We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Deciphering the response of nodule bacteriome homeostasis in the bulk soil-rhizosphere-root-nodule ecosystem to soil microplastic pollution
Summary
Researchers examined how polyethylene microplastic contamination in soil affects the bacterial communities associated with legume plant root nodules. They found that microplastic treatments accelerated nodule formation but disrupted the balance of beneficial nitrogen-fixing bacteria in the nodules. The study suggests that soil microplastic pollution may interfere with the symbiotic relationship between legume crops and their nitrogen-fixing bacterial partners.
Microplastic polyethylene (PE) is one of the most widely distributed pollutants in agricultural soils. However, its effects on the assembly and co-occurrence of the coevolved bacteriome of legume plants, especially on nodule bacteriome homeostasis, remain unclear. We analyzed nodule numbers, the difference between leaf δN and soil δN (ΔδN), and bacterial communities from nodule, root, rhizosphere, and bulk soil under different microplastic PE treatments. We found that microplastic PE treatments accelerated nodulation, resulting ΔδN decreased from -2.48 ‰ to -5.06 ‰. The microplastic PE treatments promoted the enrichment of nodule species from the root at an early stage with a source ratio increasing from 0.4 % to 46.6-89.6 %, and reduced selection on the nodule bacteriome with an increase in drift (from 2.8 % to 14.3-36.0 %), probably benefiting the function of Bradyrhizobium in the microbial network whose edges or molecularity increased. In the root, microplastic PE treatments resulted in an increase in homogeneous selection (increase from 29.2 % to 42.8-77.8 %) on the root bacteriome. This study provides new evidence that microplastics can promote nodulation and biological N fixation, revealing a mechanism by which microplastics change nodule bacteriome homeostasis in an Afisol.