Microbial mechanical insights into the cadmium accumulation of rice (Oryza sativa L.) grains in Cd-contaminated seleniferous paddy soils: A data-driven observational research.

This observational research established a methodological framework for source apportionment of heavy metal contamination and proposed novel microbial mechanical insights into the Cd accumulation processes of rice (Oryza sativa L.) grains using data-based modelling in a regional scale. Combined analysis of RF-PMF apportioned heavy metal contamination of 3067 soil samples collected from the north of Zhejiang Province, China. Parent material (22.53 %), agricultural input (9.37 %), human activity (6.23 %) and enterprise activity (4.19 %) have synergetic effects on soil Cd pollution. Moreover, PLSPM systematiclly clarified mechanical pathways of Cd accumulation in rice grains integrating all the driving factors. Representative fungal genera of Stellatospora, Zopfiella, Schizothecium, Cirrenalia released bioavailable Se and Cd into soil during decomposition of remains, thereby affecting grain Cd accumulation. The dominant bacterial genera of MBNT15, Gemmatimonas, Thermodesulfovibrio, MND1 enhanced S/N cycling and redox ability to relieve oxidative stress from bioavailable Cd, thereby reducing Cd accumulation in grains. Application of biofertilizers containing representative microbial genera above could be beneficial to future agricultural practices By elucidating interactions of environmental factors and microbial communities in rhizosphere habitats, our findings could be used as a reference for mechanical regulation of Cd accumulation in crop grains within Cd-contaminated seleniferous paddy fields.