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通过对砷的富集形态变化和亚细胞分布研究,揭示条斑紫菜中砷的区隔化效应及其对砷的解毒机理。将活体条斑紫菜分别暴露于0.05,0.1,0.5和1.0 mg/L的亚砷酸根(AsO33-)和砷酸根(AsO3-)溶液中6 d,每天取样一次,运用HPLC-ICP-MS法分析紫菜中砷的形态变化,运用差速离心技术分析砷在亚细胞水平的分布差异。结果表明,随着介质浓度的升高和暴露时间的增加,藻体中的砷含量呈线性增长趋势,统计分析表明条斑紫菜对As(Ⅲ)和As(Ⅴ)的积累与暴露浓度都呈极显著正相关,相关系数RAs(Ⅲ)=0.99960,p<0.01;R As(Ⅴ)=0.9844,p<0.01;条斑紫菜对As(Ⅲ)的富集速率略高于As(Ⅴ),暴露在0.1 mg/L As(Ⅲ)和As(Ⅴ)溶液中6 d后的富集系数分别是4718.7和4111.5。研究表明,条斑紫菜中砷的亚细胞分布与区隔化差异很大,各组分的砷含量分别为:细胞液80%>细胞壁15%>细胞器5%。藻体胞液是砷的主要储存部位,胞液对砷具有非常明显的区隔化作用。通过对其富集过程中砷形态转化规律的研究发现:As(Ⅴ)会迅速被甲基化,然后再转化成砷糖(AsX1);As(Ⅴ)会迅速被富集还原成As(Ⅲ),As(Ⅲ)被逐步甲基化,然后再转化成砷糖(AsX1)。
Through the study of arsenic enrichment and subcellular distribution, the compartmentalization of arsenic in Porphyra yezoensis and the mechanism of arsenic detoxification were revealed. Living Porphyra yezoensis was exposed to 0.05, 0.1, 0.5 and 1.0 mg / L arsenite (AsO33-) and arsenate (AsO3-) solutions for 6 days respectively. Samples were taken daily and analyzed by HPLC-ICP-MS The change of arsenic in seaweed, the use of differential centrifugation analysis of arsenic in subcellular distribution of the difference. The results showed that with the increase of medium concentration and exposure time, the content of arsenic in algae increased linearly. Statistical analysis showed that the accumulation and exposure concentrations of As (Ⅲ) and As (Ⅴ) The correlation coefficient RAs (Ⅲ) = 0.99960, p <0.01; R As (Ⅴ) = 0.9844, p <0.01. The enrichment rate of As (Ⅲ) was slightly higher than that of As The enrichment coefficients after exposure to 0.1 mg / L As (Ⅲ) and As (Ⅴ) solutions for 6 d were 4718.7 and 4111.5, respectively. Studies have shown that the arsenic subcellular distribution and compartmentalization of Porphyra yezoensis are very different. The arsenic contents of the components are as follows: cell liquid 80%> cell wall 15%> organelle 5%. The algae cytosolic fluid is the main storage site of arsenic, cytosolic arsenic has a very distinct compartmentalization. As (Ⅴ) is quickly methylated and then converted to arsenic (AsX1). As (Ⅴ) is rapidly reduced to As (Ⅲ) ), As (III) is gradually methylated and then converted to AsX1.