Enhancing Soybean Resistance to Atrazine Stress Through Seed Coating With Atrazine-Degrading Paenarthrobacter sp. AT5.

Abstract

Shifting from maize monoculture to maize-soybean rotation or intercropping is a key strategy to boost soybean self-sufficiency. However, the residual atrazine in soils, resulting from the extensive use of atrazine in long-term maize monocultures, poses a significant threat to soybean productivity, requiring immediate solutions. This study introduces a novel seed-coating method using atrazine-degrading Paenarthrobacter sp. AT5 to mitigate the adverse effects of atrazine on soybean growth. The efficacy of seed coating in reducing atrazine accumulation in seedlings and promoting seedling growth was found to vary depending on the growth stage and atrazine concentration in the soil. At low atrazine concentrations (close to safe levels for soybeans), the seed coating reduced leaf atrazine concentrations by 30.7%-46.0% at the cotyledon growth stage (VC). At high atrazine concentrations, the shoot atrazine concentrations decreased by 60.9%-88.4% at the emergence growth stage (VE) and seedling biomass was significantly increased in the VC stage. This is associated with the influence of seed coating on rhizosphere metabolites, which activate the plant defence system and recruit atrazine-degrading and plant-beneficial bacteria. This study offers comprehensive insights into the potential of seed coating with strain AT5 as a scalable solution for mitigating atrazine toxicity in soybeans.