• Korean Journal Plant Pathology
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• v.2 no.2
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• pp.96-101
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• 1986

Total 29 commercial crucifer seed lots were tested for seed transmission of Xanthomonas campestris pv. campestris by seed washing liquid plating assay. One imported cabbage seed lot was found to carry Xanthomonas campestris pv. campestris. Several methods and chemicals for eradication of Xanthomonas campestris pv. campestris in and on the cabbage seed were tested for effectiveness. Soaking cabbage seed in $3\3%$ hydrogen peroxide solution for 30 minutes effectively eradicated Xanthomonas campestris pv. campestris in a naturally infested seed lot. In a field survey, black rot turned out to be an important disease in cabbage in Korea.

• Korean Journal Plant Pathology
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• v.12 no.2
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• pp.169-175
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• 1996

콩 불마름병균 Xanthomonas campestris pv. glycines 8ra는 X. c. pv. vesicatoria에 길항력이 있는 bacteriocin인 glycinecin을 생성 분비한다. Bacteriocin 생성 분비 능력이 있는 콩 불마름병균을 효과적인 생물학적 방제원으로 활용하기 위해서는 좀더 체계적인 연구가 필요하여, bacteriocin 생성에 관계되는 유전자의 분리를 시도하였다. 약 2,000개의 Xanthomonas campestris pv. glycines 8ra cosmid library에서 bacteriocin의 생성 분비 능력을 조사하여 다섯 개의 clone을, pG011, pG0113, pG33과 pG35, 선발하였다. 그중 한 clone pG08을 임의로 선택하여 plasmid DNA를 분리하였다. Plasmid pG08에서 약 6.0 kb의 DNA를 떼어내어 다른 plasmid vector에 넣은 subclone pBL5는 bacteriocin의 생성 분비 능력이 있었다. Plasmid pG08을 제한효소 처리후 다시 접함시켜 만든 몇 개의 subclone과 pBL5의 제한효소 지도를 비교 분석한 결과 약 3.0 kb의 BamHI-HindIII 부분의 DNA가 bacteriocin의 생성에 관계함을 알았다.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.172-178
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• 1997

Xanthmonas campestris pv. campestris, causal agent of Black rot of crucifers, were isolated and identified from crucifer host. In order to determine the characters of X. c. pv. campestris associated with pathogenicity, Tn5 mutagenesis was carried out by conjugating with E. coli pJB4J1. Transconjugants were plate- assayed for missing cellulase, protease and amylase activity. A cellulase negative mutant was selected and tested for pathogenicity. Light microscopy and Scanning electron microscopy revealed that substomatal tissues were colonized by mutant, but was far less extensive than those by wild type. Stomatal surface and substomatal tissue appeared to have degraded by only wild type in 24 hrs and progression of pathogenesis was distinct in 48 hrs. In 6 days, wild type proliferated well in the tissue facilitated by cellulase activity. As a result, cellulase was determined as the important factor in pathogenesis.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.172-175
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• 1994

Xanthomonas campestris M12 carrying OCT plasmid which could dissimilate octane was able to utilize n-alkanes of eight to sixteen carbon atoms via the capacity of this plasmid. M12 strain could utilize terminal oxidation products of these primary, alkanes, alcohols, aldehydes and fatty acids but not hexanoic acid, adipic acid, pimelic acid and heptanal. This strain also biodegraded n-alkanes by monoterminal or diterminal oxdation of straight-chain fatty acids, and branched-chain alkane.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.26-32
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• 2011

Plant-pathogenic bacteria including Xanthomonas spp. carry genetic diversity in composition of avirulence genes for interaction with their host plants. Previously, we reported genetic diversity of avirulence genes in X. axonopodis pv. glycines. In this study, we determined genetic diversity of five avirulence genes, avrBs1, avrBs2, avrBs3, avrBs4, and avrRxv, in three other Xanthomonas species isolated in Korea by genomic southern hybridization. Although Korean races of X. campestris pv. vesicatoria that were isolated from year 1995 to 2002 had the same avirulence gene patterns as those that already reported, there was race shift from race 3 to race 1 by acquisition of avrBs3 genes. X. campestris pv. campestris isolated from Chinese cabbage, but not from cabbage or radish, carried two avrBs3 genes, and one of them affected HR-eliciting ability of this bacterium in broccoli. X. oryzae pv. oryzae carried eight to thirteen avrBs3 gene homologs, and this bacterium showed dynamic changes of resistance patterns in rice probably by losing or obtaining avrBs3 genes. These results indicate that avrBs3 gene is more diverse in Xanthomonas spp. than other four avirulence genes and also host ranges of these bacteria can be easily changed by loss or acquisition of avrBs3 genes.

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.18-24
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• 1994

Multiplications and pathogenic reactions of different pepper and tomato strains of Xanthomonas campestris pv. vesicatoria were evaluated in the most upper leaves of pepper and tomato plants at different growth stages. Hypersensitive reactions were induced in mature pepper plants by inoculation with only the tomato strains but not with the pepper strains, suggesting the expression of age-related resistance in pepper plants. The age-related resistance also seems to be correlated with an apparent inability of the bacteria to multiply as extensively in mature as in young plants. No significant differences among the Korean and U. S. pepper cultivars tested were found in bacterial multiplication, irrespective of bacterial stain or plant growth stage. Korean tomato cultivars tested also were highly susceptible to either tomato or pepper strains during the development of tomato plants.

• Research in Plant Disease
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• v.6 no.1
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• pp.10-14
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• 2000

In 1998, bacterial shot hole of peach (Prunus persica) and Japanese plum(Prunus salicina) was found in Naju and Milyang. Five isolates of bacteria isolates from the diseased leaves and fruits of peach and Japanese plum were classified into genus Erwinia and Xanthomonas on diagnostic characteristics. Of five isolates, two were identified as X. campestris pv. pruni, three as E. nigrifluens. E.nigrifluens is the first description of bacteria which causes the disease on peach and Japanese plum in Korea. the symptoms caused by E. nigrifluens were hardly distinguished from those caused by X. campestris pv. pruni. In addition, it was observed that two pathogenic bacteria were isolated from most of naturally infected plants at the same time. from the reason mentioned above, we proposed to use a single common name \"bacterial shot hole of peach and Japanese plum\" for the both bacterial diseases, hereafter.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.61-66
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• 1985

Seventy-one strains collected from Korea were classified into three serovars (designated A, B-I and B-II) by using agar gel diffusion test with the antisera produced against Xanthomonas campestris pv. oryzae isolates Q7472 and Q7502. Of 71 isolates tested, 65 isolates belonged to serovar A, 5 isolates were serovar B-I, and one isolate was serovar B-II. The isolates of serovar B-I and B-II could be distinguished clearly from those of serovar A showing marked autoagglutination. Xanthomonas campestris pv. oryzae was serologically diagnosed in rice leaves by agar gel diffusion tests, possibly being distinguished from Xanthomonas campestris pv. olyzicola and E. herbicola. The pathogen could be also serologically detected from the extracts of diseased leaves, squeezed immediately, heated at $100^{\circ}C$ or incubated in PSA. Serological detection of Xanthomonas campestris pv. oryzae is a more reliable and less time-comsuming method.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.285-289
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• 1994

An insecticidal crystal protein gene, cryIA(c), from Bacillus thuringiensis HD-73 was integrated into the chromosome of a xanthan-producing bacterium, Xanthomonas campestris XP92. The cryIA(c) gene expression cassette was constructed that placed the gene between the trc promoter and rrnB transcriptional terminator. The $lacl^q$ gene was also included to prevent the expression of cryIA(c) gene in X campestris cells. Southem blot analysis confirmed the integration of the cryIA(c) gene expression cassette in chromosome of X campestris XP92 transconjugant. Expression of the insecticidal crystal protein was confirmed by Western blot analysis and bioassay against the larvae of Hyphantria cunea (Lepidoptera： Arctiidae) and Plutella xylostella (Lepidoptera：Plutellidae).

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.179-183
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• 1997

We have screened hypersensitive responses of 18 cultivars of Nicotiana tabacum to Xanthomonas campestris pv. campestris. TC500 cultivar produced the most strong hypersensitive response (HR) to Xanthomonas campestris pv. campestris. By NTG mutagenesis, nonhypersensitive mutants (XHN 514-774, XHN 620-831) were generated, which does not induce hypersensitive response on tobacco leaves (Nicotiana tabacum cv. TC500). Also nonpathogenic mutant (XPN 1001), which does not incite any of the black rot symptoms on leaves was generated. We observed that HR mutants were still pathogenic on cabbage leaves producing black rot symptoms and nonpathogenic mutant induced HR in tobacco leaves. The inplanta growth of wild type and HR mutants were examined for up to 120 hrs after inoculation : population of wild type strain increased to $10^{8}$ in 24hrs, but rapidly declined thereafter; HR-mutants increased to more than $10^{6}$ in 48 hrs after inoculation but subsequently stabilized and slowly decreased. We observed that wild type and these mutans produced similar amounts of degradative enzymes such as protease, pectate lyase, cellulase and amylase.