摘要:植物内生菌（Endophyte）在宿主植物组织中的分布规律是内生菌对外界适应的重要机制。基于Illumina MiSeq测序技术，对适应青藏高原极端环境的主要疯草植物-冰川棘豆叶和根组织中的内生菌16S rRNA、ITS rDNA进行高通量测序和生物信息学分析，通过明晰内生菌在冰川棘豆组织中的菌群结构、功能以及环境之间的关系，探讨了组织间内生菌的分布特征对冰川棘豆适应极端环境的可能影响。分析结果表明，冰川棘豆组织间共有菌属丰度占菌属总丰度90%以上，不同组织间形成了保守性内生细菌和特异性内生真菌共存的群落结构特点，植物组织结构和环境的影响可能为推动内生菌选择合适的组织生态位定植提供动力，其中土壤含水量显著影响内生细菌（R²=0.241，P=0.024）和内生真菌（R²=0.223，P=0.031）的组间Beta多样性，土壤pH值显著影响内生真菌（R²=0.571，P < 0.001）Alpha多样性丰富度指数，而环境因素对组织间存在显著差异的内生菌功能和营养型解释并不显著。综合认为，保守性与差异性的内生菌菌群结构和功能为植物不同组织适应极端环境提供帮助，这有利于冰川棘豆的生存与扩散。



Abstract:The distribution of endophyte in host plant tissue is an important mechanism of endophyte adaptation to the outside world. Based on the Illumina MiSeq sequencing technique, the endophytic 16SrRNA and ITS rDNA in the leaves and roots tissues of O. glacialis, which are the main locoweed plants adapted to the extreme environment of Qinghai-Tibet Plateau, were analyzed by high-throughput sequencing and bioinformatics analysis. By clarifying the structure and function of endophytes in O. glacialis tissue and the relationship between environment and them, the possible influence of the distribution characteristics of endophytes on the adaptation of O. glacialis to extreme environment was discussed. The results showed that the abundance of co-genera in O. glacialis tissues accounted for more than 90% of the total abundance, and the community structure characteristics of coexistence of conservative endophytic bacteria and specific endophytic fungi were formed among different tissues. The effects of plant tissue structure and environment may provide impetus for endophyte to choose appropriate tissue niche colonization, in which soil moisture content significantly affects the Beta diversity of endophytic bacteria (R²=0.241, P=0.024) and endophytic fungi (R²=0.223, P=0.031), and soil pH value mainly affects the Alpha diversity richness index of endophytic fungi (R²=0.571, P < 0.001). However, the explanation of significant differences in endophyte function and nutritional type among tissues by environmental factors is not significant. It is considered that the conservative and different endophytic community structure and function provide help for different plant tissues to adapt to the extreme environment, which is beneficial to the survival and diffusion of O. glacialis.





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