Chlorine Dioxide Reprograms Rhizosphere Microbial Communities to Enrich Interactions with Tobacco (Nicotiana tabacum)

Abstract

For decades chlorine dioxide has been used in water disinfection with excellent results. As the scope of application expands, chlorine dioxide has the potential for soil disinfection. We used amplicon sequencing and gas chromatography-mass spectrometry to compare the changes of four mixed rhizosphere microbial community samples and 12 tobacco leaf volatile samples four months after the flood irrigation with chlorine dioxide in different concentrations (0, 2, 4, 8 mg/l). Phenotypic data of 60 tobacco plants were also collected. The effects of chlorine dioxide on rhizosphere microorganisms were positively correlated with dose gradients. Bacteria responded more strongly in both community structure and metabolic pathways than fungi. Five new bacterial phyla (Firmicutes, Bacteroidota, Myxococcota, Patescibacteria, Verrucomicroboata) appeared in chlorine dioxide treatment groups, while the fungal community only appeared as one new fungal phylum (Basidomycota). Alterations in 271 predicted metabolic bacterial pathways were found. However, in the fungal community were only 10 alternations. The correlations between leaf volatile compounds and rhizosphere microorganisms under the influence of chlorine dioxide treatment could be observed based on network results. However, natural connectivity had already been declining rapidly when less than 20% of the network's nodes were removed. Therefore, the microbe-metabolite network is not stable. It might be why chlorine dioxide treatments did not significantly affect tobacco quality (p = 0.754) and phenotype (p = 0.867). As a comprehensive investigation of chlorine dioxide in agriculture, this study proves the effectiveness and safety of chlorine dioxide soil disinfection and widens the application range of chlorine dioxide.