Diversity and functional roles of dark septate endophytes (DSE) in two dominant pioneer trees reclaimed from a metal mine slag heap in southwest China

This study examines the diversity and function of dark septate endophytes (DSE) that naturally colonize the roots of an artificially established Populus yunnanensis forest and the naturally reclaimed pioneer species Coriaria sinica on an abandoned tailings dam in southwest China. Our findings suggest that as plants reclaim these environments, root endophytes such as DSE also recover and succeed, playing a critical role in enhancing the host plant’s adaptability to stressful conditions. They are thereby considered an essential functional component of the root systems of reclamation plants in tailings areas.
Table 1: The colonization rates of dark septate endophytes (DSE) and arbuscular mycorrhizal fungi (AMF) in the roots of P. yunnanensis and C. sinica in the abandoned tailing area of Huangmaoshan, Yunnan Province, southwestern China.
Table 3: Siderophore activity of the six representative DSE strains in culture solutions without Fe3+ after 5 days.
Fig. 5: Tolerance of DSE strains to Cd as determined by the minimum inhibitory concentration (MIC) range, in strains colonizing the roots of P. yunnanensis and C. sinica in southwest China.
Fig. 6: Phosphorus solubilizing capacity of six representative DSE strains isolated from the roots of P. yunnanensis and C. sinica in the abandoned tailing area of Huangmaoshan, Southwest China.
Fig. 7: Indole-3-acetic acid (IAA) concentrations in the culture filtrates of six representative DSE strains isolated from the roots of P. yunnanensis and C. sinica in the abandoned tailing area of Huangmaoshan, Southwest China.
Fig. 8: Effects of two fungal inoculations (FE) on the growth (net fresh weight and net plant height) and heavy metal concentrations (Cd, Zn, and Pb) as well as on the translocation factors (TF) and bioconcentration factors (BCF) of P. yunnanensis inoculated with two DSE strains, compared to non-inoculated controls after 60 days of cultivation.
Fig. 9: HCl-extractable metal concentrations in the rhizosphere soil after 60 days of cultivation of P. yunnanensis with two DSE strains.