Response of Rhizosphere Bacterial Community of Potato Infected by Late Blight to Heavy Metal Stress in High Geological Background Area
Exploring the changes in the bacterial community and its influencing factors in the rhizosphere soil of late blight-affected potatoes under heavy metal stress in a geologically high background area is crucial to guarantee the safety of potato production.Rhizosphere soil samples were collected from both healthy and late blight-diseased potato plants('Qingshu 9','Weiyu 5'and'Weiyu 3').Subsequently,the soil pH,organic matter content and heavy metal concentrations were analyzed.The bacterial community was analyzed using Illumina MiSeq high-throughput sequencing,while the heavy metal content in the potato tubers was determined simultaneously.In the soil of the tested area,the mean concentrations of Cd,Cr and Zn were 2.14,170 and 220 mg/kg,respectively.Cd levels exceeded the risk control threshold of the national soil quality standard,while Cr and Zn levels exceeded the screening values.Among the potato tuber samples,only one exhibited a Cd concentration of 0.103 mg/kg,exceeding the national food safety limit standard.The predominant bacterial phyla and their relative abundances in the rhizosphere soil of diseased potatoes were Proteobacteria(33.16%-39.09%)and Actinobacteria(13.45%-17.11%);the predominant bacteria were primarily Sphingomonas(8.78%-12.30%)and Gemmatimonas(6.22%-7.61%).The relative abundance of dominant bacteria differed in diseased plants compared to healthy plants,with variations observed among different plant varieties in terms of bacterial diversity and abundance.After potato late blight infection,there was an increase in the diversity of the bacterial community in the rhizosphere soil,while the abundance of the bacterial community decreased.Principal component analysis revealed that the contribution rate of bacterial community differences between diseased plants and healthy plants was 29.59%.The results of redundancy analysis indicated that soil heavy metals and pH had a significant impact on the composition and structure of the soil bacterial community,particularly on the dominant bacteria.The differences in the bacterial community between healthy and diseased plants were more influenced by soil stress from Pb and Cr.Therefore,potatoes could achieve safe production even under heavy metal stress in high geological background areas.In the rhizosphere soil of infected potato plants,the diversity of the bacterial community decreased while the richness increased.The occurrence and development of late blight were affected by soil Pb and Cr through alterations in the beneficial bacteria within the rhizosphere soil bacterial community.
Karst geological high-background areaheavy metalpotato late blightsoil rhizospherebacterial community
万方数据
维普
