Cd在地肤[Kochia scoparia(L.)Schrad.]中的化学形态及亚细胞分布  

Chemical species and subcellular distribution of cadmium in Kochia scoparia(L.)Schrad.

作　　者：吴亮 朱姝 张皓 谭菊 王凡[5] 牛鸿宇 谭璐 杨海君[2] WU Liang;ZHU Shu;ZHANG Hao;TAN Ju;WANG Fan;NIU Hongyu;TAN Lu;YANG Haijun(Changsha Uranium Geology Research Institute,CNNC,Changsha 410007,China;School of Resources and Environment,Hunan Agricultural University,Changsha 410128,China;Hunan Provincial Engineering Research Centre for the Evaluation and Comprehensive Utilization of Associated Radioactive Mineral Resources,Changsha 410007,China;Changsha Ecological Environment Monitoring Center of Hunan Province,Changsha 410001,China;Changsha Environmental Protection College,Changsha 410004,China)

机构地区：[1]核工业二三〇研究所,长沙410007 [2]湖南农业大学资源环境学院,长沙410128 [3]湖南省伴生放射性矿产资源评价与综合利用工程技术研究中心,长沙410007 [4]湖南省长沙生态环境监测中心,长沙410001 [5]长沙环境保护职业技术学院,长沙410004

出　　处：《农业环境科学学报》2023年第5期1011-1022,共12页Journal of Agro-Environment Science

基　　金：湖南省科教联合基金项目(2022JJ60096)。

摘　　要：为探究镉(Cd)在地肤[Kochia scoparia(L.)Schrad.]茎部与根系中的亚细胞分布特征,在不同pH和不同Cd浓度胁迫下,对成熟期地肤生物量及Cd在地肤根系、茎部的积累状况和化学形态特征进行研究。结果表明:所有处理地肤茎部生物量均高于根系,当Cd添加量为1.5~3.0 mg·kg^(-1)时,T处理(pH 6.1)地肤总生物量高于TS处理(pH 5.0);地肤将58.09%~89.35%的Cd积累在茎部,所有处理地肤Cd的富集系数大小为茎>根系,表明地肤茎对Cd的积累能力强于根系,且在Cd添加量为1.5~9.0 mg·kg^(-1)时,T处理地肤茎Cd积累量高于TS处理;地肤根系和茎中超过85%的Cd贮存在细胞壁与液泡中,表明二者是地肤细胞中Cd区室化分布和解毒的重要场所;地肤根系细胞器Cd所占比例低于地肤茎部,这也是地肤将更多的Cd富集在茎部的一个重要原因;地肤茎和根系中均以移动性和毒性相对较低的醋酸提取态、氯化钠提取态及乙醇提取态Cd分配比例最大(T为82.96%~88.17%;TS为83.70%~89.70%),其中醋酸提取态含量最高(T为37.31%~56.24%;TS为40.98%~52.32%),氯化钠提取态与乙醇提取态Cd含量接近,这种Cd赋存形式是地肤降低Cd生物有效性和减少Cd毒害的一种重要防御机制。当土壤pH为6.1和Cd添加量为1.5 mg·kg^(-1)时,地肤对土壤Cd的解毒较好。研究表明,地肤具有对不同Cd胁迫水平的耐性,且对酸性土壤有较强的适生性,因此适用于湖南地区酸性农田土壤的修复治理。To verify the subcellular distribution and characteristics of cadmium(Cd)in the stems and root system of Kochia scoparia(L.)Schrad.,the biomass at maturity,accumulation of Cd in roots and stems,and chemical morphology of Cd were studied under varying pH and concentrations of Cd to induce stress.Results showed that the stem biomass at all treatments was higher than that of the root.When the Cd concentration was 1.5-3.0 mg·kg^(-1),the total biomass of the T treatment(pH 6.1)was higher than that of the TS treatment(pH 5.0).enrichment coefficient of Cd in all treatments was higher in the stem than that in the root,indicating that the bioconcentration ability of Cd in the stem of K.scoparia was stronger than that in the root system.At a concentration of 1.5-9.0 mg·kg^(-1),the accumulation of Cd in the stem in the T treatment was higher than that in the TS treatment.More than 85%of the Cd in the root system and stems of K.scoparia was stored in cell walls and vacuoles,indicating that both were important sites for the compartmentalized distribution and detoxification of Cd in K.scoparia plant cells.The proportion of Cd in the root organelles of K.scoparia was lower than that in the stem,which was an important reason for the high Cd concentration in the stem.The largest proportion of Cd was distributed in the acetic acid extraction,sodium chloride extraction,and ethanol extraction(T:82.96%–88.17%;TS:83.70%–89.70%)in the stem and root systems of the K.scoparia,which were relatively less mobile and toxic.The acetic acid extraction had the highest content(T:37.31%–56.24%;TS:40.98%–52.32%),and the sodium chloride extraction and ethanol extraction were close to each other.This Cd fraction was an important defense mechanism to reduce Cd bioavailability and toxicity.When the soil was under pH 6.1 and the Cd stress was 1.5 mg·kg^(-1),K.scoparia had a good detoxification effect on the Cd in the soil.Studies have reported that K.scoparia has tolerance to different levels of Cd stress and has strong adaptability to acidi

关 键 词：镉 地肤 积累 亚细胞分布 化学形态 

分 类 号：X173[环境科学与工程—环境科学]