摘要：

为探究内生真菌印度梨形孢对烟草根际微环境的影响,在温室条件下开展盆栽试验,以云烟87为试验材料,通过非靶向代谢组学、土壤酶活测定、高通量测序及微生物群落功能预测,分析了印度梨形孢对其根系分泌物、根际土壤酶活性及细菌多样性的影响。结果表明,印度梨形孢成功定殖在烟草根部,增加了18种差异根系分泌物的含量,主要包括酸类、酯类、醇类、萜类和酚类化合物,显著富集了L-苯丙氨酸代谢、牛磺酸和次牛磺酸代谢及L-色氨酸代谢途径;与对照无菌水相比,印度梨形孢提高了烟草根际土壤中脲酶、蔗糖酶和碱性磷酸酶的活性,其中脲酶和蔗糖酶活性达到显著水平;与对照相比,印度梨形孢提高了烟草根际土壤细菌群落的丰富度和多样性,Chao1指数和Observed_otus指数明显升高,改变了门、属水平的细菌群落结构,提高了酸杆菌门和放线菌门优势菌门及假单胞菌属、芽单胞菌属的相对丰度,增加了根际土壤细菌碳水化合物代谢通路和翻译通路涉及的基因丰度,对细菌群落功能产生了一定影响。研究表明,印度梨形孢能够改善烟草根际微生态环境,为揭示其促进烟草生长的机制并为烟草种植生产提供理论依据。

关键词: 烟草, 印度梨形孢, 根系分泌物, 土壤酶活性, 细菌多样性

Abstract:

In order to investigate the effects of endophytic fungus Piriformospora indica on the rhizosphere microenvironment of tobacco,a pot experiment was conducted under greenhouse conditions,using Yunyan 87 as the experimental material to analyze its effects on tobacco root exudates,rhizosphere soil enzyme activities and bacterial diversity through non-targeted metabolomics,soil enzyme activity measurement,high-throughput sequencing,and microbial community functional prediction.The results showed that the P.indica successfully colonized in the roots of tobacco,increasing the content of 18 different root exudates,mainly including acids,esters,alcohols,terpenoids,and phenolic compounds,significantly enriching the metabolism pathways of L-phenylalanine,taurine and hypotaurine,and L-tryptophan.Compared to using sterile water as a control,P.indica increased the activities of urease,sucrase,and alkaline phosphatase in tobacco rhizosphere soil,with urease and sucrase activities reaching significant levels.P.indica increased the richness and diversity of bacterial communities in tobacco rhizosphere soil,with a significant increase in Chao1 index and Observed_otus index comparing with the control.This altered the bacterial community structure at the phylum and genus levels,and increased the relative abundance of dominant phyla of Acidobacteriota and Actinobacteriaota,as well as Pseudomonas and Gemmatimonas genera.It also increased the gene abundance involved in carbohydrate metabolism and translation pathways in rhizosphere soil bacteria,which had a certain impact on bacterial community function.It indicates that P.indica could improve the rhizosphere microecological environment of tobacco,providing a theoretical basis for understanding the mechanism of their promotion of tobacco growth and tobacco planting production.

Key words: Tobacco, Pirifonospora indica, Root exudates, Soil enzyme activity, Bacterial diversity

中图分类号: 

• S572