Lombini Alessandra, Llugany Mercè, Poschenrieder Charlotte, Dinelli Enrico, Barceló Juan
Laboratorio Fisiología Vegetal, Facultad Ciencias, Universidad Autónoma de Barcelona, E-08193 Bellaterra, Spain.
J Plant Physiol. 2003 Dec;160(12):1451-6. doi: 10.1078/0176-1617-01002.
This hydroponic study addresses the influence of low (0.3) and high (4.0) Ca/Mg molar ratios on Cu resistance of Silene armeria ecotypes from different habitats: a calcareous soil (ecotype Cadriano), a Ni-rich serpentine site (ecotype Prinzera), and an acid Cu-mine spoil soil containing serpentinite (ecotype Vigonzano). Under control conditions, without excess Cu, only Cadriano was negatively affected by the low Ca/Mg ratio. Under both low and high Ca/Mg ratios Cu resistance followed the order Vigonzano more more than Prinzera > Cadriano. More efficient Cu exclusion accounted for enhanced Cu resistance in Prinzera. The low Ca/Mg ratio increased Cu uptake in Prinzera but did not worsen toxicity effects; i.e. the plants had higher internal Cu effect concentrations. In Vigonzano Cu resistance was enhanced by the low Ca/Mg ratio. This was due only in part to better Cu exclusion. Magnesium-induced tolerance to higher Cu tissue concentrations appears to be in ecotypes from serpentine and acid mine spoils, but not in plants from calcareous soil, the exposure to low Ca/Mg ratio favours internal detoxification of Cu by means of more efficient chelation and compartmentation.
这项水培研究探讨了低（0.3）和高（4.0）钙/镁摩尔比对来自不同生境的蝇子草生态型铜抗性的影响：钙质土壤（卡德里亚诺生态型）、富含镍的蛇纹石场地（普林泽拉生态型）以及含有蛇纹石的酸性铜矿废弃土壤（维贡扎诺生态型）。在无过量铜的对照条件下，只有卡德里亚诺受到低钙/镁比的负面影响。在低钙/镁比和高钙/镁比条件下，铜抗性均遵循维贡扎诺>普林泽拉>卡德里亚诺的顺序。普林泽拉中更有效的铜排斥导致其铜抗性增强。低钙/镁比增加了普林泽拉对铜的吸收，但并未加剧毒性效应；即植物具有更高的内部铜效应浓度。在维贡扎诺，低钙/镁比增强了铜抗性。这仅部分归因于更好的铜排斥。镁诱导对更高铜组织浓度的耐受性似乎存在于来自蛇纹石和酸性矿渣的生态型中，但在来自钙质土壤的植物中不存在，低钙/镁比的暴露有利于通过更有效的螯合和区室化对铜进行内部解毒。
