Audet Patrick, Charest Christiane
Ottawa-Carleton Institute of Biology, Department of Biology, University of Ottawa, Ottawa, ON, Canada.
Environ Pollut. 2007 Jun;147(3):609-14. doi: 10.1016/j.envpol.2006.10.006. Epub 2006 Nov 20.
To estimate dynamics of arbuscular mycorrhizal (AM) symbiosis in heavy metal (HM) phytoremediation, we conducted a literature survey and correlated HM uptake and relative plant growth parameters from published data. After estimating AM feedback responses for these parameters at low and high soil-HM concentration intervals, we determined that the roles of AM symbiosis are characterized by (1) an increased HM phytoextraction via mycorrhizospheric 'Enhanced Uptake' at low soil-HM concentrations, and (2) a reduced HM bioavailability via AM fungal 'Metal-Binding' processes at high soil-HM levels, hence resulting in increased plant biomass and enhanced plant tolerance through HM stress-avoidance. We present two conceptual models which illustrate the important compromise between plant growth, plant HM uptake and HM tolerance, and further emphasize the importance of AM symbiosis in buffering the soil environment for plants under such stress conditions.
为了评估丛枝菌根（AM）共生在重金属（HM）植物修复中的动态变化，我们进行了一项文献调查，并将已发表数据中的HM吸收量和相对植物生长参数进行关联。在估算低土壤HM浓度区间和高土壤HM浓度区间这些参数的AM反馈响应后，我们确定AM共生的作用表现为：（1）在低土壤HM浓度下，通过菌根际的“增强吸收”增加HM植物提取量；（2）在高土壤HM水平下，通过AM真菌的“金属结合”过程降低HM生物有效性，从而通过避免HM胁迫增加植物生物量并增强植物耐受性。我们提出了两个概念模型，阐述了植物生长、植物HM吸收和HM耐受性之间的重要权衡，并进一步强调了AM共生在为处于此类胁迫条件下的植物缓冲土壤环境方面的重要性。
