Chen Yi, Hu Guojian, Rodriguez Celeste, Liu Meiying, Binder Brad M, Chervin Christian
1College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China.
Genomics and Biotechnology of Fruits, University of Toulouse, INRA, ENSAT, 31326 Castanet-Tolosan, France.
Hortic Res. 2020 Feb 1;7:17. doi: 10.1038/s41438-020-0239-y. eCollection 2020.
Ethylene regulates many aspects of plant growth and development. It is perceived by a family of ethylene receptors (ETRs) that have been well described. However, a full understanding of ETR function is complicated by functional redundancy between the receptor isoforms. Here, we characterize a new ETR, SlETR7, that was revealed by tomato genome sequencing. expression in tomato fruit pericarp increases when the fruit ripens and its expression is synchronized with the expression of , , and which occurs later in the ripening phase than the increase observed for , , and . We uncovered an error in the sequence as documented in the ITAG 3 versions of the tomato genome which has now been corrected in ITAG 4, and we showed that it belongs to sub-family II. We also showed that SlETR7 specifically binds ethylene. Overexpression (OE) of resulted in earlier flowering, shorter plants, and smaller fruit than wild type. Knock-out (KO) mutants of produced more ethylene at breaker (Br) and Br + 2 days stages compared to wild type (WT), but there were no other obvious changes in the plant and fruit in these mutant lines. We observed that expression of the other is upregulated in fruit of KO mutants, which may explain the absence of obvious ripening phenotypes. Globally, these results show that SlETR7 is a functional ethylene receptor. More work is needed to better understand its specific roles related to the six other tomato ETRs.
乙烯调节植物生长和发育的许多方面。它由一类已被充分描述的乙烯受体（ETRs）感知。然而，受体亚型之间的功能冗余使得对ETR功能的全面理解变得复杂。在这里，我们鉴定了一种新的ETR，即SlETR7，它是通过番茄基因组测序发现的。番茄果实果皮中的表达在果实成熟时增加，并且其表达与、和的表达同步，这些基因在成熟阶段的表达比、和观察到的增加发生得晚。我们发现了番茄基因组ITAG 3版本中记录的序列错误，该错误现已在ITAG 4中得到纠正，并且我们表明它属于II亚家族。我们还表明SlETR7特异性结合乙烯。与野生型相比，的过表达（OE）导致开花提前、植株更矮和果实更小。与野生型（WT）相比，的敲除（KO）突变体在破色期（Br）和Br + 2天阶段产生更多乙烯，但这些突变系的植株和果实没有其他明显变化。我们观察到在KO突变体的果实中其他的表达上调，这可能解释了没有明显成熟表型的原因。总体而言，这些结果表明SlETR7是一种功能性乙烯受体。需要更多的工作来更好地理解其与其他六种番茄ETR相关的具体作用。
