硫对水稻幼苗铁膜生成及累积镉的影响  

Effect of sulfur addition on iron plaque formation and cadmium accumulation in rice seedlings

作　　者：韩若晴 刘哲 樊玉 庄重 李花粉 王琪 万亚男 HAN Ruoqing;LIU Zhe;FAN Yu;ZHUANG Zhong;LI Huafen;WANG Qi;WAN Yanan(Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation,College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193;Geological Survey Institute of Hebei Province,Shijiazhuang 050081)

机构地区：[1]中国农业大学资源与环境学院,农田土壤污染防控与修复北京市重点实验室,北京100193 [2]河北省地质调查院,石家庄050081

出　　处：《环境科学学报》2025年第3期393-401,共9页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2023YFD1700105);国家自然科学基金项目(No.41471271,41907146)。

摘　　要：降低水稻镉累积对保障水稻安全生产至关重要.本文通过水培试验,探究硫(S)对铁膜介导的水稻幼苗Cd吸收、转运和累积的调控作用.研究结果表明,施硫处理促进了水稻幼苗的生长,地上部和根系生物量较S0(缺S处理不施硫对照)处理最高分别增加了19%和24%.施硫处理促进了水稻根表铁膜的生成,与S0相比,施硫处理使铁膜中的铁(Fe)含量提高了37%~59%.扫描电镜结果显示,随着硫添加量的增加,水稻根系表面颗粒状团聚体更加密集.硫供应增加了铁膜中的Cd含量,S0.2和S2处理下,铁膜中Cd含量相较于S0处理分别显著提高了36%和34%(p<0.05).硫供应对水稻植株累积Cd的影响表现为使根部Cd含量增加,使地上部Cd含量降低.在无铁膜和有铁膜存在两种情况下,硫供应分别使水稻根系镉含量最高显著增加了78%和53%(p<0.05),使地上部镉含量分别降低了30%和29%.转移系数随着硫施用的增加而降低,这种现象在铁膜存在时更加明显.此外,外源添加硫提高了Cd在水稻铁膜和根部中的占比,降低了Cd在地上部的占比.结构方程模型结果显示,硫对水稻地上部Cd含量存在直接的负效应(效应系数为-0.57)和间接的正效应(效应系数为0.06).而根Cd含量和铁膜Cd含量对地上部Cd含量的总效应分别为0.14和0.10.综上所述,适量的硫供应可以促进根表铁膜的生成,使Cd更多的被固持在水稻根表铁膜中,并抑制Cd向地上部的转运从而降低水稻地上部对Cd的积累.Reducing cadmium(Cd)accumulation in rice is crucial for ensuring rice safety production.This study aims to investigate the effects of sulfur(S)addition on Cd uptake,translocation,and accumulation in rice seedlings by regulating the formation of iron plaques,using a hydroponic experimental approach.The results showed that S application promoted the growth of rice seedlings,with aboveground and root biomass increasing by 19%and 24%,respectively,compared to the S-deficient(S0)treatment.In addition,S application promoted the formation of iron plaque on the rice root surface,increasing iron(Fe)content by 37%to 59%relative to S0.Scanning electron microscopy showed that with increased S addition,the granular agglomerates on rice root surfaces became denser.Compared to the S0 treatment,Cd content within the iron plaque was significantly increased by 36%and 34%under S0.2 and S2 treatments,respectively,(p<0.05).The effect of S addition on Cd accumulation in rice plants was characterized by an increase in root Cd content and a decrease in the the aboveground Cd content.In both the absence and presence of iron plaques,S addition significantly increased root Cd content by up to 78%and 53%,respectively(p<0.05),while shoot Cd content decreased by 30%and 29%,respectively.The transfer factor(TF)decreased as S application increased,with this phenomenon being more pronounced in the presence of iron plaques.Moreover,exogenous S addition increased the percentage of Cd in rice iron plaque and roots while decreasing the percentage of Cd in the aboveground parts.Results from structural equation modeling showed that S addition led a significant effect in reducing shoot Cd concentration,which had the highest standardized total effects(direct plus indirect effects).In summary,an appropriate application of S can promote the generation of iron plaque on rice root surface,leading to more Cd being retained in the iron plaque.This effect can inhibit the transport of Cd from root to shoot and reduce Cd accumulation in the aboveground of rice.

关 键 词：镉 硫供应 铁膜 水稻 转运 

分 类 号：X53[环境科学与工程—环境工程]