Understanding the molecular function of individual causal loci at the heterostyly supergene in Primula

了解报春花杂柱超基因单个因果位点的分子功能

• 批准号: 408296963
• 负责人: Professor Dr. Michael Lenhard
• 金额: --
• 依托单位: Institut für Biochemie und Biologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408296963?language=en
• 关键词: Understanding; molecular; function; individual; causal

Heterostyly is a fascinating adaptation to promote outbreeding and a classical paradigm of botany. In the most common type of heterostyly, plants either form flowers with long styles and short stamens, or short styles and long stamens. This reciprocal organ positioning reduces pollen wastage and promotes cross-pollination, thus increasing male fitness. In addition, in many heterostylous species selfing and the generation of unfit progeny due to inbreeding depression is limited by a self-incompatibility system, thus promoting female fitness. In primroses (Primula) the two floral forms are genetically determined by the S-locus as a complex supergene, i.e. a chromosomal region containing several individual genes that control the different traits, such as style or stamen length, and are held together by very tight linkage due to suppressed recombination. Over the last years, we have identified and begun to functionally characterize the individual causal loci at the S-locus supergene in Primula, with a particular focus on the female traits of style length and female self-incompatibility type regulated by CYP734A50, and on the control of anther position by GLO2. More recently, we have also obtained evidence that the hitherto poorly understood characters of pollen size and male self-incompatiblity are controlled by an interplay between the KFB-T and PUM-T genes. These studies lay the groundwork for a more detailed mechanistic understanding of how the encoded proteins fulfil their roles in modifying the suite of heterostyly traits between the morph and how they have gained these in the course of evolution. To address these issues, we will (1) determine the structural and molecular basis for the neofunctionalization of GLO2; (2) characterize in detail the role of KFB-T and PUM-T in regulating pollen size and male self-incompatibility type; and (3) use derived homostylous Primula genotypes to elucidate the molecular basis of the female self-incompatibility reaction. Together, these studies will provide unprecedented insight into a textbook problem in plant genetics and evolution and a model for supergene evolution and function in plants and animals.

异型花柱是一种促进远系繁殖的迷人适应，也是植物学的经典范例。在最常见的异型花柱中，植物要么形成长花柱和短雄蕊的花，要么形成短花柱和长雄蕊的花。这种相互的器官定位减少了花粉浪费并促进异花授粉，从而增加了雄性的适应性。此外，在许多异型柱物种中，自交和由于近交衰退而产生的不适合后代受到自交不亲和系统的限制，从而促进雌性适合度。在报春花（Primula）中，两种花的形式由作为复杂超基因的S基因座遗传决定，S基因座即含有控制不同性状（例如花柱或雄蕊长度）的几个单独基因的染色体区域，并且由于抑制重组而通过非常紧密的连锁保持在一起。在过去的几年里，我们已经确定并开始功能上的特点，在报春花的S-位点超基因的个别因果位点，特别是专注于女性性状的花柱长度和女性自交不亲和类型的CYP 734 A50调节，和控制花药位置的GLO 2。最近，我们也获得了证据，迄今为止知之甚少的花粉大小和雄性自交不亲和性的字符之间的相互作用KFB-T和BF-T基因控制。这些研究为更详细地了解编码蛋白质如何在修改变体之间的一套异型特征中发挥作用以及它们如何在进化过程中获得这些特征奠定了基础。为了解决这些问题，我们将（1）确定GLO 2的新功能化的结构和分子基础;（2）详细描述KFB-T和KFB-T在调节花粉大小和雄性自交不亲和类型中的作用;和（3）使用衍生的同花柱报春花基因型来阐明雌性自交不亲和反应的分子基础。这些研究将为植物遗传学和进化的教科书问题提供前所未有的见解，并为植物和动物的超基因进化和功能提供模型。