Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Life Sciences

Gaca, The Response Regulator Of A Two-Component System, Acts As A Master Regulator In Pseudomonas Syringae Pv. Tomato Dc3000 By Controlling Regulatory Rna, Transcriptional Activators, And Alternate Sigma Factors, Asita Chatterjee, Yaya Cui, Hailian Yang, Alan Collmer, James R. Alfano, Arun K. Chatterjee Nov 2003

Gaca, The Response Regulator Of A Two-Component System, Acts As A Master Regulator In Pseudomonas Syringae Pv. Tomato Dc3000 By Controlling Regulatory Rna, Transcriptional Activators, And Alternate Sigma Factors, Asita Chatterjee, Yaya Cui, Hailian Yang, Alan Collmer, James R. Alfano, Arun K. Chatterjee

Department of Plant Pathology: Faculty Publications

Concerted investigations of factors affecting host-pathogen interactions are now possible with the model plant Arabidopsis thaliana and its model pathogen Pseudomonas syringae pv. tomato DC3000, as their whole genome sequences have become available. As a prelude to analysis of the regulatory genes and their targets, we have focused on GacA, the response regulator of a two-component system. The DC3000 gene was cloned by testing for the reversal of phenotypes of an Erwinia GacA– mutant. A GacA– mutant of DC3000 constructed by marker exchange produces much-reduced levels of transcripts of three alternate sigma factors: HrpL, required for the production of effector …


Effects Of Modification Of The Transcription Initiation Site Context On Citrus Tristeza Virus Subgenomic Rna Synthesis, Maria A. Ayllon, Siddarame Gowda, Satyanarayana Tatineni, Alexander V. Karasev, Scott Adkins, Munir Mawassi, Jose Guerri, Pedro Moreno, William O. Dawson Sep 2003

Effects Of Modification Of The Transcription Initiation Site Context On Citrus Tristeza Virus Subgenomic Rna Synthesis, Maria A. Ayllon, Siddarame Gowda, Satyanarayana Tatineni, Alexander V. Karasev, Scott Adkins, Munir Mawassi, Jose Guerri, Pedro Moreno, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a positive-sense RNA genome of about 20 kb organized into 12 open reading frames (ORFs). The last 10 ORFs are expressed through 3'-coterminal subgenomic RNAs (sgRNAs) regulated in both amounts and timing. Additionally, relatively large amounts of complementary sgRNAs are produced. We have been unable to determine whether these sgRNAs are produced by internal promotion from the full-length template minus strand or by transcription from the minus-stranded sgRNAs. Understanding the regulation of 10 sgRNAs is a conceptual challenge. In analyzing commonalities of a replicase complex in producing so many …


Induced Resistance As A Mechanism Of Biological Control By Lysobacter Enzymogenes Strain C3, Ozlem Kilic-Ekici, Gary Y. Yuen Apr 2003

Induced Resistance As A Mechanism Of Biological Control By Lysobacter Enzymogenes Strain C3, Ozlem Kilic-Ekici, Gary Y. Yuen

Department of Plant Pathology: Faculty Publications

Induced resistance was found to be a mechanism for biological control of leaf spot, caused by Bipolaris sorokiniana, in tall fescue (Festuca arundinacea) using the bacterium Lysobacter enzymogenes strain C3. Resistance elicited by C3 suppressed germination of B. sorokiniana conidia on the phylloplane in addition to reducing the severity of leaf spot. The pathogen-inhibitory effect could be separated from antibiosis by using heat-inactivated cells of C3 that retained no antifungal activity. Application of live or heat-killed cells to tall fescue leaves resulted only in localized resistance confined to the treated leaf, whereas treatment of roots resulted in …


Evaluation Of Resistance Screening Methods For Sclerotinia Stem Rot Of Soybean And Dry Bean, Linda S. Kull, Tri D. Vuong, Kris S. Powers, Kent M. Eskridge, James R. Steadman, Glen L. Hartman Jan 2003

Evaluation Of Resistance Screening Methods For Sclerotinia Stem Rot Of Soybean And Dry Bean, Linda S. Kull, Tri D. Vuong, Kris S. Powers, Kent M. Eskridge, James R. Steadman, Glen L. Hartman

Department of Plant Pathology: Faculty Publications

Three methods to identify levels of resistance to Sclerotinia sclerotiorum in soybean (Glycine max) and dry bean (Phaseolus vulgaris) were compared using multiple data analyses. The three methods were mycelial plug inoculations of cotyledons, cut stems, and detached leaves. Six S. sclerotiorum isolates of known relative aggressiveness were inoculated on each of three soybean and dry bean cultivars with varied response to S. sclerotiorum. For soybean, all three inoculation methods accurately identified isolate aggressiveness irrespective of cultivar, but identification of susceptible and partially resistant soybean cultivars was influenced by isolate. For dry bean, the cotyledon and cut …


Fungal Biology And Agriculture: Revisiting The Field, O. Yarden, D. J. Ebbole, S. Freeman, R. J. Rodriguez, M. B. Dickman Jan 2003

Fungal Biology And Agriculture: Revisiting The Field, O. Yarden, D. J. Ebbole, S. Freeman, R. J. Rodriguez, M. B. Dickman

Department of Plant Pathology: Faculty Publications

Plant pathology has made significant progress over the years, a process that involved overcoming a variety of conceptual and technological hurdles. Descriptive mycology and the advent of chemical plant-disease management have been followed by biochemical and physiological studies of fungi and their hosts. The later establishment of biochemical genetics along with the introduction of DNA-mediated transformation have set the stage for dissection of gene function and advances in our understanding of fungal cell biology and plant–fungus interactions. Currently, with the advent of high-throughput technologies, we have the capacity to acquire vast data sets that have direct relevance to the numerous …


Transcription Strategy In A Closterovirus: A Novel 5'-Proximal Controller Element Of Citrus Tristeza Virus Produces 5'- And 3'-Terminal Subgenomic Rnas And Differs From 3' Open Reading Frame Controller Elements, Siddarame Gowda, Maria A. Ayllon, Satyanarayana Tatineni, Moshe Bar-Joseph, William O. Dawson Jan 2003

Transcription Strategy In A Closterovirus: A Novel 5'-Proximal Controller Element Of Citrus Tristeza Virus Produces 5'- And 3'-Terminal Subgenomic Rnas And Differs From 3' Open Reading Frame Controller Elements, Siddarame Gowda, Maria A. Ayllon, Satyanarayana Tatineni, Moshe Bar-Joseph, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV) produces more than thirty 3'- or 5'-terminal subgenomic RNAs (sgRNAs) that accumulate to various extents during replication in protoplasts and plants. Among the most unusual species are two abundant populations of small 5'-terminal sgRNAs of approximately 800 nucleotides (nt) termed low-molecular-weight tristeza (LMT1 and LMT2) RNAs. Remarkably, CTV replicons with all 10 3' genes deleted produce only the larger LMT1 RNAs. These 5'-terminal positive-sense sgRNAs do not have corresponding negative strands and were hypothesized to be produced by premature termination during plus-strand genomic RNA synthesis. We characterized a cis-acting element that controls the production …