基于多位点序列分析的与阿曼猪屎豆丛枝病相关的新植原体 16SrII-W 亚组的分类。

Classification of a new phytoplasmas subgroup 16SrII-W associated with Crotalaria witches' broom diseases in Oman based on multigene sequence analysis.

机构信息

Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al Khod 123, PO Box 34, Seeb, Oman.

Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.

出版信息

BMC Microbiol. 2017 Nov 25;17(1):221. doi: 10.1186/s12866-017-1130-3.

DOI:10.1186/s12866-017-1130-3

PMID:29178845

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5702145/

Abstract

BACKGROUND

Crotalaria aegyptiaca, a low shrub is commonly observed in the sandy soils of wadis desert and is found throughout all regions in Oman. A survey for phytoplasma diseases was conducted. During a survey in a wild area in the northern regions of Oman in 2015, typical symptoms of phytoplasma infection were observed on C. aegyptiaca plants. The infected plants showed an excessive proliferation of their shoots and small leaves.

RESULTS

The presence of phytoplasma in the phloem tissue of symptomatic C. aegyptiaca leaf samples was confirmed by using Transmission Electron Microscopy (TEM). In addition the extracted DNA from symptomatic C. aegyptiaca leaf samples and Orosius sp. leafhoppers were tested by PCR using phytoplasma specific primers for the 16S rDNA, secA, tuf and imp, and SAP11 genes. The PCR amplifications from all samples yielded the expected products, but not from asymptomatic plant samples. Sequence similarity and phylogenetic tree analyses of four genes (16S rDNA, secA, tuf and imp) showed that Crotalaria witches' broom phytoplasmas from Oman is placed with the clade of Peanut WB (16SrII) close to Fava bean phyllody (16SrII-C), Cotton phyllody and phytoplasmas (16SrII-F), and Candidatus Phytoplasma aurantifolia' (16SrII-B). However, the Crotalaria's phytoplasma was in a separate sub-clade from all the other phytoplasmas belonging to Peanut WB group. The combination of specific primers for the SAP11 gene of 16SrII-A, -B, and -D subgroup pytoplasmas were tested against Crotalaria witches' broom phytoplasmas and no PCR product was amplified, which suggests that the SAP11 of Crotalaria phytoplasma is different from the SAP11 of the other phytoplasmas.

CONCLUSION

We propose to assign the Crotalaria witches' broom from Oman in a new lineage 16SrII-W subgroup depending on the sequences analysis of 16S rRNA, secA, imp, tuf, and SAP11 genes. To our knowledge, this is the first report of phytoplasmas of the 16SrII group infecting C. aegyptiaca worldwide.

摘要

背景

在沙漠的沙质土壤中，经常可以看到矮灌木田菁，它在阿曼的所有地区都有发现。进行了植原体病的调查。2015 年，在阿曼北部地区的一个野生地区进行了调查，在田菁植物上观察到了植原体感染的典型症状。受感染的植物表现出过度的芽和小叶增殖。

结果

利用透射电子显微镜（TEM）确认了在症状性田菁叶样本的韧皮部组织中存在植原体。此外，从症状性田菁叶样本和 Orosius sp.叶蝉中提取的 DNA 用植原体特异性引物对 16S rDNA、secA、tuf 和 imp 以及 SAP11 基因进行 PCR 检测。所有样本的 PCR 扩增均产生预期产物，但无症状植物样本则没有。四个基因（16S rDNA、secA、tuf 和 imp）的序列相似性和系统发育树分析表明，来自阿曼的田菁扫帚植原体与花生 WB（16SrII）分支密切相关，接近羽扇豆卷叶病（16SrII-C）、棉花卷叶病和植原体（16SrII-F）以及“Candidatus Phytoplasma aurantifolia”（16SrII-B）。然而，田菁的植原体与属于花生 WB 组的所有其他植原体在一个单独的亚群中。针对 16SrII-A、-B 和 -D 亚组 pytoplasmas 的 SAP11 基因的特异性引物组合对田菁扫帚植原体进行了检测，没有扩增出 PCR 产物，这表明田菁植原体的 SAP11 与其他植原体的 SAP11 不同。