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Main conclusions C. campestris parasitisation increases internal host defences at the expense of environmentally directed ones in the host species A. campestris, thus limiting plant defence against progressive parasitisation. Abstract Cuscuta campestris Yunck is a holoparasitic species that parasitises wild species and crops. Among their hosts, Artemisia campestris subsp. variabilis (Ten.) Greuter is significantly affected in natural ecosystems. Limited information is available on the host recognition mechanism and there are no data on the interactions between these species and the effects on the primary and specialised metabolism in response to parasitisation. The research aims at evaluating the effect of host–parasite interactions, through a GC–MS untargeted metabolomic analysis, chlorophyll a fluorescence, ionomic and δ13C measurements, as well as volatile organic compound (VOC) fingerprint in A. campestris leaves collected in natural environment. C. campestris parasitisation altered plant water status, forcing stomatal opening, stimulating plant transpiration, and inducing physical damages to the host antenna complex, thus reducing the efficiency of its photosynthetic machinery. Untargeted-metabolomics analysis highlighted that the parasitisation significantly perturbed the amino acids and sugar metabolism, inducing an increase in the production of osmoprotectants, which generally accumulate in plants as a protective strategy against oxidative stress. Notably, VOCs analysis highlighted a reduction in sesquiterpenoids and an increase in monoterpenoids levels; involved in plant defence and host recognition, respectively. Moreover, C. campestris induced in the host a reduction in 3-hexenyl-acetate, a metabolite with known repellent activity against Cuscuta spp. We offer evidences that C. campestris parasitisation increases internal host defences via primary metabolites at the expense of more effective defensive compounds (secondary metabolites), thus limiting A. campestris defence against progressive parasitisation.

Introduction In a previous work, we wanted to evaluate if the histochemical determination of lead in Gunshot Residues (GSR) on firearm wounds could be misled due to possible environmental contamination produced by heavy metals and, in particular, by lead. The Sodium Rhodizonate test and its confirmation test with 5% HCl Sodium Rhodizonate resulted to be negative and therefore we wanted to verify if these techniques were sensible enough in order to evaluate this element. We have assessed, on these same samples, a more sensitive technique, as inductive coupled plasma mass spectrometry (ICP-MS) is. This technique is able to detect elements in solution at concentrations as low as 10−15 g L−1. Materials and methods Skin samples taken from two groups of victims, whose cause of death was not related to gunshot wounds were analyzed using ICP-MS: group A included 25 corpses found in open spaces after a long time; group B included 16 corpses exhumed after a period of 11 years. As a positive control group we used skin samples from two subjects that had died due to firearm wounds: as a negative control group we used three different types of plain paraffin slides without included biological material. Results At the analysis by ICP-MS, the evaluation of the samples belonging to groups A, B and for the negative control groups resulted to be negative for traces of lead (Pb), barium (Ba) and antimony (Sb). On the other hand, high concentrations of GSR could be found in the positive control group were victims died for firearm wounds. Conclusions On these basis, we can state that environmental Pb does not contaminate cadavers exposed to open air nor those buried in soil, as confirmed using to ICP-MS technique. Sodium Rhodizonate and 5% HCl Sodium Rhodizonate confirmation test have therefore a high sensitivity, highlighting GSRs, for the diagnosis of death caused by firearm wounds.

Low-cost materials and low-tech architectures could give competitive advantage in scaling-up applications of microbial fuel cells (MFC), especially for nutrients recovery from wastewater. Here a novel concept is presented, based on cylindrical ligno-cellulosic materials, available as agricultural residues or spontaneous vegetation. Giant canes ( Arundo Donax L.) and maize ( Zea Mays ) stalks were used as porous separators (naturally tubular) for air-cathode MFC modules (GC-MFC and MS-MFC, meaning Giant Cane and Maize Stalk, respectively), with carbon cloth-based electrodes. The MFCs were operated across 100 Ω external load, enriching swine-farming wastewater with addition of sodium acetate (3 g L −1 ). Initially, these systems showed relatively high internal resistances (especially GC, with R int = 5600 Ω), before the material was completely imbibed by the anolyte. After 10–20 days acclimation, despite sufficient electrolytic conductivity was established in both systems (internal resistance around 60–90 Ω), relatively low power densities (around 40 mW m −2 , normalized by cathode's surface projection) were achieved, if compared to state-of-the-art MFCs, oriented to electricity harvesting. However, the generated electric field was enough to sustain electro-osmotic ions mobility and to establish high pH conditions (pH 11–12) at the cathode. Over 70 days of operation, electro-migration and deposition phenomena of valuable elements (Na, Ca, Mg, Mn, K, etc.) were observed, both inside the separator and on the cathode surface. Simultaneously, partial biodegradation of the ligno-cellulosic biomass, especially for MS, drove partial release of organic carbon, nitrogen, phosphorous and other elements in the anodic chamber. These relevant phenomena have to be taken into account in view of possible applications of ligno-cellulosic materials in MFC-driven nutrients recovery from wastewater.

Cattle and pig manure contain useful mineral nutrients (N, P, and K) and are therefore used as organic fertilizer. However, excessive applications of manure can cause environmental problems and threaten animal and human health because these materials also hold significant amounts of heavy metals, particularly Cu and Zn. To assess the potential risk due to the increased concentrations of heavy metals (Cu, Mn, Zn, and Cr) in a harvested crop, two maize hybrids were grown in pots on four different soils with three different fertilisers (urea, pig manure, and cattle manure). Both soil and manure characteristics influenced the heavy metal concentrations in the plant shoots. Organic fertilisation strongly interacted with the soils and, in general, reduced the shoot content of Cu, Mn, and Zn. A preliminary assessment of the heavy metal balance of the agricultural systems based on the intensive livestock production and maize cultivation showed that the potential soil enrichment of the long-term application of livestock manure arises mainly from the application of pig slurries that have a high content of Cu and Zn. The time required to apply an amount of metal that is equal to the initial soil content is 60&ndash, 300 years for Zn and 240&ndash, 450 years for Cu, depending on the soil type and the initial heavy metal content.

In this study, the in vitro stability of cisplatin (CisPt) and cationic platinum(II)-complex (caPt(II)-complex) and their in vitro activity (antiproliferative and anti-angiogenic properties) were investigated against three aggressive human tumor cell lines. caPt(II)-complex shown a high stability until 9 days of treatment and displayed a significant and higher activity than CisPt against both NCI-H28 mesothelioma (19.37 ± 9.57 μM versus 34.66 ± 7.65 μM for CisPt) and U87 MG glioblastoma (19.85 ± 0.97 μM versus 54.14 ± 3.19 for CisPt). Mesenchymal Stromal Cells (AT-MSCs) showed a significant different sensitivity (IC 50 = 71.9 ± 15.1 μM for caPt(II)-complex and 8.7 ± 4.5 μM for CisPt) to the antiproliferative activity of caPt(II)-complex and CisPt. The ability of MSCs to uptake both the drugs in a similar amount of 2.49 pM /cell, suggested a possible development of new therapies based on cell mediated drug delivery.

Spirulina was cultivated in cathodic compartments of photo-microbial fuel cells (P-MFC). Anodic compartments were fed with swine-farming wastewater, enriched with sodium acetate (2.34gCODL-1). Photosynthetic oxygen generation rates were sufficient to sustain cathodic oxygen reduction, significantly improving P-MFC electrochemical performances, as compared to water-cathode control experiments. Power densities (0.8-1Wm-2) approached those of air-cathode MFCs, run as control. COD was efficiently removed and only negligible fractions leaked to the cathodic chamber. Spirulina growth rates were comparable to those of control (MFC-free) cultures, while pH was significantly (0.5-1unit) higher in P-MFCs, due to cathodic reactions. Alkaliphilic photosynthetic microorganisms like Spirulina might take advantage of these selective conditions. Electro-migration along with diffusion to the cathodic compartment concurred for the recovery of most nutrients. Only P and Mg were retained in the anodic chamber. A deeper look into electro-osmotic mechanisms should be addressed in future studies.

The development and the synthesis of cationic platinum(II) complexes were realized and their cytotoxic activity was tested on triple negative breast cancer MDA-MB-231 cell line and in two cell lines poorly responsive to cisplatin (DLD-1 and MCF-7). The complex 2c resulted the most potent cytotoxic agent in MDA-MB-231 (IC50=61.9µM) and more effective than cisplatin on both DLD-1 (IC50=57.4µM) and MCF-7 (IC50=79.9µM) cell lines. 2c showed different cellular uptake and pharmacodynamic properties than cisplatin, interfering with the progression of the M phase of the cell cycle. Thus, 2c represents a lead compound of a new class of cytotoxic agents with promising antitumor activity.

Amyotrophic lateral sclerosis (ALS) is a fatal disorder with unknown etiology, in which genetic and environmental factors interplay to determine the onset and the course of the disease. Exposure to toxic metals has been proposed to be involved in the etiology of the disease either through a direct damage or by promoting oxidative stress. In this study we evaluated the concentration of a panel of metals in serum and whole blood of a small group of sporadic patients, all living in a defined geographical area, for which acid mine drainage has been reported. ALS prevalence in this area is higher than in the rest of Italy. Results were analyzed with software based on artificial neural networks. High concentrations of metals (in particular Se, Mn and Al) were associated with the disease group. Arsenic serum concentration resulted lower in ALS patients, but it positively correlated with disease duration. Comet assay was performed to evaluate endogenous DNA damage that resulted not different between patients and controls. Up to now only few studies considered geographically well-defined clusters of ALS patients. Common geographical origin among patients and controls gave us the chance to perform metallomic investigations under comparable conditions of environmental exposure. Elaboration of these data with software based on machine learning processes has the potential to be extremely useful to gain a comprehensive view of the complex interactions eventually leading to disease, even in a small number of subjects.

Background Among cereals, rice has a genetic propensity to accumulate high levels of cadmium (Cd) in grains. Xylem-mediated root-to-shoot translocation rather than root uptake has been suggested as the main physiological factor accounting for the genotypic variation observed in Cd accumulation in shoots and grains. Several evidence indicate OsHMA2 – a putative zinc (Zn) transporter – as the main candidate protein that could be involved in mediating Cd- and Zn-xylem loading in rice. However, the specific interactions between Zn and Cd in rice often appear anomalous if compared to those observed in other staple crops, suggesting that root-to-shoot Cd translocation process could be more complex than previously thought. In this study we performed a complete set of competition experiments with Zn and Cd in order to analyze their possible interactions and reciprocal effects at the root-to-shoot translocation level. Results The competition analysis revealed the lack of a full reciprocity when considering the effect of Cd on Zn accumulation, and vice versa, since the accumulation of Zn in the shoots was progressively inhibited by Cd increases, whereas that of Cd was only partially impaired by Zn. Such behaviors were probably dependent on Cd-xylem loading mechanisms, as suggested by: i) the analysis of Zn and Cd content in the xylem sap performed in relation to the concentration of the two metals in the mobile fractions of the roots; ii) the analysis of the systemic movement of 107Cd in short term experiments performed using a positron-emitting tracer imaging system (PETIS). Conclusions Our results suggest that at least two pathways may mediate root-to-shoot Cd translocation in rice. The former could involve OsHMA2 as Zn2+/Cd2+ xylem loader, whereas the latter appears to involve a Zn-insensitive system that still needs to be identified. Electronic supplementary material The online version of this article (doi:10.1186/s12284-016-0088-3) contains supplementary material, which is available to authorized users.

Amyotrophic Lateral Sclerosis (ALS) has often been associated with improper/altered metal metabolism. Analysis of thiophylic metals in serum from a small and geographically restricted cohort of ALS patients indicates contents of Pb and Ni much higher in patients than in controls (Ni, 5-fold; Pb, 2-fold). Se levels are also higher in the patients’ group, which has instead lower As levels than controls. Thiophylic metals may impair biogenesis of FeS clusters or substitute for iron, even in folded proteins; Se may non-functionally replace S. Thus, improper assembly/ function of FeS proteins could represent another possible issue to be considered in ALS pathogenesis.

This study investigated the effect of moderate consumption of horse meat on iron status, lipid profile and fatty acid composition of red blood cells in healthy male volunteers. Fifty-two subjects were randomly assigned to two groups of 26 subjects each: a test group consuming two portions of 175 g/week of horse meat, and a control group that abstained from eating horse meat during the 90 days trial. Before and after 90 days, blood samples were collected for analysis. Horse meat consumption significantly (p ≤ 0.05) reduced serum levels of total and low-density lipoprotein cholesterol ( - 6.2% and - 9.1%, respectively) and transferrin ( - 4.6%). Total n - 3, long chain polyunsaturated fatty acids n - 3 and docosahexeanoic acid content in erythrocytes increased (p ≤ 0.05) by about 7.8%, 8% and 11%, respectively. In conclusion, the regular consumption of horse meat may contribute to the dietary intake of n - 3 polyunsaturated fatty acids and may improve lipid profile and iron status in healthy subjects.

Analysis of rice plants exposed to a broad range of relatively low and environmentally realistic Cd concentrations showed that the root capacity to retain Cd ions rose from 49 to 79%, corresponding to increases in the external Cd 2+ concentration in the 0.01-1 μM range. Fractioning of Cd ions retained by roots revealed that different events along the metal sequestration pathway (i.e. chelation by thiols, vacuolar compartmentalization, adsorption) contributed to Cd immobilization in the roots. However, large amounts of Cd ions (around 24% of the total amount) predictable as potentially mobile were still found in all conditions, while the amount of Cd ions loaded in the xylem seemed to have already reached saturation at 0.1 μM Cd 2+ , suggesting that Cd translocation may also play an indirect role in determining Cd root retention, especially at the highest external concentrations. In silico search and preliminary analyses in yeast suggest OsHMA2 as a good candidate for the control of Cd xylem loading in rice. Taken as a whole, data indicate Cd chelation, compartmentalization, adsorption and translocation processes as components of a complex 'firewall system' which acts in limiting Cd translocation from the root to the shoot and which reaches different equilibrium positions depending on Cd external concentration.

Plant productivity and fruit quality in terms of occurrence of mineral elements and metabolites were determined on wild bilberry growing in open and forest stands in a protected area of N-Italy. Plant productivity was significantly higher in open stands (3 ± 2.5 compared with 0.03 ± 0.05 fruits per plant) suggesting that both collections in the wild and semi-wild cultivation should be planned in open habitats. Results obtained by ionomic and metabolomic analyses indicated that high quality fruits can be collected in the analyzed area and their nutritional profile did not differ between open and forest stands. Cyanidin and delphinidin proportion of bilberries from our study area was respectively 23.8% and 43.9% of total antocyanin and it is similar to that previously considered peculiar to bilberry fruits of high latitude regions of Europe and indicative of high quality food properties. A comparison between wild bilberry collected in the protected area and commercial blueberry was also performed and relevant differences between them detected, confirming the concept that wild bilberry has a better nutritional profile than blueberry. Practical ApplicationBilberry fruits provide relevant nutrients to human diet. However, the scarce availability in the wild is a limiting factor hindering a wider use of this product. In this study we compared plant productivity and nutritional profile of bilberry growing in open and forest sites, demonstrating that they do not differ in terms of mineral and metabolomic contents, whereas plant productivity is by far higher in open sites. This supports the possibility to obtain bilberry fruits by semiwild cultivation maintaining open sites that are also crucial for biodiversity conservation in mountain areas.

Saline soils often constitute sites of accumulation of industrial and urban wastes contaminated by heavy metals. Halophytes, i.e. native salt-tolerant species, could be more suitable for heavy metal phytoextraction from saline areas than glycophytes, most frequently used so far. In the framework of this approach, we assess here the Ni phytoextraction potential in the halophyte Mesembryanthemum crystallinum compared with the model species Brassica juncea. Plants were hydroponically maintained for 21 days at 0, 25, 50, and 100 μM NiCl2. Nickel addition significantly restricted the growth activity of both species, and to a higher extent in M. crystallinum, which did not, however, show Ni-related toxicity symptoms on leaves. Interestingly, photosynthesis activity, chlorophyll content and photosystem II integrity assessed by chlorophyll fluorescence were less impacted in Ni-treated M. crystallinum as compared to B. juncea. The plant mineral nutrition was differently affected by NiCl2 exposure depending on the element, the species investigated and even the organ. In both species, roots were the preferential sites of Ni2+ accumulation, but the fraction translocated to shoots was higher in B. juncea than in M. crystallinum. The relatively good tolerance of M. crystallinum to Ni suggests that this halophyte species could be used in the phytoextraction of moderately polluted saline soils.

Six barley cultivars widely differing for cadmium (Cd) tolerance, partitioning, and translocation were analyzed in relation to their thiol metabolism. Results indicated that Cd tolerance was not clearly related to the total amount of Cd absorbed by plants, resulting instead closely dependent on the capacity of the cultivars to trap the metal into the roots. Such behaviors suggested the existence of root mechanisms preserving shoots from Cd-induced oxidative damages, as indicated by the analysis of thiobarbituric acid-reactive substances--diagnostic indicators of oxidative stress--whose increases in the shoots were negatively related to Cd root retention and tolerance. Cd exposure differentially affected glutathione (GSH) and phytochelatin (PC) levels in the tissues of each barley cultivar. The capacity to produce PCs appeared as a specific characteristic of each barley cultivar, since it did not depend on Cd concentration in the roots and resulted negatively related to the concentration of the metal in the shoots, indicating the existence of a cultivar-specific interference of Cd on GSH biosynthesis, as confirmed by the existence of close positive linear relationships between the effect of Cd on GSH levels and PC accumulation in both roots and shoots. The six barley cultivars also differed for their capacity to load Cd ions into the xylem, which was negatively related to PC content in the roots. Taken as a whole, these data indicated that the different capacity of each cultivar to maintain GSH homeostasis under Cd stress may strongly affect PC accumulation and, thus, Cd tolerance and translocation.

Cadmium (Cd) exposure and sulfate limitation induce root sulfate uptake to meet the metabolic demand for reduced sulfur. Although these responses are well studied, some aspects are still an object of debate, since little is known about the molecular mechanisms by which changes in sulfate availability and sulfur metabolic demand are perceived and transduced into changes in the expression of the high-affinity sulfate transporters of the roots. The analysis of the natural variation occurring in species with complex and highly redundant genome could provide precious information to better understand the topic, because of the possible retention of mutations in the sulfate transporter genes., The analysis of plant sulfur nutritional status and root sulfate uptake performed on plants of Brassica juncea - a naturally occurring allotetraploid species - grown either under Cd exposure or sulfate limitation showed that both these conditions increased root sulfate uptake capacity but they caused quite dissimilar nutritional states, as indicated by changes in the levels of nonprotein thiols, glutathione and sulfate of both roots and shoots. Such behaviors were related to the general accumulation of the transcripts of the transporters involved in root sulfate uptake (BjSultr1;1 and BjSultr1;2). However, a deeper analysis of the expression patterns of three redundant, fully functional, and simultaneously expressed Sultr1;2 forms (BjSultr1;2a, BjSultr1;2b, BjSultr1;2c) revealed that sulfate limitation induced the expression of all the variants, whilst BjSultr1;2b and BjSultr1;2c only seemed to have the capacity to respond to Cd., A novel method to estimate the apparent kM for sulfate, avoiding the use of radiotracers, revealed that BjSultr1;1 and BjSultr1;2a/b/c are fully functional high-affinity sulfate transporters. The different behavior of the three BjSultr1;2 variants following Cd exposure or sulfate limitation suggests the existence of at least two distinct signal transduction pathways controlling root sulfate uptake in dissimilar nutritional and metabolic states.

The effect of growth under saline condition (100 mol m-3 NaCl in the nutrient solution) on the influx and the efflux of glucose from roots of cotton plants was analysed utilising the non metabolisable glucose analogue [14C]-3-O-methylglucose ([14C]3-OMG). Apical segments (1 cm long) excised from cotton roots took up [14C]3-OMG. At each tested concentration (5–500 mmol m-3), the influx was completely inhibited by the presence of the protonophore carbonylcyanide-m-chlorophenyl hydrazone (CCCP) indicating that it is mediated by a H+-coupled co-transport mechanism. The CCCP-sensitive [14C]3-OMG influx was lower in the root segments excised from plants grown on saline solution than in the controls, and this was particularly evident at lower external concentrations. This difference was not due to a lower H+ apoplastic availability. In fact, the saline condition did not affect the pH of the rhizosphere and indeed the H+–ATPase activity, evaluated in plasma membrane vesicles purified from saline-treated plants, was higher (+23%) than in the controls. The lower uptake of [14C]3-OMG into saline treated root segments was related to an enhanced value of the apparent Km of the carrier for the glucose analogue. This effect is discussed in relation to either the more positive value of the transmembrane electric potential difference (ΔΨ) measured in these root segments, or a competitive inhibition of Na+ on the H+ binding site of the carrier. Growth in saline solution slightly affected the efflux of the [14C]3-OMG preloaded in root segments, changing the membrane permeability to the molecule. The results strongly suggest that the higher (2.5 fold) net exudation of glucose, observed in short-term (4 h) collection experiments, from roots of cotton plants grown in saline condition, is mainly due to an effect of the saline growth condition on the system involved in the reabsorption of the hexose rather than on its efflux.

The synthesis and pharmacological characterisation of (1-methyl-1 H -imidazol-2-yl)-methanamine and its derivatives in Pt II complexes are described. Six out of eleven new Pt II complexes showed a significant cytotoxic effect on NCI-H460 lung cancer cell line with EC 50 values between 1.1 and 0.115 mM, determined by MTT assay. Compound Pt - 4a showed a particularly more potent cytotoxic effect than the previously described Pt II complex with 2,2′-bipyridine, [Pt(bpy)Cl 2 ], with an EC 50 value equal to 172.7 μM versus 726.5 μM respectively, and similar potency of cisplatin (EC 50 = 78.3 μM) in NCI-H460 cell line. The determination of the intracellular and DNA-bound concentrations of 195 Pt, as marker of the presence of the complexes, showed that the cytotoxic compound Pt - 4a readily diffused into the cells to a similar extent of cisplatin and directly interacted with the nuclear DNA. Pt - 4a induced both p53 and p21 Waf expression in NCI-H460 cells similar to cisplatin. A direct comparison of the cytotoxic effect between compound Pt - 4a and cisplatin on 12 different cancer cell lines demonstrated that compound Pt - 4a was in general less potent than cisplatin, but it had a comparable cytotoxic effect on non-small-cell lung cancer NCI-H460 cells, and the colorectal cancer cells HCT-15 and HCT-116. Altogether, these results suggested that the Pt II complex with 1-methyl-1 H -imidazol-2-yl)-methanamine (compound Pt - 4a ), displayed a significant cytotoxic activity in cancer cells. Similarly to cisplatin this compound interacts with nuclear DNA and induces both p53 and p21 waf , and thus it represents an interesting starting point for future optimisation of new Pt II complexes forming DNA adducts.

A low-molecular-mass protein able to bind GTP in both native and SDS-denaturating conditions was detected in the cytosol of embryos from wheat (Triticum aestivum L.) seeds germinated for 40 h. The protein fulfilled most of the distinguishing criteria common to eukaryotic small GTP-binding proteins. It retained the ability to bind GTP after SDS/PAGE and nitrocellulose blotting. The protein eluted from Sephadex G-200 gel filtration with a Ve/Vo value corresponding to a molecular mass of 18 kDa, whereas on SDS/PAGE the molecular mass was 20 kDa. The native protein, which showed an intrinsic GTPase activity highly sensitive to NaF, bound the guanine nucleotide with high specificity and with a relatively high affinity (Kd approximately 85 nM). The GTP-binding protein was not detectable in other subcellular fractions; in the microsomal fraction, two other peptides of low molecular mass (23.5 and 21.5 kDa) with GTP-binding activity were detected. These results indicate that in the cytosolic fraction of germinating wheat embryos there is a 20-kDa protein which is biochemically similar to the known small GTP-binding proteins that currently have been detected almost exclusively in the membrane fraction of plant material.

Cadmium (Cd) and zinc (Zn) translocation in rice was studied by analyzing a complete set of competition experiments in which plants were exposed to increasing Zn external concentrations (0.1, 1, and 10 µM), in the absence or presence of 0.1 µM Cd2+, or to different Cd concentrations (0, 0.01, 0.1, and 1 µM) in the presence of 1 µM Zn2+. Results revealed the lack of a full reciprocity when considering the effect of Cd on Zn accumulation, and vice versa, since the accumulation of Zn in the shoots was progressively inhibited by Cd increases, whereas that of Cd was only partially impaired by Zn. Such behaviors probably involved the mechanisms of Cd-xylem loading, as suggested by: i) the analysis of Zn and Cd content in the xylem sap performed in relation to the concentration of the two metals in the mobile fractions of the roots; ii) the analysis of the systemic movement of 107Cd in short term PETIS experiments. From these results we suggest that at least two pathways may mediate root-to-shoot Cd translocation in rice. The former could involve OsHMA2 as Zn2+/Cd2+ xylem loader, whereas the latter appears to involve a Zn-independent system that still needs to be identified.

The implication of organic acids in Pb translocation was studied in two species varying in shoot lead accumulation, Sesuvium portulacastrum and Brassica juncea. Citric, fumaric, malic and α-cetoglutaric acids were separated and determined by HPLC technique in shoots, roots and xylem saps of the both species grown in nutrient solutions added with 200 and 400. μM of Pb(II). The lead content of the xylem saps was determined by ICP-MS. Results showed that S. portulacastrum is more tolerant to Pb than B. juncea. Lead concentration in xylem sap of the S. portulacastrum was significantly greater than in that of B. juncea. For both species, a positive correlation was established between lead and citrate concentrations in xylem sap. However minor relationship was observed for fumaric, malic and α-cetoglutaric acids. In the shoots lead treatment also induced a significant increase in citric acid concentration. Both observations suggest the implication of citric acid in lead translocation and shoot accumulation in S. portulacastrum and B. juncea. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could explain its high potential to translocate and accumulate this metal in shoot suggesting their possible use to remediate Pb polluted soils. © 2012.

Analysis of rice plants exposed to a broad range of relatively low and environmentally realistic Cd concentrations showed that the root capacity to retain Cd ions rose from 49 to 79%, corresponding to increases in the external Cd²+ concentration in the 0.01-1 µM range. Fractioning of Cd ions retained by roots revealed that different events along the metal sequestration pathway (i.e. chelation by thiols, vacuolar compartmentalization, adsorption) contributed to Cd immobilization in the roots. However, large amounts of Cd ions (around 24% of the total amount) predictable as potentially mobile were still found in all conditions, while the amount of Cd ions loaded in the xylem seemed to have already reached saturation at 0.1 µM Cd²+, suggesting that Cd translocation may also play an indirect role in determining Cd root retention, especially at the highest external concentrations. In silico search and preliminary analyses in yeast suggest OsHMA2 as a good candidate for the control of Cd xylem loading in rice. Taken as a whole, data indicate Cd chelation, compartmentalization, adsorption and translocation processes as components of a complex 'firewall system' which acts in limiting Cd translocation from the root to the shoot and which reaches different equilibrium positions depending on Cd external concentration.

A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of retinol, alpha-tocopherol and retinyl palmitate in plasma. Plasma containing an internal standard (tocol) was deproteinized with ethanol, then extracted with n-hexane. The organic layer was removed and evaporated under a nitrogen stream, and chromatographed on a reversed-phase RP-18 column using a water/acetonitrile-ethyl acetate/2-propanol gradient solvent system over 15 min at 305 nm. The recovery exceeded 93%. The detection limit was 0.1 microgram/ml for retinol, 1.3 micrograms/ml for alpha-tocopherol and 0.95 micrograms/ml for retinyl palmitate. The reproducibility, precision (expressed as coefficients of variation) and accuracy were less than 8% for all analytes. The small sample requirement, the simplicity of extraction, the short run-time and the good reproducibility make this procedure particularly useful for monitoring retinol and alpha-tocopherol supplementation in premature newborns.

The authors would like to apologise for an omission in their Declaration of Interest. The declaration should read as follows:NabaCarni S.p.a, (Rezzato, Brescia, Italy) partially supported the cost ...