EDTA对波士顿蕨吸收Hg的影响及其光合响应

Effect of EDTA on Accumulation and Translocation of Hg in Nephrolepis exaltata and Responses of Photosystem Ⅱ

采用水培实验方法研究EDTA对波士顿蕨吸收和转移Hg的影响,以及波士顿蕨对Hg及Hg和EDTA胁迫下光合系统II(PSII)的响应.结果显示:波斯顿蕨的根部能富集Hg,加入EDTA可以提高Hg从其根部转移到地上部分.单独Hg处理略微抑制了叶绿素的合成,Hg或Hg与EDTA处理对叶绿素的合成没有明显的影响.Hg或Hg与EDTA对植物的光合作用产生一定程度的胁迫作用.Hg单独处理或Hg与EDTA一起处理都导致了植物光合效能指数下降,干扰光系统II中的能量转移,将部分反应中心被转化为能耗中心,在一定程度上抑制了光系统II中的电子传递.

The effect of EDTA on uptake and translocation of Hg by Nephrolepis exaltata,and the responses of pigmentation and fast rise chlorophyll fluorescence were investigated in this study.Hg was overwhelmingly accumulated in root in the absence of EDTA.Addition of EDTA along with Hg enhanced accumulation of Hg in stem and leaf,thus transfering Hg from root to above-ground tissues.The exposure to Hg alone reduced chlorophyll content slightly and the treatment with Hg plus EDTA had no significant effect on chlorophyll content.The treatment with Hg alone or Hg plus EDTA resulted in the decrease of photosynthesis performance index（PIABS）,transformation of reaction centers into dissipation sinks and inhibiting the effect on electron transport to some extent.