大别山五针松根际微生物和内生菌群落特征及功能多样性

Community characteristics and functional diversity of the rhizosphere microbiota and endophyte from Pinus dabeshanensis

关键词:  大别山五针松，根际微生物，内生菌，高通量测序，多样性

Key words:  Pinus dabeshanensis, rhizosphere microbiota, endophytes, high-throughput sequencing, diversity

摘要:

为了探明大别山五针松根际微生物和内生菌群落特征及功能多样性，该研究以大别山五针松根际土壤和根部组织为研究对象，利用高通量测序技术分析根际微生物和根部内生菌群落特征，并利用PICRUSt和FUNGuild软件分别对细菌群落和真菌群落进行功能预测。结果表明：(1)根际微生物总操作分类单元(OTUs)数目和α多样性指数均明显大于根部内生菌。(2)根际微生物主要由厚壁菌门(如李斯特氏菌属)、变形菌门(如醋杆菌属)、子囊菌门(如镰刀菌属和毛壳属)等菌群构成，而根部内生菌则以厚壁菌门(如乳杆菌属和芽孢菌属)、子囊菌门(如枝孢菌属)、担子菌门(如须腹菌属和针菌属)菌群为主。(3)功能预测结果显示，根际细菌群落在细胞运动性、环境适应性、氨基酸代谢等功能方面较为突出，而根部内生细菌功能主要体现在酶家族、消化系统、能量代谢等方面；根际真菌群落和根部内生真菌均含有共生营养型、腐生营养型、病理营养型、及多种交叉营养型的真菌类群且外生菌根更多富集在根部组织中。该研究阐明，大别山五针松根际微生物与根部内生菌在菌群丰富度、群落结构组成及功能多样性上均存在差异。研究结果为认识大别山五针松根际微生物和内生菌的结构与功能提供了依据，也为后期开发促进大别山五针松生长、防治其病害的菌剂提供了一定的理论基础。

Abstract:

Pinus dabeshanensis is an endangered plant. In order to explore the community characteristics and functional diversity of plant-associated microbes, the compositions of rhizosphere microbiota and root endophyte from P. dabeshanensis were analyzed based on the high-throughput sequencing technology. Then the functions of bacterial and fungal communities were predicted by using PICRUSt and FUNGuild software, respectively. The results were as follows: (1) The rhizosphere soil samples exhibited higher operational taxonomic units (OTUs) and α-diversity indices relative to those of the root endosphere. (2) Rhizosphere microbiota were mainly composed of Firmicutes (genus: Listeria), Proteobacteria (genus: Acetobacter), Ascomycetes (genus: Fusarium and Chaetomium), while root endophyte were mainly composed of Firmicutes (genus: Lactobacillus and Bacillus), Ascomycetes (genus: Cladosporium), and Basidiomycetes (genus: Pleurotus and Chaetomium). (3) The functional annotation results showed that the rhizosphere microbiota community was prominent in cell mobility, environmental adaptability, and amino acid metabolism, etc., while the root endosphere bacterial community was prominent in enzyme family, digestive system, and energy metabolism, etc. Both rhizosphere fungal community and root endophytes contain symbiotic, saprophytic, pathophytic and cross-trophic fungal groups, and ectomycorrhiza are more abundant in root tissue. Collectively, there were differences in flora richness, community structure and functional diversity between rhizosphere microbiota and root endophyte of P. dabeshanensis. The study contributed to knowledge of the structure and function of rhizosphere microbiota and endophytes of P. dabeshanensis, and it provided a theoretical basis for the later development of potential microbial agents for use in promoting plant growth and controlling plant diseases.