橙色微杆菌GX14001对番茄的促生及根际土壤微生物群落结构的影响

Microbacterium aurantiacum GX14001 promotes the growth of tomato plants by altering the microbial community structure in rhizosphere soil

摘要:

植物根系分泌的自毒物质，如对羟基苯甲酸(p-hydroxybenzoic acid, PHBA)等酚酸类物质，是造成植物连作障碍的主要因素。目的 为探究在PHBA胁迫下，橙色微杆菌(Microbacterium aurantiacum)对番茄生长的促生效果及其对番茄根际微生物结构的影响。方法 将橙色微杆菌GX14001菌悬液浇灌番茄根际，测定番茄的生长发育状况及其根际土壤微生物群落的变化。结果 在PHBA处理下，GX14001对番茄生长具有显著的促进的作用，叶片面积、茎粗和株高分别增加了244.0%，156.5%和128.0%。番茄根际土壤的细菌丰富度增加，但多样性无显著变化；真菌的丰富度和多样性显著降低。在门水平上，与对照组相比，细菌菌门中的放线菌门(Actinobacteriota)、绿弯菌门(Chloroflexi)和变形菌门(Proteobacteria)的相对丰度显著升高，子囊菌门(Ascomycota)为绝对优势真菌门。结论 橙色微杆菌GX14001可能通过改变番茄根际土壤的微生物群落结构，提高土壤中有益微生物的相对丰度，从而为植物提供有利的生长环境，进而促进番茄的生长发育。

Abstract:

As autotoxic substances secreted by plant roots, phenolic acids such as p-hydroxybenzoic acid (PHBA), are the main factors causing continuous cropping obstacles.Objective To study the effects of Microbacterium aurantiacum on the growth of tomato plants and the microbial community structure in rhizosphere soil under PHBA stress.Methods We irrigated tomato rhizosphere with the suspension of M. aurantiacum GX14001 and then measured the growth traits of tomato plants and the soil microbial community changes in the rhizosphere soil.Results Under the PHBA treatment, GX14001 significantly promoted the growth of tomato plants, increasing the leaf area, stem diameter, and plant height by 244.0%, 156.5%, and 128.0%, respectively. GX14001 increased the richness but did not cause changes in the diversity of bacteria in the rhizosphere soil. Meanwhile, it decreased the richness and diversity of fungi in the rhizosphere soil. At the phylum level, compared with the control group, the GX14001 group showed increased relative abundance of Actinobacteriota, Chloroflexi, and Proteobacteria, with Ascomycetes as the dominant fungal phylum.Conclusion M. aurantiacum GX14001 promotes the growth of tomato plants by changing the microbial community structure in the rhizosphere soil. It increases the relative abundance of beneficial microorganisms in the soil to create a favorable environment for tomato growth.