Characterization of cadmium-resistant endophytic fungi from Salix variegate Franch. in Three Gorges Reservoir Region, China

Publication date: Available online 2 April 2015 Source:Microbiological Research Author(s): Hongmei An , Yan Liu , Xinfei Zhao , Qian Huang , Shenhong Yuan , Xingyong Yang , Jinyan Dong The community and Cd-resistance of endophytic fungi from roots of Salix variegate Franch. collected from the water-level-fluctuation zone of Three Gorges Reservoir Region, China were investigated. A total of 53 strains were isolated and identified to 13 morphotaxa, in which Chromosporium, Fusarium and Gonatobotrys were dominant genera. Among them, 27 isolates were selected to measure their resistance to 0.02 mg·ml−1 Cd2+ and 11 were growth stimulated (Tolerance index>100%). Of these active isolates, four dark septate endophyte (DSE) isolates (Paraphaeosphaeria sp. SR46, Pyrenochaeta sp. SR35, Rhizopycnis vagum SR37 and R. vagum SR44) were further tested for minimum inhibitory concentrations (MICs) against Cd and SR46 was found to be the most tolerant isolate with MIC of 0.39 mg·ml−1. Additionally, the maximum uptake values of these DSEs ranged from 3.01 to 7.89 mg·g−1, but there was no significant correlation between metal uptake with fungal biomass and metal tolerance. Subsequently, a pot experiment was conducted for investigating the impact of SR46 on corn seedlings in Cd-enriched soil. The results obtained suggested that SR46 reduced the Cd bioaccumulation of plant under low (100 mg·kg−1) Cd stress and enhanced the Cd translocation from root zone to aerial parts...
Source: Microbiological Research - Category: Infectious Diseases Source Type: research