Cadmium alters whole animal ionome and promotes the re-distribution of iron in intestinal cells of .

The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements.

Visualizing Metal Distribution in Plants Using Synchrotron X-Ray Fluorescence Microscopy Techniques.

Recent improvements in synchrotron-based X-ray fluorescence (SXRF) microscopy established it as an advanced analytical tool for analyzing 2D- and 3D distribution of mineral elements in plants. Among existing imaging techniques, SXRF microscopy offers several unique capabilities, including in situ metal quantification in plant tissues and high sensitivity, as low as 1 mg kg, at the nanoscale spatial resolution. SXRF is increasingly utilized in different plant science disciplines to provide a fundamental understanding of metal homeostasis, and the function of trace elements in plant metabolism and development.

Information theory and machine learning illuminate large-scale metabolomic responses of Brachypodium distachyon to environmental change.

Plant responses to environmental change are mediated via changes in cellular metabolomes. However, <5% of signals obtained from liquid chromatography tandem mass spectrometry (LC-MS/MS) can be identified, limiting our understanding of how metabolomes change under biotic/abiotic stress. To address this challenge, we performed untargeted LC-MS/MS of leaves, roots, and other organs of Brachypodium distachyon (Poaceae) under 17 organ-condition combinations, including copper deficiency, heat stress, low phosphate, and arbuscular mycorrhizal symbiosis.

Loss of OPT3 function decreases phloem copper levels and impairs crosstalk between copper and iron homeostasis and shoot-to-root signaling in Arabidopsis thaliana.

Copper (Cu) and iron (Fe) are essential micronutrients that are toxic when accumulating in excess in cells. Thus, their uptake by roots is tightly regulated. While plants sense and respond to local Cu availability, the systemic regulation of Cu uptake has not been documented in contrast to local and systemic control of Fe uptake.

Iron Availability within the Leaf Vasculature Determines the Magnitude of Iron Deficiency Responses in Source and Sink Tissues in Arabidopsis.

Iron (Fe) uptake and translocation in plants are fine-tuned by complex mechanisms that are not yet fully understood. In Arabidopsis thaliana, local regulation of Fe homeostasis at the root level has been extensively studied and is better understood than the systemic shoot-to-root regulation. While the root system is solely a sink tissue that depends on photosynthates translocated from source tissues, the shoot system is a more complex tissue, where sink and source tissues occur synchronously.

Genome-wide association study suggests an independent genetic basis of zinc and cadmium concentrations in fresh sweet corn kernels.

Despite being one of the most consumed vegetables in the United States, the elemental profile of sweet corn (Zea mays L.) is limited in its dietary contributions. To address this through genetic improvement, a genome-wide association study was conducted for the concentrations of 15 elements in fresh kernels of a sweet corn association panel.

TpIRT1 from Polish wheat (Triticum polonicum L.) enhances the accumulation of Fe, Mn, Co, and Cd in Arabidopsis.

Uptake and internal transport of micronutrients are essential for plant growth, development, and yield. In this regard, Iron Regulated Transporters (IRTs) from the Zinc Regulated Transporter (ZRT)/IRT-related protein (ZIP) family play an important role in transition metal uptake. Most studies have been focused on IRT1-like proteins in diploid species.

Ferroportin 3 is a dual-targeted mitochondrial/chloroplast iron exporter necessary for iron homeostasis in Arabidopsis.

Mitochondria and chloroplasts are organelles with high iron demand that are particularly susceptible to iron-induced oxidative stress. Despite the necessity of strict iron regulation in these organelles, much remains unknown about mitochondrial and chloroplast iron transport in plants. Here, we propose that Arabidopsis ferroportin 3 (FPN3) is an iron exporter that is dual-targeted to mitochondria and chloroplasts.

ASCORBATE PEROXIDASE6 delays the onset of age-dependent leaf senescence.

Age-dependent changes in reactive oxygen species (ROS) levels are critical in leaf senescence. While H2O2-reducing enzymes such as catalases and cytosolic ASCORBATE PEROXIDASE1 (APX1) tightly control the oxidative load during senescence, their regulation and function are not specific to senescence. Previously, we identified the role of ASCORBATE PEROXIDASE6 (APX6) during seed maturation in Arabidopsis (Arabidopsis thaliana).

YSL3-mediated copper distribution is required for fertility, seed size and protein accumulation in Brachypodium.

Addressing the looming global food security crisis requires the development of high-yielding crops. In agricultural soils, deficiency in the micronutrient copper significantly decreases grain yield in wheat (Triticum aestivum), a globally important crop. In cereals, grain yield is determined by inflorescence architecture, flower fertility, grain size, and weight.

Copper deficiency alters shoot architecture and reduces fertility of both gynoecium and androecium in .

Copper deficiency reduces plant growth, male fertility, and seed set. The contribution of copper to female fertility and the underlying molecular aspects of copper deficiency-caused phenotypes are not well known. We show that among copper deficiency-caused defects in were also the increased shoot branching, delayed flowering and senescence, and entirely abolished gynoecium fertility.

N-Terminal Extension and C-Terminal Domains Are Required for ABCB6/HMT-1 Protein Interactions, Function in Cadmium Detoxification, and Localization to the Endosomal-Recycling System in .

The chronic exposure of humans to toxic metals such as cadmium from food and air causes dysfunction of vital organs, neurodegenerative conditions, and cancer. In this regard, members of the ABCB sub-family of the ATP-binding cassette (ABC) transporter superfamily, ABCB6/HMT-1, are acutely required for the detoxification of heavy metals and are present in genomes of many organisms including the nematode worm, and humans. We showed previously that ABCB6/HMT-1 detoxifies cadmium, copper, and arsenic, and is expressed in liver-like cells, the coelomocytes, head neurons and intestinal cells, which are the cell types that are affected by heavy metal poisoning in humans.

The Knockout Mutant for () Is Defective in Callose Deposition, Bacterial Pathogen Defense and Auxin Content, But Shows an Increased Stem Lignification.

The enzyme phytochelatin synthase (PCS) has long been studied with regard to its role in metal(loid) detoxification in several organisms, i.e., plants, yeasts, and nematodes.

Arabidopsis Pollen Fertility Requires the Transcription Factors CITF1 and SPL7 That Regulate Copper Delivery to Anthers and Jasmonic Acid Synthesis.

A deficiency of the micronutrient copper (Cu) leads to infertility and grain/seed yield reduction in plants. How Cu affects fertility, which reproductive structures require Cu, and which transcriptional networks coordinate Cu delivery to reproductive organs is poorly understood. Using RNA-seq analysis, we showed that the expression of a gene encoding a novel transcription factor, CITF1 (Cu-DEFICIENCY INDUCED TRANSCRIPTION FACTOR1), was strongly upregulated in flowers subjected to Cu deficiency.

Iron-Nicotianamine Transporters Are Required for Proper Long Distance Iron Signaling.

The mechanisms of root iron uptake and the transcriptional networks that control root-level regulation of iron uptake have been well studied, but the mechanisms by which shoots signal iron status to the roots remain opaque. Here, we characterize an Arabidopsis () double mutant, (), which has lost the ability to properly regulate iron deficiency-influenced gene expression in both roots and shoots. In spite of markedly low tissue levels of iron, the double mutant does not up- and down-regulate iron deficiency-induced and -repressed genes.

CsNIP2;1 is a Plasma Membrane Transporter from Cucumis sativus that Facilitates Urea Uptake When Expressed in Saccharomyces cerevisiae and Arabidopsis thaliana.

Urea is an important source of nitrogen (N) for the growth and development of plants. It occurs naturally in soils, is the major N source in agricultural fertilizers and is an important N metabolite in plants. Therefore, the identification and characterization of urea transporters in higher plants is important for the fundamental understanding of urea-based N nutrition in plants and for designing novel strategies for improving the N-use efficiency of urea based-fertilizers.

Local and systemic signaling of iron status and its interactions with homeostasis of other essential elements.

Iron (Fe) is essential for plant growth and development. However, alkaline soils, which occupy approximately 30% of the world's arable lands, are considered Fe-limiting for plant growth because insoluble Fe (III) chelates prevail under these conditions. In contrast, high bioavailability of Fe in acidic soils can be toxic to plants due to the ability of Fe ions to promote oxidative stress.

Gene functional analysis using protoplast transient assays.

The protoplast transient assay system has been widely used for rapid functional analyses of genes using cellular and biochemical approaches. This system has been increasingly employed for functional genetic studies using double-stranded (ds) RNA interference (RNAi). Here, we describe a modified procedure for the isolation of protoplasts from leaf mesophyll cells of 14-day-old Arabidopsis thaliana.

Brachypodium distachyon as a model system for studies of copper transport in cereal crops.

Copper (Cu) is an essential micronutrient that performs a remarkable array of functions in plants including photosynthesis, cell wall remodeling, flowering, and seed set. Of the world's major cereal crops, wheat, barley, and oat are the most sensitive to Cu deficiency. Cu deficient soils include alkaline soils, which occupy approximately 30% of the world's arable lands, and organic soils that occupy an estimated 19% of arable land in Europe.

OPT3 Is a Phloem-Specific Iron Transporter That Is Essential for Systemic Iron Signaling and Redistribution of Iron and Cadmium in Arabidopsis.

Iron is essential for both plant growth and human health and nutrition. Knowledge of the signaling mechanisms that communicate iron demand from shoots to roots to regulate iron uptake as well as the transport systems mediating iron partitioning into edible plant tissues is critical for the development of crop biofortification strategies. Here, we report that OPT3, previously classified as an oligopeptide transporter, is a plasma membrane transporter capable of transporting transition ions in vitro.

The CTR/COPT-dependent copper uptake and SPL7-dependent copper deficiency responses are required for basal cadmium tolerance in A. thaliana.

Copper (Cu) homeostasis in plants is maintained by at least two mechanisms: (1) the miRNA-dependent reallocation of intracellular Cu among major Cu-enzymes and important energy-related functions; (2) the regulation of the expression of Cu transporters including members of the CTR/COPT family. These events are controlled by the transcription factor SPL7 in Arabidopsis thaliana. Cadmium (Cd), on the other hand, is a non-essential and a highly toxic metal that interferes with homeostasis of essential elements by competing for cellular binding sites.

High-resolution genome-wide scan of genes, gene-networks and cellular systems impacting the yeast ionome.

Background: To balance the demand for uptake of essential elements with their potential toxicity living cells have complex regulatory mechanisms. Here, we describe a genome-wide screen to identify genes that impact the elemental composition ('ionome') of yeast Saccharomyces cerevisiae. Using inductively coupled plasma - mass spectrometry (ICP-MS) we quantify Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, S and Zn in 11890 mutant strains, including 4940 haploid and 1127 diploid deletion strains, and 5798 over expression strains.

COPT6 is a plasma membrane transporter that functions in copper homeostasis in Arabidopsis and is a novel target of SQUAMOSA promoter-binding protein-like 7.

Among the mechanisms controlling copper homeostasis in plants is the regulation of its uptake and tissue partitioning. Here we characterized a newly identified member of the conserved CTR/COPT family of copper transporters in Arabidopsis thaliana, COPT6. We showed that COPT6 resides at the plasma membrane and mediates copper accumulation when expressed in the Saccharomyces cerevisiae copper uptake mutant.