Dissertation > Excellent graduate degree dissertation topics show

Cloning and Fuctional Study of tvrR Gene of Acidovorax Avenae Subsp. Citrulli

Author: WeiNa
Tutor: HuBaiShi
School: Nanjing Agricultural College
Course: Plant Pathology
Keywords: Acidovorax avenae subsp. citrulli tvrR gene mutant pathogenicity
CLC: S436.42
Type: Master's thesis
Year: 2009
Downloads: 13
Quote: 0
Read: Download Dissertation

Abstract


Bacterial fruit blotch (BFB), caused by Acidovorax avenae subsp. citrulli, is a serious disease of melons. It mainly harms the leaves and the fruits of watermelon and melon, causes a large number of lesion and fruit decay and often induces devastating consequences. In recent years, bacterial fruit blotch has seriously occurred in Xinjiang, Inner Mongolia, Hainan, Jilin, Ningxia province, and has been an upward trend in China. This is a serious threat to the production of melon, watermelon and other Cucurbitaceae crops, and has been become the first obstacle of limiting and impeding the further development of melon crops. Therefore, we need to find the corresponding control measures as soon as possible, and the study on the pathogenesis of bacterial fruit blotch has great guiding significance to its prevention and treatment.At present, the research of bacterial fruit blotch focuses on pathogen identification, pathogen detection methods and techniques, the identification of disease-resistant varieties and so on. The first time our group identified the acyl-homoserine lactones compounds-mediated quorum sensing regulation system from A. avenae subsp. citrulli and confirmed the effect of this system on its pathogenicity. However, the pathogenic molecular mechanism of A. avenae subsp. citrulli is still poorly understood.In this study, according to the sequence of the novel virulence gene tvrR of Pseudomonas syringae pv. tomato DC3000, a tvrR homolog was found and cloned from the genomic DNA of Acidovorax avenae subsp. citrulli. The tvrR inserted mutant was constructed by homologous recombination and confirmed by PCR and Southern blot. The detection of extracellular polysaccharide (EPS), motility and chemotaxis showed that there were no significant differences between the mutants and the wild-type strains. Both the mutants and the wild-type strains could elicit the hypersensitive response (HR) in nonhost tobacco. Pathogenicity tests showed that the disease symptom caused by mutants was delayed when compared to the wild-type strains, but there were finally no significant differences in pathogenicity between the mutants and the wild-type strains. The inserted mutants grew more slowly than the wild-type strains, but their population could finally reach the maximum of the wild-type strains in inoculated leaf tissues of Hami-melon.The inserted mutants grew more slowly than the wild-type strains, but they could finally reach the maximum biomass of the wild-type strains in both nutrient-rich LB medium and nutrient-poor MMX medium. The consistency of the changes in pathogenicity and growth ability of tvrR mutants indicated that the changes in pathogenicity might be caused by the changed growth ability in A. avenae subsp. citrulli.

Related Dissertations

  1. Functional Analysis of Proteins Encoded by RNA2 of Wheat Yellow Mosaic Virus,S435.121
  2. Construction of egfp Marked-Mutants from Pseudomonas Syringae Pv.tomato and Pv.tabaci,S436.412
  3. Isolation and Identification of Avian Pathogenic Escherichia Coli from Chicken and Characterizations of Its Virulence-Associated Genes,S852.61
  4. Pathogenic Mechanism of Invasion Associated Genes in Avian Pathogenic E. Coli Duck Isolate DE205B,S852.61
  5. A Study of the Isolation and Identification of Fusarium Wilt Germ in Sesame and the Characteristics of Sesame Germplasm Anti-Fusarium Wilt Disease,S435.653
  6. Cloning and Functional Analysis of Acidovorax Avenae Subsp. Citrulli Partial hrp Gene Cluster,S436.5
  7. Cloning and Fuctional Study of clp Gene of Xanthomonas Oryzae,S435.111.4
  8. Preliminary Studies on Constructing Brassica Napus L Mutant Library by EMS Inducement,S565.4
  9. Study on the Morphology, Physiology and QTLS Mapping of a Dwarf Mutant Ari1327 from Cotton (Gossypium Hirsutum L.),S562
  10. Functional Characterization of Wheat Na~+ /H~+ Antiporter TaNHX2 and Study of TaNHX2 C- Terminus Domain,S512.1
  11. Construction of ActA/PlcB Null Mutant of Listeria Monocytogenes,S852.61
  12. Screening of Pigment-free Pullulan High Producing Microorganism and Research of Optimal Culture Media,TQ920
  13. Expression, Purification and Characterization of Trucated Type Recombinant Buckwheat Trypsin Inhibitor,R284.1
  14. The Function Analysis of Ceramidase (CER) from Arabidopsis Thaliana,Q943
  15. Screening of Cellulase-producing Mutants by T-DNA Insertional Mutagenesis and Functional Analysis of Vacuolar Protein Sorting Receptor in Trichoderma Reesei,Q93
  16. GXLC porcine encephalomyocarditis virus pathogenicity of strains,S858.28
  17. Grisea MoIAP apoptosis inhibitory protein gene functional analysis and Bcl-2 spot on the water banana peanut pathogen Fusarium impact,S435.111.4
  18. Biological Effect of Pisum Sativum L. CV MZ-1 Seed Induced by Fast Neutron,S643.3
  19. Lidamycin a cloning the bacteria atrA homologous genes and its function,TQ465
  20. Korla Pear and mutant strains grown cold resistance characteristics and results of research,S661.2
  21. Study on the Transgenic Tobacco Expressing HarpinXoo and Its Two Deletion Derivatives,S336

CLC: > Agricultural Sciences > Plant Protection > Pest and Disease Control > Horticultural Crops Pest and Disease Control > Vegetable pests > Melons, pests and diseases
© 2012 www.DissertationTopic.Net  Mobile