Hyperaccumulative property comparison of 24 weed species to heavy metals using a pot culture experiment

The screening of hyperaccumulators is still very much needed for phytoremediation. With properties such as strong tolerance to adverse environment, fast growing and highly reproductive rate, weed species may be an ideal plant for phytoremediation. The objectives of this study were to examine the tolerance and hyperaccumulative characteristics of 24 species in 9 families to Cd, Pb, Cu and Zn by using the outdoor pot-culture experiment. In the screening experiment, only Conyza canadensis and Rorippa globosa displayed Cd-hyperaccumulative characteristics. In a further concentration gradient experiment, C. canadensis was affirmed that it is not a Cd hyperaccumulator. Only R. globosa, indicated all Cd hyperaccumulative characteristics, especially Cd concentration in its stems and leaves were higher than 100 mg/kg, the minimum Cd concentration what a Cd-hyperaccumulator should accumulate. Thus, R. globosa was further validated as a Cd-hyperaccumulator.     

根瘤菌、丛枝菌根（AM）真菌与宿主植物共生的分子机理

丛枝菌根(AM)真菌和根瘤菌是两类重要的共牛微生物,分别能够与宿主植物形成丛枝菌根和根瘤,其中,对二者共有的宿主植物--豆科植物而言,则能够形成AM真菌-豆科植物-根瘤菌三重共生体.两类微生物与宿主植物共生关系建立的关键是二者之间的相互识别以及随后的侵染,其相互识别过程就是它们相互交换信号分子、相互作用的过程,而这两类微生物与宿主植物的识别过程具有许多相似之处.本文就根瘤菌、AM真菌与宿主植物在分子水平上的共生机理进行了综述,在对宿主植物分泌信号分子识别的基础上,提出植物根系对两类微生物侵染的感应机制,分析了共生体形成过程中相关基因的转录与表达,进而阐明了共生体的形成过程,并对本领域的未来发展提出了建议.     

茄子苗对镉积累和耐性的品种间差异

通过盆栽实验方法研究了13种茄子幼苗对镉(Cd)积累与耐性的品种间差异。结果表明,这些茄子幼苗根及地上部Cd含量均随土壤中外加Cd的量的增加而提高。品种间存在着显著差异(P<0.05),其中Cd含量最高品种根部和地上部的Cd含量分别为Cd含量最低品种的2.1、2.4倍(2mg·kg-1Cd处理组)和1.5、1.6倍(4mg·kg-1Cd处理组)。不同品种幼苗对Cd的富集系数均大于1,表现出较强的富集能力。但转运系数均小于1,Cd从根部向地上部转移能力较弱,大多数品种间差异不大。当Cd添加量为2mg·kg-1时,只有绿龙长茄地上部生物量显著下降(P<0.05)。当Cd添加量提高到4mg·kg-1时,6个品种地上部生物量显著下降(P<0.05),这些品种对Cd的耐性较弱。综合评价,辽茄三号对Cd积累的含量最低,富集系数和转移系数也较低,对Cd具有较强的耐性,具有Cd低积累特征。     

镉对血管内皮细胞损伤及其致动脉硬化的毒理学机制

采用人脐静脉内皮细胞体外培养和大鼠镉染毒实验,检测镉对人脐静脉内皮细胞和大鼠血清NO和ICAM-1分泌量,及大鼠主动脉病理改变的影响。结果表明,镉染毒可造成血管内皮细胞NO分泌量明显降低和ICAM-1分泌量明显升高,与镉染毒浓度剂量相关,体外细胞培养与活体动物实验的结果表现出一致性(P<0.05)。镉暴露可明显促进血管内皮细胞凋亡,主动脉HE染色见动脉硬化改变,各层均见较多ICAM-1阳性表达,主要存在于粥样斑块区。因此,过量镉摄入通过影响大鼠血管内皮细胞功能和结构促进动脉粥样硬化的形成。     

某铅锌矿坑口周围具有重金属超积累特征植物的研究

针对目前植物修复中Cd-Pb-Cu-Zn复合污染的超富集植物缺乏研究,采用野外采样系统分析方法,对青城子铅锌矿各主要坑口周围17科31种杂草植物进行其积累特性的初步研究。结果表明,全叶马兰(Kalimeris integrifolia)、蒲公英(Taraxacum mongolicum)和鬼针草(Bidens bipinnata)3种植物地上部对Cd的富集系数均>1,且地上部Cd含量大于根部Cd含量,具备了重金属超富集植物的基本特征,进一步研究的价值很大。以杂草为对象筛选超富集植物很可能获得较大突破。     

Identification of rice cultivar with exclusive characteristic to Cd using a field-polluted soil and its foreground application

Using low-accumulative plant, especially excluder crop, to safely produce food is one of the very important technologies of phytoremediation, which is practical to safe production and long-term remediation of heavy metal-contaminated soil. A pot experiment using field cadmium (Cd)-contaminated soil (Cd concentration was 0.75 mg?kg^?1) was conducted to compare Cd accumulation differences among 39 normal rice cultivars (Japonica) in Shenyang region of China for food safety and high grain yield aim. The results showed that brown grain Cd concentration in 12 rice cultivars of a total of 39 tested cultivars was lower than 0.2 mg?kg^?1 (Agricultural Trade Standard of Nonpollution Food for Rice of China, NY 5115–2008). In these 12 cultivars, Cd enrichment factors (Cd concentration ratio in shoot to that in soil) of nine cultivars were lower than 1. Likewise, Cd translocation factors (Cd concentration ratio in shoot to that in root) of eight cultivars were lower than the 0.28 average. Furthermore, grain yield per pot of seven cultivars were higher than the average 18.4 g?pot^?1. Four cultivars, i.e., Shendao 5, Tianfu 1, Fuhe 90, and Yanfeng 47 showed Cd-exclusive characteristic and better foreground application.     

土壤中重金属镉锌铅复合污染的研究

采用吸附与解吸实验及盆栽试验，研究了在重金属镉、锌、铅复合污染条件下，棕壤对重金属的吸附、解吸规律，以及菠菜吸收重金属的特点。结果表明：棕壤对铅、锌的吸附分别符合Ｌａｎｇｍｕｉｒ、Ｆｒｅｕｎｄｌｉｃｈ方程，对镉的吸附用Ｌａｎｇｍｕｉｒ、Ｆｒｅｕｎｄｌｉｃｈ及Ｔｅｍｋｉｎ方程回归都不显。重金属被吸附后的解吸率顺序为：Ｚｎ〉Ｃｄ〉Ｐｂ。Ｐｂ＾２＋与吸附位结合的牢固程度较单一污染时大，而Ｃｄ＾２＋和Ｚ     

Selective uptake,distribution, and redistribution of 109Cd, 57Co, 65Zn, 63Ni,and 134Cs via xylem and phloem in the heavy metal hyperaccumulator Solanum nigrum L

The focus of this article was to explore the translocation of ¹⁰⁹Cd, ⁵⁷Co, ⁶⁵Zn, ⁶³Ni, and ¹³⁴Cs via xylem and phloem in the newly found hyperaccumulator Solanum nigrum L. Two experiments with the uptake via the roots and transport of ¹⁰⁹Cd, ⁵⁷Co, and ⁶⁵Zn labeled by roots, and the redistribution of ¹⁰⁹Cd, ⁶⁵Zn, ⁵⁷Co, ⁶³Ni, and ¹³⁴Cs using flap label in S. nigrum in a hydroponic culture with a standard nutrient solution were conducted. The results showed that ¹⁰⁹Cd added for 24 h to the nutrient medium of young plants was rapidly taken up, transferred to the shoot, and accumulated in the cotyledons and the oldest leaves but was not efficiently redistributed within the shoot afterward leading to a rather low content in the fruits. In contrast, ⁵⁷Co was more slowly taken up and released to the shoot, but afterward, this element was redistributed from older leaves to younger leaves and maturing fruits. ⁶⁵Zn was rapidly taken up and transferred to the shoot (mainly to the youngest leaves and not to the cotyledons). Afterward, this radionuclide was redistributed within the shoot to the youngest organs and finally accumulated in the maturing fruits. After flap labeling, all five heavy metals tested (¹⁰⁹Cd, ⁵⁷Co, ⁶⁵Zn, ⁶³Ni, ¹³⁴Cs) were exported from the labeled leaf and redistributed within the plant. The accumulation in the fruits was most pronounced for ⁶³Ni and ⁶⁵Zn, while a relatively high percentage of ⁵⁷Co was finally found in the roots. ¹³⁴Cs was roughly in the middle of them. The transport of ¹⁰⁹Cd differed from that previously reported for wheat or lupin and might be important for the potential of S. nigrum to hyperaccumulate cadmium.     

镉造成心血管损害毒性机制的研究进展

镉是一种极易在人体内蓄积的有毒元素,长期的生物蓄积和生物放大,会对机体产生一系列的损伤,其中,对心血管系统的损伤包括易造成动脉硬化、高血压和心肌病等.本文将镉在心血管损伤方面的毒作用的研究进展进行了总结,包括镉对心血管的氧化损伤,对心血管粘附因子的破坏,对心血管内皮细胞的功能和DNA损伤修复机制的破坏,以及对心血管内皮...     

Cooperative identification for critical periods and critical source areas of nonpoint source pollution in a typical watershed in China

Environmental Science and Pollution Research - Critical periods (CPs) and critical source areas (CSAs) refer to the high-risk periods and areas of nonpoint source (NPS) pollution in a watershed,...