Cebrián Gustavo, Iglesias-Moya Jessica, Romero Jonathan, Martínez Cecilia, Garrido Dolores, Jamilena Manuel
Department of Biology and Geology, Agrifood Campus of International Excellence and Research Centre CIAMBITAL, University of Almería, Almería, Spain.
Department of Plant Physiology, University of Granada, Granada, Spain.
Front Plant Sci. 2022 Jan 24;12:817922. doi: 10.3389/fpls.2021.817922. eCollection 2021.
A methanesulfonate-generated mutant has been identified in that alters sex determination. The mutation converts female into hermaphrodite flowers and disrupts the growth rate and maturation of petals and carpels, delaying female flower opening, and promoting the growth rate of ovaries and the parthenocarpic development of the fruit. Whole-genome resequencing allowed identification of the causal mutation of the phenotypes as a missense mutation in the coding region of , which encodes for a type I ACO enzyme that shares a high identity with CsACO3 and CmACO1. The so-called reduced ACO1 activity and ethylene production in the different organs where the gene is expressed, and reduced ethylene sensitivity in flowers. Other sex-determining genes, such as , , and , were differentially expressed in the mutant, indicating that ethylene provided by CpACO1A but also the transcriptional regulation of , , , and are responsible for determining the fate of the floral meristem toward a female flower, promoting the development of carpels and arresting the development of stamens. The positive regulation of ethylene on petal maturation and flower opening can be mediated by inducing the biosynthesis of JA, while its negative control on ovary growth and fruit set could be mediated by its repressive effect on IAA biosynthesis.
已在[具体植物]中鉴定出一种由甲磺酸盐产生的突变体，该突变体改变了性别决定。该突变将雌花转变为两性花，并扰乱花瓣和心皮的生长速率与成熟过程，延迟雌花开放，促进子房生长速率以及果实的单性结实发育。全基因组重测序使得能够鉴定出导致这些表型的突变是[具体基因]编码区的一个错义突变，该基因编码一种I型ACO酶，与CsACO3和CmACO1具有高度同源性。所谓的[具体基因]在其表达的不同器官中ACO1活性和乙烯产生降低，并且花中乙烯敏感性降低。其他性别决定基因，如[具体基因1]、[具体基因2]和[具体基因3]，在突变体中差异表达，表明CpACO1A提供的乙烯以及[具体基因1]、[具体基因2]、[具体基因3]和[具体基因4]的转录调控负责决定花分生组织向雌花的命运，促进心皮发育并阻止雄蕊发育。乙烯对花瓣成熟和花朵开放的正向调控可通过诱导茉莉酸生物合成来介导，而其对子房生长和坐果的负向控制可能通过其对生长素生物合成的抑制作用来介导。
