Study of cadmium absorption inhibition in lettuce by phosphorus-dissolving bacteria for agricultural biotechnology applications

Abstract

The rapid advancement of industrialization has led to an increasingly severe situation of soil cadmium pollution, posing a significant challenge to the stability of the agricultural production system and the safety of human health. This experimental design focuses on the phosphorus-solubilizing bacterium Bacillus thuringiensis J16, aiming to systematically investigate its inhibitory effect on the absorption process of cadmium elements by lettuce plants. The experiment was carried out using the pot cultivation method. The variables set include three gradients of soil cadmium addition concentrations (0, 1, 2 mg/kg) and two levels of J16 inoculation amounts (0, 1%). The results show that under different degrees of cadmium pollution, compared with the non-inoculated control group, the inoculation of strain J16 significantly increased the biomass of lettuce roots and leaves by 68.81%; and significantly reduced the cadmium content in the roots and leaves of the plants by 38.86%. In addition, the inoculation of strain J16 enhanced the antioxidant capacity of lettuce. For example, the content of malondialdehyde in the leaves decreased, and the activities of peroxidase and superoxide dismutase increased. This study enriches the resources of phosphorus-solubilizing and cadmium-fixing strains, providing a theoretical basis and technical support for the remediation of heavy metal-contaminated soil.