Institute of Ecology and Geobotany, Yunnan University, Kunming, Yunnan, China.
CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China.
Genomics. 2021 Mar;113(2):447-455. doi: 10.1016/j.ygeno.2020.12.031. Epub 2020 Dec 25.
A plant parasite obligately parasitizing another plant parasite is referred to as epiparasite, which is extremely rare in angiosperms, and their complete plastome sequences have not been characterized to date. In this study, the complete plastomes of two flowering epiparasites: Phacellaria compressa and P. glomerata (Amphorogynaceae, Santalales) were sequenced. The plastomes of both species are of similar size, structure, gene content, and arrangement of genes to other hemiparasites in Santalales. Their plastomes were characterized by the functional loss of plastid-encoded NAD(P)H-dehydrogenase and infA genes, which strongly coincides with the general pattern of plastome degradation observed in Santalales hemiparasites. Our study demonstrates that the relatively higher level of nutritional reliance on the host plants and the reduced vegetative bodies of P. compressa and P. glomerata do not appear to cause any unique plastome degradation compared with their closely related hemiparasites.
一种专性寄生在另一种植物寄生物上的植物寄生虫被称为外寄生植物，这在被子植物中极为罕见，其完整的质体基因组序列迄今尚未得到描述。在这项研究中，两种开花外寄生植物：扁枝金粟兰（金粟兰科，檀香目）和球花金粟兰（金粟兰科，檀香目）的完整质体基因组序列被测序。这两个物种的质体基因组大小、结构、基因含量和基因排列与檀香目半寄生植物相似。它们的质体基因组的特征是质体编码的 NAD(P)H 脱氢酶和 infA 基因的功能丧失，这与檀香目半寄生植物中观察到的质体降解的一般模式强烈吻合。我们的研究表明，扁枝金粟兰和球花金粟兰对宿主植物较高的营养依赖性和简化的营养体，似乎并没有导致它们与亲缘关系密切的半寄生植物相比产生任何独特的质体降解。
