Fungal endophyte Penicillium janthinellum LK5 can reduce cadmium toxicity in Solanum lycopersicum (Sitiens and Rhe)

We investigated the role of gibberellins-producing endophyte Penicillium janthinellum LK5 associated with Solanum lycopersicum (host), abscisic acid (ABA)-deficient tomato mutant Sitiens and its wild-type Rheinlands Ruhm (Rhe) plants under cadmium (Cd) stress. A 100-μM Cd application to host, Sitiens and Rhe reduced the shoot growth, chlorophyll content and stomatal conductance. However, these parameters were significantly (P?<?0.0011) higher (1.0- to 2.6-folds) in host, Sitiens and Rhe under endophytic association than in non-endophyte infected plants (control) under Cd stress. Furthermore, endophytic association minimized the Cd-induced membrane injury and oxidative stress to host, Sitiens and Rhe plants by reducing electrolytes and lipid peroxidation while increasing the content of reduced glutathione and catalase activities as compared to non-endophyte-infected plants. Stress-responsive ABA content significantly increased (～2-folds) in Sitiens and Rhe under endophyte association, while in host plants it was decreased under Cd stress. Salicylic acid content was ～?1.7-fold higher in host, Sitiens and Rhe plants under Cd stress and endophyte association than in the control. Besides gibberellins production, the endophyte has the potential to solubilize phosphates (12.73?±?0.24 mg/l) since higher P was observed in the roots of Sitiens, Rhe and host plants. Similarly, nutrients like sulfur and calcium were more efficiently assimilated in roots of endophyte-associated plants than control under Cd stress. Conversely, Cd accumulation was significantly decreased (P?<?0.001) in the roots of endophyte-inoculated host, Sitiens and Rhe than control. In conclusion, endophyte symbiosis can counteract heavy metal stress which can exert negative effects on plant growth.     

Quantification of seed ionome variation in 90 diverse soybean (Glycine max) lines

Climate change and rising carbon dioxide (CO₂) levels are expected to reduce the mineral nutrient content of soybean seeds. The main objective of this study was to survey diverse soybean germplasm for variation in seed elemental concentrations and their relationships between elements, protein content, and individual seed weight. Seeds from 90 soybean genotypes were weighed and subjected to inductively coupled plasma-mass spectrometry (ICP-MS) ionomics analysis and Carbon/Nitrogen (C/N) analysis to determine protein. The results demonstrated substantial variation with the possibility of significantly improving most mineral nutrients, especially selenium (Se), copper (Cu), iron (Fe), and manganese (Mn). This diverse survey identifies genotypes that can complement existing soybean breeding programs for improving seed nutritional quality. Correlation analysis identified two clusters of co-variant elements: zinc (Zn), phosphorus (P), and sulfur (S) as well as Zn, Cu, Se, and rubidium (Rb) were positively correlated with each other. Tolerable upper limits of Rb intake are not defined for humans illustrating the need to monitor trace elements along with desirable nutrients.     

维管植物的镉毒和耐性机制

本文讨论了影响土壤中镉有效性的因素和植物对镉的吸收与转运。从植物的生长、光合作用、气孔功能、水分关系、酶活性等方面阐述了镉对维管植物的毒害机制 ;并对近年来有关维管植物通过体内镉的积累与分隔和镉结合复合物产生的镉耐性机制的研究作一综述。     

Formation of Tebuconazole Complexes with Cadmium(II) Investigated by Electrospray Ionization Mass Spectrometry

The formation of complexes between tebuconazole (Teb) and cadmium in simplified model solutions as well as soil solutions was studied using electrospray ionization mass spectrometry. Teb and cadmium form two types of complexes with the general formulas [Cd(Teb) _n ]²⁺ (n?=?1?C4) and [CdI(Teb) _m ]⁺ (m?=?1?C3), where iodine corresponds to the counterion used. The most intense Teb/cadmium complex is [CdI(Teb)₂]⁺, and the most stable one is [Cd(Teb)(Teb ? H)]⁺. Another detected complex, the dication [Cd(Teb)₄]²⁺, was considered as the origin complex for the iodine-free complexes and was found in a sample prepared from forest soil solution naturally contaminated with cadmium ions.     

The Effect of Temperature on the Accumulation of Cadmium, Copper, Zinc, and Lead by Scirpus acutus and Typha latifolia: A Comparative Analysis

Wetland plants have a capacity for metal sequestration and have been used to remediate such environmental contaminants. How this capacity will be affected by a warming environment is not well-known. Our objective was to identify the effect of small environmentally realistic increases in temperature on metal (cadmium, zinc, lead, and copper) accumulation in Typha latifolia as compared with Scirpus acutus. These common wetland plant species were grown in metal-contaminated sediments at 13??C, 16??C, and 18??C for 3?months to determine the effect of environmentally realistic temperatures on metal accumulation. Cd¹⁰⁹ was used as a radiotracer to study the effect of temperature on uptake kinetics. Growth of the two wetland plants differed markedly; S. acutus displayed linear growth reaching a maximum height of ca. 100?cm; by contrast, T. latifolia grew to ca. 40?cm by day?60 with no further growth occurring over the remainder of the 105-day growth period. S. acutus accumulated more cadmium, lead, and zinc from contaminated sediments than T. latifolia, but only within roots and rhizomes. Although not significant, uptake of cadmium, lead, and zinc by both plants was enhanced under warmer conditions and was most pronounced in S. acutus. This was supported by the radiotracer studies which indicated that under the higher temperatures, there was increased rates of Cd¹⁰⁹ uptake by shoots of S. acutus. By contrast, temperature did not affect Cd¹⁰⁹ uptake rate constants in T. latifolia. S. acutus appears to be more effective at sequestering metals from contaminated sediments; this species as compared to T. latifolia may also be more affected by a warming climate. In the design of wetlands for metal remediation, differences in how these two plants sequester metals from their environment should be considered.     

植物对锌吸收运输及积累的生理与分子机制

锌是植物必需的营养元素,也是重金属污染元素之一。现代分子生物学的发展,极大地推动了植物体内与锌吸收运输有关转运蛋白的研究。目前发现,锌铁控制运转相关蛋白(ZIP)、自然抵抗相关巨噬细胞蛋白NRAMP、重金属ATPase酶、阳离子扩散协助蛋白CDF、Mg2+/H+的反向交换转运蛋白MHX等运输蛋白参与细胞内Zn2+离子的跨膜运输,调节植物细胞内Zn2+平衡与分配。利用数量遗传学手段在在水稻上已找到与缺锌植株死亡率和叶片青铜病发生率有关QTL位点。而在Thlaspi caerulescens 和Arabidopsis halleri植物上鉴定出控制锌含量的QTLs,为寻找控制植物高效积累Zn的遗传基础规律打下了基础。     

Acetochlor Persistence in Surface and Subsurface Soil Samples

Two cadmium-resistant bacteria, Ralstonia sp. TAK1 and Arthrobacter sp. TM6, produced exopolymers that promoted cadmium solubilization in contaminated soil. The enhancement of cadmium uptake and accumulation in a monocot (Vetiveria nemoralis, vetiver grass) and a dicot (Ocimum gratissimum, African basil) was investigated in a greenhouse study. Compared with the uninoculated control, Ralstonia sp. TAK1 and Arthrobacter sp. TM6 increased cadmium accumulation in the roots and shoots of V. nemoralis. These cadmium-resistant bacteria increased the cadmium content of whole V. nemoralis plants similarly to ethylenediaminetetraacetic acid (EDTA) treatment alone. In contrast, only Arthrobacter sp. TM6 enhanced cadmium accumulation in the roots and shoots of O. gratissimum. The highest cadmium content of whole O. gratissimum plants was observed when the plant was treated with EDTA following treatment with Arthrobacter sp. TM6. The phytoextraction coefficient and translocation factor (TF) of bacteria-inoculated V. nemoralis were higher than those of O. gratissimum. Arthrobacter sp. TM6 increased the phytoextraction coefficients and TFs in V. nemoralis and O. gratissimum. These results indicate that Arthrobacter sp. TM6 and both tested plant species promote cadmium phytoextraction in contaminated soil.     

Removal of Heavy Metals in Storm Water Runoff Using Porous Vermiculite Expanded by Microwave Preparation

The main objective of this study was to examine the effectiveness of vermiculite for removing heavy metals from water. Vermiculite components were analyzed by X-ray fluorescence, and the concentrations of metal ions were measured by inductively coupled plasma spectrometry. Serial batch kinetic tests and batch sorption tests were conducted to determine the removal characteristics for heavy metals in aqueous solutions. Solution pH values of tests with the inflated vermiculites generally increased and then stabilized. Equilibrium pH was generally established within 5?h. Removal rates of inflated vermiculite were tested at the initial concentration of 3?mg/L. At equilibrium concentrations, except for chromium (36.23%), most heavy metals were effectively removed (96.08?C98.54%). Finally, sorption data were correlated with both Langmuir and Freundlich isotherms. For each metal, the Q _max obtained using the Langmuir isotherm was as follows: lead, 725.4?mg?kg^?1; cadmium, 568.8?mg?kg^?1; zinc, 540.2?mg?kg^?1; copper, 457.2?mg?kg^?1; and chromium, 0.9?mg?kg^?1. The study results indicate that inflated vermiculite has outstanding removal rates and therefore can be used as an adsorbent for various heavy metals.     

High montmorillonite content may affect soil microbial proteomic analysis

We studied the effects of high montmorillonite content in soil on the proteomic analysis of Cupriavidus metallidurans CH34 inoculated into model soils, containing a montmorilonite gradient. Bacterial proteomic analysis was conducted by two-dimensional gel electrophoresis (2-DE) coupled to mass spectrometry. The results showed that increasing the montmorillonite content in artificial soil the bacterial viability did not affect but the amount of extracted proteins and the number of protein spots in 2-DE decreased. Higher soil montmorillonite content also affected the protein identification, likely due to montomrillonite-induced conformational changes in proteins or degradation. Therefore the development of soil proteomics needs to increase the studies of interaction between protein and soil components as clays or humic substances. This experiment showed how the use of a model study can be an help to achieve more information about the complexity of soil and the fate of proteins in soil.     

Arsenic Concentration in Tobacco Leaves: A Study on Three Commercially Important Tobacco (Nicotiana tabacum L.) Types

In recent years, arsenic (As) has received increased attention as humans may be exposed to it through occupational and environmental exposure. Tobacco (Nicotiana tabacum L.) like other crops can uptake this element from the soil, which may lead to human exposure. Here, we report on a survey on arsenic in cured or processed tobacco leaves obtained from Africa, Asia, Europe, South and North America. A total of 1,431 leaf samples of flue-cured, burley, and Oriental tobaccos were obtained from various sampling locations during 2002 to 2004. Arsenic concentration in the samples averaged 0.4?±?0.6 μg g^?1 as determined by inductively coupled plasma-mass spectrometry. Recorded values from most samples showed that concentrations of arsenic were usually found at the lower end of the distribution. Significant differences were found among tobacco types, sampling locations, and crop years. Arsenic concentrations were rather low in the majority of regions investigated, which is compatible with data from the literature. However, sample size was small and sampling geographically restricted. Our results would need to be validated with a larger dataset.     

Glucosinolate Profiles of Arabidopsis thaliana in Response to Cadmium Exposure

The influence of cadmium on growth, cadmium accumulation, composition, and content of glucosinolates was investigated in Arabidopsis thaliana after 4 weeks of growth in hydroponics. Accumulation of 3,820 and 321 μg Cd g^?1 dry weight in the roots and leaves of A. thaliana, respectively, exposed to 50 μM Cd. Cadmium treatment significantly decreased the total concentration of glucosinolates both in the leaves and roots. Cd-induced alteration of total glucosinolate content in the roots was mainly due to the decrease of indolyl-glucosinolates. In the Cd treatment leaves, significant decreases were, respectively, detected for glucoibervirin and 4-methoxyglucobrassicin (P?<?0.01), while other glucosinolate levels did not decrease significantly. In response to cadmium, the three indolyl-glucosinolates all showed significant decreases in the roots. The distinctive influence of cadmium on glucosinolate profiles in Cd-sensitive A. thaliana may be of great ecological importance, decreasing the resistance to phytophage attack. Taken together, our data is discussed in relation to jasmonic acid and salicylic acid as possible molecules that modulate the alteration of glucosinolate profiles in response to cadmium. The similar effects of Cd treatment on the levels of individual glucosinolates in leaves and roots were observed at higher-concentration cadmium treatment (100 μM Cd).     

LED-Induced Chlorophyll Fluorescence Spectral Analysis for the Early Detection and Monitoring of Cadmium Toxicity in Maize Plants

Chlorophyll fluorescence spectral analysis permits detection, monitoring, and evaluation of abiotic stresses upon healthy plants using illumination of a light source in the UV?CVIS spectral range. This technique indirectly assesses the amount of physiological stress caused by photosynthetic damage, specifically damage to photosystem II, in plants. The objective of this study was to detect the toxicity of cadmium in maize plants via spectral analysis of chlorophyll fluorescence. The analysis is noninvasive and nondestructive and is used to follow the temporal evolution of changes in the chlorophyll content and physiological state of Zea mays L. seedlings under cadmium stress. Conventional techniques were also used to evaluate the dry matter production and Cd accumulation in plant leaves. Plants exhibited a notable reduction in dry matter production and chlorophyll levels with the administration of increasing doses of Cd in the nutrient solution. The fluorescence analysis was sensitive to changes caused by Cd in maize plants, detecting damage caused by different treatments before visual symptoms were observed. This technique has a practical application and produces rapid results that can be used in the evaluation of Cd-induced stress in plants and the detection of areas contaminated by this element.     

Trace Metal Contamination During Grinding of Plant Samples

Inductively coupled plasma-mass spectroscopic (ICP-MS) analysis of leaves from 22 cabbage crops in the Sa P? and B?c Hà districts of Láo Cai Province, North-Western Vi?t Nam, revealed unexpectedly high concentrations of chromium (Cr) and nickel (Ni). The concentrations were strongly linearly related (r² = 0.94), indicating sample contamination during grinding through a stainless-steel hammer mill. We tested this hypothesis in two ways. First, brown rice ground through the same mill was contaminated not only by Cr and Ni, but also cobalt (Co), iron (Fe) and molybdenum (Mo). Second, scanning electron microscopy/energy dispersive analysis of x-rays (SEM/EDS) of the ground samples revealed small fragments with co-located Fe, Cr and Ni, consistent with stainless steel wear fragments. Other grinders may perform differently and we suggest that quality assurance protocols for trace metal analysis of plants should include testing for grinder wear metals. Lastly, brown rice appears to be convenient for investigating contamination of plant tissues during grinding.     

The mycorrhizal fungus Glomus intraradices and rock phosphate amendment influence plant growth and microbial activity in the rhizosphere of Acacia holosericea

Plants inoculated with arbuscular mycorrhizal (AM) fungi utilize more soluble phosphorus from soil mineral phosphate than non-inoculated plants. However, there is no information on the response of soil microflora to mineral phosphate weathering by AM fungi and, in particular, on the catabolic diversity of soil microbial communities.The AM fungus, Glomus intraradices was examined for (i) its effect on the growth of Acacia holosericea, (ii) plant-available phosphate and (iii) soil microbial activity with and without added rock phosphate.After 4-months culture, AM fungal inoculation significantly increased the plant biomasses (by 1.78× and 2.23× for shoot and root biomasses, respectively), while mineral phosphate amendment had no effect in a sterilized soil. After 12-months culture, the biomasses of A. holosericea plants growing in a non-sterilized soil amended with mineral phosphate were significantly higher than those recorded in the control treatment (by 2.5× and 5× for shoot and root biomasses, respectively). The fungal inoculation also significantly stimulated plant growth, which was significantly higher than that measured in the mineral phosphate treatment. When G. intraradices and mineral phosphate were added together to the soil, shoot growth were significantly stimulated over the single treatments (inoculation or amendment) (1.45×). The P leaf mineral content was also higher in the G. intraradices+mineral phosphate treatment than in G. intraradices or rock phosphate amendment. Moreover, the number of fluorescent pseudomonads has been significantly increased when G. intraradices and/or mineral phosphate were added to the soil. By using a specific type of multivariate analysis (co-inertia analysis), it has been shown that plant growth was positively correlated to the metabolization of ketoglutaric acid, and negatively linked to the metabolisation of phenylalanine and other substrates, which shows that microbial activity is also affected.G. intraradices inoculation is highly beneficial to the growth of A. holosericea plants in controlled conditions. This AM symbiosis optimises the P solubilization from the mineral phosphate and affects microbial activity in the hyphosphere of A. holosericea plants.     

Chicory (Cichorium intybus L.) and dandelion (Taraxacum officinale Web.) as phytoindicators of cadmium contamination

Chicory (Cichorium intybus L.) and dandelion (Taraxacum officinale Web.) were demonstrated to be potential indicator plants for heavy metal contaminated sites. Chicory, grown with 0.5–50 μM cadmium (Cd) in nutrient solution, accumulated 10–300 μM Cd g^?1 in shoots and 10–890 μg Cd μg^?1 in roots and rhizomes. With dandelion, 20–410 μg Cd μg^?1 was found in shoots and 20–1360 μg Cd μg^?1 in roots and rhizomes. An inverse correlation existed between chlorophyll and Cd concentrations in shoots of both species. Accumulation of Cd from nutrient solution was similar with the counter-anions SO₄ ^2?, Cl^1? and NO₃ ^? in chicory. In chicory grown in Cd-amended (11.2 kg Cd ha^?1 applied five years previously) soils, Cd concentrations were substantially higher than in controls in all plant parts following the order: leaf > caudex > stem > root and rhizome. The above trend was the opposite of that observed in solution culture, where Cd accumulation was higher in roots and rhizomes than in shoots. Higher cadmium accumulation was found from a Cd-treated sand (Grossarenic Paleudult) than from a loamy sand (Typic Kandiudult) soil type. Chicory and dandelion are proposed indicator plants of cadmium contamination, and both have the potential to be an international standard heavy phytomonitor species of heavy metal contaminantion.     

Biosorption Capacity for Cadmium of Brown Seaweed Sargassum sinicola and Sargassum lapazeanum in the Gulf of California

Brown algae Sargassum sinicola and Sargassum lapazeanum were tested as cadmium biosorbents in coastal environments close to natural and enriched areas of phosphorite ore. Differences in the concentration of cadmium in these brown algae were found, reflecting the bioavailability of the metal ion in seawater at several sites. In the laboratory, maximum biosorption capacity (q _max) of cadmium by these nonliving algae was determined according to the Langmuir adsorption isotherm as 62.42?±?0.44 mg g^?1 with the affinity constant (b) of 0.09 and 71.20?±?0.80 with b of 0.03 for S. sinicola and S. lapazeanum, respectively. Alginate yield was 19.16?±?1.52% and 12.7?±?1.31%, respectively. Although S. sinicola had far lower biosorption capacity than S. lapazeanum, the affinity for cadmium for S. sinicola makes this alga more suitable as a biosorbent because of its high q _max and large biomass on the eastern coast of the Baja California Peninsula. Sargassum biomass was estimated at 180,000 t, with S. sinicola contributing to over 70%.     

浦江葡萄同位素与矿物元素特征及地理标志保护模型构建

为探讨稳定同位素与矿物元素在葡萄产地鉴别上的可行性,本研究分别从浦江、浙江其他产地(慈溪、温岭)、上海和安徽4个不同产地采集代表性葡萄样品;通过稳定同位素比率质谱(EA-IRMS)元素分析仪和电感耦合等离子体质谱(ICP-MS)测定其同位素比率与矿物质元素含量,结合化学计量学统计工具对浦江葡萄开展原产地判别研究.结果表...     

Determination of Heavy Metal Concentrations and Metal Fingerprints of Sewage Sludge from Eastern Cape Province,South Africa by Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)

Sewage sludge from Schornville, Zwelitsha and Dimbaza Sewage Treatment Plants (STPs) in the Eastern Cape province, South Africa were analyzed for the heavy metal contents by inductively coupled plasma-mass spectrometry (ICP) while metal fingerprints of the sludge were determined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Levels of Cd ranged from 1.1 mg kg^-1 at Zwelitsha STP to1.9 mg kg^-1 at Shornville STP while the levels of Zn varied between 1600 mg kg^-1 also at Zwelitsha STP and 4100 mg kg^-1 at Dimbaza STP. The levelsof Ni also ranged from 37 mg kg^-1 again at Zwelitsha STP to 86 mg kg^-1 at Dimbaza STP while the levels of Cr varied between 70 mg kg^-1 at Zwelitsha STP) and 120 mg kg^-1 at Dimbaza STP). The levels of Cu varied between 245 mg kg^-1 at Zwelitsha STP and 441 mg kg^-1 at Dimbaza STP while the levels of Pb ranged from 69 mg kg^-1 at Zwelitsha STP and 365 mg kg^-1 at Dimbaza STP. The fingerprint studies showed that metals like Si, K, Cu, Pt, Ni and Ag probably havenatural bedrock sources from the study area while others like Zn, Pb and Cd may have anthropogenic sources in addition to natural sources. Generally, sludge from Zwelitsha STP has the lowest concentration of heavy metals and has the greatest potential for agricultural use whilesludge from Dimbaza STP has the highest concentration of heavy metals with the least potential for agricultural use.     

Comparison of Open Digestion Methods for the Determination of Rare Earth Elements in Plant Samples by ICP-MS

An analytical procedure for the reliable determination of rare earth elements (REEs) in plant samples by inductively coupled plasma-mass spectrometry (ICP-MS) was developed. The influence of the main matrix elements was investigated first. It was established that moderate amounts (0.1–1.0%) of dissolved solids decreased the REEs signals significantly. Internal standardization with indium proved to be useful for obtaining correct results. Various digestion procedures were next applied to converting various solid plant samples to aqueous solution, namely dry-ashing, dry-ashing including a hydrofluoric acid (HF) step, and wet digestion using hydrogen peroxide (H₂O₂) and nitric acid (HNO₃). Obtained results showed that the simple dry-ashing procedure was sufficient for plants. A certified reference material (BCR-670, aquatic plant) was used to validate the accuracy of the method. Relative standard deviations varied from 1% (holmium, gadolinium) to 4% (europium). Detection limits between 13 (lanthanum) and 0.02 ng L^?1 (lutetium) were achieved.     

The effect of mycorrhizal inoculation and phosphorus application on the growth and mineral nutrient status of apple seedlings

Apple seedlings cv. Antonovka were grown in soil taken from an orchard with a distinctive specific apple replant disease. The influence of the different available soil phosphorus (P) level (0, 20, 40 and 80 mg P dm^?3 of soil) and arbuscular mycorrhizae fungi (AMF) inoculation on the vegetative growth, chlorophyll fluorescence, and the frequency of mycorrhizae were assessed. Moreover, leaf and root mineral composition was ascertained by means of the inductively coupled plasma mass spectrometry (ICP-MS) method. The inoculation with AMF influenced seedlings growth as well as the biomass production and partitioning. The method of inoculation (granular, quick root dip or irrigation) had a great impact on the frequency of mycorrhizae (83.3, 98.8 and 100%, respectively) as well as on the abundance of arbuscules (36.4, 62.9 and 67.3%) as compared to the control (11.7%). The beneficial effect of AMF on leaf PSII efficiency was established. AMF inoculated plants had a significantly higher content of nitrogen, potassium, phosphorus and boron (N, K, P and B) in the shoots and a higher content of nitrogen, sulfur, copper, iron, manganese, molybdenum and titanium (N, S, Cu, Fe, Mn, Mo and Ti) in the roots. Although roots showed a higher concentration of aluminium, barium, lithium, cadmium, lead and vanadium (Al, Ba, Li, Cd, Pb, and V) but upon AMF inoculation, the concentration of these cations was much lower.