# overview
Compartmentalization of metabolic pathways and other cellular functions is a hallmark of eukaryotic cells. This feature is extreme in plants due to the presence of organelles not found in most other eukaryotes - plastids. Plastids are a diverse group of interrelated organelles that perform a wide range of metabolic functions including photosynthesis, nitrogen and sulfur assimilation and the synthesis of amino acids, starch and fatty acids. These functions are coordinated with metabolic processes in the cytosol through dynamic exchange of metabolites and ions across the plastid inner envelope membrane.

My lab is studying phosphate (Pi) transport processes that link the metabolic pathways in the plastid and cytosol. The concentrations of Pi in the cytosol and plastid stroma influence photosynthesis and the partitioning and storage of fixed carbon. Transporters involved in the movement of Pi across the plastid inner membrane include members of the pPT, PHT2 and PHT4 families. We are using genetics, cell biology, biochemistry and molecular physiology to investigate the function and physiological roles of these transporters. Recent findings suggest that some members of the PHT4 family are targeted to chloroplasts, whereas others function in heterotrophic plastids and one resides in the Golgi apparatus.

Other projects in the lab include the genetic and biochemical characterization of Pi transport processes in the filamentous fungus Neurospora crassa. Mutants with altered phosphate uptake properties have been isolated, and these have led to the identification of Pi transporter genes, as well as genes with putative regulatory functions.

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Reverse Transcriptase Polymerase Chain Reaction

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Fluorescence Resonance Energy Transfer (fret)

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30 Agricultural, Veterinary And Food Sciences

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Samuel Roberts Noble Foundation - (Ardmore, Oklahoma, United States)

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University of Nebraska–Lincoln - (Lincoln, United States)

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University of Wisconsin - Madison - (Madison, Wisconsin, United States)

# educationAndTraining[].organization.label
University of Nebraska–Lincoln - (Lincoln, United States)

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Differential expression and phylogenetic analysis suggest specialization of plastid-localized members of the PHT4 phosphate transporter family for photosynthetic and heterotrophic tissues.

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Purification and properties of a 4-nitrophenylphosphatase from Aspergillus niger.

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Rapid genetic mapping in Neurospora crassa.

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Editorial overview: Cell signaling and gene regulation: nutrient sensing, signaling, and transport.

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Methods to estimate the proportion of plant and fungal RNA in an arbuscular mycorrhiza.

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Live imaging of inorganic phosphate in plants with cellular and subcellular resolution.

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ATP compartmentation in plastids and cytosol of Arabidopsis thaliana revealed by fluorescent protein sensing.

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Proceedings of the National Academy of Sciences

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Transformation of Medicago truncatula via infiltration of seedlings or flowering plants with Agrobacterium

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The Arabidopsis thylakoid transporter PHT4;1 influences phosphate availability for ATP synthesis and plant growth.

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Intracellular phosphate--water oxygen exchange measured by mass spectrometry.

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Enhancement of beta-globin locus control region-mediated transactivation by mitogen-activated protein kinases through stochastic and graded mechanisms.

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Closely related members of the Medicago truncatula PHT1 phosphate transporter gene family encode phosphate transporters with distinct biochemical activities.

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A phosphate-repressible, high-affinity phosphate permease is encoded by the pho-5+ gene of Neurospora crassa.

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Proceedings of the National Academy of Sciences

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Genetically encoded sensors for monitoring the transport and concentration of nitrogen-containing and phosphorus-containing molecules in plants.

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Functional analysis of the Arabidopsis PHT4 family of intracellular phosphate transporters.

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Spatial Profiles of Phosphate in Roots Indicate Developmental Control of Uptake, Recycling, and Sequestration.

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Environmental Risks of Nano Zerovalent Iron for Arsenate Remediation: Impacts on Cytosolic Levels of Inorganic Phosphate and MgATP2– in Arabidopsis thaliana

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Genetically manipulated chloroplast stromal phosphate levels alter photosynthetic efficiency.

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A genetically encoded biosensor reveals spatiotemporal variation in cellular phosphate content in Brachypodium distachyon mycorrhizal roots.

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Quantitative Imaging of FRET-Based Biosensors for Cell- and Organelle-Specific Analyses in Plants.

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The Physiological Role of Arabidopsis Thylakoid Phosphate Transporter PHT4;1

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A phosphate transporter from Medicago truncatula is expressed in the photosynthetic tissues of the plant and located in the chloroplast envelope.

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Intracellular transport and compartmentation of phosphate in plants.

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An Improved Colorimetric Assay for Bacterial Lipase in Nonfat Dry Milk

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The Sink-Specific Plastidic Phosphate Transporter PHT4;2 Influences Starch Accumulation and Leaf Size in Arabidopsis

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A Role for the Plastidial GPT2 Translocator in the Modulation of Lignin Biosynthesis.

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A Chloroplast Phosphate Transporter, PHT2;1, Influences Allocation of Phosphate within the Plant and Phosphate-Starvation Responses

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Mitogen-activated protein kinases enhance long-range activation by the β-globin locus control region

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Proceedings of the National Academy of Sciences

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Imaging Cellular Inorganic Phosphate in Caenorhabditis elegans Using a Genetically Encoded FRET-Based Biosensor.

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Phosphate transporters of Medicago truncatula and arbuscular mycorrhizal fungi

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Activator-independent gene expression in Neurospora crassa

# researcherOn[].label
Development of Biosensors to Measure the Spatial and Temporal Concentration Profiles of Inorganic Phosphate in Plants During Arbuscular Mycorrhizal Symbiosis

# researcherOn[].awardedBy.label
United States Department of Energy - (Washington D.C., District of Columbia, United States)

# streetAddress
Texas A&M University; Biology; 3258 TAMU