Response of Bacterial Community Structure and Function in Rhizosphere Soil on the Photosynthesis of Selected Plant Types C 3 and C 4 under Bis(2,4,6-tribromophenoxy) Ethane Exposure

This study investigated the response of a bacterial community’s structure and function in the rhizosphere soil of C 3 and C 4 plants under bis(2,4,6-tribromophenoxy) ethane (BTBPE) exposure. The bacterial community composition was determined using 16S rRNA sequencing, while FAPROTAX and PICRUSt 2 were employed for functional predictions. Results showed significant differences between C 3 and C 4 plants in terms of bacterial community structure. C 3 plants exhibited higher abundances of Proteobacteria, Bacteroidetes at the phylum level and Sphingomicrobium at the genus level, compared to C 4 plants. Conversely, C 4 plants had higher abundances of Actinobacteria and Patescibacteria at the phylum level and Nocardioides at the genus level. LEfSe and function prediction analyses revealed that the rhizosphere soil bacteria in C 3 plants exhibited significantly higher enrichment in nitrogen fixation functions ( p < 0.05), whereas C 4 plants showed a significantly higher relative abundance of bacteria and functions related to organic pollutant degradation ( p < 0.05). These findings suggest that the rhizosphere soil bacteria of C 3 plants exhibit a stronger response to BTBPE exposure in nitrogen metabolism-related processes, while C 4 plants possess superior biodegradation ability compared to C 3 plants.