Low molecular weight plant extract induces metabolic changes and the secretion of extracellular enzymes, but has a negative effect on the expression of the type-III secretion system in Xanthomonas campestris pv. campestris

2009 ◽  
Vol 140 (1-2) ◽  
pp. 59-67 ◽  
Author(s):  
Tony Francis Watt ◽  
Mihael Vucur ◽  
Birgit Baumgarth ◽  
Steven Alexander Watt ◽  
Karsten Niehaus
Keyword(s):  
Molecular Weight ◽  
Plant Extract ◽  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Extracellular Enzymes ◽  
Secretion System ◽  
Metabolic Changes ◽  
Low Molecular Weight ◽  
Negative Effect ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals Characterization, Phylogeny, and Genome Analyses of Nonpathogenic Xanthomonas campestris Strains Isolated from Brassica Seeds

2020 ◽  
Vol 110 (5) ◽  
pp. 981-988 ◽  
Author(s):  
Yung-An Lee ◽  
Pei-Yu Yang ◽  
Shau-Chang Huang
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Pathogenicity Island ◽  
Whole Genome Sequence ◽  
Effector Protein ◽  
Type Iii Effector ◽  
Type Iii ◽  
Effector Genes ◽  
Genome Analyses ◽  
Xanthomonas Campestris Pv Campestris

Xanthomonads were detected by using the Xan-D(CCF) medium from the brassica seeds, and their pathogenicity was determined by plant inoculation tests. It was found that some seed lots were infested with Xanthomonas campestris pv. campestris, some with X. campestris pv. raphani, and some with nonpathogenic xanthomonads. The nonpathogenic xanthomonad strains were identified as X. campestris, and the multilocus sequence analysis showed that the nonpathogenic X. campestris strains were grouped together with pathogenic X. campestris, but not with nonpathogenic strains of X. arboricola. In addition, all isolated X. campestris pv. campestris and X. campestris pv. raphani strains were positive in the hrpF-PCR, but the nonpathogenic strains were negative. It was further found that nonpathogenic X. campestris strain nE1 does not contain the entire pathogenicity island (hrp gene cluster; type III secretion system) and all type III effector protein genes based on the whole genome sequence analyses. The nonpathogenic X. campestris strain nE1 could acquire the entire pathogenicity island from the endemic X. campestris pv. campestris and X. campestris pv. raphani strains by conjugation, but type III effector genes were not cotransferred. The studies showed that the nonpathogenic X. campestris strains indeed exist on the brassica seeds, but it could be differentiated by the PCR assays on the hrp and type III effector genes. Nevertheless, the nonpathogenic X. campestris strains cannot be ignored because they may be potential gene resources to increase genetic diversity in the endemic pathogenic X. campestris pv. campestris and X. campestris pv. raphani strains.

Pretreatment to improve adsorption and effectiveness of wet end chemicals for a bleached chemithermomechanical pulp

TAPPI Journal ◽  
2011 ◽  
Vol 10 (8) ◽  
pp. 43-49 ◽  
Author(s):  
LIJUN WANG ◽  
LINGZHI LUO ◽  
JIN WANG
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Spectroscopic Methods ◽  
Cationic Starch ◽  
Fluorescent Whitening Agent ◽  
Whitening Agent ◽  
Negative Effect ◽  
Uv Visible ◽  
Retention And Drainage

Bleached chemithermomechanical pulp (BCTMP) contains high amounts of anionic trashes that can seriously reduce the efficiency of many wet end functional and process chemicals. Fixing agents have been used to offset this negative effect, with varying success. In this study, we used a specially designed, starch-based fixing agent, namely, a low molecular weight, highly cationic starch (LHCS) to pretreat a BCTMP. We used ultraviolet (UV)-visible spectroscopic methods to investigate the effectiveness of LHCS use on the adsorption of some typical wet end chemicals, such as fluorescent whitening agent, tinting dye, wet strengthening agent, dry strengthening agent, neutral sizing agent, and retention agent onto the BCTMP. The results show that the adsorbed amounts and the adsorption efficiencies of these chemicals can be improved by LHCS pretreatment, variously resulting in higher brightness, better tinting, higher wet and dry strengths, better sizing, and higher retention and drainage.

The type III secretion effector XopXccN of Xanthomonas campestris pv. campestris is required for full virulence

2008 ◽  
Vol 159 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Bo-Le Jiang ◽  
Yong-Qiang He ◽  
Wei-Jian Cen ◽  
Hong-Yu Wei ◽  
Guo-Feng Jiang ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Type Iii ◽  
Type Iii Secretion Effector ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals The Type III Secretion System of Xanthomonas fuscans subsp. fuscans Is Involved in the Phyllosphere Colonization Process and in Transmission to Seeds of Susceptible Beans

2008 ◽  
Vol 74 (9) ◽  
pp. 2669-2678 ◽  
Author(s):  
A. Darsonval ◽  
A. Darrasse ◽  
D. Meyer ◽  
M. Demarty ◽  
K. Durand ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Regulatory Genes ◽  
Population Densities ◽  
Host Colonization ◽  
Plant Pathogenic Bacteria ◽  
Type Iii

ABSTRACT Understanding the survival, multiplication, and transmission to seeds of plant pathogenic bacteria is central to study their pathogenesis. We hypothesized that the type III secretion system (T3SS), encoded by hrp genes, could have a role in host colonization by plant pathogenic bacteria. The seed-borne pathogen Xanthomonas fuscans subsp. fuscans causes common bacterial blight of bean (Phaseolus vulgaris). Directed mutagenesis in strain CFBP4834-R of X. fuscans subsp. fuscans and bacterial population density monitoring on bean leaves showed that strains with mutations in the hrp regulatory genes, hrpG and hrpX, were impaired in their phyllospheric growth, as in the null interaction with Escherichia coli C600 and bean. In the compatible interaction, CFBP4834-R reached high phyllospheric population densities and was transmitted to seeds at high frequencies with high densities. Strains with mutations in structural hrp genes maintained the same constant epiphytic population densities (1 × 105 CFU g−1 of fresh weight) as in the incompatible interaction with Xanthomonas campestris pv. campestris ATCC 33913 and the bean. Low frequencies of transmission to seeds and low bacterial concentrations were recorded for CFBP4834-R hrp mutants and for ATCC 33913, whereas E. coli C600 was not transmitted. Moreover, unlike the wild-type strain, strains with mutations in hrp genes were not transmitted to seeds by vascular pathway. Transmission to seeds by floral structures remained possible for both. This study revealed the involvement of the X. fuscans subsp. fuscans T3SS in phyllospheric multiplication and systemic colonization of bean, leading to transmission to seeds. Our findings suggest a major contribution of hrp regulatory genes in host colonization processes.

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