Biosynthesis of phytochelatins and arsenic accumulation in the marine microalga Phaeodactylum tricornutum in response to arsenate exposure
Biosynthesis of phytochelatins and arsenic accumulation in the marine microalga Phaeodactylum tricornutum in response to arsenate exposure
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DOI：
10.1007/s10534-005-2998-1
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发表时间：
2005-12-01
期刊：
影响因子：
3.5
通讯作者：
Scarano, G
中科院分区：
文献类型：
--
作者：
Morelli, E;Mascherpa, M;Scarano, G
砷酸盐诱导的植物螯合素 (PC)、细胞内富含半胱氨酸的金属结合肽的合成及其与毒性和细胞内砷积累的关系已在海洋微藻三角褐指藻的实验室培养物中进行了研究。短期暴露中细胞 PC 和 As 的时间进程表明，PC 参与 As 解毒以及细胞 As 的途径取决于 As 积累的程度和 PC 合成的速率。当砷酸盐浓度导致砷积累速度超过 PC 合成速度时，细胞似乎激活了主要以不与 PC 复合的化学形式释放砷的机制。在砷酸盐浓度下，PC 的合成速度足以使细胞中积累的大部分 As 结合，细胞 As 的命运似乎主要由 PC 控制。讨论了这些不同的砷解毒途径的发生，以解释在生长抑制浓度和无生长抑制浓度的砷酸盐下生长三天的细胞中细胞砷和 PC 的模式。
The arsenate-induced synthesis of phytochelatins (PC), intracellular cysteine-rich metal-binding peptides, and its relationship with toxicity and with As accumulation in the cell have been studied in laboratory cultures of the marine microalga Phaeodactylum tricornutum. The time course of cellular PC and As in short-term exposures showed that the involvement of PC in the As detoxification as well as the pathway of cellular As depend on the extent of As accumulation and on the rate of PC synthesis. At arsenate concentrations causing As accumulation at a rate exceeding that of PC synthesis, cells seem to activate a mechanism of release of As mainly in a chemical form not complexed with PC. At arsenate concentrations at which the synthesis of PC occurs at a rate sufficient to allow a significant portion of As accumulated in the cell to be bound, the fate of cellular As seems to be mainly controlled by PC. The occurrence of these different pathways of As detoxification was discussed to explain the pattern of cellular As and PC in cells grown for three days at growth-inhibitory and at no growth-inhibitory concentration of arsenate.