• Korean Journal Plant Pathology
• /
• v.2 no.2
• /
• pp.96-101
• /
• 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
• /
• v.13 no.3
• /
• pp.172-178
• /
• 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.

• The Plant Pathology Journal
• /
• v.39 no.5
• /
• pp.494-503
• /
• 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.

• The Plant Pathology Journal
• /
• v.15 no.1
• /
• pp.57-61
• /
• 1999

Xanthomonas campestris pv. glycines causes bacterial pustule disease on susceptible soybean leaves and produces a bacteriocin, named glycinecinA, against most xanthomonads including Xanthomonas campestris pv. vesicatoria. One of the 5 isolated DNA regions responsible for bacteriocin production, a 1.7 kb DNA region for the glycinecinA gene, was used as a probe to detect the presence of the homolog DNA in other bacterial strains. Among 55 bacterial strains tested, only X. campestris pv. glycines showed the positive signal with glycinecinA DNA. Two oligomers, heu2 and heu4, derived from a glycinecinA DNA were used to carry out the polymerase chain reaction (PCR) analysis with chromosomal DNA from 55 different bacterial strains including 24 different strains of X. campestris pv. glycines, 9 different pathovars of xanthomonads, and other 22 bacterial strains of different genus and species. By separation of the PCR products on agarose gel, a 0.86 kb DNA fragment was specifically detected when X. campestris pv. glycines was present in the amplification assay. The 0.86 kb fragment was not amplified when DNA from other bacteria was used for the assay. Southern analysis with glycinecinA DNA showed that the PCR signal was obtained with X. campestris pv. glycines isolates from various geographic regions and soybean cultivars. Therefore, the 1.7 kb DNA region for the glycinecinA gene can be used for the pathovar-specific probe for the DNA hybridization and the primers heu2 and heu4 can be used for the pathovar-specific primers for the PCR analysis to detect X. campestris pv. glycines.

• Research in Plant Disease
• /
• v.12 no.2
• /
• pp.134-138
• /
• 2006

A new bacterial disease of broccoli (Brassica oleracea var. italica) was observed on field-grown plants in Pyungchang during 2003 and 2004. Seedling infections first appeared as a blackening along the margins of the cotyledon. Cotyledon shriveled and dropped off. Infected seedlings were stunted and yellowed and eventually died. The disease was easily recognized by the presence of yellow, V-shaped, or U-shaped areas extending inward from margin of the leaf. As the disease progressed, the yellow lesions turned brown and the tissues died. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for further tests. Pathogenicity of strains was confirmed on 3-week-old crucifer (cabbage, Chinese cabbage, kale, radish and broccoli) plants cut by scissors with bacterial suspensions containing $10^8 cfu/ml$ of phosphate buffered saline. The Biolog and fatty acid analyses and 16S rDNA sequencing of two strains (SL4797 and SL4800) from broccoli black rot showed that they could be identified as X. campestris pv. campestris because of their high similarity to the tester strain (X. campestris pv. campestris NCPPB528) with a match probability of 100%. This is the first report of black rot of broccoli in Korea.

• The Plant Pathology Journal
• /
• v.28 no.3
• /
• pp.322-329
• /
• 2012

This study was conducted to investigate host and non-host disease resistances of kimchi cabbage plants to bacterial infection. Kimchi cabbage leaves responded differently to infections with a virulent strain of Xanthomonas campestris pv. campestris (Xcc) 8004 and two strains (85-10 and Bv5-4a.1) of non-host bacteria X. campestris pv. vesicatoria (Xcv). Non-host bacteria triggered a rapid tissue collapse of the leaves showing as brown coloration at the infected sites, highly increased ion leakage, lipid peroxidation and accumulation of UV-stimulated autofluorescence materials at the inoculated sites. During the observed interactions, bacterial proliferations within the leaf tissues were significantly different. Bacterial number of Xcc 8004 progressively increased within the inoculated leaf tissues over time, while growths of two non-host bacteria Xcv strains were distinctly limited. Expressions of pathogenesis-related genes, such as GST1, PR1, BGL2, VSP2, PR4 and LOX2, were differentially induced by host and non-host bacterial infections of X. campestris pathovars. These results indicated that rapid host cellular responses to the non-host bacterial infections may contribute to an array of defense reactions to the non-host bacterial invasion.

• The Plant Pathology Journal
• /
• v.15 no.1
• /
• pp.21-27
• /
• 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.

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

• Journal of Plant Biology
• /
• v.12 no.2
• /
• pp.1-6
• /
• 1969

Effects of the special media on the mycelium growth in Agaricus campestris were studied. The results might be summarized as follows: 1. The mycelium growth fo Agaricus campestris were scarecely stimulated on the Peptone basal medium which was added 0.5gr. of Peptone and Dextrose basal medium which was added 1.5gr. of dextrose during the culture for 144 hours. 2. The mycelium of Agaricus campestris on the media which was added the several kinds of vegetable extracts showed a considerable growth for 144 hours. The order is as follows; Carrot-basal medium(4ml./100ml.)>Tomato-basal medium(2ml./100ml.)>Spinach-basal medium(3ml./100ml.). However, the spinach-basal medium among these three media were no significant difference.

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