蜈蚣草的超微结构和砷、钙的亚细胞分布

本文对砷和钙处理下蜈蚣草羽叶中砷、钙的亚细胞分布、超微结构变化及钙定位进行了研究。无砷处理下,各亚细胞组分中砷的分布为:细胞壁>胞质>细胞器。0.2.mmol/L砷处理下,羽叶各亚细胞组分中砷的分布为:胞质>>细胞壁>细胞器。不同处理下,各亚细胞组分中钙含量变化规律相似:细胞壁最高,胞质其次,而细胞器远低于前两者。5.mmol/L钙处理对蜈蚣草羽叶细胞超微结构产生破坏,使细胞出现明显的质壁分离。在高砷高钙环境中,钙可能会增强砷对蜈蚣草的毒害效应,导致羽叶细胞的超微结构受到破坏。

Ultrastructure and subcellular distributions of arsenic and calcium in Pteris vittata L.

The purpose of this research was to understand the effects of As and Ca concentrations(As: 0 and 0.2 mmol/L;Ca: 0.03 and 5 mmol/L) on cellular ultrastructure,Ca localization and elemental subcellular distributions in Pteris vittata L.,an As-hyperaccumulator.When the plants were grown in a nutrient solution without additional As,the As concentration in each fraction decreased in the following pattern: cell wall > cyplasmic supernatant > cell organelle.However,most of the As was localized in the cytoplasmic fraction of the pinna in plants treated with 0.2 mmol/L As.The results suggested that the plant cell of pinna had been capable of self-improvement when it was intimidated by arsenic.In all the treatments,subcellular distribution of Ca present similarly as: cell wall> cytoplasmic supernatant >> organelle.When the plant was grown in a nutrient solution with 5 mmol/L of Ca,the cellular ultrastructure was damaged and plasmolysis was appeared.As toxicity to the plant was strengthened by high addition of Ca, therefore the cellular ultrastructure was heavily damaged and it resulted in a decrease of As accumulation by the plant.