探讨樟科寄生植物无根藤与不同寄主植物之间的水平基因转移

Horizontal gene transfer (HGT) is crucial to the evolution of life and speciation. HGT between parasitic plants and their host plants accounts for a large proportion of the identified cases. However, despite rapid progress in this field, much has remained unknown, such as whether other parasitic plants other than those reported cases could lead to HGT and whether HGT varies according to different hosts of a parasitic plant. The project aims to study HGT between a parasitic plant Cassytha in the family Lauraceae and its ten major host plants based on 10 mitochondrial gene segments since mitochondrial genes are most prone to HGT in plants, investigate systematically HGT from different perspectives of mitochondrial genome, chloroplastic genome and transcriptome, and verify these findings by resequencing additional PCR-amplified segments in larger population and host range. The completion of the project will contribute to our understanding of HGT between parasitic plants and host plants with Cassytha as an example, widening our knowledge in the host range and flow directions of HGT as well as the functions and numbers of genes involved in this process, and promoting our awareness and application of the importance of parasitic plants to the evolution of plants as well as the ecological system.

水平基因转移在生命起源和物种进化中扮演着重要作用。寄生植物与寄主植物之间的水平基因转移在植物界已发现的水平基因转移中占很大一部分比例。不过除了已知的这些案例，是否其他寄生植物与其寄主植物之间存在水平基因转移以及这种水平基因转移是否因寄主植物而异，目前还不清楚。本研究项目拟通过从水平基因转移发生较多的线粒体基因出发，根据10个线粒体片断的系统发育关系对樟科寄生植物无根藤与10个代表性寄主植物之间的水平基因转移情况进行研究，并从线粒体基因组、叶绿体基因组和转录组水平进行深入分析，分析结果通过PCR在更大范围进行验证。本项目的完成将有助于我们通过无根藤了解寄生植物与寄主植物之间水平基因转移的寄主范围、流动方向以及参与这一过程的基因功能和基因数目,从而更好地认识和利用寄生植物对于植物进化和生态系统的重要作用。