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Characterization Of The Osmoprotectant Transporter Opuc From Pseudomonas Syringae And Demonstration That Cystathionine-Β-Synthase Domains Are Required For Its Osmoregulatory Function, Chiliang Chen, Gwyn A. Beattie Oct 2007

Characterization Of The Osmoprotectant Transporter Opuc From Pseudomonas Syringae And Demonstration That Cystathionine-Β-Synthase Domains Are Required For Its Osmoregulatory Function, Chiliang Chen, Gwyn A. Beattie

Plant Pathology and Microbiology Publications

The plant pathogen Pseudomonas syringae may cope with osmotic stress on plants, in part, by importing osmoprotective compounds. In this study, we found that P. syringae pv. tomato strain DC3000 was distinct from most bacterial species in deriving greater osmoprotection from exogenous choline than from glycine betaine. This superior osmoprotection was correlated with a higher capacity for uptake of choline than for uptake of glycine betaine. Of four putative osmoregulatory ABC transporters in DC3000, one, designated OpuC, functioned as the primary or sole transporter for glycine betaine and as one of multiple transporters for choline under high osmolarity. Surprisingly, the ...


Synergistic Substrate Inhibition Of Ent-Copalyl Diphosphate Synthase: A Potential Feed-Forward Inhibition Mechanism Limiting Gibberellin Metabolism, Sladjana Prisic, Reuben J. Peters May 2007

Synergistic Substrate Inhibition Of Ent-Copalyl Diphosphate Synthase: A Potential Feed-Forward Inhibition Mechanism Limiting Gibberellin Metabolism, Sladjana Prisic, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Gibberellins (GAs) or gibberellic acids are ubiquitous diterpenoid phytohormones required for many aspects of plant growth and development, including repression of photosynthetic pigment production (i.e. deetiolation) in the absence of light. The committed step in GA biosynthesis is catalyzed in plastids by ent-copalyl diphosphate synthase (CPS), whose substrate, (E,E,E,)-geranylgeranyl diphosphate (GGPP), is also a direct precursor of carotenoids and the phytol side chain of chlorophyll. Accordingly, during deetiolation, GA production is repressed, whereas flux toward these photosynthetic pigments through their common GGPP precursor is dramatically increased. How this is accomplished has been unclear because no ...


Spatial Analysis Of Arabidopsis Thaliana Gene Expression In Response To Turnip Mosaic Virus Infection, Chunling Yang, Rong Guo, Fei Jie, Dan Nettleton, Jiqing Peng, Tyrell Carr, Joanne M. Yeakley, Jian-Bing Fan, Steven A. Whitham Apr 2007

Spatial Analysis Of Arabidopsis Thaliana Gene Expression In Response To Turnip Mosaic Virus Infection, Chunling Yang, Rong Guo, Fei Jie, Dan Nettleton, Jiqing Peng, Tyrell Carr, Joanne M. Yeakley, Jian-Bing Fan, Steven A. Whitham

Statistics Publications

Virus-infected leaf tissues comprise a heterogeneous mixture of cells at different stages of infection. The spatial and temporal relationships between sites of virus accumulation and the accompanying host responses, such as altered host gene expression, are not well defined. To address this issue, we utilized Turnip mosaic virus (TuMV) tagged with the green fluorescent protein to guide the dissection of infection foci into four distinct zones. The abundance of Arabidopsis thaliana mRNA transcripts in each of the four zones then was assayed using the Arabidopsis ATH1 GeneChip oligonucleotide microarray (Affymetrix). mRNA transcripts with significantly altered expression profiles were determined across ...


A Study Of The Impact Of Mazie Sbe I On The [Alpha]-Polyglucan Produced In Synechocystis Sp. Strain Pcc 6803, Shayani Deborah Nesaranjani Pieris Jan 2007

A Study Of The Impact Of Mazie Sbe I On The [Alpha]-Polyglucan Produced In Synechocystis Sp. Strain Pcc 6803, Shayani Deborah Nesaranjani Pieris

Retrospective Theses and Dissertations

Starch is a biopolymer synthesized primarily in plants and is made of alpha-1,4 linked glucose chains with alpha-1,6 glycosidic bonds at branch points. Amylose and amylopectin, the component molecules of starch are essentially linear and 4-5% branched respectively. Amylopectin, thought to be responsible for the semi-crystalline nature of starch, is chemically similar but physically distinct from water-soluble glycogen. Amylopectin is distinct from glycogen in having longer chains, fewer branch points and a clustered branching pattern. The hypothesis that the presence of a branching enzyme that can transfer long branches will facilitate the formation and perpetuation of a cluster ...


Phytoremediation Of Landfill Leachate Using Populus, Jill Annette Zalesny Jan 2007

Phytoremediation Of Landfill Leachate Using Populus, Jill Annette Zalesny

Retrospective Theses and Dissertations

Resource managers are challenged with waste disposal and leachate produced from its degradation. Poplar (Populus spp.) trees offer an opportunity for ecological leachate disposal as an irrigation source for managed tree systems. Information about sodium (Na+), chloride (Cl -), and nutrient uptake and distribution into tissues of Populus genotypes irrigated with landfill leachate helps to maximize biomass production and to understand impacts of leachate chemistry on tree health. However, such knowledge about the response of poplar genotypes to landfill leachate irrigation is limited, along with efficient methods for choosing genotypes based on leachate composition.;During initial greenhouse research, poplar clones were ...


Starch Function In Ornamental Tobacco Floral Nectary Development, Gang Ren Jan 2007

Starch Function In Ornamental Tobacco Floral Nectary Development, Gang Ren

Retrospective Theses and Dissertations

Morphological changes of floral nectary gland and subcellular transition of floral nectary cells of ornamental tobacco LxS8 were exclusively investigated in this study. Enlargement of the floral nectary gland of ornamental tobacco LxS8 that occurs during development is accompanied by a major accumulation of Periodic Acid-Schiff's staining (PAS-staining) starch grains in nectary amyloplasts. Quantification of starch purified from the nectary at various stages of development showed little starch at an early developmental stage, soon thereafter the amount of starch increased dramatically, reaching a peak approximately 24 hours prior to anthesis. After this time, the amount of starch declined dramatically ...


Signaling Dynamics In Rice Expressing Constitutively Active Nicotiana Protein Kinase 1 (Npk1), Andréa Lu Scarpa Jan 2007

Signaling Dynamics In Rice Expressing Constitutively Active Nicotiana Protein Kinase 1 (Npk1), Andréa Lu Scarpa

Retrospective Theses and Dissertations

Signaling components such as mitogen-activated protein kinases (MAPKs) regulate stress-induced pathways and are potentially a powerful means of genetically engineering plant tolerance to abiotic stress. The kinase domain of tobacco mitogen-activated protein kinase Nicotiana protein kinase 1 (NPK1) into rice cultivar Nipponbare. Four-week old transgenic and wild type plants treated with moderate (150mM) or severe (300mM) salt stress did not differ in visible signs of leaf damage, electrolyte leakage, malondialdehyde content or ion content within leaves. Expression of caNPK1 alters gene transcript abundance in the absence of stress as assessed by microarray analysis. Genes potentially related to flowering and development ...


Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill]: Ii. Phenotypic Recurrent Selection, E. Ortiz-Perez, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer Jan 2007

Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill]: Ii. Phenotypic Recurrent Selection, E. Ortiz-Perez, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer

Genetics, Development and Cell Biology Presentations, Posters and Proceedings

Recurrent selection (RS) includes the systematic selection of desirable individuals from a population followed by recombination of the selected individuals to form a new population [ l]. Nuclear male-sterility with insect-mediated cross-pollination has been successfully used in RS schemes in soybean [Glycine max (L.) Merrill]. However, selection to increase the seed-set on male-sterile plants per se has received minimal attention. Preferential pollination observed through seed-set suggested that selection on male-sterile plants for high seed-set can be attained [2, 3]. Thus, selected male-sterile, female-fertile lines could be suitable to produce larger amounts of hybrid soybean seed.


Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill] : I. Agronomic Performance, E. Ortiz-Perez, S. R. Cianzio, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer Jan 2007

Insect-Mediated Cross-Pollination In Soybean [Glycine Max (L.) Merrill] : I. Agronomic Performance, E. Ortiz-Perez, S. R. Cianzio, H. Wiley, Harry T. Horner, W. H. Davis, R. G. Palmer

Genetics, Development and Cell Biology Publications

In soybean, manual cross-pollination to produce large quantities of F1 hybrid seed for yield trials is difficult and time-consuming. Conversely, insect-mediated cross-pollination has been shown to produce large quantities of hybrid seed in soybean and could facilitate the identification of heterotic patterns. The objective of our study was: (1) evaluate F1hybrid soybean plants from single crosses for yield and agronomic traits over several environments and (2) compare hybrid performance of the single crosses to lines developed from three-way crosses and backcrosses. In 2003, F1 seed of single-crosses and their parent lines were evaluated in replicated experiments ...


Molecular Mapping Of Male-Sterility Loci Ms2 And Ms9 In Soybean, I. Cervantes-Martinez, M. Xu, L. Zhang, Z. Huang, K. K. Kato, Harry T. Horner, R. G. Palmer Jan 2007

Molecular Mapping Of Male-Sterility Loci Ms2 And Ms9 In Soybean, I. Cervantes-Martinez, M. Xu, L. Zhang, Z. Huang, K. K. Kato, Harry T. Horner, R. G. Palmer

Genetics, Development and Cell Biology Publications

Markers linked to male-sterile, female-fertile loci on the soybean [Glycine max (L.) Merr.] molecular map would facilitate early identification of male-sterile plants. The objectives were to verify the chromosome location of the ms2 (A00–63) mutation, to determine the allelism and the chromosome location of the suspected ms2 [ms? (A00–39)] mutation, and to determine the chromosome location of the ms9 (T359) mutation. Simple sequence repeat (SSR) markers were used to molecularly map the male-sterile, female-fertile loci reported in this study. Segregating F2 populations were developed from crosses of ms?ms? (A00–39) × ‘Minsoy’ (PI 278901), ms2ms2 (A00–63 ...