灯盏花内生真菌多样性、群落结构及生态功能预测

Diversity, community structure, and ecological roles of endophytic fungi in Erigeron breviscapus

摘要:

【背景】灯盏花(Erigeron breviscapus)是国内知名的传统中药材，但关于灯盏花内生真菌多样性、群落结构和生态功能研究报道比较缺乏。【目的】探究灯盏花不同药用部位内生真菌多样性、群落结构组成及生态功能。【方法】采用ITS序列的高通量测序技术对比研究云南道地药材灯盏花根、茎、叶和花的内生菌群落结构及生物多样性差异，并利用FUNGuild数据库预测真菌群落生态功能。【结果】12个样品共获得540个操作分类单元(operational taxonomic unit, OTU)，分属于5个门22个纲55个目114个科188个属。4个不同药用部位共有的OTU数目仅占14.45%，以根部独有OTU最多。各组织均以子囊菌门和担子菌门为优势菌门；其中，根部以子囊菌门为主，花部位以担子菌门为主。亚隔孢壳属(Didymella)为灯盏花植物的核心属，在各组织中均有分布；其余优势属尚有线黑粉菌属(Filobasidium)、Cystofilobasidium、织球壳属(Plectosphaerella)，灯盏花4个组织中优势属和特有属分布各不相同。α多样性分析表明，根部内生真菌丰度显著高于其他组织，但多样性方面组织差异不明显。PCoA结果表明，根部菌落结构相对独立，而叶与茎中菌落结构较为相似。利用FUNGuild数据库分析发现，腐生真菌在各组织中占比较高，并含有大量未知功能菌群。【结论】灯盏花不同药用部位内生真菌群落组成存在明显差异，具有组织偏好。以上研究完善了灯盏花内生真菌资源的生物信息，为灯盏花内生真菌资源的开发利用提供了理论依据。

关键词:灯盏花;内生真菌;多样性;生态功能;高通量测序

Abstract:

[Background] Erigeron breviscapus is a famous Chinese medicinal plant, while little is known about the diversity, community structure, and ecological roles of endophytic fungi (EF) in this plant. [Objective] To reveal the diversity, community structure, and ecological roles of EF in E. breviscapus. [Methods] The high-throughput sequencing of the ITS region was performed to profile the fungal community in the roots, stems, leaves, and flowers of E. breviscapus in Yunnan. FUNGuild was employed to predict the ecological functions of the fungi. [Results] A total of 540 operational taxonomic units (OTUs) were obtained from 12 samples. All of the OTUs were assigned into 188 genera, 114 families, 55 orders, 22 classes of 5 phyla. Only 14.45% of OTUs were shared by the four medicinal parts, and the unique OTUs were the most in the roots. Ascomycota and Basidiomycota were the dominant phyla in all the samples. The EF in the roots and flowers were dominated by Ascomycota and Basidiomycota, respectively. Didymella was the dominant genus, existing in all the four organs. Other dominant genera were Filobasidium, Cystofilobasidium and Plectosphaerella. The dominant and unique genera of EF varied in the four organs of E. breviscapus. The alpha diversity analysis showed that the roots had the highest richness of EF, while there was no significant difference in the diversity of EF among the four organs. Principal coordinate analysis indicated that the EF had similar community structures between leaves and stems, while the composition of EF in roots was different. FUNGuild prediction revealed that saprophytic fungi accounted for a high proportion in the EF of different samples and contained a large number of undefined taxa. [Conclusion] The EF of E. breviscapus has significant differences in community structure among different organs and demonstrates organ specificity. The findings provide a theoretical reference for the further development and utilization of EF resources in E. breviscapus.

Key words:Erigeron breviscapus;endophytic fungi;species diversity;ecological role;high-throughput sequencing