Elucidating the genetic basis and molecular mechanism of dioecy in Populus

阐明杨树雌雄异株的遗传基础和分子机制

• 批准号: 406678375
• 负责人: Dr. Niels Müller
• 金额: --
• 依托单位: Institut für Forstgenetik
• 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/406678375?language=en
• 关键词: Elucidating; genetic; basis; molecular; mechanism

While most plant species are hermaphrodites, the separation of female and male flowers onto different individuals, called dioecy, has evolved independently hundreds if not thousands of times. Still, the underlying genetic basis remains mostly elusive. In the proposed project, we want to elucidate the genetic and molecular basis of dioecy in poplars to address overarching questions concerning the evolution of plant sexual systems. Despite an ancient origin of dioecy in the genus Populus, the underlying sex chromosomes appear to have diverged only recently. Different locations of the sex-determining regions (SDRs) and varying heterogametic parents (XY- vs. ZW-system) in different poplar species further indicate independent evolution. However, our preliminary analyses suggest that the observed complexity represents variations on the same theme. A shared single-gene-based mechanism, with important implications for sex chromosome evolution in general, appears to be underlying dioecy across different Populus species.In the proposed project we want to experimentally test whether (i) the SDRs of white poplar and aspen lack a region of suppressed recombination and show opposite heterogamety (XY vs. ZW), whether (ii) the poplar homolog of the ARABIDOPSIS RESPONSE REGULATOR 17 (ARR17) gene is controlling sex determination across the genus via a single-gene-based mechanism, and whether (iii) the molecular mechanisms causing differential sex manifestation are conserved between different poplar species.We will do this by (i) mapping the white poplar SDR, determining recombination frequencies along the SDRs of males and females in large F1 populations and examining reciprocal P. alba x P. tremula crosses, (ii) generating early-flowering transgenic poplar lines knocking out or complementing ARR17 expression and molecularly characterizing the ARR17 locus in different poplar species, and (iii) performing RNA-sequencing of male and female flower buds and integrating the results with other functional genomics data to identify the gene networks causing differential sex manifestation.The results will provide valuable information for breeding programs involving dioecious crop plants, and advance our understanding of the genetic, molecular and evolutionary processes shaping unisexuality and dioecy in plants.

虽然大多数植物是雌雄同体的，但雌雄异株的分离，称为雌雄异株，已经独立进化了数百次，甚至数千次。尽管如此，潜在的遗传基础在很大程度上仍然难以捉摸。在拟议的项目中，我们想要阐明杨树雌雄异株的遗传和分子基础，以解决有关植物有性系统进化的主要问题。尽管杨属雌雄异株的起源由来已久，但潜在的性染色体似乎直到最近才出现分歧。不同杨树物种的性别决定区(SDR)和不同的异交亲本(XY-VS ZW-系统)的不同位置进一步表明了独立进化。然而，我们的初步分析表明，观察到的复杂性代表了同一主题的变化。在我们提出的项目中，我们希望通过实验测试(I)白杨和杨树的SDR是否缺乏抑制重组的区域并表现出相反的异交(XY与ZW)，(Ii)杨树的拟南芥反应调节17(ARR17)基因的同源基因是否通过基于单基因的机制控制整个属的性别决定，以及(Iii)导致不同杨树品种性别差异表现的分子机制是否保守。我们将通过(I)定位白杨SDR，在大的F1群体中测定雌雄花序的重组频率，并检测白杨与白杨的正反交组合，(Ii)获得敲除或互补ARR17表达的早花转基因杨树品系，并对不同杨树物种的ARR17基因座进行分子特征分析，(Iii)对雄性和雌性花蕾进行RNA测序，并与其他功能基因组数据相结合，识别导致性别差异的基因网络。这些结果将为雌雄异株作物育种提供有价值的信息，并促进我们对植物雌雄异株和雌雄异株形成的遗传、分子和进化过程的理解。