A5006910937- Plant Molecular Biology Research
- Plant Reproductive Biology
- Light effects on plants
- Photosynthetic Processes and Mechanisms
- Plant nutrient uptake and metabolism
- Legume Nitrogen Fixing Symbiosis
- Risk and Safety Analysis
- Energetic Materials and Combustion
- Nuclear and radioactivity studies
- Infrastructure Resilience and Vulnerability Analysis
- Nuclear Engineering Thermal-Hydraulics
- High-Velocity Impact and Material Behavior
- Engineering and Material Science Research
- Polysaccharides and Plant Cell Walls
- Electromagnetic Launch and Propulsion Technology
- Plant Gene Expression Analysis
- Plant Stress Responses and Tolerance
- Semiconductor Quantum Structures and Devices
- Combustion and Detonation Processes
- Plant Micronutrient Interactions and Effects
- Inorganic and Organometallic Chemistry
- Rocket and propulsion systems research
- Plant Virus Research Studies
- Porphyrin Metabolism and Disorders
- Seismic Performance and Analysis
University of North Carolina at Chapel Hill
2014-2024
Oregon Health & Science University
2012-2022
Laboratoire Reproduction et Développement des Plantes
2019-2022
École Normale Supérieure de Lyon
2019
University of Wisconsin–Madison
2007
University of Missouri
2004
Mound Laser & Photonics Center (United States)
1976-2003
Salk Institute for Biological Studies
1992-2000
Kent State University
1987-1996
Applied Technologies (United States)
1995
Phytochromes are a family of plant photoreceptors that mediate physiological and developmental responses to changes in red far-red light conditions. In Arabidopsis, there genes for at least five phytochrome proteins. These control such as germination, stem elongation, flowering, gene expression, chloroplast leaf development. However, it is not known which controlled by species, or whether the different phytochromes have overlapping functions. We report here previously described hy3 mutants...
Pollination in flowering plants requires that anthers release pollen when the gynoecium is competent to support fertilization. We show Arabidopsis thaliana, two paralogous auxin response transcription factors, ARF6 and ARF8, regulate both stamen maturation. arf6 arf8 double-null mutant flowers arrested as infertile closed buds with short petals, filaments, undehisced did not immature gynoecia. Numerous developmentally regulated genes failed be induced. ARF8 thus coordinate transition from...
In flowering plants, diploid sporophytic tissues in ovules and anthers support meiosis subsequent haploid gametophyte development. These analogous reproductive functions suggest that common mechanisms may regulate ovule anther Two Arabidopsis Auxin Response Factors, ARF6 ARF8, gynoecium stamen development immature flowers. Wild-type pollen grew poorly arf6 arf8 gynoecia, correlating with ARF8 expression style transmitting tract. transcripts are cleavage targets of the microRNA miR167,...
Plant responses to red and far-red light are mediated by a family of photoreceptors called phytochromes. In Arabidopsis thaliana, there genes encoding at least five phytochromes, it is interest learn if the different phytochromes have overlapping or distinct functions. To address this question for two in Arabidopsis, we compared wild type with those phyA null mutant, phyB double mutant. We found that both mutants deficiency germination, mutant dark. Furthermore, germination defect caused...
In plants, both endogenous mechanisms and environmental signals regulate developmental transitions such as seed germination, induction of flowering, leaf senescence shedding senescent organs. Auxin response factors (ARFs) are transcription that mediate responses to the plant hormone auxin. We have examined Arabidopsis lines carrying T-DNA insertions in AUXIN RESPONSE FACTOR1 (ARF1) ARF2 genes. found promotes between multiple stages development. arf2 mutant plants exhibited delays several...
Abstract The plant hormone auxin controls many aspects of development and acts in part by inducing expression various genes. Arabidopsis thaliana semidominant shy2 (short hypocotyl) mutations cause leaf formation dark-grown plants, suggesting that SHY2 has an important role regulating development. Here we show the gene encodes IAA3, a previously known member Aux/IAA family auxin-induced Dominant amino acid changes domain II, conserved among all members this family. We isolated...
Phytochrome, a red/far-red-light photoreceptor protein of plants, is encoded by small gene family. Phytochrome A (PHYA), the product PHYA gene, predominant molecular species phytochrome in etiolated tissue and has been best characterized biochemically. To define role for PHYA, we isolated new mutants, designated fre1 (far-red elongated), Arabidopsis thaliana that were specifically deficient spectral activity accumulation. These mutants identified on basis their long hypocotyl phenotype under...
Abstract The dominant gain-of-function axr2-1 mutation of Arabidopsis causes agravitropic root and shoot growth, a short hypocotyl stem, auxin-resistant growth. We have cloned theAXR2 gene using map-based approach, find that it is the same as IAA7, member IAA(indole-3-acetic acid) family auxin-inducible genes. Theaxr2-1 changes single amino acid in conserved domain II AXR2/IAA7. isolated loss-of-function mutations inAXR2/IAA7 intragenic suppressors ofaxr2-1 or screen for insertion inIAA A...
Auxin response factors (ARFs) bind auxin promoter elements and mediate transcriptional responses to auxin. Five of the 22 ARF genes in Arabidopsis thaliana encode ARFs with glutamine-rich middle domains. Four these can activate transcription have been ascribed developmental functions. We show that ARF19, fifth Q-rich ARF, also activates transcription. Mutations ARF19 little effect on their own, but combination mutations NPH4/ARF7, encoding most closely related they cause several phenotypes...
Auxin regulates plant growth and development in part by activating gene expression. Arabidopsis thaliana SMALL AUXIN UP RNAs (SAURs) are a family of early auxin-responsive genes with unknown functionality. Here, we show that transgenic lines expressing artificial microRNA constructs (aMIR-SAUR-A or -B) target SAUR subfamily (SAUR61-SAUR68 SAUR75) had slightly reduced hypocotyl stamen filament elongation. In contrast, plants SAUR63:GFP SAUR63:GUS fusions long hypocotyls, petals filaments,...
Effective regulation of water balance in plants requires localized extracellular barriers that control and solute movement. We describe a clade five Arabidopsis thaliana ABCG half-transporters are required for synthesis an effective suberin barrier roots seed coats (ABCG2, ABCG6, ABCG20) intact pollen wall (ABCG1 ABCG16). Seed abcg2 abcg6 abcg20 triple mutant had increased permeability to tetrazolium red decreased content. The root system was more permeable salts zone complementary affected...
For self-pollinating plants to reproduce, male and female organ development must be coordinated as flowers mature. The Arabidopsis transcription factors AUXIN RESPONSE FACTOR 6 (ARF6) ARF8 regulate this complex process by promoting petal expansion, stamen filament elongation, anther dehiscence, gynoecium maturation, thereby ensuring that pollen released from the anthers is deposited on stigma of a receptive gynoecium. ARF6 induce jasmonate production, which in turn triggers expression MYB21...
Auxin regulates the expression of diverse genes that affect plant growth and development. This regulation requires AUXIN RESPONSE FACTORS (ARFs) bind to promoter regions these genes. ARF6 ARF8 in Arabidopsis thaliana are required promote inflorescence stem elongation late stages petal, stamen, gynoecium All seed plants studied thus far have orthologues as well microRNA miR167, which targets ARF8. Whether broadly conserved roles flower development is not known. To address this question,...
Abstract The complete genomic sequence for Arabidopsis provides the opportunity to combine phylogenetic and approaches study evolution of gene families in plants. Aux/IAA ARF families, consisting 29 23 loci Arabidopsis, respectively, encode proteins that interact mediate auxin responses regulate various aspects plant morphological development. We developed scenarios proliferation by combining analysis with information on relationship between each locus previously identified duplicated...
In Arabidopsis, SHY2 encodes IAA3, a member of the auxin-induced Aux/IAA family. Gain-of-function mutations in SHY2/IAA3 cause enlarged cotyledons, short hypocotyls, and altered auxin-regulated root development. Here we show that gain-of-function mutation shy2-2 decreases both induction repression genes, suggesting acts as negative regulator auxin signaling. affects many previously characterized primary response implying it might repress responses. addition, also expression multiple...
Potassium ions (K+) are the most abundant cations in plants and necessary for cell growth. Arabidopsis shy3-1 mutant have a short hypocotyl, small leaves, flowering stem, these defects result from decreased expansion. The semidominant mutation changes an amino acid KT2/KUP2, K+ transporter related to Escherichia coli Kup protein. Second mutations KT2/KUP2/SHY3 gene, including presumed null mutations, suppress phenotypes. Plants with intragenic suppressor appear similar wild-type plants,...
Rhizobium meliloti produces an acidic, Calcofluor-binding exopolysaccharide which plays a role in nodulation of alfalfa plants by this bacterium. We constructed and mapped 102 transposon insertions 48-kilobase (kb) region previously shown to contain several exo genes. Mutations affecting production the were clustered 22-kb fell into 12 complementation groups. Strains carrying mutations seven groups (exoA, exoB, exoF, exoL, exoM, exoP, exoQ) produced no induced non-nitrogen-fixing nodules on...