Environmental scanning electron microscope(ESEM)fitted with an energy disper-sive X-ray microanalyzer(EDX)was used to investigate the surface micromorphology and arse-nic(As)micro-distribution in Chinese brake(Pteris ...Environmental scanning electron microscope(ESEM)fitted with an energy disper-sive X-ray microanalyzer(EDX)was used to investigate the surface micromorphology and arse-nic(As)micro-distribution in Chinese brake(Pteris vittata L.).It was found that amounts of trichome,which possessed multicellular structure with the average length of 160μm and with an average diameter of 28μm,existed in the frond of P.vittata,and the density of trichome on the pinnate axial surface was higher than that on the petiole.Visible X-ray peak of As was recorded in the epidermal cell and trichome.The relative weight of As in the pinnate trichome,which con-tained the highest concentration of As among all tissues of the plant,was 2.4 and 3.9 times as much as that in the epidermal and mesophyllous cells,respectively.The As concentrations in the basal and stalk cells of the same trichome were higher than that in its cap cell.This is the first time to report that the trichome of P.vittata plays an important role in arsenic hyperaccumulation.The finding from the present study implies that much attention should be paid to the role of the trichome in understanding the hyperaccumulation and detoxicity of As in the hyperaccumulator and improving the ability of As accumulation.展开更多
基金This work was supported by the National Science Fund for Distinguished Young Scholar(Grant No.40325003)the China State Program for Basic Research(No.2002CCA03800)+1 种基金the National Natural Science Foundation of China(Grant No.40232022)the National High-Tech R&D Program(No.2001AA6450).
文摘Environmental scanning electron microscope(ESEM)fitted with an energy disper-sive X-ray microanalyzer(EDX)was used to investigate the surface micromorphology and arse-nic(As)micro-distribution in Chinese brake(Pteris vittata L.).It was found that amounts of trichome,which possessed multicellular structure with the average length of 160μm and with an average diameter of 28μm,existed in the frond of P.vittata,and the density of trichome on the pinnate axial surface was higher than that on the petiole.Visible X-ray peak of As was recorded in the epidermal cell and trichome.The relative weight of As in the pinnate trichome,which con-tained the highest concentration of As among all tissues of the plant,was 2.4 and 3.9 times as much as that in the epidermal and mesophyllous cells,respectively.The As concentrations in the basal and stalk cells of the same trichome were higher than that in its cap cell.This is the first time to report that the trichome of P.vittata plays an important role in arsenic hyperaccumulation.The finding from the present study implies that much attention should be paid to the role of the trichome in understanding the hyperaccumulation and detoxicity of As in the hyperaccumulator and improving the ability of As accumulation.
