Dissertation Research: Chloroplast Genome Evolution in a Non-photosynthetic Plant

芋螺属Conopholis属于寄生科 列当科植物 这些植物是专性寄生在 其他植物，他们从中获得所有的营养， 水 可能是这种寄生的直接结果 植物失去了光合作用的能力， 绿色：由下列物质的存在所赋予的特有的绿色颜色 叶绿素 质体（在绿色植物中 容纳光合代谢，并有自己的循环 基因组包含大约120个基因，其中包括一些 参与光合作用），仅含有基因组 绿色植物的三分之一， 重要的光合作用基因。 这是通过 几个大的DNA缺失的积累。 大量 在质体基因组中检测到的不同 Conopholis的种群表明它正在继续 以更快的速度进化。 DNA测序方法将被用来研究这些基因是如何被发现的。 发生了缺失，质体基因 没有被删除。 那些保持完整的将是 研究非光合作用功能。 的演变 质体中的无功能光合作用基因 基因组将与核中的对应物进行比较， 基因组，以找出他们是否有不同的命运作为一个 这两种细胞中发生的不同分子过程的结果 基因组

The genus Conopholis belongs to a family of parasitic plants, the Orobanchaceae. The plants are obligate parasites on other plants, from which they derive all of their nutrients and water. Possibly as a direct result of this parasitism these plants have lost the ability to photosynthesize and lack the characteristic green color conferred by the presence of chlorophyll. The plastids (the organelle which in green plants houses the photosynthetic metabolism and has its own circular genome containing about 120 genes, including some of those involved in photosynthesis) of Conopholis contain a genome only a third the size of that in green plants and have lost several important photosynthesis genes. This has occurred through the accumulation of several large deletions of DNA. The large amount of variation in the plastid genome detectable between different populations of Conopholis indicate that it is continuing to evolve at an accelerated rate. DNA sequencing methods will be used to investigate how these deletions have occurred and what has happened to plastid genes which have not been deleted. Those that remain intact will be investigated for non-photosynthetic functions. The evolution of the non-functional photosynthesis genes remaining in the plastid genome will be compared with their counterparts in the nuclear genome in order to find out if they have had different fates as a result of different molecular processes occurring in these two genomes.