Combined Effect of Zinc and Cadmium Levels on Root Antioxidative Responses in Three Different Zinc‐Efficient Wheat Genotypes

This work was undertaken to investigate the effect of zinc (Zn) nutrition on root antioxidative responses to cadmium (Cd) toxicity of three wheat genotypes differing in Zn efficiency. A hydroponic experiment was carried out in which two bread wheat genotypes (Triticum aestivum L. cvs. ‘Rushan’ and ‘Cross’) and one durum wheat genotype (Triticum durum L. cv. Durum) were exposed to three Zn²⁺ (10^?11.11, 10^?9.11 and 10^?8.81 μm ) and two Cd²⁺ (10^?11.21 and 10^?10.2 μm ) activity levels. ‘Durum’ showed the highest root sulfhydryl (‐SH) groups content and activity of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) and the lowest root membrane permeability among the studied wheat genotypes. In ‘Durum’, Zn nutrition increased root ‐SH groups concentration of seedlings in Cd‐free nutrient solution. In ‘Cross’, as Zn²⁺ activity increased from 10^?11.11 to 10^?9.11 μm , root ‐SH groups concentration was increased while decreased with increasing Zn²⁺ to 10^?8.81 μm . Cadmium increased root membrane permeability at both 10^?11.11 and 10^?9.11 μm Zn²⁺ levels. Activity of CAT and APX increased in roots of ‘Durum’ plants exposed to Cd at Zn²⁺ = 10^?9.11 μm and thereafter decreased with increasing Zn²⁺ activity. In contrast, CAT and APX activity in roots of ‘Cross’ and ‘Rushan’ genotypes exposed to Cd decreased by increasing Zn activity to 10^?9.11 μm and then increased at Zn²⁺ = 10^?8.81μm . The results showed an increase in activities of antioxidative enzymes in Cd‐treated plants, although this increase was dependent on the crop genotype and Zn levels in the media.     

兴安白芷茎水溶性成分HPLC图谱分析

以兴安白芷茎水溶性化学成分为研究对象,运用HPLC指纹图谱的分析方法,考察了洗脱时间、柱温、流速、检测波长、进样量对HPLC图谱质量的影响。结果表明,以Hypersil GOLD C18柱为色谱柱,甲醇-2％甲酸为流动相梯度洗脱,紫外检测波长：340nm,柱温：25℃,进样量：20μL,流速：1mL/min,洗脱时间：82min为洗脱条件,各色谱峰响应较均匀,色谱信息较全,分离度好,保留时间适中。     

外源添加物降低镉胁迫下香菇体内镉含量及对酶活性的影响

香菇等可食用菇类比绿色植物体内更能逐步聚集浓度大的镉等重金属。子实体中的镉危及食用者的健康,因此减少菇类子实体中镉的含量,对人体健康意义重大。本研究检测了5种外源添加物水杨酸、沸石、石膏、壳聚糖及硫酸锌对镉胁迫下香菇体内镉含量的降低作用,并测定不同添加物对香菇羧甲基纤维素酶和漆酶活性的影响。试验结果表明,被测试的添加物中,硫酸锌对香菇808和868子实体中的镉含量著,石膏次之,表明硫酸锌是5种外源添加物中降低香菇体内镉浓度的最佳选择。此外,通过测定5种外源添加物在3 mg·kg-1镉胁迫下对香菇羧甲基纤维素酶和漆酶活性的影响,试验数据表明菌丝满袋期时,在添加硫酸锌或石膏时,香菇羧甲基纤维素酶和漆酶活性达到最高,说明培养料中添加硫酸锌或石膏在降低香菇体内镉含量的同时,也可以一定程度上增强生长代谢酶的活性。     

改性花生壳对水中Cd^2＋和Pb^2＋的吸附研究

用高锰酸钾对花生壳进行改性,制成改性花生壳吸附材料,并进一步就该吸附剂对水中重金属离子Pb^2＋、Cd^2＋的吸附去除性能进行了考察,结果表明,吸附在18h后基本达到平衡,吸附Pb^2＋和Cd^2＋最佳初始pH值分别为4.5和6.5,对Pb^2＋的吸附量最大达到104.75mg·g^-1,对Cd^2＋的吸附量最大达到43.11mg·g^-1。对Pb^2＋和Cd^2＋在该吸附剂上的竞争吸附研究结果表明,竞争吸附的干扰使得Cd^2＋的吸附量降低88.47%,Pb^2＋的吸附量降低20.80%,且Pb^2＋的吸附量为Cd^2＋的5-6倍,吸附剂对重金属离子的吸附选择顺序为Pb^2＋〉Cd^2＋。     

不同磷水平下玉米和小麦植株亚细胞中镉的积累

Corn and wheat plants were grown in a nutrient culture solution at four levels of phosphorus (0,0.12,0.60 and 3.0mmol L^-1) and two levels of cadmium(0 and 4.0umol L^-1) in greenhouse for a 18-day period.The concentrations of phosphorus and cadmium in cell wall,cytoplasm and vacuoles of roots and leaves were examined by cell fractionation techniques.With increasing phosphorus in medium,the contents of P in cell wall,cytoplasm and vacuoles of corn and wheat roots and leaves increased.The highest content of P was observed in cell wall,next in vacuoles,and the lowest in cytoplasm.The wheat subcellular fractions in both roots and leaves hab higher concentrations of phosphorus than those of corn.Increasing phosphorus in medium significantly inhibited the intracellular Cd accumulation in both species,However,at P concentration up to 3.0mmol L^-1,the Cd content in cell wall was increased.Increasing phosphorus resulted in reduction of the subcellular Cd content in cell wall was increased.Increasing phosphorus resulted in reduction of the subcellualr Cd content in corn and wheat leaves.Compared with corn,the wheat roots had a higher Cd content in the cell wall and vacuoles and a lower in cytoplasm,while in leaf subcellular fractions the wheat cell had a higher Cd content in its vacuoles and a lower one in its cytoplasm,The results indicate that phosphorus may be involved in sequestration of Cd ionic activity in both cell wall and vaculoes by forming insoluble Cd phosphate.