• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.61-65
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• 1995

Photosynthetic characteristics of soybean leaves infected with Pseudomonas syringae pv. glycinea were investigated for 8 days. The difference in photosynthesis rate between healthy and diseased soybean leaves decreased for 2 to 4 days after inoculation and then increased. In respiration rate, healthy and diseased leaves showed the same tendency as photosynthetic rate. The stomatal resistance increased following Pseudomonas syringae pv. glycinea infection. The total chlorophyll content of the infected leaf was less than that of the uninfected. Pseudomonas syringae pv. glycinea infection induced the malformation of stacked grana in chloroplast. Dry matter production declined after infection.

• Research in Plant Disease
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• v.22 no.3
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• pp.158-167
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• 2016

A pathogen that causes a new disease on green pumpkin in the nursery and the field was characterized and identified. Symptoms of the disease on green pumpkin were water soaking lesions and spots with strong yellow halo on leaf, brown lesion on flower, and yellow spot on fruit. The bacterial isolates from the leaf spot were pathogenic on the 8 curcubitaceae crop plants, green pumpkin, figleaf gourd, wax gourd, young pumpkin, zucchini, cucumber, melon, and oriental melon, whereas they did not cause the disease on sweet pumpkin and watermelon. They were Gram-negative, rod shape with polar flagella, fluorescent on King's B agar and LOPAT group 1a by LOPAT test. Their Biolog substrate utilization patterns were similar to Pseudomonas syringae pv. syringae's in Biolog database. Phylogenetic trees with 16S rRNA gene sequences and multilocus sequence typing (MLST) with nucleotide sequences of 4 housekeeping genes, gapA, gltA, gyrB, rpoD and those of P. syringae complex strains in the Plant Associated and Environmental Microbes Database (PAMDB) showed that the green pumpkin isolates formed in the same clade with P. syringae pv. syringae strains. The clade in MLST tree was in the genomospecies 1 group. The phenotypic and genotypic characteristics suggested that the isolates from green pumpkin lesion were P. syringae pv. syringae.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.337-340
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• 2007

Pseudomonas syringae Pv. syringae is a causal agent of bacterial blossom blight of kiwifruit in Korea. Eleven strains of the pathogen were isolated from different kiwifruit orchards in Korea and the plasmid profiles were obtained by pulsed-field gel electrophoresis. They could be clustered into six groups according to the number and size of plasmids. The number of plasmids per strain and size of these plasmids ranged from 0 to 4 and from 22 to 160 kb, respectively. Among them, four strains belonging to Group III which harbored two plasmids were resistant to copper sulfate. Southern blot hybridization of the plasmid DNA indicated that the copper resistance determinant was carried on a 48 kb plasmid.

• Research in Plant Disease
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• v.13 no.2
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• pp.88-92
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• 2007

A total of 41 Pseudomonas syringae pv. syringae, the causal agent of bacterial blossom blight, were isolated from kiwifruit plants in Korea. Among them, two strains showing streptomycin resistance were examined to investigate the structure of resistant determinants by PCR and nucleotide sequence analysis. PCR results suggested that the streptomycin resistance is mediated by strA-strB genes carried on Tn5393a. Insertion sequences, IS6100 and IS1133, which were located within or downstream of tnpR gene in Xanthomonas campestris and Erwinia amylovora were not found. Nucleotide sequences of strA-strB were 100% identical with Tn5393a. Two stretomycin resistant strains had three plasmids. Southern blot hybridization using strA-strB probe indicated that the resistant genes were carried on a 100kb plasmid.

• The Plant Pathology Journal
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• v.38 no.6
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• pp.603-615
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• 2022

Soybean (Glycine max (L) Merr.) provides plant-derived proteins, soy vegetable oils, and various beneficial metabolites to humans and livestock. The importance of soybean is highly underlined, especially when carbon-negative sustainable agriculture is noticeable. However, many diseases by pests and pathogens threaten sustainable soybean production. Therefore, understanding molecular interaction between diverse cultivated varieties and pathogens is essential to developing disease-resistant soybean plants. Here, we established a pathosystem of the Korean domestic cultivar Kwangan against Pseudomonas syringae pv. syringae B728a. This bacterial strain caused apparent disease symptoms and grew well in trifoliate leaves of soybean plants. To examine the disease susceptibility of the cultivar, we analyzed transcriptional changes in soybean leaves on day 5 after P. syringae pv. syringae B728a infection. About 8,900 and 7,780 differentially expressed genes (DEGs) were identified in this study, and significant proportions of DEGs were engaged in various primary and secondary metabolisms. On the other hand, soybean orthologs to well-known plant immune-related genes, especially in plant hormone signal transduction, mitogen-activated protein kinase signaling, and plant-pathogen interaction, were mainly reduced in transcript levels at 5 days post inoculation. These findings present the feature of the compatible interaction between cultivar Kwangan and P. syringae pv. syringae B728a, as a hemibiotroph, at the late infection phase. Collectively, we propose that P. syringae pv. syringae B728a successfully inhibits plant immune response in susceptible plants and deregulates host metabolic processes for their colonization and proliferation, whereas host plants employ diverse metabolites to protect themselves against infection with the hemibiotrophic pathogen at the late infection phase.

• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.125-128
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• 1997

Reactions of Pseudomonas syringae pv. actinidiae to 95 carbon sources in a 96-well microplate (BiOLOG GN MicroPlateTM) were investigated. The bacterium used 9 carbon sources such as D-mannitol, sucrose, etc., but did not use 62 carbon sources such as $\alpha$-cyclodextrin, dextrin, etc. Based on the reactions, a user data base for identification of P. syringae pv. actinidiae was constructed in Biolog program (BiOLOG MicroLogTM 2 system). P. syringae pv. actinidiae isolates collected from kiwifruits could be identified automatically with high similarity using the user data base, which could diagnose rapidly and easily whether the tree was infected with bacterial canker or not.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.220-224
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• 2009

The causal agents of bacterial blossom blight in kiwifruit were isolated from flowers displaying symptoms in Korea. The pathogens were characterized by biochemical and physiological tests, and identified on the basis of 16S rDNA and 16S-23S internal transcribed spacer (ITS) sequences. Pathogenicity tests demonstrated that the blossom blight of kiwifruit in Korea is caused by two pathogens, Pseudomonas syringae pv. syringae and P. fluorescens. Carbon source utilization and DNA-DNA hybridization experiments confirmed P. fluorescens as one of the causal agents of blossom blight of kiwifruit. P. syringae pv. syringae and P. fluorescens can be distinguished from each other by the symptoms they produce in flowers. P. syringae pv. syringae primarily affected the stamen, while P. fluorescens caused rotting of all internal tissues of buds or flowers.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.563-567
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• 2014

Pseudomonas syringae pv. syringae (Psy) is a major bacterial pathogen of many economically important plant species. Despite the severity of its impact, the genome sequence of the type strain has not been reported. Here, we present the draft genome sequence of Psy ATCC 19310. Comparative genomic analysis revealed that Psy ATCC 19310 is closely related to Psy B728a. However, only a few type III effectors, which are key virulence factors, are shared by the two strains, indicating the possibility of host-pathogen specificity and genome dynamics, even under the pathovar level.

• Research in Plant Disease
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• v.21 no.1
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• pp.1-5
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• 2015

A PCR method has been developed for the pathovar-specific detection of Pseudomonas syringae pv. tagetis, which is the causal agent of bacterial leaf spots and apical chlorosis of several species within the Compositae family. One primer set, PSTF and PSTR, was designed using a genomic locus derived from an amplified fragment length polymorphism (AFLP) fragment produced a 554-bp amplicon from 4 isolates of P. syringae pv. tagetis. In DNA dot-blot analysis with the PCR product as probe, a positive signal was identified in only 4 isolates of P. syringae pv. tagetis. These results suggest that this PCR-based assay will be a useful method for the detection and identification of P. syringae pv. tagetis.

• Research in Plant Disease
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• v.11 no.2
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• pp.135-139
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• 2005

Bacterial canker of Japanese apricot (Prunus mume Sieb. et Zucc.) was found in all orchards located at southern area of Korea. Typical symptoms were characterized by dark spots formed on fruits, brown lesions on leaves, and bacterial exudate oozed out of the cracked bark of diseased tree. Thirty-eight isolates from 16 different areas were identified on the basis of biochemical and physiological characteristics (LOPAT and GATTa test) and also on the basis of 165 rDNA and ITS sequences. Pathogenicity tests confirmed that bacterial canker of Japanese apricot in Korea is caused by Pseudomonas syringae pv. morsprunorum.