Wheat rhizosphere: Bacillus velezensis improved salinity stress

A group from Key Laboratory of Biochemistry and Molecular Biology in University of Shandong Province, Weifang University, Weifang, China, etc. has reported Bacillus velezensis JC-K3 inoculation in wheat rhizosphere to improve salinity stress.

Soil salinity is one of the main manifestations of global land degradation. At present, at least 20% of the cultivated land in the world is threatened by salinization to varying degrees.

In this study, a strain of endophytic Bacillus velezensis JC-K3 was isolated from wheat grown on saline soils. This strain not only showed strong salt tolerance and alkali resistance, but also produced IAA, siderophore, proline, soluble sugar, protease, cellulase, and glucanase, which have the potential to improve plant salt tolerance and induce systemic tolerance. Actually, comparing with the control group, inoculation with endophytic Bacillus velezensis JC-K3 increased the accumulation of wheat biomass (the plant height increased by 12.69%, the root length increased by 27.59%, the fresh weight of wheat shoot increased by 13.55%) under the tested salinity stress (Salt tolerance (12% NaCl, w/v) was tested on DF agar medium supplemented with 1-aminocyclopropane-1-carboxylate).

There was no significant difference in the content of endophytic bacteria in wheat roots after JC-K3 inoculation when compared with the control. The contents of Cyanobacteria in the shoots of wheat were significantly decreased after inoculation with JC-K3 (p ≤ 0.001), while the contents of Proteobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospirae, Saccharibacteria, and Parcubacteria were significantly increased (p ≤ 0.001). The contents of Actinobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, and Nitrospirae in wheat leaves were significantly increased after inoculation with JC-K3 (p ≤ 0.001). The content of Parcubacteria in rhizosphere soil decreased significantly (p ≤ 0.05).

After inoculation with JC-K3, there was no significant difference in the content of endophytic fungi in wheat roots and leaves. The content of Glomeromycota in wheat shoots decreased significantly (p ≤ 0.05), the content of Ascomycota in rhizosphere soil of wheat decreased significantly, and the content of Basidiomycota and Rozellomycota increased significantly (p ≤ 0.05).