中文摘要：

为了研究根表铁膜和硒对水稻吸收、转运不同形态的汞的影响,用Fe2＋溶液诱导根表形成铁膜后,将水稻植株分别暴露于无机汞（HgCl2）、甲基汞（MeHgCl）、无机汞和亚硒酸钠（HgCl2＋Na2SeO3）混合溶液、甲基汞和亚硒酸钠（MeHgCl＋ Na2SeO3）混合溶液的培养液中继续培养72h.用DCB （dithionite-citrate-bicarbonate）提取根表铁膜,并用电感耦合等离子体质谱（ICP-MS）测定DCB溶液中Fe、Hg含量及水稻根、茎叶中Hg含量.结果表明：水稻根表铁膜对MeHgCl和HgCl2均有吸附,对MeHgCl的吸附作用高于HgCl2.根表铁膜的形成显著降低了汞暴露水稻根、茎叶中汞的含量;铁膜的形成也显著降低了HgCl2和MeHgCl从水稻根部到茎叶部分的转运效率.硒的存在可增加铁膜对HgCl2和MeHgCl的吸附,降低水稻对HgCl2和MeHgCl的吸收和转运.研究结果表明：根表铁膜和硒单独或联合作用能显著抑制水稻对无机汞和甲基汞的吸收和转运,进而可以减少汞在稻米中的蓄积.研究的开展对于提高汞污染区稻米的质量和保证粮食安全具有一定的现实意义.

英文摘要：

To investigate the effects of iron plaque and selenium （Se）on the absorption and translocation of different mercury species in rice plant,the rice seedlings were exposed to HgCl2,MeHgCl,HgCl2 ＋Na2SeO3,MeHgCl ＋Na2SeO3 for 72 h after formation of iron plaque on root surface induced with Fe2＋.Iron plaque was extracted with DCB （dithionite-citrate-bicarbonate）.The concentrations of Hg and Fe in the DCB extraction,and Hg content in roots and shoots were determined by Inductively Coupled Plasma Mass Spectrometry （ICP-MS）.It is shown that both mercury species,especially MeHgCl can be absorbed by the iron plaque.The contents of rig in the root and shoot of the rice were significantly reduced with the formation of iron plaque.The translocation of HgCl2 and MeHgCl from root to leaf was also inhibited by iron plaque.Furthermore,the adsorption of HgCl2 and MeHgCl by the iron plaque can be enhanced with the addition of Se in the culture media,which efficiently inhibited the translocation of HgCl2 and MeHgCl in rice plant.In conclusion,the iron plaque or/and Se can actively inhibit the absorption and tmnslocation of Hg in rice,and then reduce IHg and MeHg accumulation in rice grain,which then improve the rice grain quality and food safety in the Hg contaminated areas.