledl）中的EMB1444样表达通过降低1-氨基环丙烷-1-羧酸合酶2/4（ACS2/4）和ACC氧化酶1（ACO1）的表达来减少乙烯的产生。正反馈回路。sledl番茄也显示出与果实成熟相关的许多品质性状的差异，与野生型相比，如延迟的染色体分化，类胡萝卜素积累的减少，以不依赖乙烯的方式延迟果实成熟，或至少在YFT1/SlEIN2介导的成熟上游。本研究阐明了番茄果实成熟的调控框架，提供可用于培育具有最佳保质期平衡的番茄杂交品种的信息，耐用性,和高质量。
