scholarly journals Mutants of Xanthomonas oryzae pv. oryzae Deficient in General Secretory Pathway Are Virulence Deficient and Unable to Secrete Xylanase

2000 ◽  
Vol 13 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Suvendra K. Ray ◽  
R. Rajeshwari ◽  
Ramesh V. Sonti
Keyword(s):  
Xanthomonas Campestris ◽  
Secretory Pathway ◽  
Genomic Library ◽  
Xanthomonas Oryzae ◽  
Enzyme Assays ◽  
Specific Primers ◽  
Xylanase Production ◽  
Protein Secretion System ◽  
Serious Disease ◽  
Xanthomonas Campestris Pv Campestris

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight, a serious disease of rice. A virulence- and xylanase-deficient mutant of Xoo was isolated following ethyl methane sulfonate (EMS) mutagenesis. A cosmid clone that restored virulence and xylanase secretion was obtained from a genomic library by functional complementation. Trans-poson mutagenesis and marker exchange studies revealed genes on the cloned DNA that were required for xylanase production and virulence. Sequence analysis with trans-poson-specific primers revealed that these genes were homologues of xps F and xps D, which encode components of a protein secretion system in Xanthomonas campestris pv. campestris. Enzyme assays showed xylanase accumulation in the periplasmic space and cytoplasm of the xps F mutant and the complementing clone restored transport to the extracellular space.

rpfF Mutants of Xanthomonas oryzae pv. oryzae Are Deficient for Virulence and Growth Under Low Iron Conditions

2002 ◽  
Vol 15 (5) ◽  
pp. 463-471 ◽  
Author(s):  
Subhadeep Chatterjee ◽  
Ramesh V. Sonti
Keyword(s):  
Xanthomonas Campestris ◽  
Iron Supplementation ◽  
Extracellular Enzymes ◽  
Phenotypic Expression ◽  
Tetracycline Resistance ◽  
Extracellular Enzyme ◽  
Extracellular Polysaccharide ◽  
Xanthomonas Oryzae ◽  
Uptake System ◽  
Serious Disease

Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. In the related bacterium Xanthomonas campestris pv. campestris, the rpfF gene is involved in production of a diffusible extracellular factor (DSF) that positively regulates synthesis of virulence-associated functions like extracellular polysaccharide (EPS) and extracellular enzymes. Transposon insertions in the rpfF homolog of X. oryzae pv. oryzae are deficient for virulence and production of a DSF but are proficient for EPS and extracellular enzyme production. The rpfF X. oryzae pv. oryzae mutants exhibit an unusual tetracycline susceptibility phenotype in which exogenous iron supplementation is required for phenotypic expression of a tetracycline resistance determinant that is encoded on an introduced plasmid. The rpfF X. oryzae pv. oryzae mutants also overproduce one or more siderophores and exhibit a growth deficiency under low iron conditions as well as in the presence of reducing agents that are expected to promote the conversion of Fe+3 to Fe+2. Exogenous iron supplementation promotes migration of rpfF X. oryzae pv. oryzae mutants in rice leaves. The results suggest that rpfF may be involved in controlling an iron-uptake system of X. oryzae pv. oryzae and that an inability to cope with the conditions of low iron availability in the host may be the reason for the virulence deficiency of the rpfF X. oryzae pv. oryzae mutants.

Development of race-specific molecular marker for Xanthomonas campestris pv. campestris race 3, the causal agent of black rot of crucifers

2018 ◽  
Vol 98 (5) ◽  
pp. 1119-1125 ◽  
Author(s):  
Khandker Shazia Afrin ◽  
Md Abdur Rahim ◽  
Mehede Hassan Rubel ◽  
Sathishkumar Natarajan ◽  
Jae-Young Song ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Bacterial Species ◽  
Causal Agent ◽  
Black Rot ◽  
Specific Marker ◽  
Dna Fragments ◽  
Specific Primers ◽  
Scar Primer ◽  
Xanthomonas Campestris Pv Campestris

Race-specific molecular markers were established to distinguish Xanthomonas campestris pv. campestris (Xcc) race 3, the causal agent of black rot disease of crucifers. The available genome sequences of Xcc races were aligned and identified three DNA fragments specific to Xcc race 3. The identified race-specific DNA fragments namely XccR3-49, XccR3-52, and XccR3-55 were used for designing the race-specific primers to detect and identify Xcc race 3. The specificity of race-specific primers was tested against the genomic DNA extracted from Xcc (races 1–7), Xcc strains, Xc pathovars, and other bacterial species. XccR3-49, a specific sequence characterized amplified region (SCAR) primer set, gave a single band with 867 bp length for Xcc race 3 only. The remaining two markers XccR3-52 and XccR3-55 showed polymorphic amplification with amplicon sizes of 1889 and 2109 bp for Xcc race 3, respectively. Additionally, the SCAR primer set detected Xcc race 3 rapidly and efficiently in artificially infected cabbage leaves with bio-PCR. This result showed that the newly developed race-specific markers can successfully and efficiently detect and identify Xcc race 3 from Xanthomonas campestris pv. campestris races, Xanthomonas species/pathovars, as well as other plant pathogenic bacteria (Pseudomonas syringae pv. maculicola and Erwinia carotovora subsp. carotovora). Up to now, this is the first report describing the race-specific marker for the detection of Xcc race 3.

scholarly journals PhyA, a Secreted Protein of Xanthomonas oryzae pv. oryzae, Is Required for Optimum Virulence and Growth on Phytic Acid as a Sole Phosphate Source

2003 ◽  
Vol 16 (11) ◽  
pp. 973-982 ◽  
Author(s):  
Subhadeep Chatterjee ◽  
Rajan Sankaranarayanan ◽  
Ramesh V. Sonti
Keyword(s):  
Phytic Acid ◽  
Xanthomonas Campestris ◽  
Xanthomonas Oryzae ◽  
Bacillus Species ◽  
Active Site Residues ◽  
Significant Similarity ◽  
Reading Frame ◽  
Predicted Signal Peptide ◽  
Serious Disease ◽  
Phosphate Source

Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. We have identified a novel virulence deficient mutant (BXO1691) of X. oryzae pv. oryzae that has a Tn5 insertion in an open reading frame (phyA; putative phytase A) encoding a 373-amino acid (aa) protein containing a 28-aa predicted signal peptide. Extracellular protein profiles revealed that a 38-kDa band is absent in phyA mutants as compared with phyA+ strains. A BLAST search with phyA and its deduced polypeptide sequence indicated significant similarity with conserved hypothetical proteins in Xanthomonas axonopodis pv. citri and Xanthomonas campestris pv. campestris and limited homology to secreted phytases of Bacillus species. Homology modeling with a Bacillus phytase as the template suggests that the PhyA protein has a similar six-bladed β-propeller architecture and exhibits conservation of certain critical active site residues. Phytases are enzymes that are involved in degradation of phytic acid (inositol hexaphosphate), a stored form of phosphate in plants. The phyA mutants exhibit a growth deficiency in media containing phytic acid as a sole phosphate source. Exogenous phosphate supplementation promotes migration of phyA X. oryzae pv. oryzae mutants in rice leaves. These results suggest that the virulence deficiency of phyA mutants is, at least in part, due to inability to use host phytic acid as a source of phosphate. phyA-like genes have not been previously reported to be involved in the virulence of any plant pathogenic bacterium.

Virulence deficiency caused by a transposon insertion in the purH gene of Xanthomonas oryzae pv. oryzae

2005 ◽  
Vol 51 (7) ◽  
pp. 575-581 ◽  
Author(s):  
Subhadeep Chatterjee ◽  
Ramesh V Sonti
Keyword(s):  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Minimal Medium ◽  
Pathogen Resistance ◽  
Xanthomonas Oryzae ◽  
Chromosomal Dna ◽  
Transposon Insertion ◽  
Growth Deficiency ◽  
Related Plant ◽  
Serious Disease

Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. We have identified a Tn5-induced virulence-deficient mutant (BXO1704) of X. oryzae pv. oryzae. The BXO1704 mutant exhibited growth deficiency in minimal medium but was proficient in inducing a hypersensitive response in a non-host tomato plant. Sequence analysis of the chromosomal DNA flanking the Tn5 insertion indicated that the Tn5 insertion is in the purH gene, which is highly homologous to purH genes of other closely related plant pathogenic bacteria Xanthomonas axonopodis pv. citri and Xanthomonas campestris pv. campestris. Purine supplementation reversed the growth deficiency of BXO1704 in minimal medium. These results suggest that the virulence deficiency of BXO1704 may be due to the inability to use sufficient purine in the host.Key words: auxotroph, plant pathogen, resistance.

scholarly journals Identification of Crucifer Accessions from the NC-7 and NE-9 Plant Introduction Collections That Are Resistant to Black Rot (Xanthomonas campestris pv. campestris) Races 1 and 4

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 284-288 ◽  
Author(s):  
Phillip D. Griffiths ◽  
Laura Fredrick Marek ◽  
Larry D. Robertson
Keyword(s):  
Xanthomonas Campestris ◽  
Plant Introduction ◽  
Black Rot ◽  
Sources Of Resistance ◽  
Race 1 ◽  
Incomplete Resistance ◽  
Serious Disease ◽  
Race 4 ◽  
Interspecific Crossing ◽  
Xanthomonas Campestris Pv Campestris

Black rot, caused by Xanthomonas campestris pv. campestris (Pam.) Dawson (Xcc), is a serious disease of vegetable crucifers worldwide. The USDA NC-7 and NE-9 regional PI stations maintain vegetable, mustard, and oilseed crucifers, of which 4084 accessions were available for testing, representing 23 genera and 125 species. These accessions were evaluated for resistance to black rot after wound inoculation with race 1 of the pathogen. Accessions that were symptomless for race 1 of Xcc were replanted and inoculated with race 4 of the pathogen to identify accessions with resistance to both races. Symptomless responses were observed in 362 accessions of the mustard species (Brassica juncea, Brassica carinata, and Brassica nigra), in particular, B. juncea for which 353 of the 389 accessions tested were symptomless. Resistance was identified in five accessions of B. carinata out of 63 evaluated (PI 193460, PI 193959, PI 194254, PI 280230, PI 633077) determined by repeated symptomless responses after inoculation and four accessions of B. nigra from the 83 evaluated (PI 197401, A 25399, A 25401, PI 458981). Five accessions of Brassica rapa (PI 633154, A9285, PI 340208, PI 597831, PI 173847) were identified, which represent promising new sources of resistance to Xcc. Incomplete resistance was identified in an accession of Eruca sativa (PI 633207), an accession of Lepidium spp. (PI 633265), an accession of Sinapis arvensis (PI 296079), and two accessions of B. napus (PI 469733 and PI 469828). These identified accessions represent germplasm that can be used in breeding for resistance to Xcc in vegetable crucifers through interspecific crossing.

BIOCHEMICAL IDENTIFICATION OF PATOVARS OF THE PATHOGEN OF VASCULAR BACTERIOSIS OF THE CRUCIFEROUS XANTHOMONAS CAMPESTRIS PV. CAMPESTRIS

2020 ◽  
Vol 15 (1) ◽  
pp. 82-88
Author(s):  
Mikhail Kuznetsov ◽  
◽  
Anatoly Scherbakov ◽  
Elena Gorelnikova ◽  
Nadezhda Chervyakova ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Biochemical Identification ◽  
Xanthomonas Campestris Pv Campestris
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