不同品种桃树根部内生细菌群落结构、多样性及功能分析

Structures, diversity, and functions of endophytic bacterial communities in the roots of different peach varieties

摘要:

【背景】桃树的根部内生细菌群落具有促进植物生长和抗逆性的潜力。研究这些微生物群落的组成和功能可以进一步挖掘内生菌在桃树根部生长发育中的作用，可为后续微生物资源开发和利用提供参考。【目的】分析不同品种桃树根部的内生细菌群落的组成、多样性和功能，为进一步研究桃树与内生菌之间共生关系奠定基础。【方法】采用16S rRNA基因扩增子测序技术，并运用多种生物信息学方法进行数据分析，对北京市平谷区国桃基地7个不同品种桃树根内生细菌进行群落组成、多样性分析、LEfSe分析和PICRUSt2功能预测。【结果】发现不同品种桃树的根部内生细菌群落在红毛桃、白毛桃和黄肉桃中的组成存在显著差异。主要优势菌门为放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)，其中放线菌门在大部分样品中占优势地位。微生物群落多样性分析显示，品种间的Shannon、Simpson指数差异显著，表明不同桃品种根内生菌的多样性存在差异性，并较复杂。LEfSe分析识别了与特定品种相关的根内生菌标志物，例如双歧杆菌属(Bifidobacterium)在红毛桃和白毛桃中具有较高相对丰度。PICRUSt2功能预测表明，内生细菌生物学功能在不同红毛桃品种间差异较大，主要参与碳水化合物代谢和氨基酸代谢，展示了内生菌群对宿主植物生理功能的潜在影响。【结论】本研究揭示了不同品种桃树根部内生细菌群落的组成、多样性和功能，拓宽了对桃树内生菌的认识，为后续桃树内生细菌资源的开发利用奠定了基础。

Abstract:

[Background] Endophytic bacterial communities in the roots of peach plants have the potential to promote plant growth and enhance stress resistance. Studying the structures and functions of these microbial communities can reveal the role of endophytes in peach root growth and development. The results can serve the subsequent development and utilization of microbial resources. [Objective] To study the structures, diversity, and functions of endophytic bacterial communities in the roots of different peach varieties, laying a foundation for further research on the relationship between peach plants and endophytes. [Methods] We employed 16S rRNA gene amplicon sequencing to study the community structure and diversity of endophytic bacteria in the roots of seven different peach varieties in the National Peach Base in Pinggu District, Beijing. Furthermore, we performed linear discriminant analysis effect size (LEfSe) and used PICRUSt2 for function prediction. [Results] Significant differences existed in the structures of endophytic bacterial communities in the roots among red-skin, white-skin, and yellow-fleshed peach varieties. The dominant phyla were Actinobacteriota, Proteobacteria, and Firmicutes, with Actinobacteriota being predominant in most samples. The Shannon and Simpson indices of the bacterial communities were significantly different among the varieties, indicating the varied and complex diversity of root endophytes among different peach varieties. LEfSe identified the root endophyte biomarkers associated with peach varieties, such as Bifidobacterium, which had higher relative abundance in red-skin and white-skin peach varieties. The endophytic bacteria showcased varied biological functions among different red-skin peach varieties, mainly participating in carbohydrate and amino acid metabolism, which highlighted the potential impact of endophytic bacteria on the physiological functions of host plants. [Conclusion] This study revealed the structures, diversity, and functions of endophytic bacterial communities in the roots of different peach varieties, enriching our knowledge and laying a foundation for the development and utilization of endophytic bacterial resources in peach plants.