还亮草（毛茛科）不同类型花瓣身份决定的分子机制研究

In angiosperms, flowers have petals with various types. The issues of petal determination have been the main focus of botanical studies. So far, however, the molecular mechanisms that control the identity of different types of petals in a flower are still unclear. Previous studies showed that APETALA3-3 (AP3-3) gene is the key regulator of specifying the petal identity in the buttercup family (Ranunculaceae), which can explain the mechanisms underlyging the petal identity in most species with actinomorphic flowers. However, the tribe Delphineae with zygomorphous flowers consists of several types of petals in a flower, and the constitution of petals differs between genera, indicating a complex mechanism underlying the identity determination of different types of petals. Therefore, we speculate that the AP3-3 and the genes promoting floral zygomorphy, coordinately contribute to the identity of different types of petals in Delphineae. Based on previous work, in this project, Delphinium anthriscifolium was selected as materials, we will, first, reveal the basic characteristics of the petal developmental process by morphological studies; second, uncover the expression patterns of AP3-3 and the floral zygomorphy identity genes by expression analyses; three, elucidate the functional properties of these genes in promotion of different types of petals. This study will provide new insights into the mechanisms for the determination of different types of petals in Ranunculaceae or even the angiosperms.

被子植物花瓣的类型丰富，关于花瓣身份决定的问题是植物学研究的重要内容。然而，决定一朵花中不同类型花瓣身份的分子机制尚不清楚。我们前期研究发现，毛茛科APETALA3-3（AP3-3）基因是决定该科植物花瓣身份的关键，可解释绝大多数具辐射对称花的花瓣身份决定机制。但在两侧对称花的翠雀族中，一朵花中花瓣的类型多种，且不同属花瓣的构成不同，表明决定该族不同类型花瓣身份的机制复杂。我们推测除AP3-3以外，决定花两侧对称性的调控基因可能也参与其中。本项目拟在已有基础上，以还亮草（Delphinium anthriscifolium）为材料，通过形态学研究揭示不同类型花瓣的发育过程和规律；通过基因表达研究揭示AP3-3和两侧对称决定基因在花中的表达式样；通过功能研究揭示这些基因在不同类型花瓣身份决定中的功能特征。本项目将为认识毛茛科乃至被子植物花瓣类型多样化的遗传基础和适应性意义提供新的思路和见解。

被子植物花瓣的类型丰富，关于花瓣身份决定的问题是植物学研究的重要内容。然而，决定一朵花中不同类型花瓣身份的分子机制尚不清楚。前期研究发现，毛茛科APETALA3-3（AP3-3）基因是决定该科植物花瓣身份的关键，可解释绝大多数具辐射对称花的花瓣身份决定机制。但在两侧对称花的翠雀族中，一朵花中花瓣的类型多种，且不同属花瓣的构成不同，表明决定该族不同类型花瓣身份的机制复杂。我们推测除AP3-3以外，决定花两侧对称性的调控基因可能也参与其中。本项目以还亮草（Delphinium anthriscifolium）为材料：1）通过模式标本考证、居群调查和主成分分析、染色体核型比较和系统发育重建等研究，澄清了还亮草、卵瓣还亮草和大花还亮草三者的分类学问题和系统发育关系；2）采用体视显微镜和扫描电子显微镜，对还亮草花芽及其器官发生和发育过程进行了观察，揭示了还亮草花器官的发生和法律规律，重点阐明了2个带距花瓣、2个扁平花瓣和4个退化花瓣的发育过程和命运；3）利用PacBio Sequel测序平台完成了还亮草全长转录组测序，获得高质量去冗余后的基因96954个，预测到的CDS区95666个，SSR位点48024个，转录因子（TF）3360个。目前，本项目为第一资助或第二资助项目发表的SCI学术论文有3篇，正在评审或撰写的论文有4篇，基本完成项目所规定的考核任务。