Influence of calcium and calcium ion channel blockers on the uptake of cadmium by arbuscular mycorrhizal fungus
钙和钙离子通道阻断剂对丛枝菌根真菌吸收镉的影响

Arbuscular mycorrhizal fungi (AMF) in combination with phytoremediation have been regarded as effective strategy in resolving the increasingly serious heavy metal (HM) contamination nowadays. However, the mechanisms underlying the uptake of HM by AMF hyphae are still unclear. In the present study, clover (Trifolium repense L.) and Glomus intraradices were taken as host plant and AMF species, respectively. The extraradical hyphae and the roots were separated using compartmented system. After the Cd2+, Ca2+ and Ca2+ channel blockers (verapamil or LaCl3) were added into the hyphal compartment, the uptake of Cd2+ and Ca2+ by hyphae and their relations with the Ca2+ channel were explored. Results indicated that high level of Cd2+ and LaCl3 increased the hyphal development. High level of Cd2+, verapamil and LaCl3 decreased the uptake of Ca2+ by hyphae to different degrees, while high level of Cd2+ and LaCl3 promoted the uptake of Cd2+ by hyphae. It is suggested that the transmembrane transport of Cd2+ is not achieved via the Ca2+ channel, and furthermore high level of Ca2+ is beneficial to the uptake of Cd2+ by hyphae.