High Concentrations Of Zinc Research Articles

Structural traits of leaf epidermis correspond to metal tolerance in Rumex acetosella populations growing on metal-contaminated soils

The pseudometallophyte Rumex acetosella L. occupies habitats with normal and high soil concentrations of zinc (Zn), lead (Pb), and copper (Cu). It remains unclear if the plants respond to the toxic metals by altering their morphology and increasing the resilience of their cells. We compared plants growing on soils contaminated with Zn/Pb (populations Terézia, Lintich), or Cu (populations Špania Dolina, Staré Hory), with those from non-contaminated soil (Dúbravka) in Slovakia, and analysed leaf structure, physiology, and metal contents by light and electron microscopy, element localization by energy-dispersive X-ray analysis (EDX) in scanning electron microscope, and by specific fluorescence dyes. In control population, the epidermis of the amphistomatic leaves of R. acetosella contained capitate glandular trichomes, consisting of four head (secretory), two stalk, and two basal cells. The ultrastructure of secretory cells revealed fine wall ingrowths bordered by plasma membrane protruding into the cytoplasm. The metallicolous populations had higher contents of Zn and Cu in the epidermal and glandular cells, and a higher density of both stomata and trichomes. Extensive cell wall labyrinth was present in the trichome secretory cells. Their abnormal number and elevated metal contents might indicate effects of heavy metals, especially of Cu, on mitosis and cell plate formation. Differences in leaf physiology were indicated by significantly higher cytoplasmic tolerance to Zn and Cu in metallicolous populations and by structural properties of glandular heads suggesting secretion of toxic metals. Our findings are suggestive of plant reactions to metal stress, which facilitate the populations to occupy the metal-contaminated sites.

Investigation of Genotype by Environment Interactions for Seed Zinc and Iron Concentration and Iron Bioavailability in Common Bean.

Iron and zinc malnutrition are global public health concerns afflicting mostly infants, children, and women in low- and middle-income countries with widespread consumption of plant-based diets. Common bean is a widely consumed staple crop around the world and is an excellent source of protein, fiber, and minerals including iron and zinc. The development of nutrient-dense common bean varieties that deliver more bioavailable iron and zinc with a high level of trait stability requires a measurement of the contributions from genotype, environment, and genotype by environment interactions. In this research, we investigated the magnitude of genotype by environment interaction for seed zinc and iron concentration and seed iron bioavailability (FeBIO) using a set of nine test genotypes and three farmers’ local check varieties. The research germplasm was evaluated for two field seasons across nine on-farm locations in three agro-ecological zones in Uganda. Seed zinc concentration ranged from 18.0 to 42.0 μg g–1 and was largely controlled by genotype, location, and the interaction between location and season [28.0, 26.2, and 14.7% of phenotypic variability explained (PVE), respectively]. Within a genotype, zinc concentration ranged on average 12 μg g–1 across environments. Seed iron concentration varied from 40.7 to 96.7 μg g–1 and was largely controlled by genotype, location, and the interaction between genotype, location, and season (25.7, 17.4, and 13.7% of PVE, respectively). Within a genotype, iron concentration ranged on average 28 μg g–1 across environments. Seed FeBIO ranged from 8 to 116% of Merlin navy control and was largely controlled by genotype (68.3% of PVE). The red mottled genotypes (Rozi Koko and Chijar) accumulated the most seed zinc and iron concentration, while the yellow (Ervilha and Cebo Cela) and white (Blanco Fanesquero) genotypes had the highest seed FeBIO and performed better than the three farmers’ local check genotypes (NABE-4, NABE-15, and Masindi yellow). The genotypes with superior and stable trait performance, especially the Manteca seed class which combine high iron and zinc concentrations with high FeBIO, would serve as valuable parental materials for crop improvement breeding programs aimed at enhancing the nutritional value of the common bean.

New data on the chemical composition of the non-ferrous metal products of the X–XVIII centuries on the territory of Northern and Central Belarus

The article presents the results of analysis of new data on the elemental composition of non-ferrous metal products on the territory of certain archaeological sites in Northern and Central Belarus. The author distinguishes two main stages in the non-ferrous metalworking of the region: the X–XIII centuries and XIV–XVIII centuries. It is noted that the period of the X–XIII centuries is characterized by a significant predominance of copper-zinc alloys with average and high concentrations of zinc in metal. Meanwhile, bronze alloys also play an important role, accounting for 35 % of the total number of the items studied. Samples made of copper-zinc and bronze alloys are also characterized by a significant amount of lead. As a result of the analysis of the data on the elemental composition of non-ferrous metal products of the XIV–XVIII centuries, it is concluded that non-ferrous metalworking of this period is characterized by the continuity of traditions with handicraft production of the previous period, which manifested itself in the widespread use of copper-zinc alloys, as well as of tin-lead and multicomponent bronzes. At the same time, a significant difference is the increase in the proportion of alloys with high concentrations of alloying components.

Non-glandular trichomes of sunflower are important in the absorption and translocation of foliar-applied Zn.

Trichomes are potentially important for absorption of foliar fertilizers. A study has shown that the non-glandular trichromes (NGTs) of sunflower (Helianthus annuus) accumulated high concentrations of foliar-applied zinc (Zn); however, the mechanisms of Zn accumulation in the NGTs and the fate of this Zn are unclear. Here we investigated how foliar-applied Zn accumulates in the NGTs and the subsequent translocation of this Zn. Time-resolved synchrotron-based X-ray fluorescence microscopy and transcriptional analyses were used to probe the movement of Zn in the NGTs, with the cuticle composition of the NGTs examined using confocal Raman microscopy. The accumulation of Zn in the NGTs is both an initial preferential absorption process and a subsequent translocation process. This preferred absorption is likely because the NGT base has a higher hydrophilicity, whilst the subsequent translocation is due to the presence of plasmodesmata, Zn-chelating ligands, and Zn transporters in the NGTs. Furthermore, the Zn sequestered in the NGTs was eventually translocated out of the trichome once the leaf Zn concentration had decreased, suggesting that the NGTs are also important in maintaining leaf Zn homeostasis. This study demonstrates for the first time that trichomes have a key structural and functional role in the absorption and translocation of foliar-applied Zn.

Genome Analysis of Mungbean [Vigna radiata (L.) Wilczek] using Simple Sequence Repeats (SSR) Mapping Data

Background: Agricultural research chiefly focuses on the ways to increase productivity of staple food crops like wheat and rice, but still there are crops where research focus is meagre like nutritionally important mungbean crop grown by marginal farmers in crop rotation systems. Mungbean is leguminous crop which is high in protein content thus it offers health benefits at cheaper rates. The present work emphasizes on finding genetic diversity in mungbean germplasm on the basis of chemical and molecular analysis for micronutrients variation (iron and zinc). The identified molecular markers having linkage with high iron and zinc concentrations in the seeds can prove helpful in expansion of biofortification programme.Methods: Fifty-one green gram genotypes viz. varieties released from CCS Haryana Agricultural University (HAU), Hisar, Punjab Agricultural University (PAU), Ludhiana, Indian Institute of Pulse Research (IIPR), Kanpur and some advanced breeding lines were included in the study. Acid digested samples were used for determination of Fe and Zn by Atomic Absorption Spectrophotometer. Young seedlings leaves were used for isolation of genomic DNA using 2% CTAB (cetyltrimethyl ammonium bromide). Result: Total of fifty-one mungbean genotypes were tested using fifty simple sequence repeat (SSR) primers. Out of fifty primers screened, 16 primers generated 35 bands. Iron (Fe) and zinc (Zn) in mungbean lines was 36.90 to 107.1 mg/kg and 14.2 to 53.8 mg/kg respectively. The molecular studies based on SSR markers also indicates existence of ample genetic diversity at molecular level.

Heavy Metals Phytoremidiation Potential of Napier Grass Cultivated on Tannery Sludge in Bangladesh

Phytoremediation is a cost effective and eco-friendly method for cleanup of contaminated soil. This study focused on the assessment of phytoremediation potential of Napier grass (Pennisetum purpureum) and Indian mastered (Brassica juncea) yielding in tannery sludge. Initial characterization of tannery sludge showed a high concentration of chromium, lead, copper and zinc which were 6845.5±50.2, 73±2.5, 93±1.5 and 29±2.5 mg/kg, respectively. Both seeds of these plants were sown on tannery sludge kept in baskets and harvested after 8 and 12 weeks of plantation. Analysis indicated that both Napier grass and Indian mustard accumulated heavy metals in the order of Cr>Zn>Cu>Pb at different parts of these plants. Transfer factor (TF) for both plants were greater than 1 for Cu, Zn, Pb though it was less than 1 for Cr. Indian mustard accumulated highest concentration of Cr, Cu, and Pb whereas Napier grass showed highest Zn uptake and good Cr and Cu accumulation capacity. The uptake rate of Cr increased in Napier grass with the increase of plant age. Moreover, Napier grass is one of the rapid yielding tropical grasses and can retain for a longer period than Indian mustard for that attribute, it may accumulate more heavy metals than Indian mustard within its life span. Both of these plants can be used for remediating heavy metals from contaminated tannery sludge.
 Journal of Engineering Science 12(1), 2021, 35-41

Inhibition of RNA-dependent RNA polymerase from SARSCoV-2 by compounds in Vangag herbal preparation: an in silico evaluation

Coronavirus disease (COVID-19) has presented unprecedented challenges to healthcare systems worldwide. There are no proven effective therapeutic agents or vaccines. Some antiviral agents and micronutrients have been repurposed for the management. There are claims of herbal preparations with therapeutic effects. Vangag herbal formulation for the management of COVID-19 is a combination of six plants. Molecular docking and virtual screening were used for the study. Ligands and protein target for molecular docking were prepared in Autodock Tools using PyRx 0.8 package. 3D structures of 24 phytochemicals in Vangag were downloaded from PubChem and optimized in Discovery Studio 4.5 visualizer. Nine agents currently used for management of COVID-19 were also downloaded and included in the ligand library to serve as control. Results of the binding affinities of phytochemicals in constituentplants of Vangag to SARS-CoV-2 molecular target (7BV2.pdb) were ranked from 1 to 21. Kolaviron (binding affinity -8.1 Kcal/mol) ranked 1, Ritonavir 5, Remdesivir 6, Quinine 7, Hydroxychloroquine 9, Chloroquine 18 and the least Allicin 21 (binding affinity -3.7 Kcal/mol). Phytochemicals in Vangag have good binding affinity to COVID-19 viral target proteins. Vangag also contains high concentration of zinc and other micronutrients, making it a promising formula for management of COVID-19.
 Keywords: COVID-19; SARS-CoV-2; Molecular docking; Herbal formulation

Effect of terminal heat stress on physiological traits, grain zinc and iron content in wheat (Triticum aestivum L.)

Heat stress is one of the major wheat (Triticum aestivum) production constraints in South Asia (SA), particularly in the Eastern Gangetic Plains (EGP) of India and Bangladesh. Malnutrition is also a severe problem among children and women in SA. Wheat varieties with high grain Zn/Fe are a sustainable, cost-effective solution in the fight against hidden hunger. Thirty wheat genotypes were characterised under the optimum temperature and heat stress conditions in 2016–2017 and 2017–2018 to study the response of the stress on the yield, physiological traits and grain Zn/Fe content. A significant genetic variation was observed for all the traits under the optimum temperature and stress conditions. The yield was reduced by an average of 59.5% under heat stress compared to that of the optimum temperature. A strong positive association of the canopy temperature depression (CTD) with the grain yield (GY) was observed under the heat stress. A negative correlation of the grain Zn/Fe with the yield was observed under the optimum temperature and heat stress conditions, while the association between the grain Zn and Fe was positive. The genotypes BRW 3723, BRW 3759, BRW 3797, BRW 160, HD 2967, HD 2640 were found to be heat-tolerant in both years. Among the tolerant genotypes, BRW 934, BRW 3807 and BRW 3804 showed a high zinc content and BRW 934, BRW 3797, BRW 3788 and BRW 3807 showed a high iron content, respectively. These genotypes can be explored in future breeding programmes to address the problem of nutritional deficiency.

Separate deposition of metals from highly concentrated solutions with granulated magnesia-silicate reagent

Multi-stage deposition of metals from a sulfate solution with a high concentration of iron, aluminum, copper, zinc, and nickel has been studied. The concentrations of the components correspond to the composition of the sub-basement waters of the Gaisky GOK. Granular magnesia-silicate reagent based on serpentinite (Khalilovsk magnesite deposit, the Orenburg region, Russia) has been used as an alkaline agent. The magnesia-silicate reagent's ability to reduce the acidity of solutions is due to the presence of products of destruction of the original serpentine mineral, mainly magnesium oxide. The results of the solutions multi-stage purification from metals simulation have been presented. It has been found that the reagent did not wholly exhaust its activity during a single contact with the solution. Therefore, the possibility of its repeated use for the 2nd and 3rd time has been studied. As the solution is neutralized according to the known pH range of the beginning and complete deposition of metal compounds, first iron, and then aluminum are deposited. For copper and nickel, the effect of co-precipitation is observed until the pH of precipitation of poorly soluble compounds is reached. Iron is the main component of precipitations at the 1st, 2nd, and 3rd stages, which corresponds to pH = 2.4-3.7. At the 4th stage (pH = 4.0), the precipitations consisted mainly of aluminum compounds. The copper and nickel content in precipitations increase due to decreased concentration of major components (aluminum and iron) and a pH increase. The deposition of zinc from the solution occurs not to the precipitations, but on the granules surfaces. Precipitations enriched in aluminum and iron have been obtained. Sorption and co-precipitation processes have been observed for copper, zinc, and nickel, which prevents individual precipitation by these metals. Thermally activated serpentine minerals can be considered a promising alkaline reagent for technogenic solutions neutralization and purification.

The effects of zinc biofortification of seeds and NPK fertilizer application on the growth and yield of sesame (Sesamum indicum L.)

Soils of the southern Guinea savanna zone of Nigeria are inherently infertile due to shortened fallow period and the continuous use of inorganic fertilizer which depletes the soil of micronutrients such as zinc over time. A field trial was carried out at the Teaching and Research Farm of the University of Ilorin, Nigeria during the 2016 and 2017 cropping seasons to evaluate the effect of zinc and NPK fertilizer on the growth, yield and zinc concentration of seeds of sesame. The experiment was laid out as a factorial fitted into a randomized complete block design (RCBD), replicated thrice. The treatment consisted of four levels of ZnSO4 (0, 5, 10 and 15 kg ha-1) and four levels of NPK 15:15:15 (0, 100, 200 and 300 kg ha-1). Data collected were subjected to analysis of variance (ANOVA) and means were separated using new Duncan multiple range test at 5 % level of probability. Results obtained showed significant effects of Zn and NPK rates on plant height, number of leaves, yield per plot and yield per hectare. The application of 15 kg ha-1 Zn and 300 kg ha-1 (15:15:15) NPK resulted in high yield and high zinc content of seeds.

Organic zinc supplementation modifies the metalloproteome of royal jelly produced by Apis mellifera

In this study, we analyzed Apis mellifera royal jelly proteome alterations induced by supplementation with different concentrations of dietary organic zinc (0, 25, 50, and 75 ppm). Proteins extracted from royal jelly were separated by electrophoresis and isoelectric focusing, and zinc-containing protein spots were identified by tandem mass spectrometry. Organic zinc-containing diets modified total royal jelly protein content and altered the expression of five major royal jelly proteins (MRJP1, MRJP2, MRJP3, MRJP5, and MRJP8). While the diet with the lowest tested zinc content (Zn25) increased total royal jelly protein content and expression of MRJP1, diets with higher zinc contents (Zn50 and Zn75) decreased MRJP expression. Our results demonstrate that important proteins and metabolic processes are modified in royal jelly produced by honey bees supplemented with different concentrations of organic zinc source, affecting nutrition and maintenance of colonies.

COMPONENT COMPOSITION OF THE BIODEGRADATION PRODUCT OF FALLEN LEAVES BY BASIDIOMY-CETES PLEUROTUS PULMONARIUS (STRAIN PP-3.2)

Today, plant waste, including fallen poplar leaves (litter), are a promising raw material for the production of useful products using bioconversion, such as protein feed additives.
 The aim of this study was to study the component composition of the products obtained as a result of the bioconversion of leaf litter. The strain PP-3.2 Pleurotus pulmonarius (Fr.) Quél. In the process of substrate conversion, strain PP-3.2 primarily utilizes extractives and easily hydrolyzable polysaccharides, the amount of which decreases by 44 and 36%, respectively. The total content of polysaccharides is reduced by 20%, lignin substances - 9.4%. The loss of substrate mass based on leaf litter was 23%. The product obtained after cultivation contains 28% protein. Analysis of the amino acid composition of the protein showed a high rate of phenylalanine with tyrosine (115), threonine (117.5), valine (110) and isoleucine (105%). Also, the biodegradation product has a high content of glutamic and aspartic acids (11.2 and 25.3% of the total amino acids, respectively). The levels of cadmium, lead and copper revealed as a result of studies do not exceed the maximum permissible concentrations established by the veterinary department. At the same time, there is a high content of iron (166.0 μg/kg) and zinc (256.7 mg/kg) in the feed product. The digestibility of the product is 54%, the content of nucleic substances is up to 0.3%.
 Thus, the results obtained show the possibility of using the product of the conversion of poplar fallen leaves as a protein feed additive.

The interaction of zinc with the multi-functional plasma thyroid hormone distributor protein, transthyretin: evolutionary and cross-species comparative aspects

A considerable body of evidence has been accumulated showing the interrelationship between zinc and the plasma thyroid hormone (TH) distributor protein, transthyretin (TTR). TTR is a multi-functional protein, which emerged from 5-hydroxyisourate hydrolase (HIUHase) by neo-functionalization after gene duplication during early chordate evolution. HIUHase is also a zinc-binding protein. Most biochemical and molecular biological findings have been obtained from mammalian studies. However, in the past two decades, it has become clear that fish TTR displays zinc-dependent TH binding. After a brief introduction on plasma zinc, THs and their binding proteins, this review will focus on the role of zinc in TTR functions of various vertebrates. In particular primitive fish TTR has an extremely high zinc content, with an increased number of histidine residues which are involved in TH binding. However, zinc-dependent TH binding may have been gradually lost from TTRs during higher vertebrate evolution. Although human TTR has a low zinc content, zinc plays an essential role in TTR functions other than TH binding: the stability of TTR-holo retinol binding protein 4 (holoRBP4) complex, TTR amyloidogenesis, the sequestration of amyloid β (Aβ) fibrils and cryptic proteolytic activity. The interaction of TTR with metallothioneins may be a critical step in the exertion of some of these functions. Evolutionary and physiological insights on zinc-dependent functions of TTRs are also discussed.

Dietary organic zinc promotes growth, immune response and antioxidant capacity by modulating zinc signaling in juvenile Pacific white shrimp (Litopenaeus vannamei)

An 8-week feeding trial was conducted to evaluate effects of dietary organic zinc (zinc amino acid chelate) on growth performance, mineral bioaccumulation in whole body, hepatopancreas and carapace, innate immune response and antioxidant capacity of juvenile Pacific white shrimp Litopenaeus vannamei. Five isonitrogenous and isolipidic diets were formulated to contain different zinc levels of 46.4 (basal diet), 65.5, 85.9, 108.4 and 130.6 mg kg−1. Dietary zinc level significantly influenced growth and feed utilization, with the lowest weight gain and highest feed conversion ratio observed in shrimp fed the basal diet. The optimal dietary zinc requirement was estimated to be 104.8 mg kg-1 for juvenile Pacific white shrimp. Shrimp fed the diet containing 130.6 mg kg−1 Zn had the highest zinc concentration in hepatopancreas and carapace, but there were no significant differences in calcium or phosphorus concentration in tissues. Dietary Zn increased the activities of lysozyme, alkaline phosphatase and polyphenol oxidase in hepatopancreas. Shrimp fed the diets supplemented with zinc had significantly higher activity of Cu/Zn SOD and lower content of malondialdehyde in hepatopancreas. The expression levels of toll, imd, lzm, proPO and alp involved in immunity and Cu/Zn sod related to oxidation resistance were up-regulated. Zinc also promoted the expression levels of mt and mtf-1, and up-regulated the expression of SLC39 family genes (zip3, zip9, zip11, zip14) in hepatopancreas. These data provided novel insights in the potential mechanism of organic zinc-induced enhancement of immunity and antioxidant capacity in Pacific white shrimp.

Low Zinc Status Among Palestinian University Students is Related to Hair Loss But Not Diet Score

Introduction: Zinc is an essential nutrient that is related to many health issues, including cutaneous and hair health Aims: To study the prevalence of low and high zinc concentrations among university students and to evaluate the association between zinc status and various health issues including hair loss, skin health, immunity, diarrhea and weight status. Methods: Study outcomes which included age, BMI, gender, health variables such as diarrhea, hair loss, weight loss and others were collected using a structured questionnaire, whereas serum zinc concentration was measured using spectrophotometry. Results: 33% of the study participants had low zinc level, whereas 34.7% had zinc levels higher than normal. Both high and low zinc status were associated with significant hair loss (p<0.0001). High and low zinc status were not significantly related to other study outcomes such as diarrhea, acne and weight loss. Healthy diet score was not significantly different between zinc status categories and was not significantly related to other study outcomes. Conclusion: Appropriate intake of zinc and zinc concentration may protect from hair loss and should be promoted.

Adaptation of Cupriavidus metallidurans CH34 to Toxic Zinc Concentrations Involves an Uncharacterized ABC-Type Transporter.

Cupriavidus metallidurans CH34 is a well-studied metal-resistant β-proteobacterium and contains a battery of genes participating in metal metabolism and resistance. Here, we generated a mutant (CH34ZnR) adapted to high zinc concentrations in order to study how CH34 could adaptively further increase its resistance against this metal. Characterization of CH34ZnR revealed that it was also more resistant to cadmium, and that it incurred seven insertion sequence-mediated mutations. Among these, an IS1088 disruption of the glpR gene (encoding a DeoR-type transcriptional repressor) resulted in the constitutive expression of the neighboring ATP-binding cassette (ABC)-type transporter. GlpR and the adjacent ABC transporter are highly similar to the glycerol operon regulator and ATP-driven glycerol importer of Rhizobium leguminosarum bv. viciae VF39, respectively. Deletion of glpR or the ABC transporter and complementation of CH34ZnR with the parental glpR gene further demonstrated that loss of GlpR function and concomitant derepression of the adjacent ABC transporter is pivotal for the observed resistance phenotype. Importantly, addition of glycerol, presumably by glycerol-mediated attenuation of GlpR activity, also promoted increased zinc and cadmium resistance in the parental CH34 strain. Upregulation of this ABC-type transporter is therefore proposed as a new adaptation route towards metal resistance.

Evaluation of anti-nutrient and mineral content in different pearl millet varieties

Pearl millet is one of the most popular crops in India. It is nutritionally comparable and even superior to major cereals with respect to protein, fat, energy, vitamins & minerals. The present investigation was carried out to evaluate the mineral content and the anti-nutrients present in pearl millet varieties i.e., white grain variety (ICMV-221), hybrids varieties (HHB-226, HHB-223 and HHB-197) and HC-20 variety. Calcium content was highest in HHB-226 and lowest in ICMV-221. No significant differences in calcium content of HHB-197 and HHB-223 was witnessed. Significant (P< 0.05) differences in iron content of different varieties of pearl millet were observed. ICMV-221 contained significantly (P< 0.05) higher zinc content than all the other varieties of pearl millet however, no significant difference in zinc content of HC-20 and HHB-223 as well as HHB-197 and HHB-226 were noticed. The phytic acid and polyphenol content of all pearl millet varieties varied from 620.00 to 875.00 and 304.17 to 438.33 mg/100g.

A relatively higher concentration of zinc and strontium within normal levels in breast milk is associated with higher growth rates among breastfed neonates

A relatively higher concentration of zinc and strontium within normal levels in breast milk is associated with higher growth rates among breastfed neonates

Study on the Effect of Cu (II) and Zn (II) on the Accumulation of Pb (II) from Soil to the Biomass of Vegetable

Among soil pollutants, lead (Pb) is one of the toxic metal pollutants widely used in many industrial processes and occurs as a contaminant in environment. In this study, a field experiment was carried out to investigate the accumulation of lead from soil contaminated by this metal ion on the biomass of some vegetables, including spinach, lettuce, carrots, and potatoes. The results showed that lead was cumulative metal. Besides, the level of lead accumulation in soil of the studied vegetables decreased in the order of tubers of carrots, tubers of potato, spinach root, lettuce root, stems and leaves of spinach, stem and leaves of carrot, stems and leaves of potato, and stem and leaves of lettuce, respectively. Our investigations demonstrate the effect of copper and zinc micronutrient elements which play an important role in the growth and development of plants, on the accumulation of lead from contaminated soil of the studied vegetables. The obtained results showed that high concentration of copper and zinc in soil cause competition with lead in the process of absorption and accumulation in the plant. Specifically, copper and zinc showed the inhibition effect on the uptake and accumulation of lead by these plants.

Harnessing reaction-based probes to preferentially target pancreatic β-cells and β-like cells.

Highly sensitive approaches to target insulin-expressing cells would allow more effective imaging, sorting, and analysis of pancreatic β-cells. Here, we introduce the use of a reaction-based probe, diacetylated Zinpyr1 (DA-ZP1), to image pancreatic β-cells and β-like cells derived from human pluripotent stem cells. We harness the high intracellular zinc concentration of β-cells to induce a fluorescence signal in cells after administration of DA-ZP1. Given its specificity and rapid uptake by cells, we used DA-ZP1 to purify live stem cell-derived β-like cells as confirmed by immunostaining analysis. We tested the ability of DA-ZP1 to image transplanted human islet grafts and endogenous mouse pancreatic islets in vivo after its systemic administration into mice. Thus, DA-ZP1 enables purification of insulin-secreting β-like cells for downstream applications, such as functional studies, gene-expression, and cell-cell interaction analyses and can be used to label engrafted human islets and endogenous mouse islets in vivo.