硫酸亚铁诱导根表铁膜形成对水稻吸收和转运铜锌的影响

通过水培条件下添加硫酸亚铁诱导水稻根表铁膜的形成,利用连二亚硫酸钠-柠檬酸钠-碳酸氢钠(DCB)溶液对根表铁膜进行提取后测定,采用扫描电镜-能谱仪(SEM-EDS)和X射线衍射仪(XRD)等手段对硫酸亚铁诱导产生的根表铁膜进行表征,并分析根表铁膜对水稻吸收铜锌的影响。结果表明,添加硫酸亚铁可以诱导根表铁膜在水稻根系表面产生,未处理的水稻根表Fe含量为731 mg·kg~(-1),80 mg·kg~(-1) Fe~(2+)处理下水稻根表Fe含量为53 562 mg·kg~(-1);SEM-EDS和XRD分析发现大量颗粒状含铁化合物附着于水稻根表。与未经硫酸亚铁处理相比,有根表铁膜水稻的铁膜中,其Cu含量最高增加73.16%,Zn含量最高增加112.10%;水稻根系Cu含量最高降低31.15%,Zn含量最高降低13.02%;水稻茎叶Cu含量最高降低19.50%,Zn含量最高降低25.56%。土壤添加硫酸亚铁可以显著降低水稻对Cu和Zn的吸收与积累。

Effects of ferrous sulfate induced iron plaque formation on root uptake and transport of copper and zinc in rice

The iron plaque of rice root was induced by adding ferrous sulfate under the condition of hydroponics. The iron plaque of root surface was extracted by the dithionite-citrate-bicarbonate (DCB) solution. Afterwards, the iron plaque induced with ferrous sulfate was characterized by scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and X-ray diffraction. And the effect of iron plaque on the absorption of copper and zinc in rice was studied. The results showed that the addition of ferrous sulfate could induce the formation of root iron plaque on the surface of rice roots. The Fe content in the surface of rice root without treatment and treated with 80 mg·kg^-1 of Fe²⁺ was 731 and 53 562 mg·kg^-1, respectively. The analyses of SEM-EDS and X-ray diffraction found a large number of granular iron-containing compounds attached to the rice root surface. Compared with no ferrous sulfate treatment, the the maximum increment of Cu and Zn contents could reach up to 73.16% and 112.10% in the iron plaque of rice root, correspondingly, whereas the highest reduction of Cu and Zn contents in the stem and leaf could reach up to 31.15%,19.50% and 13.02%, 25.56% , respectively. The addition of ferrous sulfate could significantly reduce the uptake and accumulation of Cu and Zn in rice.