We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
From active defense to cross-kingdom alarm: Rhizosphere microenvironment remodeling in soybean under polylactic acid nanoplastics and cadmium Co-stress
Summary
When soybean plants are exposed to both cadmium (a toxic heavy metal) and nanoplastics from "biodegradable" plastics at the same time, the two pollutants team up to stress the plant more than either would alone — triggering a chain reaction where the roots' chemical defenses, the surrounding soil, and soil microbes all shift in ways that create a feedback loop of worsening stress. This matters because soybeans are a major food crop, and understanding how these combined pollutants disrupt plant health from the roots up could help explain contamination risks in our food supply as both plastic pollution and heavy metal contamination increase in
As foundational components of the food web, plants face significant environmental threats caused by the coexistence of micro/nanoplastics (MNPs) and heavy metals. This study investigates the combined effects of cadmium and biodegradable polylactic acid nanoplastics on soybean. Under co-exposure conditions, toxicity progressively diminishes from the roots to the leaves of soybeans. By integrating root transcriptomics, root exudate metabolomics, rhizosphere soil metagenomics, and soil physicochemical analyses within a Bayesian structural equation modeling framework, we identified the Flavonoid biosynthesis pathway as a central mediating hub in the rhizosphere microenvironment under combined stress. Soybean roots modulated this pathway as a response strategy, which concurrently served as a signal for rhizosphere microbes to downregulate energy-intensive processes such as Methane metabolism, facilitating microbial adaptation. The down-regulation of the Flavonoid biosynthesis pathway in root exudates further altered rhizosphere soil properties, creating a feedback loop that amplified the expression of stress-related genes in soybean roots.