Community Composition and Metabolic Potential of Endophytic Actinobacteria From Coastal Salt Marsh Plants in Jiangsu, China
Community Composition and Metabolic Potential of Endophytic Actinobacteria From Coastal Salt Marsh Plants in Jiangsu, China
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DOI：
10.3389/fmicb.2019.01063
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发表时间：
2019-05-14
影响因子：
5.2
通讯作者：
Qin, Sheng
中科院分区：
文献类型：
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作者：
Chen, Pan;Zhang, Chunmei;Qin, Sheng
植物内生放线菌在独特生境中的多样性和功能作用仍然知之甚少。本文采用培养和基于16 S rRNA基因的高通量测序（HTS）方法，对江苏沿海盐沼植物内生放线菌的系统发育多样性和群落组成进行了研究。此外，我们通过基因筛选来评估分离物的抗真菌、纤溶活性和次级代谢产物的生物合成潜力。从19份植物样品中分离到278株放线菌。16 S rRNA基因测序结果显示，分离株是高度多样性的，属于放线菌目内的23个属，链霉菌属，多孢链霉菌属和假诺卡氏菌属组成的最丰富的属。此外，超过10个菌株是新的放线菌类群分布在8个属。对7个代表性植物根样的HTS分析表明，放线菌门占根内生细菌群落的0.04-28.66%。共检测到4个放线菌纲，14个目，35个科，63个已知属，通过HTS，这些社区被发现占主导地位的放线菌目的成员，包括属链霉菌，分枝杆菌，节杆菌，Nocardioides，和小单孢菌。此外，30.4%的代表菌株具有抗真菌活性，40.5%的代表菌株具有纤溶活性，43.0%的代表菌株具有次生代谢产物合成基因。这些结果表明，沿海盐沼植物在江苏省代表了一个未充分开发的新水库的多样性和新型内生放线菌，可能是潜在的兴趣，在发现具有潜在的生物活性化合物作为生物控制剂和纤溶酶的生产。
The diversity and functional roles of the plant associated endophytic actinobacteria in unique habitats remain poorly understood. In this paper, we examined the phylogenetic diversity and community composition of endophytic actinobacteria associated with native coastal salt marsh plants in Jiangsu, China using a combination of cultivation and 16S rRNA gene-based high-throughput sequencing (HTS) methods. Further, we evaluated the antifungal, fibrinolytic activities and the secondary metabolite biosynthesis potential of isolates via gene screening. A total of 278 actinobacterial isolates were isolated from 19 plant samples. 16S rRNA gene sequencing revealed that the isolates were highly diverse and belonged to 23 genera within the Actinomycetales order, with Streptomyces, Saccharopolyspora, and Pseudonocardia comprising the most abundant genera. In addition, more than 10 of the isolates were novel actinobacterial taxa distributed across eight genera. HTS analyses of seven representative plant root samples revealed that Actinobacteria phylum constituted 0.04-28.66% of root endophytic bacterial communities. A total of four actinobacterial classes, 14 orders, 35 families, and 63 known genera were detected via HTS, and these communities were found to be dominated by the members of the order Actinomycetales including the genera Streptomyces, Mycobacterium, Arthrobacter, Nocardioides, and Micromonospora. In addition, 30.4% of the representative isolates exhibited antifungal activities, 40.5% of them showed fibrinolytic activities, while 43.0% of the strains harbored secondary metabolite biosynthesis genes. These results demonstrated that coastal salt marsh plants in the Jiangsu Province represented an underexplored new reservoir of diverse and novel endophytic actinobacteria that may be of potential interest in the discovery of bioactive compounds with potential as biocontrol agents and for fibrinolytic enzyme production.