Plant Zn Concentration Research Articles

Heavy metal bioaccumulation and mobility from rice plants to Nilaparvata lugens (Homoptera: Delphacidae) in China.

Samples of soils, rice plants, and the adult, long-winged, brown planthoppers, Nilaparvata lugens (Stål) (Homoptera: Delphacidae), were collected from 18 sites of 9 regions in southern China. The concentrations of seven elements (Cu, Zn, As, Mo, Ag, Cd, and Pb) were measured using inductively coupled plasma mass spectrometry. Heavy metal mobility and bioaccumulation were analyzed in the rice plant-N. lugens system. The concentrations of Zn, As, Cd, and Pb in rice plants were positively correlated with their relevant concentrations in soil samples The bioconcentration factors of the seven elements in the rice plant-N. lugens system showed that the order of metal accumulation was Mo>Zn>Ag>Cd>Cu>Pb>As. In particular, Mo and Zn showed significantly high accumulation in N. lugens. A cluster analysis and factor analysis showed that the bioaccumulation of these seven elements in the rice plant-N. lugens system could be classified into two groups, closely related to their molar mass. The first group consisted of five elements with relatively light molar masses: Cu, Zn, As, Mo, and Ag. Cu and Zn, which have nearly equal molar masses, showed similar accumulation levels in N. lugens. The second group included two elements with relatively heavy molar masses: Cd and Pb. This study demonstrated that bioaccumulation of seven heavy metals was regular in the rice plant-N. lugens system. N. lugens could be used as bioindicators of the contaminated degree for Zn in rice paddy fields. This information may provide a basis for future ecological research on the bioaccumulation mechanism in N. lugens.

Effect of phosphorus‐enriched biochar and poultry manure on growth and mineral composition of lettuce (Lactuca sativa L. cv.) grown in alkaline soil

AbstractThe use of pyrolysis products of manures gives positive effects on soil fertility, crop productivity and soil carbon sequestration. However, effects depend on soil characteristics, plant species and the raw material from which the biochar is derived, and some negative effects of biochar have been reported. The objective of this study was to evaluate the effectiveness of poultry manure (PM)‐derived biochar on the growth, and P, N, K, Ca, Mg, Fe, Zn, Cu and Mn concentration of lettuce (Lactuca sativa L.) plant. The treatments as follows: control, 20 g/kg poultry manure (PM), 20 g/kg phosphorus‐enriched poultry manure (PM+P), 10 g/kg Biochar (B), 10 g/kg Biochar+P (B+P). Application of biochar and PM significantly increased lettuce growth, and P‐enriched forms of PM and biochar gave the higher growth. PM has no significant effect on the N concentrations but biochar and, P‐enriched PM and biochar treatments significantly increased N concentrations. Phosphorus concentration of the lettuce leaves significantly increased by PM and biochar treatments. Plant K concentrations were also increased by PM and biochar, and their P‐enriched forms. Leaf Ca and Mg concentrations were lower in Biochar and B+P treatments than that of PM and PM+P treatments. Compared to control and PM treatments, biochar applications reduced Fe, Zn, Mn and Cu concentrations of the lettuce plants. The results of this study indicated that application of biochar to alkaline soil is beneficial for crop growth and N, P and K nutrition, but it certainly reduced Fe, Cu, Zn and Mn nutrition of lettuce.

Repeated phytoextraction of four metal-contaminated soils using the cadmium/zinc hyperaccumulator Sedum plumbizincicola

A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible.

Critical limits of zinc in soil and rice plant grown in alluvial soils of West Bengal, India

A study was conducted in 22 alluvial soils of West Bengal, India to estimate the critical limit of Zn in soil and rice plant for predicting the response of rice (Oryza sativa) to zinc application. The DTPA-extractable Zn was positively and significantly correlated with CEC, organic carbon and clay contents and negatively correlated with pH, silt and sand contents of soil. The DTPA-extractable Zn also showed a positive correlation with dry matter yield and plant Zn content. The critical concentration of Zn in these soils was established at 0.75 mg kg-1 for rice and that of 28.0 mg kg-1 in the plant tissue. Soil containing Zn below the critical limit responded appreciably to Zn fertilization. A negative response to Zn application was also observed at its higher level. The average dry matter yield increases with increasing level of Zn application up to 2.5 mg kg-1 in Zn deficient soils. The average response to Zn application in rice in Zn deficient soils was found to be 68.5% and 19.9% in Zn adequate soils. DOI: http://dx.doi.org/10.3329/sja.v10i2.18334 SAARC J. Agri., 10(2): 137-146 (2012)

CONTENT OF REDUCED GLUTATHIONE FORM AS A BIOMARKER OF OXIDATIVE STRESS IN SPINACH PLANTS GROWING IN SOIL CONTAMINATED WITH ZINC

The aim of the paper is the assessment of the efficiency of anti-oxidative system in spinach plants growing in the substratum polluted with zinc. The assessment was conducted on the basis of changes of reduced glutathione (GSH) form concentration in the plant aboveground organs. Spinach plants, ‘Matador’ c.v., were cultivated in soils contaminated with zinc in two pot experiments conducted in 2010 and 2011. The experimental substratum was light, slightly soil with granulometric composition of sandy silt loam. Zinc in the acetate form, was supplied to the soil in four doses corresponded to this metal critical concentrations in soil with 0, I, II and III degrees of pollution with this element according to IUNG classification. Simultaneously, the control with natural Zn content in soil was maintained. Zn concentrations in spinach ranged from 412.8 to 1722 mg ∙ kg -1 d.m. and increased with growing degree of substratum pollution with this element. Over the course of the vegetation period the content of Zn in plants was generally greater. GSH content in spinach grown in both years of experiments fluctuated from 31.70 to 238 µg ∙ g -1 f.m. The biggest content of this compound in spinach was stated in the initial phase of plants growth. The plants tolerated only the first two Zn doses supplied to the substratum. Spinach growing in the objects where zinc additions to the soil equalled II and III degree of substratum pollution died shortly after germination. The plants from these objects in the initial growth phase contained significantly less GSH than spinach from the objects with two first degrees (0 and I) of substratum pollution with zinc or from the control. The content of reduced glutathione form in spinach is a good biomarker of oxidative stress caused by zinc presence in plants. Synthesis of a bigger amount of GSH conditions spinach plant resistance to over the norm zinc content in soil. The efficiency of anti-oxidative system in spinach is bigger in the initial phase of this plant growth.

Bioaccumulation of zinc, lead, copper, and cadmium from contaminated sediments by native plant species and Acrida cinerea in South China

This research was conducted to search and identify spontaneously growing heavy metal-tolerant plant species that are potentially useful for phytoremediation in contaminated sediment. Five sites were selected for collection of plants growing on polluted shore (river bank) sediment of the Xiang River, China. The concentrations of Zn, Pb, Cu and Cd in plants, sediments, and grasshoppers were determined using flame atomic absorption spectrophotometer (AAS700, Perkin-Elmer, USA). Considering translocation factor and bioaccumulation factor, Rumex crispus (Polygonaceae), Rumex dentatus (Polygonaceae), and Lagopsis supina (Labiatae) could be potentially useful for phytostabilization of metals. R. crispus can be considered potentially useful for phytoextraction of Cd. In light of the biomagnification factors, grasshoppers are deconcentrators for Pb and Cd, microconcentrators for Zn and macroconcentrators for Cu to the plants, respectively. To the best of our knowledge, the present study is the first report on Zn, Pb, Cu and Cd accumulation in R. crispus and L. supina, providing a pioneer contribution to the very small volume of data available on the potential use of native plant species from contaminated sediments in phytostabilization and phytoremediation technologies.

Suitability of biochars (pyro‐ and hydrochars) for metal immobilization on former sewage‐field soils

SummaryMineralization of organic material and decreasing pH are expected to increase bioavailability and leaching of metals in soils formerly contaminated by irrigation with wastewater. Biochar has recently been proposed as a sorbent for metals, although the effects described in the literature are still inconsistent. Therefore, we conducted pot experiments to study the effects of the application of two different biochars to a sewage‐field soil on growth and nutrition of oat (Avena sativa L.) as well as on the mobility of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the soil solution. Poplar‐derived hydrochar (obtained by hydrothermal carbonization) and maize‐derived pyrochar (obtained by pyrolysis) were mixed with the soil at concentrations of 0, 1, 2.5 and 5% (g 100 g−1). Soils were leached after 2, 3 and 5 weeks with deionized water. Hydrochar reduced biomass production and had almost no effect on metal concentrations in plants and leachates. The negative effect on biomass yield may be attributable to decreased nitrogen (N) availability. Pyrochar increased biomass production and reduced plant Zn and Cd concentrations. In contrast, metal concentrations in soil leachates generally increased. Comparison of ultra‐centrifuged and filtered samples, microprobe analysis of centrifugation residues and Visual Minteq calculations suggest colloidal transport of Zn precipitates, whereas Cu is transported in the dissolved fraction. We conclude that the tested hydrochar is not suitable for metal immobilization. In the case of pyrochar, further research on colloidal transport of metal precipitates is needed to assess its suitability for soil remediation, despite positive effects on plant growth and the reduced uptake of Zn and Cd.

Study on Citrus Response to Huanglongbing Highlights a Down-Regulation of Defense-Related Proteins in Lemon Plants Upon ‘Ca. Liberibacter asiaticus’ Infection

Citrus huanglongbing (HLB) is a highly destructive disease of citrus presumably caused by ‘ Candidatus Liberibacter asiaticus ’ (Las), a gram-negative, insect-transmitted, phloem-limited α-proteobacterium. Although almost all citrus plants are susceptible to HLB, reports have shown reduced susceptibility to Las infection in lemon ( Citrus limon ) plants. The aim of this study is to identify intra-species specific molecular mechanisms associated with Las-induced responses in lemon plants. To achieve this, comparative 2-DE and mass spectrometry, in addition to Inductively Coupled Plasma Spectroscopy (ICPS) analyses, were applied to investigate differences in protein accumulation and the concentrations of cationic elements in leaves of healthy and Las-infected lemon plants. Results showed a differential accumulation of 27 proteins, including an increase in accumulation of starch synthase but decrease in the production of photosynthesis-related proteins in Las-infected lemon plants compared to healthy plants. Furthermore, there was a 6% increase (P > 0.05) in K concentration in leaves of lemon plants upon Las infection, which support results from previous studies and might represent a common response pattern of citrus plants to Las infection. Interestingly, contrary to reports from prior studies, this study showed a general reduction in the production of defense-related pathogen-response proteins but a 128% increase in Zn concentration in lemon plants in response to Las infection. Taken together, this study sheds light on general and intra-species specific responses associated with the response of citrus plants to Las.

Effect of compost and manure amendments on zinc soil speciation, plant content, and translocation in an artificially contaminated soil

The addition of organic matter in soil can modify the bioavailability of heavy metals. A greenhouse pot experiment was carried out using an edible plant species Eruca vesicaria L. Cavalieri grown on an artificially contaminated soil with Zn (665 mg kg(-1)). In this study, the effect of compost at 20 t ha(-1) (C20) and at 60 t ha(-1) (C60), manure at 10 t ha(-1) (M10) and at 30 t ha(-1) (M30), and chemical fertilizers (NPK) on Zn fate in a soil-plant system was evaluated. At the end of the experiment, the main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original Community Bureau of Reference sequential extraction and diethylene triamine pentaacetic acid extraction. Zinc, though an essential element for plant growth, caused toxicity effects in plants grown on control and manure treatments, while in the compost treatments, plants showed no visual toxicity symptoms. The concentrations of Zn in roots were similar for all treatments, while significant differences were observed for shoots. In fact, in the compost treatments, plants showed the lowest Zn concentration in shoots. Zinc speciation seems not to be affected by the applied treatments. Indeed, Zn plant content and translocation to shoots seems to be affected. Compost amendments significantly reduced Zn content and translocation in comparison to other treatments.

USING PSEUDOMONAS SPP. AND ARBUSCULAR MYCORRHIZAL FUNGI TO ALLEVIATE THE STRESS OF ZINC POLLUTION BY CORN (ZEA MAYS L.) PLANT

The objective was to test the single and combined use of Pseudomonas spp. and Glomus versiforme on the stress of high zinc (Zn) concentration in soil on corn growth as such data are little. Accordingly, in a greenhouse research work the effects of Zn concentrations (control, 100, 200 and 300 mg kg −1 ) and the microbial treatment (control, Pseudomonas spp. and G. versiforme) were tested on corn (single cross 704) growth. Almost three months after planting, plants were harvested. Plant dry weight and Zn uptake were determined. Zn significantly (P = 0.01) affected different measured parameters. The microbes increased plant dry weight related to the control treatment and the highest increase was related to the bacterial application (1.28 times higher). Both bacteria and mycorrhizal fungi and their combined use decreased Zn concentration in plant. The right combination of soil microbes can efficiently affect the process of bioremediation with respect to plant properties.

Viscum album versus host (Sorbus aucuparia) as bioindicators of urban areas with various levels of pollution

In this investigation we focus on the concentration of elements in Viscum album and its host (Sorbus aucuparia) as bioindicators of urban pollution. These broadly widespread species, very common in polluted areas may provide important information to monitor environmental quality throughout the year, especially for V. album. Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb and Zn concentrations were measured in the leaves and soil of the tree S. aucuparia as well as in V. album, a semi-parasite living on this tree species. The tree and the semi-parasite were studied in the urban environment of Oława (SW Poland). This area was selected because of the influence of a zinc smelter on the level of metal pollution of soil and plants and to compare the ability of S. aucuparia and V. album to accumulate metals. V. album appeared to be a better bioaccumulator of Cd, Ni, Pb and Zn and a weaker accumulator of Co than S. aucuparia in less polluted sites of Oława. S. aucuparia was a better bioaccumulator of Cd, Ni, Pb and Zn and a weaker accumulator of Co than V. album in more polluted sites. Cluster analysis of Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb and Zn concentrations in plants distinguished sites with lower and higher pollution levels which suggests a possibility of using these species for bioindication. However, the ratio of metals in V. album to S. aucuparia was different depending on the pollution level.

沣河沿岸土壤和优势植物重金属富集特征和潜在生态风险

PDF HTML阅读 XML下载 导出引用 引用提醒 沣河沿岸土壤和优势植物重金属富集特征和潜在生态风险 DOI: 10.5846/stxb201206150859 作者: 作者单位: 陕西师范大学旅游与环境学院,陕西师范大学,陕西师范大学旅游与环境学院,陕西师范大学物理学与信息技术学院,陕西师范大学数学与信息科学学院,陕西师范大学旅游与环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家水体污染控制与治理科技重大专项渭河典型重污染支流综合整治技术集成与示范子课题（2008ZX07012-002-004）；国家级大学生创新项目（1110718025） Enrichment and ecological risk of heavy metal in soils and dominant plants in the riparian of the Fenghe River Author: Affiliation: College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Physics and Information Technology,Shaanxi Normal University,Xi’an Shaanxi,College of Mathematics and Information Science,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:测定陕西省沣河沿岸32个土壤样品和16个优势植物样品中Cr、Cu、Mn、Pb、Zn和Ni 6种重金属元素的含量，并结合数据统计与GIS制图，对土壤和植物中重金属的空间分布、富集特征及潜在风险进行分析。结果表明沣河中下游沿岸土壤和植物中Cr、Mn、Pb、Zn和Ni含量空间分布呈明显富集。土壤中Cr、Mn和Pb的几何均值分别为92.1、611.1和32.9 mg/kg，均高于陕西省土壤元素背景值；植物中Mn、Zn含量在正常范围内，Cr、Cu、Ni含量部分超标，Pb含量整体较高，地上部分对Pb的积累量达到15.5 mg/kg，约为正常情况下的7.8倍。马齿苋、艾蒿、芦苇和水蓼4种植物生物量大，对这六种重金属富集能力均较强，可作为该地区耐重金属植物。沣河沿岸土壤和植物中重金属污染值得关注。 Abstract:Heavy metal contamination in rivers has become a major issues in recent decades due to their biogeochemical cycling, environmental persistence, and ecological risks. Intensive attention has been given to river sediment contamination but heavy metals in soils and plants along the river ecosystem have been inadequately studied. The results of this research will contribute to a better understanding of heavy metal characteristics, pollution status assessment, affect in river ecosystems, and environmental protection of rivers. A total of 32 soils and 16 dominant plants samples were collected in the riparian of the Fenghe river of Shaanxi Province from the headwater to the river mouth. The spatial distribution, accumulation characteristics, and potential risk of heavy metals in the soils and plants were investigated by measuring total concentrations of Cr, Cu, Mn, Pb, Zn, and Ni in soils and plants via X-Ray fluorescence spectrometry and atomic absorption spectroscopy, GIS mapping, and by analyzing the relationship between heavy metal concentrations in soils and plants. Significant spatial accumulation of Cr, Mn, Pb, Zn, and Ni in soils and plants were found midstream and downstream. The geometrical mean concentrations of Cr, Mn, and Pb in soils were 92.1, 611.1, and 32.9 mg/kg, respectively. The average concentrations of Cr, Mn, and Pb exceeded the corresponding background values of Shaanxi topsoil while the average concentrations of Zn, Cu, and Ni were lower. Taking the China Environmental Quality Standard (GB15618-1995, GradeⅠ) for soils as a reference, the ratio of all the samples in soils above the limit were 75% for Cr, 19% for Cu, 63% for Mn, 25% for Pb, and 6% for Ni, which indicates the pollution characteristics of multi-metals in soils are mainly due to Cr. The Nemero Index showed that the soils in the riparian of the Fenghe River were moderately polluted. The Geo-accumulation Index showed that soils were not polluted with Mn and Zn but there was mild Pb, Ni, Cr, and Cu contamination in some samples. The heavy metal concentrations in plants in the riparian of the Fenghe River had normal distribution. The Cr, Cu, and Ni concentrations of Pb in some samples were above critical values, while the Pb concentrations were high in all samples. The geometrical mean concentrations of Pb in the above-ground biomass, which accumulated to 15.5 mg/kg, was 7-8 times the normal concentrations in plants. This paper did not screen out new plants which satisfied with the standard of hyperaccumulators, but Portulaca oleracea., Artemisia argyi, Phragmites communis, and Polygonum hydropiper grew well and were potentially tolerant species. There were significant positive correlations among the concentrations of Cr, Cu, Zn, Mn, Ni, and Pb in the soils and plants, and the Cr concentrations in soils promoted the accumulation of Ni in the underground biomass. Along with Pb increase in the soil was a corresponding increase in Zn, Mn, and Pb in plant roots. It is necessary to focus on the potential risk of heavy metals for water safety and human health in soils and plants in the riparian of the Fenghe River. 参考文献 相似文献 引证文献

Short-term usage of sewage sludge as organic fertilizer to sugarcane in a tropical soil bears little threat of heavy metal contamination

A field experiment was carried out to study the effect of application rates of sewage sludge and mineral nitrogen and phosphate fertilizers on As, Ba, Cd, Cr, Cu, Ni, Pb, Se, and Zn concentration in soil, cane plant, and first ratoon (residual effect) in a Typic Hapludult soil. To allow an analysis by means of response surface modeling, four rates of sewage sludge (0, 3.6, 7.2 and 10.8 t ha−1, dry base), of N (0, 30, 60 and 90 kg ha−1) and of P2O5 (0, 60, 120 and 180 kg ha−1) were applied in randomized block design, in a 4 × 4 × 4 factorial scheme, with confounded degrees of freedom for triple interaction, with two replications. To evaluate the residual effect of the sludge applied to cane plant on the cane ratoon growth, mineral NK fertilizers were applied at the rates of 120 kg ha−1 N and 140 kg ha−1 of K2O, on all treatments. The application rates of mineral nitrogen and phosphate fertilizers did not affect statistically the heavy metal concentration in the soil and in the sugarcane plants. Sewage sludge application increased As, Cd, Cu, Ni, Pb, and Zn concentrations in soil, but values did not exceed the quality standard established by legislation for agricultural soils. Although the concentrations of metals in the plants were very low, the uptake of heavy metal by sugarcane plants was generally increased by sewage sludge doses. The use of sewage sludge based on N criteria introduces a small amount of heavy metal into the agricultural system, however it poses no hazard to the environment.

Expression of a rice Zn transporter, OsZIP1, increases Zn concentration in tobacco and finger millet transgenic plants

Zinc (Zn) deficiency is very widespread both from the plant and human nutrition perspective. One of the approaches to improve Zn in crop plants is by over-expression of Zn transporters such that plants can uptake and accumulate additional Zn added to soil. The ZIP family transporters generally contribute to Zn homeostasis in plants by regulating Zn transport into the cell. We over-expressed OsZIP1 in finger millet and model plant tobacco under the control of constitutive (35S) and endosperm-specific (Bx17) promoters to study the improvement in Zn accumulation. The transcript analysis revealed the induction of ZIP1 in leaf and root tissue under Zn deprivation in finger millet cultivars. Ectopic expression of OsZIP1 in tobacco under CaMV35S (n35S) and Bx17 (nBx17) improved seed Zn concentration compared to untransformed wild-type plants. In addition, we successfully developed finger millet transgenic plants, f35S and fBx17, expressing the OsZIP1 under 35S (f35S) and Bx17 (fBx17) promoter, respectively. The transgenic plants accumulated significantly higher Zn in seeds compared to untransformed wild-type finger millet plants. Plants expressing the gene under Bx17 promoter accumulated more Zn in seed than 35S plants. Apart from Zn, finger millet transgenic plants also showed increased Mn content in seeds. Our results show the involvement of OsZIP1 in improving Zn concentration in tobacco and finger millet. Using endosperm-specific promoter, it is possible to improve the seed Zn concentration in the edible part of cereals.

Response of antioxidant defences to Zn stress in three duckweed species

In the plants, Lemna gibba, Lemna minor and Spirodela polyrrhiza L., the effect of different concentrations of zinc (0.01, 0.05, 0.1, 0.5 and 1.5mgL−1 Zn) applied for four day was assessed by measuring changes in the chlorophyll, protein, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and guiacolperoxidase (GPX) activity of the plants. According to results, Zn contents in plants increased with increasing Zn supply levels. The level of photosynthetic pigments and soluble proteins reduced only upon exposure to high Zn concentrations. At the same time, the level of malondialdehyde (MDA) increased with increasing Zn concentration. These results suggested an alleviation of stress that was possibly the result of antioxidants such as catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) as well as guaiacol peroxidise (GPOX), which increased linearly with increasing Zn levels. Cellular antioxidant levels showed an increase suggesting a defensive mechanism to preserve against oxidative stress given rise to by Zn. Besides, the proline amount in L. gibba, L. minor and S. polyrrhiza increased with increasing zinc levels. These conclusions proposed that L. gibba, L. minor and S. polyrrhiza are supplied with an efficient antioxidant mechanism against Zn-induced oxidative stress which saves the plant's photosynthetic machinery from damage.It is concluded that higher zinc levels cause oxidative stress in L. gibba, L. minor and S. polyrrhiza cells and may reason membrane damage through production of ROS and interferes with chlorophyll metabolism.

CRITICAL DEFICIENCY LEVEL OF ZINC FOR CORN ON CALCAREOUS SALT-AFFECTED SOILS IN CENTRAL IRAN

A greenhouse experiment with 11 soil series and two zinc (Zn) rates (0 and 15 mg Zn kg−1 as zinc sulfate) was performed to determine critical deficiency level of Zn for corn (Zea mays L.) on calcareous salt-affected soils in central Iran. In addition, the most important soil properties affecting Zn phytoavailability were determined. Critical Zn deficiency levels were determined using the Cate-Nelson and Mitscherlich procedures. In most soils, application of Zn increased the dry matter yield, and Zn concentration and content in the shoot and root of corn. A positive correlation was observed between the soil electrical conductivity (EC) with Zn concentration in shoots, roots and whole plant while shoot Zn content was negatively correlated with buffer capacity of Zn in soil. Critical deficiency levels of Zn in soil for corn based on the Cate-Nelson and Mitscherlich method were 1.35 and 1.23 mg kg−1 for diethylenetriaminepentaacetic acid (DTPA)-extracted soil Zn, respectively.

The Influence of Cadmium Stress on the Content of Mineral Nutrients and Metal-Binding Proteins in Arabidopsis halleri.

We investigated the influence of cadmium stress on zinc hyperaccumulation, mineral nutrient uptake, and the content of metal-binding proteins in Arabidopsis halleri. The experiments were carried out using plants subjected to long-term cadmium exposure (40 days) in the concentrations of 45 and 225 μM Cd2+. Inductively coupled plasma-mass spectrometry, size exclusion chromatography coupled with plasma-mass spectrometry, and laser ablation inductively coupled plasma-mass spectrometry used for ablation of polyacylamide gels were employed to assess the content of investigated elements in plants as well as to identify metal-binding proteins. We found that A. halleri is able to translocate cadmium to the aerial parts in high amounts (translocation index >1). We showed that Zn content in plants decreased significantly with the increase of cadmium content in the growth medium. Different positive and negative correlations between Cd content and mineral nutrients were evidenced by our study. We identified more than ten low-molecular-weight (<100 kDa) Cd-binding proteins in Cd-treated plants. These proteins are unlikely to be phytochelatins or metallothioneins. We hypothesize that low-molecular-weight Cd-binding proteins can be involved in cadmium resistance in A. halleri.Electronic supplementary materialThe online version of this article (doi:10.1007/s11270-012-1292-4) contains supplementary material, which is available to authorized users.

Influence of iodine form and application method on the effectiveness of iodine biofortification, nitrogen metabolism as well as the content of mineral nutrients and heavy metals in spinach plants (Spinacia oleracea L.)

Biofortification of vegetables with iodine can become an alternative (in reference to salt iodization) method of introducing this element to human diet. Side-effects of iodine application on mineral nutrition of plants have not yet been thoroughly documented. The aim of the study was to evaluate the effect of iodine form and the method of I fertilization on iodine biofortification, nitrogen metabolism and the level on mineral nutrients and selected heavy metals in spinach plants. In the present research, pot cultivation of spinach ‘Olbrzym zimowy’ cv. was carried out on heavy soil including the following treatments: 1 – control (without iodine application), 2 – pre-sowing KI fertilization, 3 – pre-sowing KIO3 fertilization, 4 – fertigation with KI, 5 – fertigation with KIO3. In treatments no. 2 and 3 iodine was applied in a dose of 1mgIper1dm3 of soil. In treatments no. 4 and 5, water solution of iodine in the concentration of 0.0004% was used – approximately 1.1mgIdm−3 of soil was introduced during the cultivation. Introduction of iodine by fertigation proved to be much more effective for iodine biofortification of spinach than pre-sowing fertilization with this element – by 339% and 498% respectively for KI and KIO3. Pre-sowing soil fertilization with KI and KIO3 improved accumulation of nitrates(V) and chlorides in spinach. Soil application of iodine (in the form of KI and KIO3 – combination no. 2 and 3) increased N-total content in spinach plants. Fertigation of plants with KI and KIO3 significantly reduced the level of ammonium ions in spinach. Lowered content of Ca as well as higher accumulation of Fe were found in plants from treatments no. 2, 4 and 5. Application of iodine (irrespective of its chemical form and method) in spinach cultivation (treatments 2–5) decreased Na and Zn content in plants. Pre-sowing fertilization with KI and KIO3 reduced Pb accumulation in spinach. No influence of iodine fertilization and fertigation was found in reference to yield as well as the content of P, K, Mg, S, B, Cu, Mn, Mo and Cd in spinach plants.

Effects of Municipal Sewage Sludge Doses on the Chlorophyll Contents and Heavy Metal Concentration of Sugar Beet (Beta vulgaris var. saccharifera)

ABSTRACT The present study was conducted to assess the suitability of sewage sludge amendment (SSA) in soil for Beta vulgaris var. saccharifera (sugar beet) by evaluating the heavy metal accumulation and physiological responses of plants grown at a 10%, 25%, and 50% sewage sludge amendment rate. The sewage sludge amendment was modified by the physicochemical properties of soil, thus increasing the availability of heavy metals in the soil and consequently increasing accumulation in plant parts. Cd, Pb, Ni, and Cu concentrations in roots were significantly higher in plants grown at 25% as compared to 50% SSA; however, Cr and Zn concentration was higher at 50% than 25% SSA. The concentrations of heavy metal showed a trend of Zn > Ni > Cu > Cr > Pb > Cd in roots and Zn > Cu > Ni > Cr > Pb > Cd in leaves. The only instance in which the chlorophyll content did not increase after the sewage sludge treatments was 50%. There were approximately 1.12-fold differences between the control and 50% sewage sludge application for chlorophyll content. The sewage sludge amendment led to a significant increase in Pb, Cr, Cd, Cu, Zn, and Ni concentrations of the soil. The heavy metal accumulation in the soil after the treatments did not exceed the limits for the land application of sewage sludge recommended by the US Environmental Protection Agency (US EPA). The increased concentration of heavy metals in the soil due to the sewage sludge amendment led to increases in heavy metal uptake and the leaf and root concentrations of Ni, Zn, Cd, Cu, Cr, Pb, and Zn in plants as compared to those grown on unamended soil. More accumulation occurred in roots and leaves than in shoots for most of the heavy metals. The concentrations of Cd, Cr, and Pb were more than the permissible limits of national standards in the edible portion of sugar beet grown on different sewage sludge amendment ratios. The study concludes that the sewage sludge amendment in the soil for growing sugar beet may not be a good option due to risk of contamination of Cr, Pb, and Cd.

Testing amendments for remediation of military range contaminated soil

Military range soils are often strongly contaminated with metals. Information on the effectiveness of remediation of these soils is scarce. We tested the effectiveness of compost and mineral treatments for remediation and revegetation of military range soil collected in Aberdeen, MD. The soil was barren due to zinc (Zn) phytotoxicity while lead (Pb) posed a substantial risk to soil biota, wildlife and humans through various pathways. Seven treatments were tested: untreated control, agricultural NPK fertilization, high phosphate fertilization plus agricultural rates of NK, CaCO(3), "Orgro" biosolid compost, "Orgro" + CaCO(3), "Orgro" + CaCO(3) + Mn sulfate. All compost treatments alleviated Zn phytotoxicity to tall fescue; however compost combined with liming reduced plant Zn content up to 158-162 mg kg(-1). Compost added with lime reduced Pb in-vitro bioaccessibility from 32.5 to 20.4% of total Pb and was the most effective among the tested treatments. The study revealed the effectiveness of biosolids compost and lime mixture in the rapid stabilization of metals and revegetation of military range contaminated soils. The persistence of the remediation needs to be, however, confirmed in the long-term field study.