Endophytic Fungus Talaromyces sp. MR1 Promotes the Growth and Cadmium Uptake of Arabidopsis thaliana L. Under Cadmium Stress

Endophytes play essential roles in plant growth under metal(loid)s stress. An endophytic fungus strain MR1 was isolated from the roots of Miscanthus floridulus collected from a lead–zinc mining area (Huayuan, China), which could produce indole-3-acetic acid and have Cadmium (Cd) tolerance. Further 18S rRNA sequencing analysis showed that it was highly similar (99.83%) to Talaromyces pinophilus. In pot experiments, we explored the effects of strain MR1 on the growth and Cd uptake of a wide-type Arabidopsis thaliana under low (LC) and high (HC) Cd concentrations. The results showed that MR1 effectively increased the dry weight of aboveground and underground tissues by 25.95–107.21% in both LC and HC groups. Due to MR1 inoculation, the Cd content in the underground tissues was significantly (p < 0.05) decreased by 39.28% under low Cd concentration, while it was significantly (p < 0.05) increased by 28.28% under high Cd concentration. Besides, MR1 inoculations significantly (p < 0.05) increased the total content of removed Cd (17.080 μg) and BCF (0.064) by 129.77% and 153.95% under high Cd concentration. Therefore, we speculated that MR1 might be selected as the effective microbial agent to increase crop yield and control Cd content in the crop in light Cd-contaminated soil. Besides, MR1 could potentially enhance the phytoremediation efficiency of extremely Cd-contaminated soil.