• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1492-1495
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• 2008

Successful control of Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak, requires a specific and reliable diagnostic tool. A pathovar-specific PCR assay was developed for the rapid and accurate detection ofthe plant pathogenic bacterium Xanthomonas oryzae pv. oryzicola in diseased plant. Based on differences in a membrane fusion protein gene of Xanthomonas oryzae pv. oryzicola and other microorganisms, which was generated from NCBI (http://www.ncbi.nlm.nih.gov/) and CMR (http://cmr.tigr.org/) BLAST searches, one pair of pathovar-specific primers, XOCMF/XOCMR, was synthesized. Primers XOCMF and XOCMR from a membrane fusion protein gene were used to amplity a 488-bp DNA fragment. The PCR product was only produced from 4 isolates of Xanthomonas oryzae pv. oryzicola among 37 isolates of other pathovars and species of Xanthomonas, Pectobacterium, Pseudomonas, Burkholderia, Escherichia coli, and Fusarium oxysporum f.sp. dianthi. The results suggested that the assay detected the pathogen more rapidly and accurately than standard isolation methods.

• 미생물학회지
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• 제44권1호
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• pp.1-9
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• 2008

본 논문은 벼 흰 잎마름병균인 Xanthomonas oryzae pv. oryzae(Xoo)의 병원성 유전자의 분자유전학적 연구현황을 기술하고자 한다. 또한 국내 고유 벼 흰 잎마름병균 KACC10331의 유전체해독 정보를 기반으로 다른 Xanthomonas의 유전체와 비교 분석함으로써, Xoo의 주요 병원성 유전자의 분자구조를 구명하고자 한다. 이를 통해 Xoo 고유 병원성 유전자 탐색 및 기능 해석을 위한 기초자료를 제공하는데 목적이 있다. Xoo 유전체에는 5개 과(family)에 속하는 9 type의 Insertion sequence(IS)가 611 copy로 존재하고 있으며, 주로 병원성 관련 유전자군 주위에 많이 분포하고 있는 것으로 나타났다. 현재까지 연구가 수행된 주요 병원성 관련 유전자인 hypersensitive response and pathogenicity (hrp) 유전자, extracellular polysaccharide (EPS) 유전자, extracellular enzyme 유전자, lipopolysaccharides (LPS) 유전자, 그리고 avilulence 유전자의 분자유전학적 연구현황을 기술하였다.

• 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.

• 한국식물병리학회지
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• 제10권1호
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• pp.13-17
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• 1994

A semiselective agar medium (XCO) was developed for the isolation of bacterial blight pathogen, Xanthomonas campestris pv. oryzae, from rice seed. The medium contained yeast extract 1.0 g, peptone 2.0 g, sucrose 5.0 g, sodium glutamate 1.0 g, FeSO4.7H2O 0.05 g, Fe.EDTA 1 mg, cephalexin 20 mg, Evan blue (0.1%) 1.5 ml, bromcresol purple (0.1%) 2.5ml, cycloheximide 100 mg and agar 15.0 g per liter. Colonies of X. c. pv. oryzae were 4~5 mm in diameter, smooth, round, blue (darker center) and convex after 6 days incubation at 28$^{\circ}C$. The recovery of 6 isolates of X. c. pv. oryzae on the XOC medium ranged from 81% to 120% (mean 98.2%) in comparison to Wakimoto's medium. The number of saprophytic bacteria from 10 rice seed lots on XCO medium was reduced to 70.4% of that on Wakimoto's medium. The recovery of X. c. pv. oryzae added to rice seed on XOC medium ranged from 67% to 87% (mean 75.6%) of that on Wakimoto's medium.

• Journal of Microbiology
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• 제45권2호
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• pp.175-178
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• 2007

An endonuclease from Xanthomonas oryzae pathovar oryzae KACC 10331, XorII, was recombinantly produced in Escherichia coli using a T7 system. XorII was purified using a combination of ion exchange and immobilized metal affinity chromatography (IMAC). An optimized washing protocol was carried out on an IMAC in order to obtain a high purity product. The final amount of purified XorII was approximately 2.5 mg/L of LB medium. The purified recombinant XorII was functional and showed the same cleavage pattern as PvuI. The enzyme activity tested the highest at $25^{\circ}C$ in 50 mM NaCl, 10 mM Tris-HCl, 10 mM $MgCl_{2}$, and 1 mM dithiothreitol at a pH of 7.9.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1287-1292
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• 2013

Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

• Plant Resources
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• 제7권1호
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• pp.65-68
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• 2004

We used an amplified fragment length polymorphism (AFLP) analysis, a novel PCR-based technique, to differentiate Xanthomonas oryzae pv. oryzae (Xoo) of Korean races. The 6 strains of Xoo K1, K2, K3 races were tested with 81 AFLP primer combinations to identify the best selective primers. The primer combinations were selected according to their reproducibility, number of polymorphic bands and polymorphism detected among Xoo strains. 18 strains of Xoo K1, K2 and K3 races were analyzed with the selected combinations of primer set. Some primer combinations (Eco R I +1 / Mse I+1) could differentiate Xoo of Korean races that were not distinguished by other fingerprinting analysis. Thus AFLP fingerprinting permitted very fine discrimination among different races.

• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.2071-2078
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• 2018

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight, which results in severe economic damage to rice farms. Xoo produces biofilms for pathogenesis and survival both inside and outside the host. Biofilms, which are important virulence factors, play a key role in causing the symptoms of Xoo infection. In the present study, we investigated the nutritional conditions for biofilm formation by Xoo. Although Xoo biofilm formation may be initiated by interactions with the host, Xoo biofilm cannot mature without the support of favorable nutritional conditions. Nitrogen sources inhibited Xoo biofilm formation by overwhelming the positive effect that cell growth has on it. However, limited nutrients with low amino acid concentration supported biofilm formation by Xoo in the xylem sap rather than in the phloem sap of rice.

• 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.

• 한국작물학회지
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• 제55권4호
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• pp.306-311
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• 2010

저항성원이 다른 7개이 근동질 저항성 계통과 감수성 품종인 Toyonishiki에서 X. oryzae pv. oryzae의 증식과 이동에 관한 시험을 실시하였다. 접종 10일 후, NIL의 접종부위 잎의 세균밀도는 약 $10^5{\sim}10^6\;cfu/cm^2$이었으나 감수성 품종인 Toyonishiki에서는 약 $10^7\;cfu/cm^2$로 높게 나타났다. 이와 같이 감수성 품종에서의 세균 수는 급속히 증가하였으나 NIL에서는 점차적으로 증식하였다. IRBB 103과 Toyonishiki는 접종 25일 후에 접종부위로부터 20cm 위쪽에서 세균이 검출되었으나 다른 NIL에서는 검출되지 않았다. 이와같이 Xa1, Xa4, xa5, Xa7 저항성 유전자는 세균의 이동을 크게 억제하였다.