• The Plant Pathology Journal
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• 제27권1호
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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.

• The Plant Pathology Journal
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• 제15권1호
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• pp.21-27
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• 1999

Nonpathogenic mutants of Xanthomonas campestris pv. glycines were generated with Omegon-Kim to isolate genes essential for pathogenicity and inducing hypersensitive response (HR). Three nonpathogenic multants and two mutants showing slow symptom development were isolated among 1,000 colonies tested. From two nonpathogenic mutants, 8-13 and 26-13, genes homologous to hrcC and hrpF of X. campestris pv. vesicatoria were identified. The nonpathogenic mutant 8-13 had a mutation in a gene homologous to hrpF of X. campestris pv. vesicatoria and failed to cause HR on pepper plants but still induced HR on tomato leaves. The nonpathogenic mutant 26-13 had an insertional mutation in a gene homologous to hrcC of X. campestris pv. vesicatoria and lost the ability to induce HR on pepper leaves but still caused HR on tomato plants. Unlike other phytopathogenic bacteria, the parent strain and these two mutants of X. campestris pv. glycines did not cause HR on tobacco plants. a cosmid clone, pBL1, that complemented the phenotypes of 8-13 was isolated. From the analysis of restriction enzyme mapping and deletion analyses of pBL1, a 9.0-kb Eco RI fragment restored the phenotypes of 8-13. pBL1 failed to complement the phenotypes of 26-13, indicating that the hrcC gene resides outside of the insert DNA of pBL1. One nonpathogenic mutant, 13-33, had a mutation in a gene homologous to a miaA gene encoding tRNA delta (2)-isopentenylpyrophosphate transferase of Escherichia coli. This indicated that tRNA modifications in X. campestris pv. glycines may be required for expression of genes necessary for pathogenicity. The mutant 13-33 multiplied as well as the parent strain did in the culture medium and in planta, indicating that loss of pathogenicity is not due to the inability of multiplication in vivo.

• 한국미생물·생명공학회지
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• 제32권3호
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• pp.256-264
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• 2004

본 연구는 벼의 세균병 중 치명적인 흰잎마름병을 유발하는 Xanthomonas oryzae pv. oryzae를 검출할 수 있는 프라이머를 개발하기 위해 실시하였다. X. o. pv. oryzae str. KACC10331의 hpaA유전자 염기서열로부터 흰잎마름병만을 특이적으로 검출할 수 있는 프라이머를 제작하여 중합효소연쇄반응에 사용하였다. 개발된 특이 프라이머는 X. o. pv. oryzae str. KACC10331과 X. campestris pv. vesicatoria, X. campestris pv. campestris, X. axonopodis pv. citri 그리고 X. axonopodis pv. glycines의 phaA유전자 염기서열의 상동성을 비교하여, 그 중 X. o. pv. oryzae만이 가지는 특이적인 부분을 바탕으로 각각 20-mer인 XOF와 XOR를 제작하였다. 제작된 프라이머를 이용하여 중합효소 연쇄반응을 실시한 결과 반응 후 생성된 단편의 크기는 534-bp였다. 반응 후 생성된 단편은 Southern hybridization을 통하여 Xanthomonas 균주들의 hpaA유전자 존재 여부 및 그 상동성을 비교분석하기 위해 사용하였다. 또한 제작된 프라이머를 이용하여 흰잎마름병에 감염된 벼 잎에서의 검출 여부를 확인하였고 X. o. pv. oryzae의 순수 균주 배양액을 중합효소연쇄반응에 이용하여 검출한계를 검정하였다. 본 연구에서 제작된 프라이머를 사용한 중합효소연쇄 반응 방법은 X. o. pv. oryzae의 검출 뿐만 아니라 흰잎마름병의 발생 예찰에 매우 유용할 것으로 판단 되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.71.1-71
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• 2003

Most major plant pathogenic bacteria in Korea belong to Xanthomonas spp.. Xanthomonas oryzae pv. oryzae is a major pathogen in rice, X. campestris pv. vesicatoria in pepper, X. axonopodis pv. giycines in soybean, X. campestris pv. campestris in cabbage, and X. axonoposid pv. citri in tangerin. Host specificity of the bacterial pathogen depends on the avirulence gene in the pathogen and the corresponding resistance gene in host plants. Many avirulence genes in bacteiral pathogen located on the native plasmids. However, the presence of the native plasmids in Xanthomonas spp. was not investigated well. In order to study the host specificity, we isolated native plasmids from Xanthomonas spp. and compared those plasmids each other, The presence of the native plasmids and the characteristics of the plasmids depended on the bacterial strains. In the X. axonopodis pv. glycines, most strains carried native plasmids but some strains did not. Some strains carry about 60 kb native plasmids including 3 different aviurlence genes. We will discuss the characteristics of the native plasmids isolated from the Xanthomonas spp.

• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.253-258
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• 2015

Xanthomonas oryzae pv. oryzae (Xoo), X. campestris pv. vesicatoria (Xcv), and Pectobacterium carotovorum pv. carotovorum (Pcc) are the causative agents of bacterial blight in rice, bacterial spot in pepper, and bacterial soft rot in carrot and cabbage, respectively. To isolate novel microbial extracts with antimicrobial activities against these bacteria, approximately 5,300 different Streptomyces extracts were prepared and tested. Microbial cultures from various Streptomyces strains isolated from the Jeju Island, Baekam, Mankyoung river, Jiri mountain etc. in Korea were extracted into three different factions -secreted hydrophobic, secreted hydrophilic, and mycelia- using ethyl acetate, water, and methanol. Initially, 34, 29, and 10 extracts were selected as having antibacterial activities against Xoo, Xcv, and Pcc, respectively. Extracts 1169G4, 1172E9, and 1172E10 had the highest growth inhibition activities against both Xoo and Xcv, and extracts 1151H7 and 1152H7 showed the highest growth inhibition activities against Pcc.

• 한국식물병리학회지
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• 제14권3호
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• pp.212-216
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• 1998

Capsicum pepper selections fro PI163192, PI241670, PI244670, PI271322, PI308787, PI322719, and PI369994 were confirmed to be non-hypersensitively resistant to race 3 of Xanthomonas campestris pv. vesicatoria. A resistant cultivar,‘SR’, was shown to be hypersensitive. Four Koran local cultivars, a cytoplasmic male sterile line (A-line) and its maintainer (B-line) were highly susceptible. The resistant selections and cultivars were crossed with a male sterile A-line (Smsms) and fertility of their F1 hybrids was examined by observing he pollen production, testing pollen germination, and quantifying the amount of pollen produced per anther to identify the genotype interacting with the male sterile cytoplasm. The seven resistant PI selections turned out to be restorers (N(S)MsMs) and‘SR’to be a maintainer (Nmsms).

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.64.1-64
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• 2003

Inoculation of primary pepper leaves with an avirulent strain of Xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (SAR) in secondary leaves. This SAR response was accompanied by the systemic expression of defense-related genes, a systemic microoxidative burst generating H2O2, and the systemic induction of ion-leakage and callose deposition in the non-inoculated, secondary leaves. Some defense-related genes encoding PR-1, chitinase, peroxidase, PR10, thionin, defensin and zinc-finger protein were distiilctly induced in the systemic leaves. The systemically striking accumulation of H$_2$O$_2$and strong increase in peroxidase activity in pepper was suggested to contribute to the triggering of cell death In the systemic micro-HRs, leading to the induction of SAR. Treatment of non-inoculated, secondary leaves with diphenylene iodinium (DPI), an inhibitor of the oxidative burst, substantially reduced the induction of some defense-related genes and subsequently SAR.

• The Plant Pathology Journal
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• 제40권4호
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• pp.358-376
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• 2024

Inoculation of Chinese cabbage leaves with high titer (10⁷ cfu/ml) of the non-adapted bacteria Xanthomonas campestris pv. vesicatoria (Xcv) strain Bv5-4a.1 triggered rapid leaf tissue collapses and hypersensitive cell death (HCD) at 24 h. Electrolyte leakage and lipid peroxidation markedly increased in the Xcv-inoculated leaves. Defence-related gene expressions (BrPR1, BrPR4, BrChi1, BrGST1 and BrAPX1) were preferentially activated in the Xcv-inoculated leaves. The Xcv-triggered HCD was attenuated by continuous light but accelerated by a dark environment, and the prolonged high relative humidity also alleviated the HCD. Constant dark and increased relative humidity provided favorable conditions for the Xcv bacterial growth in the leaves. Pretreated fluridone (biosynthetic inhibitor of endogenous abscisic acid [ABA]) increased the HCD in the Xcv-inoculated leaves, but exogenous ABA attenuated the HCD. The pretreated ABA also reduced the Xcv bacterial growth in the leaves. These results highlight that the onset of HCD in Chinese cabbage leaves initiated by non-adapted pathogen Xcv Bv5-4a.1 and in planta bacterial growth was differently modulated by internal and external conditional changes.

• Current Research on Agriculture and Life Sciences
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• 제23권
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• pp.43-51
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• 2005

멕시코와 네팔에서 수집한 고추 유전자원 50점과 이병성 및 저항성 대조품종에 Stemphylium solani와 S. lycopersici 의 혼합접종으로 흰별무늬병(gray leaf spot)에 대한 저항성을 검정하고, 살균제를 살포하여 회복시킨 다음 다시 Xanthomonas campestris pv. vesicatoria를 접종하여 더뎅이병에 대한 저항성을 검정하였다 더뎅이병에는 KC866, KC872, KC902, KC905이 이미 알려진 KC43, KC47, KC220, KC319, KC320, KC380 등과 함께 저항성으로 나타났다. 더뎅이병, bacterial spot)에는 KC897이 이미 저항성으로 보고된 KC177(PI163192)보다 발병이 적어 가장 우수한 것으로 나타났으며 이어서 네팔에서 도입된 KC889, KC896, KC898이 저항성으로 나타났다.

• The Plant Pathology Journal
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• 제39권5호
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• pp.494-503
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• 2023

Xanthomonas campestris pv. campestris (Xcc) is a plant pathogen of Brassica crops that causes black rot disease throughout the world. At present, 11 physiological races of Xcc (races 1-11) have been reported. The conventional method of using differential cultivars for Xcc race detection is not accurate and it is laborious and time-consuming. Therefore, the development of specific molecular markers has been used as a substitute tool because it offers an accurate and reliable result, particularly a quick diagnosis of Xcc races. Previously, our laboratory has successfully developed race-specific molecular markers for Xcc races 1-6. In this study, specific molecular markers to identify Xcc race 7 have been developed. In the course of study, whole genome sequences of several Xcc races, X. campestris pv. incanae, X. campestris pv. raphani, and X. campestris pv. vesicatoria were aligned to identify variable regions like sequence-characterized amplified regions and insertions and deletions specific to race 7. Primer pairs were designed targeting these regions and validated against 22 samples. The polymerase chain reaction analysis revealed that three primer pairs specifically amplified the DNA fragment corresponding to race 7. The obtained finding clearly demonstrates the efficiency of the newly developed markers in accurately detecting Xcc race 7 among the other races. These results indicated that the newly developed marker can successfully and rapidly detect Xcc race 7 from other races. This study represents the first report on the successful development of specific molecular markers for Xcc race 7.