• The Plant Pathology Journal
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• 제28권4호
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• pp.409-417
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• 2012

We identified two novel expansin (EXP) genes in the expressed sequence tag database of Bursaphelenchus xylophilus, designated as Bx-EXPB2 and -EXPB3. Novel Bx-EXPBs encoded 150 amino acids and their similarities in coding sequence were 70.7-84.0% to the previously reported EXPB1 of B. xylophilus. Bx-EXPB2 and Bx-EXPB3 were clustered with Bx-EXPB1 and Bm-EXPB1, respectively, forming the independent phylogeny with other nematode EXPs. All identified Bx-EXPBs contained the signal peptide and were only expressed during the propagative stage, suggesting that they are secreted to facilitate nematode migration through hosts by loosening cell walls during infection. Quantitative real-time PCR analysis showed that the relative accumulation of Bx-EXPB3 mRNAs was the highest among the three Bx-EXPs examined and the order of mRNA accumulation was as follows: Bx-EXPB3 > Bx-EXPB2 >> Bx-EXPB1. Homology modeling of Bx-EXPBs showed that the structurally optimum template was EXLX1 protein of Bacillus subtilis, whichshared residues essential for catalytic activity with Bx-EXPB1 and Bx-EXPB2 except for Bx-EXPB3. Taken together, Bx-EXPB1 and Bx-EXPB2 may be involved migration through plant tissues and play a role in pathogenesis.

• The Plant Pathology Journal
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• 제32권4호
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• pp.311-320
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• 2016

Xanthomonas axonopodis pv. glycines (Xag) is a necrotrophic bacterial pathogen of the soybean that causes bacterial pustules and is a nonhost pathogen of the chili pepper. In the current study, chili pepper fruit wound inoculated in planta with Xag 8ra formed necrotic lesions on the fruit surface and induced several structural and chemical barriers systemically in the fruit tissue. The initial defense response included programmed cell death of necrotizing and necrotized cells, which was characterized by nuclear DNA cleavage, as detected by TUNEL-confocal laser scanning microscopy (CLSM), and phosphatidylserine exposure on cell walls distal to the infection site, as detected by Annexin V FLUOS-CLSM. These two responses may facilitate cell killing and enhance transportation of cell wall materials used for cell wall thickening, respectively. The cells beneath the necrotic tissue were enlarged and divided to form periclinal cell walls, resulting in extensive formation of several parallel boundary layers at the later stages of infection, accompanying the deposition of wall fortification materials for strengthening structural defenses. These results suggest that nonhost resistance of chili pepper fruit against the nonhost necrotrophic pathogen Xag 8ra is activated systematically from the initial infection until termination of the infection cycle, resulting in complete inhibition of bacterial pathogenesis by utilizing organspecific in situ physiological events governed by the expression of genes in the plant fruit organ.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.121-121
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• 2019

In Islamic dietary guidelines, Halal foods are allowed as edible blessed food. Most foods were categorized within halal for Muslims. The main point of Halal food is that foods are clean in every process and based on Halal standard which might be different in each country. Most pancreatic ${\beta}$ cells synthetize, store, and release insulin. Specific molecular, functional as well as ultrastructural traits of pancreatic ${\beta}$ cells could control their insulin secretion properties and survival phentoype. Insulin-secreting pancreatic ${\beta}$-cells are essential regulators of mammalian metabolism. In addition, the pancreatic ${\beta}$ cell plays an important role in the pathogenesis of type 1 and type 2 diabetes as improving glucose homeostasis by preserving, expanding and improving the function of this key cell type. However, the pharmacological effect of halal food has not been unclear yet, especially food habit-dependent diabetes. The aim of the this study was to determine the preventive effect of Iran plants extract (Almond, Garlic, Cumin, Ginkgo biloba, Holy basil, Psyllium, Satureja khuzistanica, Fenugreek, Green tea, Ipomoea betatas, Blueberry) on RINm5F cells and MIN6 cells as pancreatic ${\beta}$ cell line. The cytotoxicity of the extracts of Iran plants on RINm5F cells and MIN6 cells were measured by using MTT assays. The preventive effects of Iran plant extracts were measured by WST-8 cell proliferation assay on streptozotocin (STZ)-induced cell death in MIN6 cells. In presented result showed that all extract of Iran plants (0.01-10mg/ml) did not show cytotoxicity in RINm5F cells and MIN6 cells. Among non-cytotoxic extract, the protective effects could be detect in high dose concentration. These results suggest that the extract of Iran plants may serve as a potential therapy for diabetes.

• The Plant Pathology Journal
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• 제35권5호
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• pp.445-458
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• 2019

The lipopolysaccharide (LPS) composed of lipid A, core, and O-antigen is the fundamental constituent of the outer membrane in gram-negative bacteria. This study was conducted to investigate the roles of LPS in Burkholderia glumae, the phytopathogen causing bacterial panicle blight and seedling rot in rice. To study the roles of the core oligosaccharide (OS) and the O-antigen region, mutant strains targeting the waaC and the wbiFGHI genes were generated. The LPS profile was greatly affected by disruption of the waaC gene and slight reductions were observed in the O-antigen region following wbiFGHI deletions. The results indicated that disruption in the core OS biosynthesis-related gene, waaC, was associated with increased sensitivity to environmental stress conditions including acidic, osmotic, saline, and detergent stress, and to polymyxin B. Moreover, significant impairment in the swimming and swarming motility and attenuation of bacterial virulence to rice were also observed in the waaC-defective mutant. The motility and virulence of O-antigen mutants defective in any gene of the wbiFGHI operon, were not significantly different from the wild-type except in slight decrease in swimming and swarming motility with wbiH deletion. Altogether, the results of present study indicated that the LPS, particularly the core OS region, is required for tolerance to environmental stress and full virulence in B. glumae. To our knowledge, this is the first functional study of LPS in a plant pathogenic Burkholderia sp. and presents a step forward toward full understanding of B. glumae pathogenesis.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.287-287
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• 2022

In this study, we analyze RNA-seq data from OxF3Hand WT at several points (Oh, 3 h, 12 h, and 24 h) after WBPH infection. A number of the genes were further validated by RT-qPCR. Results revealed that highest number of DEGs (4,735) between the two genotypes detected after 24 h of infection. Interestingly, many of the DEGs between the WT and OsF3H under control conditions were also found to be differentially expressed in OsF3H in response to WBPH infestation. These results indicate that significant differences in gene expression between the "OxF3H" and "WT" exist as the infection time increases. Many of these DEGs were related to oxidoreductase activity, response to stress, salicylic acid biosynthesis, metabolic process, defense response to pathogen, cellular response to toxic substance, and regulation of hormones level. Moreover, genes involved in salicylic acid (SA) and Ethylene (Et) biosynthesis were upregulated in OxF3H plants while jasmonic acid (JA), Brassinosteroid (Br), and abscisic acid (ABA) signaling pathways were found downregulated in OxF3H plant during WBPH infestation. Interestingly, many DEGs related to pathogenesis such as OsPR1, OsPR1b, NPR1, OsNPR3 and OsNPR5 were found significantly upregulated in OxF3H plants. Additionally, genes related to MAPKs pathway, and about 30 WRKY genes involved in different pathways were found upregulated in OxF3H plants after WBPH infestation. This suggests that overexpression of the OxF3H gene leads to multiple transcriptomic changes and impact plant hormones, pathogenic related and secondary metabolites related genes and enhancing the plant resistance to WBPH infestation.

• 식물병연구
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• 제17권2호
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• pp.136-141
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• 2011

본 연구는 세계적으로 참나무류 집단고사를 일으켜 문제가 되고 있는 R. quercivorus 균의 방제를 위한 연구로 최근 나노기술을 활용하여 참나무시들음병(Oak wilt)의 원인균인 R. quercivorus를 방제하고 매개충인 광릉긴나무좀(Platypus koryoensis)의 생태 및 형태연구에 관한 것이다. Nano-silver 용액 WA-AT-WB13R을 이용하여 R. quercivorus 균에 대한 in vitro 실험을 실시하였으며, WAAT-WB13R 용액이 100 ppm에서 균사 및 포자의 생장 억제 효과가 있음을 확인하였다. 각각 10, 30, 50, 100 ppm 처리하여 SEM 관찰 결과, 무처리구에서는 균사의 형태가 정상적임을 확인하였고 30 ppm에서부터 균사의 형태가 조금씩 변형이 일어나다가 100 ppm에서는 균사 및 포자가 비정상적으로 일그러져 있는 것을 확인하였다. 또한 매개충인 P. koryoensis의 충체에 붙어있는 균사와 포자를 SEM을 이용하여 위와 같은 방법으로 처리 관찰 결과, 표면과 균낭의 균사 및 포자의 형태가 100 ppm에 가까울수록 형태적인 변화를 관찰할 수 있었다. 기내에서의 R. quercivorus의 균사 생장억제효과를 바탕으로 수간주사(Trunk injection)를 실시한 결과, 철원과 홍천에서는 시들음 및 약해 증상을 확인할 수 없었다. 또한 춘천은 7월 시들음 증상을 보였으나 그 후 시들음 증상 및 약해를 보이지 않았다. 본 연구를 통하여 nano-silver 용액을 이용한 참나무시들음병의 원인균인 R. quercivorus의 생장억제 효과를 확인하였으며, nano-silver를 이용한 R. quercivorus 방제할 수 있음을 확인하였다.

• Journal of Plant Biotechnology
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• 제47권2호
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• pp.157-163
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• 2020

급속한 산업화와 인구증가에 따른 심각한 환경과 식량문제는 인류의 생존을 위협하는 가장 중요한 현안문제로 대두되고 있다. 또한, 인구 증가에 따른 식량부족을 해결하기 위하여 농약과 화학비료의 무분별한 사용으로 인하여 농토는 산성화되어 황폐화가 되고 있고 먹이사슬 및 자연생태계의 파괴는 더 많은 농약의 사용을 필요하고 있다. 과다한 농약 사용으로 경제적인 부담의 가중과 잔류 농약으로 인한 소비자의 건강을 위협하고 있다. 또한, 증가된 화석연료의 사용은 공기중의 이산화탄소를 증가시켜 지구 온도의 상승을 초래하고 있으며, 결과적으로 기상이변, 지구온난화 및 사막화 등의 심각한 환경문제를 초래했다. 특히, 서늘한 기온에서 잘 자라는 배추, 무우, 감자 등의 고령지 농작물의 질적인 저하를 초래하여 피해가 증가하고 있지만, 최근들어 감자와 같은 알카리성 건강식품의 붐으로 수요가 증가되고 있다. 본 연구에서 환경스트레스에 관여하는 대두의 특이적인 칼모듈린, GmCaM-4 유전자를 감자에 과발현 시켜서 PR 유전자들의 발현이 지속적으로 유지되어 식물방어 기작이 활성화 되었음을 확인하였다. 또한, 그 형질전환 식물체는 초민감성 세포사멸 현상을 보였고, 무름병을 일으키는 병원균인 Erwinia carotovora subsp. Carotovora (Ecc)를 이용하여 GmCaM-4가 과발현된 감자에서 병 저항성이 증가하는 것을 확인 하였다. 최종적으로 지금까지 많이 연구되고 보고된 유전자원인 대두의 GmCaM-4 유전자를 활용하여 주요 식량자원인 감자에서 과발현 형질전환 식물체를 확보하여 다양한 병 저항성 증가를 통한 작물 생산성 향상에 매우 우수한 기술로 기대되는 바이다.

• The Plant Pathology Journal
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• 제34권4호
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• pp.316-326
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• 2018

The effect of simulated climate changes by applying different temperatures and $CO_2$ levels was investigated in the Blumeria graminis f. sp. tritici/wheat pathosystem. Healthy and inoculated plants were exposed in single phytotrons to six $CO_2$+temperature combinations: (1) 450 ppm $CO_2/18-22^{\circ}C$ (ambient $CO_2$ and low temperature), (2) 850 ppm $CO_2/18-22^{\circ}C$ (elevated $CO_2$ and low temperature), (3) 450 ppm $CO_2/22-26^{\circ}C$ (ambient $CO_2$ and medium temperature), (4) 850 ppm $CO_2/22-26^{\circ}C$ (elevated $CO_2$ and medium temperature), (5) 450 ppm $CO_2/26-30^{\circ}C$ (ambient $CO_2$ and high temperature), and (6) 850 ppm $CO_2/26-30^{\circ}C$ (elevated $CO_2$ and high temperature). Powdery mildew disease index, fungal DNA quantity, plant death incidence, plant expression of pathogenesis-related (PR) genes, plant growth parameters, carbohydrate and chlorophyll content were evaluated. Both $CO_2$ and temperature, and their interaction significantly influenced powdery mildew development. The most advantageous conditions for the progress of powdery mildew on wheat were low temperature and ambient $CO_2$. High temperatures inhibited pathogen growth independent of $CO_2$ conditions, and no typical powdery mildew symptoms were observed. Elevated $CO_2$ did not stimulate powdery mildew development, but was detrimental for plant vitality. Similar abundance of three PR transcripts was found, and the level of their expression was different between six phytotron conditions. Real time PCR quantification of Bgt was in line with the disease index results, but this technique succeeded to detect the pathogen also in asymptomatic plants. Overall, future global warming scenarios may limit the development of powdery mildew on wheat in Mediterranean area, unless the pathogen will adapt to higher temperatures.

• Journal of Plant Biotechnology
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• 제38권1호
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• pp.62-68
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• 2011

원예작물의 생육을 저하시키는 각종 병충해로 인한 과도한 농약과 화학비료의 사용은 환경오염뿐만 아니라 작물의 생산량에도 큰 영향을 미치고 있다. 식물생명공학기술을 이용하여 농약이나 화학비료 사용량을 획기적으로 줄일 수 있는 식물체의 개발, 즉 형질전환을 이용한 분자 육종기술은 병충해 내성 농작물을 개발하여 과도한 화학비료의 사용에 따르는 여러가지 문제점들을 극복할 수 있는 대안으로 대두되고 있다. 본 연구에서는 모델식물인 애기장대에서 분리한 식물생체방어 신호전달에 관련된 AtCBP63 유전자를 감자에 과발현시켰고, 이러한 형질 전환 감자에서 병저항성에 관여하는 유전자인 PR-2, PR-3, PR-5 유전자들의 발현이 증가되어 지속적으로 식물 방어 기작이 활성화되어 있음을 확인하였다. 또한, 감자에서 무름병 (soft rot disease)을 일으켜 막대한 피해를 유발하는 병원성 세균인 Erwinia carotovora subsp. Carotovora (Ecc)를 이용하여 AtCBP63 유전자를 과발현한 감자에 감염시켰을 때, 병 저항성이 증가한다는 사실을 검증하였다. 앞으로, 다양한 곰팡이 균에 대응하여 AtCBP63 유전자를 과발현한 감자에 저항성을 검증하고자 한다.

• 생명과학회지
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• 제19권8호
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• pp.1177-1182
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• 2009

배추 무름병을 대상으로 식물병원균 감염모델을 확립하기 위하여 무름병변을 가진 배추조직으로부터 80개의 독립된 세균집락을 순수 분리하였다. 이들 균을 감염되지 않은 배추 잎의 주맥부위에 접종하여 24${\sim}$48 시간 만에 무름병변을 나타내는 8개의 균주를 1차 선별하였다. 다양한 미생물학적, 생화학적, 형태학적인 시험을 통하여 분석한 결과 서로 다른 특성을 나타내는 균이라고 여겨지는 3개의 균을 최종 선정하였고 이들은 모두 그람 음성균으로 판명되었고 RB1, RB2 및 RB6로 명명하였다. API 20E시험, VITEK 2 COMPACT 분석, 16S rRNA 염기서열 분석 등을 종합할 때 RBl 및 RB2는 Erwinia carotovorum subsp. odoriferum 아종으로, RB6는 Erwinia carotovorum subsp. carotovorum 아종으로 추정되었다. 이들 균들은 $30^{\circ}C$, 생리적 pH인 중성 pH에서 최적생육을 하였다. 이들은 배추의 상처 유무에 상관없이 초기 접종양과 비례하여 무름병을 유발하였으며, 상처가 없는 경우보다 상처가 있는 경우에 더욱 명확한 병변을 유발하였다. RBl의 경우 $8.0{\times}10^8$ CFU/ml, RB2 균주는 $10^9$ CFU/ml, RB6는$4.7{\times}10^6$ CFU/ml에서 최초로 무름 증상을 나타냈다. 이들 균의 숙주 특이성을 관찰하기 위하여 14종의 야채에 접종한 결과 배추, 가지 파프리카에서만 무름병변을 유발하는 숙주 특이성을 나타내었다. 이 연구에서 사용된 실험재료들 및 감염모델은 향후 식물병원균의 감염기작해석에 크게 기여할 것으로 예상된다.