Roles of SlETR7, a newly discovered ethylene receptor, in tomato plant and fruit development
Résumé
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 functionalredundancy between the receptor isoforms. Here, we characterize a new ETR, SlETR7, that was revealed by tomatogenome sequencing.SlETR7expression in tomato fruit pericarp increases when the fruit ripens and its expression issynchronized with the expression ofSlETR1,SlETR2, andSlETR5which occurs later in the ripening phase than theincrease observed forSlETR3,SlETR4, andSlETR6. We uncovered an error in theSlETR7sequence as documented in theITAG 3 versions of the tomato genome which has now been corrected in ITAG 4, and we showed that it belongs tosub-family II. We also showed that SlETR7 specifically binds ethylene. Overexpression (OE) ofSlETR7resulted in earlierflowering, shorter plants, and smaller fruit than wild type. Knock-out (KO) mutants ofSlETR7produced more ethyleneat breaker (Br) and Br+2 days stages compared to wild type (WT), but there were no other obvious changes in theplant and fruit in these mutant lines. We observed that expression of the otherSlETRsis upregulated in fruit ofSlETR7KO mutants, which may explain the absence of obvious ripening phenotypes. Globally, these results show that SlETR7is a functional ethylene receptor. More work is needed to better understand its specific roles related to the six othertomato ETRs
Domaines
Biologie végétale
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