Effects of the ectomycorrhizal fungus Pisolithus tinctorius and Cd on physiological properties and Cd uptake by hybrid poplar Populus alba × glandulosa

The effects of the ectomycorrhizal fungus Pisolithus tinctorius and cadmium (Cd) on physiological properties and Cduptake by Populus alba × glandulosa was investigated under greenhouse conditions. Cd treatment decreased the photosyntheticrate (PN) of both non-mycorrhizal (NM) plants (16.3%) and ectomycorrhizal (ECM) plants (11.5%). In addition,the reduction in total dry weight by Cd treatment was greater in ECM plants (24.3%) than that in NM plants (17.6%). Mycorrhizalinfection increased the PN and transpiration rate in both control and Cd-treated plants. Cd treatment increasedsuperoxide dismutase (SOD) activity and decreased glutathione reductase activity, and the increase of SOD activity byCd treatment was greater in NM plants (40.3%) than that in ECM plants (3.7%). Thiol content increased in both NM andECM plants treated with Cd solution, and the increase in thiol content in NM plants (43.9%) was greater than that of ECMplants (15.6%). Cd uptake in the leaves, stems, and roots of ECM plants was 69.9%, 167.2% and 72.8%, respectively, higherthan in the NM plants. However, the increase in Cd uptake ability of ECM plants resulted in a reduction in dry weight.