转座子微进化与基因组结构变异对莲两生态型适应性作用机制研究

转座子作为植物基因组主要成分，对表观遗传修饰和基因表达调控有重要作用，其转座会引起染色体重排、存在缺失等各类结构变异，进而驱动着基因组进化。然而，我们对转座子与结构变异在植物种内自然群体适应性进化中的作用机制仍知之甚少。水生经济植物莲具两生态型（热带莲和温度莲），低纬度分布的热带莲地下茎不膨大且花期长，而高纬度温带莲地下茎膨大、花期短，莲两生态型是研究植物种内群体适应性进化的极好材料。本项目拟选取热带莲和温带莲自然群体植物材料，通过从头组装与构建莲的泛基因组以探寻转座子和结构变异在莲自然群体中的进化式样，并与地理气候因子的关联分析挖掘响应气候变化的转座子与结构变异；结合分析莲两生态型地下茎表型与花期分化相关新的和前期积累的表达、甲基化等多组学数据，从多维度揭示转座子转座与结构变异在莲适应性相关表型分化中的具体作用机制。本项目将为理解植物适应性进化机制提供新的视野。

As the main component of the plant genome, transposon plays an important regulatory role in epigenetic modification and gene expression. Its transposition can cause chromosomal rearrangement, presence-and-absence and other structural variations, driving the genome evolution. However, the role of transposon and structural variation in plant adaptive evolution is unclear. The economic aquatic plant, sacred lotus, has two ecotypes (temperate and tropical). The low-latitude tropical lotus has a thin rhizome and a long florescence, whereas the high-latitude temperate lotus shows an enlarged rhizome and a short florescence. Therefore, the two ecotypes of the lotus are excellent materials for studying the adaptive evolution of populations within a plant species. We choose natural populations from temperate and tropical lotus as our study materials, by de novo genome assembly and constructing a lotus pangenome we explore the evolutionary trajectories of transposons and structural variations in lotus natural populations and investigate how transposon and structural variation respond to climate change through genome-wide association study with geographic climate factors; combining the expression, methylation modification and other multiple omic results of rhizome and florescence of lotus from futural and our previous study, we attempt to reveal the key role of transposon transposition and structural variation in the adaptive differentiation of the crucial phenotypes of lotus from multiple dimensions of analyses. This study will provide a new perspective for understanding the adaptive evolutionary mechanism of plants.