Unveiling the rhizosphere microbial community of castor plant (Ricinus communis L.) grown in textile effluent contaminated ecosystem and assessing its phylogenetic traits for plant growth promotion

Various factors influence the microbial community in the plant rhizosphere, including the variety, activity, and population structure. Plant species and soil type are critical determinants of the composition and diversity of the microbial communities linked to plant roots. Understanding these interactions is crucial for enhancing plant development and soil vitality, especially under adverse conditions such as salt-affected soils. This study evaluated the structure and composition of rhizosphere microbial communities in response to castor plant (Ricinus communis L.), a crop known for its resilience to various soil conditions. The bacterial community in the castor rhizosphere was examined by 16S rDNA sequencing in conjunction with an assessment of various plant growth-promoting (PGP) characteristics of the isolated bacterial strains. These findings indicated that the rhizosphere bacterial community was primarily comprised of Bacillus species, which are essential plant growth-promoting rhizobacteria (PGPR). These bacteria exhibit considerable potential to augment nutrient absorption, strengthen stress resilience, and promot overall plant vitality. Their supremacy underscores their adaptability and functional significance in castor root systems, particularly under diverse soil conditions. This study elucidates the microbial dynamics of the castor rhizosphere, highlighting the crucial role of Bacillus species in enhancing plant growth and soil fertility. These findings indicate that Bacillus-dominated microbial communities can be efficiently utilized for sustainable agriculture and soil remediation initiatives.