Bleeker Petra M, Schat Henk, Vooijs Riet, Verkleij Jos A C, Ernst Wilfried H O
Department of Ecology and Physiology of Plants, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
New Phytol. 2003 Jan;157(1):33-38. doi: 10.1046/j.1469-8137.2003.00542.x.
• Arsenate tolerance, uptake and arsenate-induced phytochelatin (PC) accumulation were compared at different phosphorus supply rates in two populations of the broom, Cytisus striatus , one from an arsenic-enriched gold mine and one from a nonmetalliferous site. • After 7 d of exposure, arsenate tolerance was higher in the mine population. Arsenate uptake was phosphate-suppressible, and much lower in the mine plants. When compared at equal levels of stress, the mine plants and the nonmetallicolous plants exhibited similar arsenic accumulation, suggesting that reduced arsenate uptake is mainly responsible for superior tolerance. • Arsenate-induced PC accumulation occurred in both plant types. The γ-glutamylcysteine synthetase inhibitor, L-buthioninesulfoximine, caused arsenate hypersensitivity in both plant types, suggesting that PC-based arsenic sequestration is essential for both normal and enhanced arsenate tolerance. Mine plants produced longer PCs than the nonmetallicolous plants, possibly due to a differential temporal pattern of arsenate accumulation. • Our results are consistent with a similar mechanism underlying arsenate hypertolerance in C. striatus and grasses, that is reduced arsenate uptake through suppression of phosphate transporter activity.
• 在两种金雀儿（Cytisus striatus）种群中，比较了不同磷供应速率下对砷酸盐的耐受性、吸收以及砷酸盐诱导的植物螯合肽（PC）积累情况。这两个种群，一个来自富含砷的金矿，另一个来自非金属矿场。
• 暴露7天后，来自金矿的种群对砷酸盐的耐受性更高。砷酸盐的吸收可被磷酸盐抑制，且金矿植物中的吸收量要低得多。在同等胁迫水平下比较时，金矿植物和非矿场植物表现出相似的砷积累情况，这表明砷酸盐吸收减少是其耐受性更强的主要原因。
• 两种植物类型中均发生了砷酸盐诱导的PC积累。γ-谷氨酰半胱氨酸合成酶抑制剂L-丁硫氨酸亚砜胺在两种植物类型中均导致对砷酸盐过敏，这表明基于PC的砷螯合对于正常和增强的砷酸盐耐受性都至关重要。金矿植物产生的PC比非矿场植物更长，这可能是由于砷酸盐积累的时间模式不同。
• 我们的结果与金雀儿和禾本科植物中砷酸盐超耐受性的类似机制一致，即通过抑制磷酸盐转运蛋白活性来减少砷酸盐吸收。
