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

• The Plant Pathology Journal
• /
• 제20권1호
• /
• pp.1-6
• /
• 2004

The diseases caused by Xylella fastidiosa are associated with aggregation of the bacteria m xylem vessels, formation of a gummy matrix and subsequent blockage of water uptake. In the closely related pathogen, Xanthomonas campestris, xanthan gum is known to be an important virulence factor, probably contributing to bacterial adhesion, aggregation and plugging of xylem. Xanthan gum, produced by X. campestris, is an extra-cellular polysaccharide consisting of a cellulose backbone ($\bate$-1,4-linked D-glucose) with trisaccharide side chains composed of mannose, glucuronic acid and mannose attached to alternate glucose residues in the backbone. We had constructed a mutant of X. campestris lacking gumI gene that is responsible for adding the terminal mannose for producing modified xanthan gum which is similar to xanthan gum fromX. fastidiosa. The modified xanthan gum degrading endgphytic bacterium Acineto-bacter johnsonii GX123 isolated from the oleander infected with leaf scorch disease.

• 한국미생물·생명공학회지
• /
• 제40권4호
• /
• pp.356-363
• /
• 2012

The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xanthan gum production by Xanthomonas campestris fermentation. Deffated rice bran was enzymatically hydrolyzed using cellulase, gluco-amylase, alpha-amylase and xylanase at various pHs and temperatures within 0-12 h. The highest sugar content reached at $35^{\circ}C$, pH 5.5 in 6 h with 41.66%. The enzymatic hydrolysate was used as the carbon source for xanthan gum production by X. campestris NRRL B-1459 and X. campestris pv. campestris. The highest productivities obtained were 21.87 and 17.10 g/L, respectively. Viscosity measurement for the obtained xanthan gums and commercial gum was carried out in gum solutions at various pHs and temperatures. The highest viscosity was reached with 1% gum solutions at $20^{\circ}C$ and pH 5.5 for all gums with viscosity values of 470, 131 and 138 mPa sec, respectively. This work has provided relevant scientific information about the use of rice bran, an abundant agroindustrial residue, to produce xanthan gum.

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.376-381
• /
• 1998

Xanthomonas campestris pv. glycines 8ra causes bacterial pustule disease on susceptible soybean leaves and produces a bacteriocin, named glycinecin, against related bacteria such as Xanthomonas campestris pv. vesicatoria. The antimicrobial activity of the glycinecin was effective to most tested Xanthomonas species. X. c. pv. glycines 8ra was able to produce the glycinecin in liquid media as well as solid media. Maximal productivity of glycinecin was obtained at 3$0^{\circ}C$ in the early stationary phase of growth of the X. c. pv. glycines 8ra. The production of glycinecin was not dependent on the initial inoculum level but on cell density. Glycinecin was very sensitive to proteolytic enzymes such as trypsin and proteinase K but resistant to DNase and RNase. The culture supernatant of X. c. pv. glycines 8ra retained some of its antimicrobial activity after 15 min at 6$0^{\circ}C$. It is stable at wide range of pH. The glycinecin showed the bactericidal activity after the adsorption of the glycinecin to the sensitive bacterial cell.

• The Plant Pathology Journal
• /
• 제18권1호
• /
• pp.54-55
• /
• 2002

Soaked black rot symptom was observed on the stem of Angelica acutiloba from July to August 2000 at Kumsan, Chungnam in Korea. This disease usually occurred under humid and high temperature conditions. The lesions on the stem appeared as soft rot with brown elliptical spots, which developed into large black spots at a later stage. When the bacterial isolates from the diseased plants were inoculated onto healthy plants by artificial needle prick method, symptoms similar to that observed in the fields developed. According to the cultural characteristics and pathogenicity of the isolates on the host plant the causal bacterium was identified as Xanthomonas campestris. This study proposed that the disease be named "bacterial black stem rot of A. acutiloba"loba".

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

• 농업과학연구
• /
• 제15권2호
• /
• pp.132-137
• /
• 1988

최근(最近)에 세균(細菌)에 의한 양배추 부패병(魔敗病)은 주목할 만큼 증가(增加)되어 양배추 생산(生産)에 중대(重大)한 문제(問題)가 되고 있는 세균성(細團性) 부패병(腐敗病)의 원인(原因)을 구명(究明)하기 위하여 실시(實施)하였다. 시장(市場)과 주요(主要) 양배추 생산지(生産地)로부터 26개(個)의 양배추 부패(腐敗) 병반(病斑)을 수집하여 병원세균(病原細菌)을 분리(分離)하였다. 분리(分離) 세균(細菌)의 세균학적(細菌學的) 특성(特性)과 병원성(病原性)에 따라 분리세균(分離細菌)을 Erwinia carotovora subsp. carotovora, Pseudomonas cichorii, P. viridiflava 그리고 X-anthomonas campestris pv. campestris로 동정(同定) 되었다. 이 중에서 E. carotovora subsp. carotovora와 X. campestris pv. campestris가 널리 분포(分布)되어 있으며 양배추 생산(生産)에도 중대(重大)한 피해(被害)를 준다는 것이 밝혀졌다. 경우에 따라서는 한개의 양배추 병반(病斑)으로부터 2종류(種類)의 세균(細園)이 분리(分離)되는 것으로 보아 포장(圃場)에서 2종류(種類)의 세균(細菌)이 복합(複合) 감염(感染)된 것으로 추정되었다.

• 대한본초학회지
• /
• 제28권4호
• /
• pp.7-16
• /
• 2013

Objectives : Brassica campestris var narinosa (BCN), Canavalia gladiata DC semen (CGD) and their combinational prescription (BCN+CGD) have been use to demonstrate to regulate hematopoiesis. In the current study, we investigated whether Brassica campestris var narinosa, Canavalia gladiata DC semen and their combinational prescription is related to hemato-potentiating function using Sca-$1^+$ hematopoietic stem cells (Sca-$1^+HSCs$) as a testing system. Methods : Sca-$1^+HSCs$ isolated from femur in C57bl/6 mice with leukopenia and thrombocytopenia induced by cyclophosphamide (CTX). Then, Real-time PCR was performed to measure the mRNA expression, ELISA and haematopoiesis-related gene (EPO, TPO, IL-3, SCF, c-kit, GM-CSF), the phosphorylation of JAK2, GATA-1 and STAT-5a/b were observed by western blot, and the numbers of $CD117^+/Sca-1^+$ cell and the number of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E), semisolid clonogenic assay was performed. Result : When Sca-$1^+HSCs$ were treated with Brassica campestris var narinosa, Canavalia gladiata DC semen and their combinational prescription with rIL-3/rSCF, the expression of haematopoiesis-related (EPO, TPO, IL-3, SCF, c-kit, and GM-CSF) were significantly increased at the levels of mRNA as well as production in Sca-$1^+HSCs$. Additionally, CGS enhanced phosphorylation of JAK2, GATA-1, and signal transducer and activator of transcription-5a/b (STAT-5a/b) in Sca-$1^+HSCs$. Furthermore, their combinational prescription (BCN+CGD) significantly enhanced the growth rate of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E) in vitro. Conclusion : These result suggest that Brassica campestris var narinosa (BCN) and Canavalia gladiata DC have hematopoietic enhancement via hematopoietic cytokine-mediated JAK2/GATA-1/STAT-5a/b pathway, and their combinational prescription (BCN+CGD) has superior hematopoietic enhancement to those of individual extracts.

• 식물병연구
• /
• 제19권2호
• /
• pp.95-101
• /
• 2013

Xanthomonas campestris pv. campestris(Xcc)에 의한 검은썩음병은 세계적으로 배추과 작물에 발생하여 큰 피해를 주고 있는 주요 식물병이다. Xcc에 대한 양배추의 효율적인 저항성 검정법을 확립하기 위해, Xcc에 대한 저항성 정도가 서로 다른 '루비아', '오조라', '그린핫', 'Saint', 'Joeun-ACE', 'Wonderball' 및 'XCCR 500' 등 7개 양배추 품종을 대상으로 접종 방법, 접종 위치, 재배 기간 그리고 재배 온도에 따른 검은썩음병 발생을 조사하였다. 양배추 품종들의 저항성은 18핀이나 가위를 사용하여 접종하는 것보다 핀셋(mouth-tooth forceps)을 사용하여 접종하였을 때 가장 큰 차이를 보이며, 직접적으로 엽맥에 접종하는 것보다 엽맥 주변에 접종이 더 효과적이었다. 그리고 접종한 유묘를 $30^{\circ}C$ 보다 $22^{\circ}C$에서 재배하였을 때에 감수성과 저항성 반응이 더 분명하게 나타났다. 이상의 결과로부터 양배추 검은썩음병에 대한 효과적인 저항성 검정법으로 4주 재배한 유묘의 엽맥 주변을 핀셋(mouth-tooth forceps)으로 상처 접종한 후 $22^{\circ}C$ 생육상에서 재배하는 방법을 제안하고자 한다.

• The Plant Pathology Journal
• /
• 제37권5호
• /
• pp.476-488
• /
• 2021

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot for cruciferous vegetables worldwide, especially for the cole crops such as cabbage and cauliflower. Due to the lack of resistant cabbage cultivars, black rot has brought about considerable yield losses in recent years in China. Understanding of the pathogen features is a key step for disease prevention, however, the pathogen diversity, population structure, and virulence are largely unknown. In this study, we studied 50 Xcc strains including 39 Xcc isolates collected from cabbage in 20 regions across China, using multilocus sequence genotyping (MLST), repetitive DNA sequence-based PCR (rep-PCR), and pathogenicity tests. For MLST analysis, a total of 12 allelic profiles (AP) were generated, among which the largest AP was AP1 containing 32 strains. Further cluster analysis of rep-PCR divided all strains into 14 DNA groups, with the largest group DNA I comprising of 34 strains, most of which also belonged to AP1. Inoculation tests showed that the representative Xcc strains collected from diverse regions performed differential virulence against three brassica hosts compared with races 1 and 4. Interestingly, these results indicated that AP1/DNA I was not only the main pathotype in China, but also a novel group that differed from the previously reported type races in both genotype and virulence. To our knowledge, this is the first extensive genetic diversity survey for Xcc strains in China, which provides evidence for cabbage resistance breeding and opens the gate for further cabbage-Xcc interaction studies.