• The Plant Pathology Journal
• /
• 제17권6호
• /
• pp.336-341
• /
• 2001

The distribution of citrusphages and phage types of Xanthomonas axonopodis pv. citri was investigated in Korea. Forty-eight strains of the bacterial pathogen and 28 bacteriophage strains were isolated from citrus leaves showing the citrus canker symptom. Only a single bacteriophage group, named CPK, was identified based on their aggressiveness to the bacterial pathogen. The bacterial strains were differentiated into two Iysotypes based on their sensitivity to CPK. Lysotype I, which was sensitive to CPK, was more predominant (96%), while only 4% belonged to Iysotype II, which was resistant to CPK. Among the 13 xanthomonads including Iysotype A and Iysotype B of X axonopodis pv. citri, CPKs were only aggressive to BC 83 (=Xc 62) strain of X. axonopodis pv, citri reported as Iysotype A. Thus, bacterial pathogens and citrusphages related to citrus plants mainly distributed in Korea were presumed as Iysotype A of X. axonopodis pv, citri, and Iysotype A-infecting CP$_1$ respectively.

• The Plant Pathology Journal
• /
• 제22권4호
• /
• pp.314-317
• /
• 2006

A phage technique for detection of Xanthomonas axonopodis pv. citri, a causal bacterium of canker on Sastuma mandarin fruits was developed. Phage and ELISA techniques were compared for their sensitivity for detection of Xanthomonas axonopodis pv. citri on orange fruits. Both of techniques revealed a similar efficiency for the bacterial detection; the pathogenic bacteria were observed in pellet from the fruits with over one canker spot with below 2 mm in diameter. In field assays, the increase of phage population(120%) on surface of the fruits related to the disease development one month later indicated that the bacterial pathogens inhabit on the surface. The procedure will be effectively used for detection of only living bacterial pathogen on fruit surfaces of Satsuma mandarin and for the disease forecasting.

• The Plant Pathology Journal
• /
• 제26권1호
• /
• pp.90-92
• /
• 2010

Staining profiles and bacterial morphology were compared in Xanthomonas citri pv. citri by a transmission electron microscopy. Four types of negative staining regimes were employed depending on culture media and heavy metal stains. The bacterial cells grown on LB agar media often appeared clustered on the supporting film. Meanwhile, individual bacterial cells could be readily found on the preparations from LB broth media. Typical rod-shaped cells (ca. $1\;{\mu}m$ in length) and their flagella were observed in either 2% uranyl acetate (UA) or 2% neutralized potassium phosphotungstate (PTA) staining. The UA-stained bacteria often showed relatively intact cell morphology and rather positively stained cells with a thin electron-dense stain depth around bacteria. The PTA-stained bacteria were characterized by the wrinkled cell surface where the stain was entrapped in grooves. In addition, distinct electron-dense stain depth was evident around the PTA-stained preparations. Numerous fimbriae could be mostly observed from the PTA-stained preparations of the two culture media, but not from the UA-stained preparations.

• 식물병연구
• /
• 제10권2호
• /
• pp.94-99
• /
• 2004

청견과 퐁깐의 교배종인 부지화 감귤은 그 모양이 독특하고 당 함량이 높은 고품질의 감귤로서 최근 재배면적과 농가수가 크게 증가하고 있는 품종이다. 대부분이 비닐하우스에서 재배되기 때문에 병이 크게 문제가 되지 않았지만 최근 몇몇 농가에서 병이 발생하여 큰 피해를 주는 경우가 있었다. 조사 결과 부지화 하우스에서 주로 발생하는 병은 Phytophthora citrophthora에 의한 역병, Alternaria sp.에 의한 배꼽썩음병, Penicillium digitatum에 의한 녹색곰팡이병, Botrytis cinerea에 의한 잿빛곰팡이병, Diaporthe citri에 의한 꼭지썩음병 그리고 Xanthomonas axonopodis pv. citri에 의한 궤양병 등 6종이 조사되었다.

• The Plant Pathology Journal
• /
• 제38권4호
• /
• pp.372-382
• /
• 2022

Soybean is an important source of protein and for a wide range of agricultural, food, and industrial applications. Soybean is being affected by Xanthomonas citri pv. glycines, a causal pathogen of bacterial pustule disease, result in a reduction in yield and quality. Diverse microbial communities of plants are involved in various plant stresses is known. Therefore, we designed to investigate the microbial community differentiation depending on the infection of X. citri pv. glycines. The microbial community's abundance, diversity, and similarity showed a difference between infected and non-infected soybean. Microbiota community analysis, excluding X. citri pv. glycines, revealed that Pseudomonas spp. would increase the population of the infected soybean. Results of DESeq analyses suggested that energy metabolism, secondary metabolite, and TCA cycle metabolism were actively diverse in the non-infected soybeans. Additionally, Streptomyces bacillaris S8, an endophyte microbiota member, was nominated as a key microbe in the healthy soybeans. Genome analysis of S. bacillaris S8 presented that salinomycin may be the critical antibacterial metabolite. Our findings on the composition of soybean microbiota communities and the key strain information will contribute to developing biological control strategies against X. citri pv. glycines.

• The Plant Pathology Journal
• /
• 제19권4호
• /
• pp.205-209
• /
• 2003

Dispersal of citrus bacterial canker caused by Xanthomonas axonopodis pv. citri on Unshiu orange was investigated in naturally infested nursery plot at Seogwipo in Jeju island, Korea. Based on phage detection, over 2% of the bacterial pathogen over-wintered in canker lesions and started to multiply in late May. However, symptoms were first observed 1 month after the phage detection. The disease dispersed non-directionally to nearby plants possibly because of indirect dissemination of the bacterium by rain splashes. The disease increased from late June to late August and decreased thereafter. Population of phage increased constantly, however, disease occurrence somewhat fluctuated due to environmental factors. Disease incidence and severity were correlated with rainfall with wind that occurred 14-32 days earlier from late May to late August.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.135.1-135
• /
• 2003

A technique for detection of Xanthomonas axonopodis pv. citri, a causal bacterium of canker on Unshiu orange fruits, was developed using bacteriophage. Procedure for the detection was designed on the basis of the previous reports that one group(CPI) of X. axonopodis pv. citri bacteriophage and corresponding two Iysotypes distributed in Korea. First, fruit surface was washed with sterile distilled water and pellet was obtained from centrifugation. The pellet was resuspended in Wakimoto's potato semi-synthetic broth medium and divided equally into two parts. One part was heated in boiling water to kill bacterial cells. Bacteriophages(CP$_1$) were respectively added into two parts and 0.1 ml from each part was mixed with soft agar medium. After incubation for 18 hrs at 25$^{\circ}C$, the causal bacterium of canker was determined based on plaques formed on the medium. This procedure can be effectively used for detection of living bacterial pathogen on fruit surfaces of Unshiu orange.

• The Plant Pathology Journal
• /
• 제24권3호
• /
• pp.357-360
• /
• 2008

Several pathotypes have been recognized in citrus bacterial canker, which causing serious damage in citrus cultivation area. To control the disease, it is important to understand the pathological diversity and reason of difference in virulence of the causal pathogen. We analyzed 124 strains of Xanthomonas causing citrus bacterial canker by southern hybridization with an internal 3.4-kb BamHI fragment from pthA gene. Assuming each band represented an intact gene, each strain of Xanthomonas was estimated to have approximately 1 to 4 copies of pthA gene. X. a. pv. citri A type had more than 3 copies of pthA gene, and the number of pthA gene in X. a. pv. citri $A^*,\;A^w$, and X. a. pv. aurantifolii B, C were different from 1 to 3 according to the strains. When the pthA gene profile was classified into 13 groups according to the number and size of hybridization bands, most of the A types belong to the 3A group, and 4A and 4B type was dominant when they had 4 bands. However, there was no general pattern of difference between the virulence and pthA gene group in this test.

• The Plant Pathology Journal
• /
• 제24권4호
• /
• pp.423-432
• /
• 2008

The difference of carbon source utilization and fatty acid composition between the pathotypes of Xanthomonas strains, which causing citrus bacterial canker was compared, and the physiochemical characteristics were used to analyze relationship of the strains for the first time. The pattern of several carbon sources utilization and fatty acids composition reliably discriminated the pathotypes of Xanthomonas strains. The dendrogram which was constructed by 95 carbon source utilization profiles differentiated X. axonopodis pv. citri A, $A^*$ and $A^w$ from the other pathotypes. When the dendrogram was drawn by combined analysis of carbon source utilization pattern and fatty acid composition, X. axonopodis pv. aurantifolii B, C and X. axonopodis pv. citrumelo formed a distinct cluster. The difference of carbon source utilization and fatty acid composition could be used effectively for the identification of pathotypes of citrus bacterial canker. The physiochemical characteristics strongly indicated that the strains isolated in Korea belong to X. axonopodis pv. citri A type. The cluster analysis by the band patterns of ERIC-, BOX- and REP-PCR allowed the discrimination of the pathotypes isolated from Korea. However, the rep-PCRs could not differentiate X. axonopodis pv. citri A types from $A^*$ and $A^w$ types. The overall results of metabolic profiles and rep-PCRs strongly indicated that the Korean isolates are X. axonopodis pv. citri A type.

• The Plant Pathology Journal
• /
• 제18권6호
• /
• pp.333-337
• /
• 2002

Bacteriophage of Xanthomonas axonopodis pv. citri, a causal agent of citrus canker disease, was studied for its cultural characteristics. The relative efficiency of plat-ing (EOP) of 11 phages used to 13 strains off, axonopodis pv. citri tested ranged from 0.8 to 1, indicating that the phages are homogeneous. Homogeneity of the phages suggests that citrusphage belongs to a single group CPK as reported in a previous study. Typical one-step growth of a phage P5 selected from the citrusphages was observed. The EOP of the P5 was dependent upon the media, pH, and temperature. It was observed that multiplication of the phage cultured in Wakimotos potato semisynthetic media at $25^{\circ}C$ was more effective than that in other temperatures, regardless of the bacterial strains and media used. It was observed that pH 6.5 is optimal for multiplication of the phage. In comparison of the EOP among citrusphages $CP_1$, $CP_2$, and P5, multiplicative characteristic of phage P5 in the bacteria on time-course was similar with that of phage $CP_1$. Thus, it was concluded that citrusphage group CPK from Korea is $CP_1$ based on host specificity of the phage as described in a previous study, homogeneity, and its multiplication pattern.