• Research in Plant Disease
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• v.17 no.3
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• pp.376-380
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• 2011

The bacterial speck of tomato caused by Pseudomonas syringae pv. tomato leads to serious economic losses especially on fruits of susceptible genotype. Thus, Pseudomonas syringae pv. tomato is a plant quarantine bacterium in many countries including Korea. In this study, we developed specific PCR assays for detection of the bacterium from tomato seeds. A specific primer set is designed from the hrpZ gene for specific detection of Pseudomonas syringae pv. tomato. A 501 bp PCR product corresponding to hrpZ gene was amplified only form Pseudomonas syringae pv. tomato strains, but no PCR product was amplified from other tomato bacterial pathogens, such as Pseudomonas syringae pv. glycinea, P. syringae pv. maculicola, P. syringae pv. atropurpurea, P. syringae pv. morsprunorum, and from other P. syringae pathovar strains. The nested-PCR primer set corresponding to an internal fragment of the 501 bp sequence (hrpZ) gine was used to specific detection of Pseudomonas syringae pv. tomato in tomato seed. A 119 bp PCR product using nested PCR primer was highly specific and sensitive to detect low level of Pseudomonas syrigae pv. tomato in tomato seeds. We believe that the PCR assays developed in this study is very useful to detect Pseudomonas syringae pv. tomato from the tomato seeds.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.60-67
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• 2012

For the genetic differentiation of $Pseudomonas$ $syringae$ pathovar $tomato$, a total of 51 $P.$ $syringae$ pv. strains infecting 33 different host plants were analyzed using repetitive element PCR(REP-PCR) and universal rice primer PCR(URP-PCR). The entire DNA fingerprint profiles were analyzed using unweighted pair-group method with arithmetic averages (UPGMA). The 51 $P.$ $syringae$ pv. strains could be divided into five clusters based on 65% similarity by Rep-PCR using BOX, ERIC, and REP primers. $P.$ $syringae$ pv. $tomato$ cluster was well separated from other 31 $P.$ $syringae$ pathovars. $P.$ $syringae$ pv. $tomato$ cluster included only $P.$ $syringae$ pv. $maculicola$ and $P.$ $syringae$ pv. $tomato$. $P.$ $syringae$ pv. $tomato$ strains could be divided into two genetic groups. Meanwhile, the Pseudomonas pv. strains could be divided into four clusters based on 63% similarity by URP-PCR using 2F, 9F, and 17R primers. $P.$ $syringae$ pv. $tomato$ cluster was also well separated from 30 other $P.$ $syringae$ pathovars. In this case, $P.$ $syringae$ pv. $tomato$ cluster included $P.$ $syringae$ pv. $maculicola$, $P.$ $syringae$ pv. $berberidi$, and $P.$ $syringae$ pv. $tomato$. $P.$ $syringae$ pv. $tomato$ strains was also separated into two genetic groups by URP-PCR analysis. Overall, our work revealed that $P.$ $syringae$ pv. $tomato$ can be genetically differentiated from other $P.$ $syringae$ pathovars by the DNA fingerprint profiles of REP-PCR and URP-PCR. We first report that there are two genetically diverged groups in $P.$ $syringae$ pv. $tomato$ strains.

• Mycobiology
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• v.46 no.2
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• pp.147-153
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• 2018

Certain beneficial microorganisms isolated from rhizosphere soil promote plant growth and induce resistance to a wide variety of plant pathogens. We obtained 49 fungal isolates from the rhizosphere soil of paprika plants, and selected 18 of these isolates that did not inhibit tomato seed germination for further investigation. Based on a seed germination assay, we selected four isolates for further plant tests. Treatment of seeds with isolate JF27 promoted plant growth in pot tests, and suppressed bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000. Furthermore, expression of the pathogenesis-related 1 (PR1) gene was higher in the leaves of tomato plants grown from seeds treated with JF27; expression remained at a consistently higher level than in the control plants for 12 h after pathogen infection. The phylogenetic analysis of a partial internal transcribed spacer sequence and the b-tubulin gene identified isolate JF27 as Aspergillus terreus. Taken together, these results suggest that A. terreus JF27 has potential as a growth promoter and could be used to control bacterial speck disease by inducing resistance in tomato plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.143-143
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• 2022

Plant defense systems against pathogens have been studied extensively and are currently a hot topic in plant science. Using a reverse genetics technique, this study looked into the involvement of the NO-downregulated NAD(P)-binding Rossmann-fold superfamily gene in plant growth and defense in Arabidopsis thaliana. For this purpose, the knockout and overexpressing plant of the candidate gene along with the relevant controls were exposed to control, oxidative and nitro-oxidative stresses. The results showed that candidate gene negatively regulates plants' root and shoot lengths. To investigate the role of the candidate gene in plant basal defense, R-gene-mediated resistance and systemic acquired resistance (SAR) plants were challenged with virulent or avirulent strains of Pseudomonas syringae pathovar tomato (Psf) DC3000. The results showed that the candidate gene negatively regulates plants' basal defense, R-gene-mediated resistance and SAR. Further characterization via GO analysis associated the candidate gene with metabolic and cellular processes and response to light stimulus, nucleotide binding and cellular location in the cytosol and nucleus. Protein structure analysis indicated the presence of a canonical Oxidoreductase family NAD (P)-binding Rossmann fold domain of 120 amino acids with a total of 121 plant homologs across 35 different plant species in the clad streptophyta. Arabidopsis eFP browser showed its expression in almost all the above-ground parts. Protein analysis indicated C225 and C359 as potential targets for S-Nitrosylation by NO. SMART analysis indicated possible interactions with mevalonate/galactokinase, galacturonic acid kinase, arabinose kinase, putative xylulose kinase, GroES-like zinc-binding alcohol dehydrogenase and various glyceraldehyde-3-phosphate dehydrogenases.