Effects of Burkholderia sp. D54 on growth and cadmium uptake of tomato, ryegrass and soybean plants

Cadmium (Cd) contamination of agricultural soil is a serious global problem. Plant growth-promoting bacteria could modulate growth and Cd uptake of plants. In this study, the effects of rhizobacterium Burkholderia sp. D54 on growth and Cd uptake of tomato, ryegrass and soybean plants were investigated. The bacterial inoculation increased at least one pigment content of all tested plants. In soybean plants, chlorophyll a, chlorophyll b and carotenoid concentrations were increased by 63.19%, 73.15% and 57.58%, respectively. The dry mass of aerial parts was increased by 67.38%, 19.13% and 67.41% in tomato, ryegrass and soybean plants, respectively. The total Cd uptake in tomato and ryegrass plants was increased upon bacterial inoculation, while the Cd concentration varied among plant species. Burkholderia sp. D54 inoculation decreased Cd concentration in aerial parts of tomato and Cd translocation from roots to aerial parts (p < 0.05). The Cd concentration in roots and aerial parts of ryegrass was increased, and Cd translocation from roots to aerial parts was enhanced. By contrast, Cd concentration in aerial parts and roots of the soybean plants was decreased. Burkholderia sp. D54 also modulated the nutrient uptake of the tested plants. The K, Ca and Zn concentrations were decreased in tomato and soybean but enhanced in ryegrass. These results indicated that Burkholderia sp. D54 could modulate growth, nutrient element concentration and Cd uptake of the tested plants. This study might provide a promising way of using PGPR control Cd uptake in food crops or assisting phytoremediation by hyperaccumulators.