Zeng Lingtian, Zhang Jiao, Wang Xuan, Liu Zhixiong
College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China.
Plants (Basel). 2021 Aug 10;10(8):1644. doi: 10.3390/plants10081644.
Common buckwheat () produces distylous flowers with undifferentiated petaloid tepals, which makes it obviously different from flowers of model species. In model species , () is expressed in petal and stamen and specifies petal and stamen identities during flower development. Combining with our previous studies, we found that small-scale gene duplication (GD) event and alternative splicing (AS) of common buckwheat orthologs resulted in , and . and were mainly expressed in the stamen of thrum and pin flower. Promoters functional analysis suggested that intense GUS staining was observed in the whole stamen in transgenic , while intense GUS staining was observed only in the filament of stamen in transgenic These suggested that and had overlapping functions in specifying stamen filament identity and work together to determine normal stamen development. Additionally, and owned the similar ability to rescue stamen development of mutant, although AS resulted in a frameshift mutation and consequent omission of the complete PI-derived motif and euAP3 motif of . These suggested that the MIK region of -like proteins was crucial for determining stamen identity, while the function of -like proteins in specifying petal identity was gradually obtained after Orthologs acquiring a novel C-terminal euAP3 motif during the evolution of core eudicots. Our results also provide a clue to understanding the early evolution of the functional specificity of euAP3-type proteins involving in floral organ development in core eudicots, and also suggested that holds the potential application for biotechnical engineering to develop a sterile male line of
普通荞麦（）产生具有未分化花瓣状花被片的二型花，这使其明显不同于模式物种的花。在模式物种中，（）在花瓣和雄蕊中表达，并在花发育过程中确定花瓣和雄蕊的身份。结合我们之前的研究，我们发现普通荞麦直系同源基因的小规模基因复制（GD）事件和可变剪接（AS）导致了、和。和主要在针式花和线式花的雄蕊中表达。启动子功能分析表明，在转基因的整个雄蕊中观察到强烈的GUS染色，而在转基因的中仅在雄蕊的花丝中观察到强烈的GUS染色。这些表明和在确定雄蕊花丝身份方面具有重叠功能，并共同作用以确定正常的雄蕊发育。此外，和具有类似的拯救突变体雄蕊发育的能力，尽管AS导致了移码突变并因此缺失了完整的PI衍生基序和的euAP3基序。这些表明类蛋白的MIK区域对于确定雄蕊身份至关重要，而类蛋白在确定花瓣身份方面的功能是在核心真双子叶植物进化过程中直系同源基因获得新的C末端euAP3基序后逐渐获得的。我们的结果还为理解参与核心真双子叶植物花器官发育的euAP3型蛋白功能特异性的早期进化提供了线索，并且还表明在生物技术工程中具有开发不育雄性系的潜在应用
