• YAKHAK HOEJI
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• v.56 no.6
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• pp.364-365
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• 2012

Liver is the major organ to regulate the systemic glucose homeostasis and insulin resistance. Excess energy intake leads to triglyceride accumulation in adipose tissue first and subsequent accumulation in liver, resulting in obesity and type 2 diabetes. The representative pathological animal model for obesity associated insulin resistance is a high fat diet (HFD) fed mice model. Given the essential role of liver fat accumulation in developing systemic insulin resistance in obesity, I measured the liver triglyceride contents in HFD fed mice as a function of time. As such, in this report, I show the cause and effect relationship with regard to time during a HFD feeding between a variety of factors that are related to systemic insulin resistance including glucose intolerance, plasma insulin level and inflammatory gene expression in liver and adipose tissue.

• Mycobiology
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• v.29 no.1
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• pp.19-26
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• 2001

Defense mechanisms against anthracnose disease caused by Colletotrichum orbiculare on the leaf surface of cucumber plants after pre-treatment with plant growth promoting rhizobacteria(PGPR), amino salicylic acid(ASA) or C. orbiculare were compared using a fluorescence microscope. Induced systemic resistance was mediated by the pre-inoculation in the root system with PGPR strain Bacillus amylolquefaciens EXTN-1 that showed direct antifungal activity to C. gloeosporioides and C. orbiculare. Also, systemic acquired resistance was triggered by the pre-treatments on the bottom leaves with amino salicylic acid or conidial suspension of C. orbiculare. The protection values on the leaves expressing SAR were higher compared to those expressing ISR. After pre-inoculation with PGPR strains no change of the plants was found in phenotype, while necrosis or hypersensitive reaction(HR) was observed on the leaves of plants pre-treated with ASA or the pathogen. After challenge inoculation, inhibition of fungal growth was observed on the leaves expressing both ISR and SAR. HR was frequently observed at the penetration sites of both resistance-expressing leaves. Appressorium formation was dramatically reduced on the leaves of plants pre-treated with ASA, whereas EXTN-1 did not suppress the appressorium formation. ASA also more strongly inhibited the conidial germination than EXTN-1. Conversely, EXTN-1 significantly increased the frequency of callose formation at the penetration sites, but ASA did not. The defense mechanisms induced by C. orbiculare were similar to those by ASA. Based on these results it is suggested that resistance mechanisms on the leaf surface was different between on the cucumber leaves expressing ISR and SAR, resulting in the different protection values.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.64.1-64
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• 2003

Inoculation of primary pepper leaves with an avirulent strain of Xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (SAR) in secondary leaves. This SAR response was accompanied by the systemic expression of defense-related genes, a systemic microoxidative burst generating H2O2, and the systemic induction of ion-leakage and callose deposition in the non-inoculated, secondary leaves. Some defense-related genes encoding PR-1, chitinase, peroxidase, PR10, thionin, defensin and zinc-finger protein were distiilctly induced in the systemic leaves. The systemically striking accumulation of H$_2$O$_2$and strong increase in peroxidase activity in pepper was suggested to contribute to the triggering of cell death In the systemic micro-HRs, leading to the induction of SAR. Treatment of non-inoculated, secondary leaves with diphenylene iodinium (DPI), an inhibitor of the oxidative burst, substantially reduced the induction of some defense-related genes and subsequently SAR.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.172-176
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• 2004

Bacterial isolates TRL2-3 and TRK2-2 showing anti-fungal activity in vitro test against some plant pathogens were identified as Pseudomonas putida and Micrococcus luteus, respectively. Pre-treatment with both bacterial isolates at the concentration 1.0$\times$ $10^7$ and $10^6$cfu/ml in the rhizosphere could trigger induced systemic resistance in the aerial part of cucumber plants against anthracnose caused by Colletotrichum orbiculare. However, the pre-treatment with the higher concentration at 1.0 $\times$ $10^8$ cfu/ml of both isolates could not induce resistance after challenge inoculation with C. orbiculare. As a positive control, the treatment with DL-3 amino butyric acid caused a remarkable reduction of disease severity whereas the lesions on the leaves of untreated plants developed apparently after the fungal inoculation. From these results, it was recomended that disease control using both bacterial isolates inducing systemic resistance in the field where chemical application is forbid.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.7-12
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• 2005

Plant growth-promoting rhizobacteria (PGPR) are a wide range of root-colonizing bacteria with the capacity to enhance plant growth and control plant pathogens. Here we review recent progress that indicate some PGPR strains release a blend of volatile organic compounds (VOCs) that promote growth in Arabidopsis seedlings and induce resistance against Erwinia carotovora subsp. carotovora. In particular, the volatile components 2,3-butanediol and acetoin released exclusively from the PGPR strains triggered the greatest level of growth promotion and induced systemic resistance. Pharmacological applications of 2,3-butanediol promoted the plant growth and induced resistance, while bacterial mutants blocked in 2,3-butanediol and acetoin synthesis was devoid of growth-promotion and induced resistance capacities. The results suggested that the bacterial VOCs play a critical role in the plant growth promotion and induced resistance by PGPR. Using transgenic and mutant lines of Arabidopsis, we provide evidences that the signal pathway activated by volatiles from one PGPR strain is dependent on cyto-kinin activation for growth promotion and dependent on an ethylene-signaling pathway for induced pathogen resistance. This discovery provides new insight into the role of bacterial VOCs as initiators of both plant growth promotion and defense responses in plants.

• Mycobiology
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• v.33 no.1
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• pp.35-40
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• 2005

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that an the bacterial isolates produced more salicylic acid (SA) at low iron ($10\;{\mu}M$ EDDHA) than high iron availability ($10\;{\mu}Fe^{3+}$ EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.360-363
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• 2006

Efficacy of plant growth promoting rhizobacteria(PGPR) Bacillus vallismortis strain EXTN-1 has been proved in eliciting induced systemic resistance(ISR) in several crops. The present paper described the beneficial effects of EXTN-1 in potato as increase in yield and chlorophyll content, and plant protection against Potato Virus Y and X(PVY & PVX). EXTN-1 induced systemic resistance to the plants resulting in significant disease suppression in the field. Also the plants under treatment with EXTN-1 had higher chlorophyll content. The bacterized plants had significantly higher yields over the untreated control plants. The strain induced activation of defense genes, PR-1a and PDF 1.2 in transgenic tobacco model, which indicated the possible role of both SA, and JA pathways in EXTN-1 mediated plant protection against crop diseases.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.174-181
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• 2013

The plant growth-promoting rhizobacterium Ochrobactrum lupini KUDC1013 elicited induced systemic resistance (ISR) in tobacco against soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. We investigated of its factors involved in ISR elicitation. To characterize the ISR determinants, KUDC1013 cell suspension, heat-treated cells, supernatant from a culture medium, crude bacterial lipopolysaccharide (LPS) and flagella were tested for their ISR activities. Both LPS and flagella from KUDC1013 were effective in ISR elicitation. Crude cell free supernatant elicited ISR and factors with the highest ISR activity were retained in the n-butanol fraction. Analysis of the ISR-active fraction revealed the metabolites, phenylacetic acid (PAA), 1-hexadecene and linoleic acid (LA), as elicitors of ISR. Treatment of tobacco with these compounds significantly decreased the soft rot disease symptoms. This is the first report on the ISR determinants by plant growth-promoting rhizobacteria (PGPR) KUDC1013 and identifying PAA, 1-hexadecene and LA as ISR-related compounds. This study shows that KUDC1013 has a great potential as biological control agent because of its multiple factors involved in induction of systemic resistance against phytopathogens.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.3
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• pp.206-212
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• 2023

Objective: The aim of the present study was to evaluate the associations between hematologic parameters related to systemic inflammation and insulin resistance-associated metabolic parameters in women with polycystic ovary syndrome (PCOS). Methods: Eighty-two women between the ages of 18 and 35 years who were diagnosed with PCOS were included in this study. A 2-hour 75-g oral glucose tolerance test (OGTT) was administered to all study participants; fasting and postprandial glucose and insulin levels were measured simultaneously during the 2-hour OGTT. Hematologic parameters were derived from a standard complete blood count and a differential count of fasting-state blood samples. The correlations between hematologic parameters and insulin resistance-associated clinical and metabolic parameters were evaluated using the Spearman rank correlation and partial correlation coefficients. Hematologic parameters related to systemic inflammation were compared between the two groups, categorized by the presence or absence of insulin resistance. Results: Significant differences in the absolute neutrophil count, absolute monocyte count, platelet count, and neutrophil-lymphocyte ratio were found between the insulin-resistant group and insulin-nonresistant group. Correlation analysis found that all hematological parameters, except for the platelet-lymphocyte ratio, were associated with at least one insulin resistance-associated metabolic parameter. However, these significant correlations between hematological and metabolic parameters were attenuated after controlling for the effects of other covariates using partial correlation analysis. Conclusion: The association between hematologic parameters indicative of systemic inflammation and insulin resistance-associated metabolic parameters seems to be strongly influenced by other anthropometric covariates in women with PCOS.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.21-27
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• 2023

In plants, salicylic acid (SA) is a central immune signal that is involved in both local and systemic acquired resistance (SAR). In addition to SA, several other chemical signals are also involved in SAR and these include N-hydroxy-pipecolic acid (NHP), a newly discovered plant metabolite that plays a crucial role in SAR. Recent discoveries have led to a better understanding of the biosynthesis of SA and NHP and their signaling during plant defense responses. Here, I review the recent progress in role of SA and NHP in SAR. In addition, I discuss how these signals cooperate with other SAR-inducing chemicals to regulate SAR.