Regulative effect of imazethapyr on Arabidopsis thaliana growth and rhizosphere microbial community through multiple generations of culture

Background and aims Imazethapyr (IM) is a chiral herbicide with two enantiomers, with a much stronger herbicidal effect of R-IM than S-IM. Pesticide residues are a common problem, and multi-generation cultivation method can reveal the consequences of long-term pesticide residues. Methods This study verified the effects of R-IM on the growth of Arabidopsis thaliana and rhizosphere microorganisms by treating A. thaliana with different concentrations of R-IM successively passaging experimental rhizospheres for three generations, and measured the changes of A. thaliana rhizosphere microbes. Results The growth of A. thaliana treated with R-IM (0.5 g/ha and 1.5 g/ha) was significantly inhibited especially after successive generations of culture. At the same time, R-IM treatment decreased chlorophyll and chlorophyll parameters to inhibit the photosynthetic efficiency, and it also reshaped the rhizosphere bacterial community structure of A. thaliana. This bio-effect was transmitted to the next generation of plants along with the soil microbiota. Conclusions The treatment of A. thaliana by R-IM in multi-generation culture resulted in an increasingly obvious growth inhibitory effect, the higher concentration of R-IM inhibited A. thaliana more strongly, and changed the abundance of rhizosphere microbes. With the cultivation of generations, the influence of pesticide residues on plants also became significant.

Automated summary

This study verified the effects of the chiral herbicide R-IM on the growth and rhizosphere microorganisms of Arabidopsis thaliana. The results showed that R-IM inhibited the growth of A. thaliana, decreased chlorophyll parameters, and reshaped the rhizosphere bacterial community structure. The influence of pesticide residues on plants became significant with the cultivation of generations.