Abstract：
Shifts in pollinator occurrence and their pollen transport effectiveness drive the evolution of mating systems in flowering plants. Understanding the genomic basis of these changes is essential for predicting the persistence of a species under environmental changes. We investigated the genomic changes in Brassica rapa over nine generations of pollination by hoverflies associated with rapid morphological evolution toward the selfing syndrome. We combined a genotyping-by-sequencing (GBS) approach with a genome-wide association study (GWAS) to identify candidate genes, and assessed their functional role in the observed morphological changes by studying mutations of orthologous genes in the model plant Arabidopsis thaliana. We found 31 candidate genes involved in a wide range of functions from DNA/RNA binding to transport. Our functional assessment of orthologous genes in A. thaliana revealed that two of the identified genes in B. rapa are involved in regulating the size of floral organs. We found a protein kinase superfamily protein involved in petal width, an important trait in plant attractiveness to pollinators. Moreover, we found a histone lysine methyltransferase (HKMT) associated with stamen length. Altogether, our study shows that hoverfly pollination leads to rapid evolution toward the selfing syndrome mediated by polygenic changes.
摘要：
传粉媒介发生的变化及其花粉运输效率驱动了开花植物交配系统的进化。了解这些变化的基因组基础对于预测环境变化下物种的持久性至关重要。我们调查了9代气蝇授粉过程中芸苔属的基因组变化，这些变化与向自交综合征的快速形态进化有关。我们将基因分型测序（GBS）方法与全基因组关联研究（GWAS）相结合，以鉴定候选基因。并通过研究模型植物拟南芥中直系同源基因的突变来评估它们在观察到的形态变化中的功能作用。我们发现31个候选基因涉及从DNA/RNA结合到转运的广泛功能。我们对拟南芥直向同源基因的功能评估表明，在拟南芥中鉴定出的两个基因参与调节花器官的大小。我们发现了一个与花瓣宽度有关的蛋白激酶超家族蛋白，植物对传粉者吸引力的重要特征。此外，我们发现了与雄蕊长度相关的组蛋白赖氨酸甲基转移酶（HKMT）。总之,我们的研究表明，hoverfly授粉导致由多基因变化介导的自交综合征的快速进化。
