• Journal of Plant Biotechnology
• /
• v.4 no.1
• /
• pp.1-6
• /
• 2002

Plants have developed a sophisticated battery of defence responses to protect themselves against attempted pathogen ingress. Manipulation of these defence mechanisms may provide significant opportunities for crop improvement. While plant resistance genes have had a long service history in plant breeding, they possess significant limitations. Recent advances are now providing significant insights into strategies designed to increase the field durability of this class of genes. Hypersensitive cell death is a common feature underlying the deployment of plant defence responses against biographic pathogens. In contrast, necrotrophic pathogens actively kill plant cells. Recently, transgenic plants have been developed that either promote or suppress cell death, providing resistance against either biotrophic or necrotrophic pathogens respectively. Methyl-jasmonate is a key signalling molecule in the establishment of resistance against some fungal pathogens. Increasing the concentration of this molecule in plant cells has been shown to increase resistance against Botrytis cineria, without significantly imparting plant growth or development. Due to the multifarious infection strategies employed by plant pathogens, how-ever, it is unlikely a single commercial product will prove a panacea for global disease control. Future stategies will more likely entail an integrated disease management approach.

• Biomedical Science Letters
• /
• v.27 no.2
• /
• pp.59-68
• /
• 2021

Multidrug-resistant strain of Acinetobacter baumannii (MDRAB) is an emerging pathogen in health care facilities, preventing MDRAB is a public health concern. We conducted this experiment on a clinical isolate of A. baumannii with two main goals: the role of the efflux pump system in the stress provision of carbapenem and the response to the transcription level of the efflux pump gene. A total of 34 strains of A. baumannii was isolated from the Yangsan Hospital of Pusan National University. First, when we compared and observed the expression of the efflux pump gene and antibacterial resistance to carbapenem, a strong correlation was observed between carbapenem resistance and overexpression of adeB (P=0.0056). Second, a correlation between the efflux pump and concentration gradient and tolerance to carbapenem stress at the AdeABC efflux pump genes transcription level was confirmed. Our results revealed that the expression of the AdeABC efflux pump is an important resistance determinant in obtaining antibiotic resistance of the carbapenem group in A. baumannii.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.1
• /
• pp.89-99
• /
• 2007

To develop durable and stable breeding strategies far the control of rice bacterial blight (BB) disease, the near-isogenic lines (NILs) with diverse resistance genes to BB isolates were evaluated in plant at three different growth stages using four Korean ($K_1,\;K_2,\;K_3,\;K_{3a}$) and three Japanese isolates (I, II, III). The resistance of the NILs to seven BB isolates tended to increase with plant aging. At the seedling stage, the NILs with single resistance genes were mostly resistant to $K_1$ race but they showed partial or no resistance to other isolates. A NILs (IRBB5) possessing xa5 had full resistance to the four Korean isolates, illustrating that it is a useful source to give enhancement to Korean breeding program. At the maximum tillering stage, resistance of NILs to $K_2,\;K_3$, I and II isolates considerably increased while resistance to $K_1,\;K_{3a}$ and III were similar to those of seedling stage. NILs with resistance gene of Xa4, xa5 and Xa7 proved to be the most stable to BB isolates at the maximum tillering stage. At the heading stage, most resistance genes of NILs were effective against BB isolates, and xa5 showed the consistent resistance to all the BB isolates including $K_{3a}$ and III isolates, demonstrating that resistance genes of Xa4, xa5 and Xa7 can be used either alone or combined to enhance resistance to BB disease in Korea.

• The Plant Pathology Journal
• /
• v.21 no.3
• /
• pp.195-206
• /
• 2005

Spatial and temporal expression of pathogenesis-related (PR) gene and proteins has been recognized as inducible defense response in pepper plants. Gene expression and/or protein accumulation of PR-1, $\beta-1,3-glucanase$ and chitinase was predominantly found in pepper plants during the inoculations by Xanthomonas campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum coccodes. PR-1 and chitinase genes were also induced in pepper plants in response to environmental stresses, such as high salinity and drought. PR-1 and chitinase gene expressions by biotic and abiotic stresses were regulated by their own promoter regions containing several stress-related cis-acting elements. Overexpression of pepper PR-1 or chitinase genes in heterogeneous transgenic plants showed enhanced disease resistance as well as environmental stress tolerances. In this review, we focused on the putative function of pepper PR-1, $\beta-1,3-glucanase$ and chitinase proteins and/or genes at the biochemical, molecular and cytological aspects.

• The Plant Pathology Journal
• /
• v.29 no.1
• /
• pp.110-115
• /
• 2013

Theobroxide, a novel compound isolated from a fungus Lasiodiplodia theobromae, stimulates potato tuber formation and induces flowering of morning glory by initiating the jasmonic acid synthesis pathway. To elucidate the effect of theobroxide on pathogen resistance in plants, Nicotiana benthamiana plants treated with theobroxide were immediately infiltrated with Pseudomonas syringae pv. tabaci. Exogenous application of theobroxide inhibited development of lesion symptoms, and growth of the bacterial cells was significantly retarded. Semiquantitative RT-PCRs using the primers of 18 defense-related genes were performed to investigate the molecular mechanisms of resistance. Among the genes, the theobroxide treatment increased the expression of patho-genesis-related protein 1a (PR1a), pathogenesis-related protein 1b (PR1b), glutathione S-transferase (GST), allen oxide cyclase (AOC), and lipoxyganase (LOX). All these data strongly indicate that theobroxide treatment inhibits disease development by faster induction of defense responses, which can be possible by the induction of defense-related genes including PR1a, PR1b, and GST triggered by the elevated jasmonic acid.

• Korean Journal of Microbiology
• /
• v.53 no.4
• /
• pp.337-339
• /
• 2017

Here we report the draft genome sequence of the Caballeronia sordidicola strain PAMC 26633, isolated from Psoroma species, a lichen material from Barton Peninsula, King George Island in Antarctica. As we have observed in previous genomic studies in the genus Caballeronia from polar lichen, draft genomic sequences of PAMC 26633 had an assortment of genes of ecological importance and of biotechnical potentials, which include diverse metabolic genes for carbohydrates, amino acids, and genes for nitrogen/sulfur metabolisms, stress responses, membrane transporters, antibiotic resistance, and heavy metal resistance. CRISPR genes and sequences were not found and there were some phage remnants and transposons.

• Korean Journal of Breeding Science
• /
• v.43 no.4
• /
• pp.241-251
• /
• 2011

Bacterial blight(BB) caused by Xanthomonas oryzae pv. oryzae(Xoo) is one of the most economically destructive bacterial diseases of rice in worldwide. Utilization of resistant cultivars carrying resistant gene(s) is relatively an effect method to control this disease. About 34 resistant genes for BB resistance have been identified in many countries. Among them, Xa1 and Xa3 genes against bacterial blight have been incorporated into improved korean japonica rice varieties. Now, Ilmi carrying Xa1 gene and severial cultivars carrying Xa3 gene are widely grown in our country. In recent year, xa5, Xa21 and Xa23 genes are using in rice breeding programs for japonica resistant cultivars to bacterial blight. Resistant cultivars incorporated with a diverse single gene and two, three, or the more major gene necessite in the future.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.80.1-80
• /
• 2003

Several plant and microbial genes that could confer disease resistance in transgenic rice plants are being cloned and characterized. We are currently constructing transgenic rice lines that overexpress the gene products, such as a galactinol synthase, a defensin, and a bacterial ACC deaminase. Subtractive hybridization of a rice cDNA library constructed from the Xanthomonas oryzae-infected ice leaves resulted in isolation of many inducible cDNA clones including a elongation factor EF2, a oryzain alpha, a catalase, a aldehyde dehydrogenase, a S-adenosylmethionine synthetase, a caffeic acid O-methyltransferase, a glyceraldehyde-3-phosphate dehydrogenase, a light-regulated protein, nKY transcription factors, and a nucleotide diphosphate kinase. Some genes among those may be useful genetic sources for construction of disease resistant transgenic rice. Full lengths of the rice OsFIERG and a rice oryzain genomic clones were cloned, and serial deletion fragments of the promoter regions of these genes were fused with GUS reporter gene in pCAMBIA1201, respectively. Promoter activities of these constructs will be examined upon various stresses and Pathogen infections to obtain the pathogen specific inducible-promoter. This work was supported by a grant from BioGreen 21 Program, Rural Development Administration, Republic of Korea.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.257-264
• /
• 2011

Seventy five methicillin- resistant Staphylococcus aureus (MRSA) strains and 24 methicillin- susceptible S. aureus (MSSA) were isolated from clinical specimens obtained from a hospital in Suncheon, Jeonnam province, Korea, from July to December, 2009. Antibiotic resistance was determined using the disc diffusion method. Genes encoding enterotoxin (SE), toxic shock syndrome toxin-1 (TSST-1), exfoliative toxin (ET) and Panton-Valentine leukocidin (PVL) were detected by multiplex PCR-mediated amplification using specific primers. Sixty (80%) MRSA isolates possessed either one or more toxin genes and the most common pattern that coexisted in MRSA was seb, sec, seg, sei and tst (22.7%) followed by coexistence of sec, seg, sei and tst genes (18.7%). Gene pvl encoding leukocidin was not found. Significant correlation between the production of sec, seg, sei and tst genes was found. MRSAs were resistant to erythromycin (89% of the isolates), gentamicin (70.7%), ciprofloxacin (69.3%), clindamycin (61.3%) and tetracycline (58.7%), while MSSAs were susceptible to the antibiotics with the exception of erythromycin. Toxin genes seb, sec and tst were related to the tetracycline resistance of MRSA.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.413-419
• /
• 2021

The purpose of this study was to investigate the ability to treat and prevent infection by multiple Gram-negative bacterial pathogens as a last choice option in the treatment of serious infections in clinical settings. The global spread of extended-spectrum 𝛽-lactamases (ESBLs) and/or carbapenemases in microorganisms are of enormous concern to health services because they are often associated with multi-drug resistance which significantly restricts the antibiotic treatment options. In this study, the antimicrobial resistance profiles of bacteria isolated from South Korean market-derived meat samples were determined by the disc diffusion method. PCR was used to detect the presence of antibiotic resistance genes and ESBL producing genes. In total, we tested 181 isolated colonies from 36 market-derived meat samples. Single PCR and DNA sequencing results revealed that genes blaVIM, blaBIC, blaKPC, and blaSIM were present in the bacteria isolated from retail meat. The bacteria in the meat were separately sequenced and based on alignment, four different bacteria were identified. These findings suggest that bacteria found in retail meats are a reservoir for the spreading of ESBL blaVIM, blaBIC, blaKPC, and blaSIM resistance genes and bacteria strains.