Effect of Purpureocillium lilacinum on inter-root soil microbial community and metabolism of tobacco

Abstract

Abstract Numerous chemical pesticides have been used in agricultural production to combat crop diseases and pests. Despite ensuring certain economic advantages, they have also resulted in issues like environmental contamination, declining soil quality, and pesticide residues. Because biological control is environmentally friendly and difficult to acquire resistance to, it has been used in practice recently. We isolated the endophytic fungus Purpureocillium lilacinum from Portulaca oleracea L., which was previously found to have inhibitory effects on soil pathogens in tobacco fields. In order to explore the effects of the biocontrol agent Purpureocillium lilacinum on soil microorganisms and plant metabolism in tobacco cultivation, we combined amplicon sequencing technology and gas chromatography-mass spectrometry to carry out the analysis of soil microbial community structure and microbial-metabolite interaction network in inter-rhizosphere soil of tobacco field under different application method of P. lilacinum treatment. The findings showed that there was a trend toward less microbial diversity among inter-root microorganisms as solid-state fermentation (SSF) products of P. lilacinum increased; however, submerged fermentation (SmF) had no discernible impact on microbial diversity when compared to the direct use of SSF. Additionally, the relationship between inter-root fungi and volatile compounds of tobacco leaves was dominated by a negative correlation. The result demonstrated that P. lilacinum's antagonistic interaction in the inter-rhizosphere microbial community was dominant and valuable for biopesticide application. P. lilacinum can work more effectively on tobacco roots by using SSF products. P. lilacinum's opposition to fungal colonies may enhance the volatile chemicals in tobacco leaves.