Noval bio-organic fertilizer containing Arthrobacter sp. DNS10 alleviates atrazine-induced growth inhibition on soybean by improving atrazine removal and nitrogen accumulation

Abstract

Herbicide atrazine restricts nutrient accumulation and thus inhibits the growth of sensitive crops. The application of organic fertilizer is a common measure that contributes to modulating abiotic tolerance of crops and providing nutrients, but its advantages in combination with atrazine degrading microorganisms as bio-organic fertilizer to alleviate atrazine stress on sensitive crops and the associated mechanisms are unknown. We investigated the beneficial effects of organic and bio-organic fertilizer (named DNBF10) containing Arthrobacter sp. DNS10 applications on growth, leaf nitrogen accumulation, root surface structure and root physiological properties of soybean seedlings exposed to 20 mg kg−1 atrazine in soil. Compared with organic fertilizer, bio-organic fertilizer DNBF10 exhibited more reduction in soil atrazine residue and plant atrazine accumulation, as well as alleviation in atrazine-induced root oxidative stress and damaged cells of soybean roots. Transcriptome analysis revealed that DNBF10 application enhanced nitrogen utilization by improving the expression of genes involved in nitrogen metabolism in soybean leaves. Besides, genes expression of cytochrome P450 and ABC transporters involved in atrazine detoxification and transport in soybean leaves were also down-regulated by DNBF10 to diminish phytotoxicity of atrazine to soybean seedlings. These results illustrate the molecular mechanism by which the application of DNBF10 alleviates soybean seedlings growth under atrazine stress, providing a step forward for mitigate the atrazine induced inhibition on soybean seedlings growth through decreasing atrazine residues as well as enhancing damaged root repair and nitrogen accumulation.