Two androecious mutations reveal the crucial role of ethylene receptors in the initiation of female flower development inCucurbita pepo
Two androecious mutations reveal the crucial role of ethylene receptors in the initiation of female flower development inCucurbita pepo
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DOI：
10.1111/tpj.14846
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发表时间：
2020-07-27
期刊：
影响因子：
7.2
通讯作者：
Jamilena, Manuel
中科院分区：
文献类型：
--
作者：
Garcia, Alicia;Aguado, Encarnacion;Jamilena, Manuel
在葫芦科雌雄同株物种中，乙烯是性别决定的关键调节因子。这种激素决定了哪些个体的花分生组织发育为雌花或雄花，以及雌花的开花过渡。到目前为止，发现的性别决定基因编码了乙烯生物合成酶，但人们对乙烯信号成分的重要性知之甚少。在这篇文章中，我们鉴定了两个新的乙烯不敏感突变(etr1a-1和detr1b)，它们阻止了西葫芦的雌花转换，使植物无限期地产生雄花(雄花)。通过全基因组测序，发现乙烯受体CpETR1A或CpETR1B的乙烯结合区的两个错义突变是导致这些表型突变的原因。四个突变的单突变和双突变的不同表型表明，乙烯不敏感的最终水平取决于至少三个协同ETR基因的突变等位基因的强度和剂量，而乙烯不敏感的水平决定了植物最终的性别表型。雌雄同株的性别表型从对乙烯敏感的野生型植物中的雌雄同株到最强的乙烯不敏感植物中的雄蕊同株，到部分乙烯不敏感植物中的雄蕊雌雄同株。雌花转换的诱导与CpACS11、CpACO2和CpACS27这三个雌花发育所需的乙烯生物合成基因的上调有关。这里提出了一个模型，将乙烯生物合成和受体基因整合到调节性别决定的遗传网络中。佩波。
Ethylene is the key regulator of sex determination in monoecious species of the family Cucurbitaceae. This hormone determines which individual floral meristems develop as female or male flowers and the female flowering transition. The sex determination genes discovered so far code for ethylene biosynthesis enzymes, but little is known about the importance of ethylene signaling components. In this paper we characterize two novel ethylene-insensitive mutations (etr1a-1andetr1b) which block the female flowering transition ofCucurbita pepo; this makes plants produce male flowers indefinitely (androecy). Two missense mutations in the ethylene-binding domain of the ethylene receptors CpETR1A or CpETR1B were identified as the causal mutations of these phenotypes by using whole-genome resequencing. The distinctive phenotypes of single and double mutants for fouretrmutations have demonstrated that the final level of ethylene insensitivity depends upon the strength and dosage of mutant alleles for at least three cooperatingETRgenes, and that the level of ethylene insensitivity determines the final sex phenotype of the plant. The sex phenotype ranges from monoecy in ethylene-sensitive wild-type plants to androecy in the strongest ethylene-insensitive ones, via andromonoecy in partially ethylene-insensitive plants. The induction of female flowering transition was found to be associated with upregulation ofCpACS11,CpACO2andCpACS27, three ethylene biosynthesis genes required for female flower development. A model is proposed herein, integrating both ethylene biosynthesis and receptor genes into the genetic network which regulates sex determination inC. pepo.