Detoxification mechanism of herbicide in Polypogon fugax and its influence on rhizosphere enzyme activities

Plasma Membrane (PM) H+-ATPase Mediates Rhizosphere Acidification and Regulates Herbicide Imazethapyr Toxicity in Wheat

The plasma membrane (PM) H+-ATPase is crucial for a plant defense system. However, there is currently no consensus on whether the PM H+-ATPase plays a role in alleviating the toxic effects of herbicides on nontarget plants. We found that under the herbicide imazethapyr (IM) exposure, PM H+-ATPase activity in wheat roots increased by approximately 69.53%, leading to rhizosphere acidification. When PM H+-ATPase activity is inhibited, the toxicity of IM significantly increases: When exposed to IM alone, the total Fe content of wheat roots decreased by 29.07%, the relative Fe2+ content increased by 27.75%, and the ROS content increased by 27.74%. When the PM H+-ATPase activity was inhibited, the corresponding data under IM exposure were 37.36%, 215%, and 57.68%, respectively. This work delves into the role of PM H+-ATPase in mediating the detoxification mechanism in plants exposed to herbicides, offering new insights into enhancing crop resistance against herbicides.

The impact of microplastics on sulfur REDOX processes in different soil types: A mechanism study

Microplastics can potentially affect the physical and chemical properties of soil, as well as soil microbial communities. This could, in turn, influence soil sulfur REDOX processes and the ability of soil to supply sulfur effectively. However, the specific mechanisms driving these effects remain unclear. To explore this, soil microcosm experiments were conducted to assess the impacts of polystyrene (PS) and polyphenylene sulfide (PPS) microplastics on sulfur reduction-oxidation (REDOX) processes in black, meadow, and paddy soils. The findings revealed that PS and PPS most significantly decreased SO42- in black soil by 9.4%, elevated SO42- in meadow soil by 20.8%, and increased S2- in paddy soil by 20.5%. PS and PPS microplastics impacted the oxidation process of sulfur in soil by influencing the activity of sulfur dioxygenase, which was mediated by α-proteobacteria and γ-proteobacteria, and the oxidation process was negatively influenced by soil organic matter. PS and PPS microplastics impacted the reduction process of sulfur in soil by influencing the activity of adenosine-5'-phosphosulfate reductase, sulfite reductase, which was mediated by Desulfuromonadales and Desulfarculales, and the reduction process was positively influenced by soil organic matter. In addition to their impacts on microorganisms, it was found that PP and PPS microplastics directly influenced the structure of soil enzymes, leading to alterations in soil enzyme activity. This study sheds light on the mechanisms by which microplastics impact soil sulfur REDOX processes, providing valuable insights into how microplastics influence soil health and functioning, which is essential for optimizing crop growth and maximizing yield in future agricultural practices.