Arnetoli Miluscia, Vooijs Riet, ten Bookum Wilma, Galardi Francesca, Gonnelli Cristina, Gabbrielli Roberto, Schat Henk, Verkleij Jos A C
Section of Plant Ecology and Physiology, Department of Plant Biology, University of Florence, via Micheli 1, 50121 Firenze, Italy.
Environ Pollut. 2008 Apr;152(3):585-91. doi: 10.1016/j.envpol.2007.07.002. Epub 2007 Aug 16.
Arsenate tolerance, As accumulation and As-induced phytochelatin accumulation were compared in populations of Silene paradoxa, one from a mine site enriched in As, Cu and Zn, the other from an uncontaminated site. The mine population was significantly more arsenate-tolerant. Arsenate uptake and root-to-shoot transport were slightly but significantly higher in the non-mine plants. The difference in uptake was quantitatively insufficient to explain the difference in tolerance between the populations. As accumulation in the roots was similar in both populations, but the mine plants accumulated much less phytochelatins than the non-mine plants. The mean phytochelatin chain length, however, was higher in the mine population, possibly due to a constitutively lower cellular glutathione level. It is argued that the mine plants must possess an arsenic detoxification mechanism other than arsenate reduction and subsequent phytochelatin-based sequestration. This alternative mechanism might explain at least some part of the superior tolerance in the mine plants.
对两种蝇子草种群的砷酸盐耐受性、砷积累及砷诱导的植物螯合肽积累进行了比较，一种来自富含砷、铜和锌的矿区，另一种来自未受污染的地点。矿区种群对砷酸盐的耐受性显著更强。非矿区植物对砷酸盐的吸收及从根到地上部分的转运略高但也显著更高。吸收量的差异在数量上不足以解释种群间耐受性的差异。两种种群根系中的砷积累相似，但矿区植物积累的植物螯合肽比非矿区植物少得多。然而，矿区种群中植物螯合肽的平均链长更高，这可能是由于细胞内谷胱甘肽水平本就较低。有人认为，矿区植物必定拥有除砷酸盐还原及随后基于植物螯合肽的螯合作用之外的砷解毒机制。这种替代机制可能至少部分解释了矿区植物更强的耐受性。
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