Mitigating risks from atrazine drift to soybeans through foliar pre-spraying with a degrading bacterium

Area of Science:

• Agricultural Science
• Environmental Microbiology
• Plant Science

Background:

• Herbicides are vital for crop production but herbicide drift can harm sensitive plants.
• Atrazine drift negatively impacts soybean by reducing chlorophyll and disrupting metabolic and antioxidant systems.
• Ecosystem-based solutions are needed to mitigate herbicide drift risks.

Purpose of the Study:

• To evaluate the efficacy of foliar pre-spraying with atrazine-degrading Paenarthrobacter sp. AT5 to mitigate atrazine drift damage in soybeans.
• To investigate the mechanisms by which Paenarthrobacter sp. AT5 protects soybeans from atrazine exposure.
• To explore the impact of this approach on phyllosphere bacterial communities.

Main Methods:

• Soybean plants were treated with foliar pre-spraying of Paenarthrobacter sp. AT5 before exposure to atrazine.
• Chlorophyll levels, antioxidant system status, and metabolic processes in soybean leaves were analyzed.
• Atrazine absorption, degradation rate (half-life), and degradation pathways were quantified.
• Phyllosphere bacterial community interactions were assessed.

Main Results:

• Pre-spraying with Paenarthrobacter sp. AT5 successfully colonized soybean leaf surfaces and mitigated atrazine-induced damage.
• Atrazine absorption by soybean leaves was slowed, and its degradation was expedited (half-life reduced from 2.22 d to 0.86 d).
• The degradation pathway shifted towards hydroxylation, and phyllosphere bacterial communities showed enhanced interactions.

Conclusions:

• Foliar pre-spraying with Paenarthrobacter sp. AT5 offers a novel, eco-friendly, and user-friendly strategy to reduce herbicide drift risks to sensitive crops like soybeans.
• This method enhances crop resilience and promotes sustainable agricultural practices, such as mixed cropping.
• The study highlights the potential of microbial interventions in integrated weed management systems.