• The Plant Pathology Journal
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• 제38권5호
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• pp.432-448
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• 2022

Planthopper infestation in rice causes direct and indirect damage through feeding and viral transmission. Host microbes and small RNAs (sRNAs) play essential roles in regulating biological processes, such as metabolism, development, immunity, and stress responses in eukaryotic organisms, including plants and insects. Recently, advanced metagenomic approaches have facilitated investigations on microbial diversity and its function in insects and plants, highlighting the significance of microbiota in sustaining host life and regulating their interactions with the environment. Recent research has also suggested significant roles for sRNA-regulated genes during rice-planthopper interactions. The response and behavior of the rice plant to planthopper feeding are determined by changes in the host transcriptome, which might be regulated by sRNAs. In addition, the roles of microbial symbionts and sRNAs in the host response to viral infection are complex and involve defense-related changes in the host transcriptomic profile. This review reviews the structure and potential functions of microbes and sRNAs in rice and the associated planthopper species. In addition, the involvement of the microbiota and sRNAs in the rice-planthopper-virus interactions during planthopper infestation and viral infection are discussed.

• Molecules and Cells
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• 제27권5호
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• pp.563-570
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• 2009

We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.

• 생명과학회지
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• 제14권4호
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• pp.650-656
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• 2004

야생벼의 일종인 Oryza grandiglumis (CCDD, 2n=48)는 도열병, 잎집무늬마름병, 흰빛잎마름병, 그리고 벼멸구와 같은 병충해에 저항성을 가지는 것으로 알려져 있다. 이와 같은 곰팡이와 해충에 반응하여 차별 발현하는 유전자를 클로닝 하기 위하여 상처처리와 yeast extract를 Oryza grandiglumis에 0시간과 24시간 각각 처리하였다. 유전자의 클로닝을 위하여 희귀 발현유전자의 클로닝에 효율적인 것으로 알려진 Suppression Subtractive Hybridization (SSH) 방법이 처리 후 24시간 된 식물을 재료로 사용되었다. 그 결과, 776개의 cDNA clones이 확보되었으며, 유전자 발현의 진위여부를 빠르게 스크린하기 위하여 colony array가 수행되었다. 115개의 colony가 positive로 판명되었고, 이들의 평균 insert size는 400 bp에서 700 bp에 이르렀고, 이들에 대한 염기서열 분석이 수행되었다. 염기서열 분석 결과, 68개 clone들이 알려진 기능의 유전자와 homology를 나타냈으며, 이중에서 16개 clone이 일차대사에 관련된 것과 유사성을, 5개가 plant retrotransposon과 유사성을, 5개가 식물 방어기작 관련 metallothionein-like gene과 염기서열 유사성을 보였다. 이외에 다양한 유전자들이 아미노산 합성관련, membrane transport, signal transduction등에 관여하는 유전자들과 상동성을 나타내었다. 이들 유전자중에서 4 개의 클론(ogwfi-161, ogwfi-646, ogwfi-663, ogwfi-695)들이 선발되었고 이들에 대한 Northern 분석이 수행되었다. Northern 분석 결과 ogwfi-161, ogwfi-646, ogwfi-663, ogwfi-695는 wounding과 yeast extract처리 에 의한 차별 발현이 확인되었다. 이상의 결과를 종합하여 볼 때, SSH방법은 병충해등과 같은 조건에 의해 차별 발현되는 유전자들을 빠른 시간 내에 다량으로 발굴할 수 있는 매우 효율적인 방법이라고 생각된다.

• The Plant Pathology Journal
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• 제21권2호
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• pp.149-157
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• 2005

A novel rice (Oryza sativa L.) gene, homologous to Arabidopsis pathogenesis-related NDR1 gene, was cloned from cDNA library prepared from 30 min Magnaporthe grisea -treated rice seedling leaves, and named as OsNDR1. OsNDR1 encoded a 220-aminoacid polypeptide and was highly similar to the Arabidopsis AtNDR1 protein. OsNDR1 is a plasma membrane (PM)-localized protein, and presumes through sequence analysis and protein localization experiment. Overexpression of OsNDR1 promotes the expression of PBZ1 that is essential for the activation of defense/stressrelated gene. The OsNDR1 promoter did not respond significantly to treatments with either SA, PBZ, or ETP. Exogenously applied BTH induces the same set of SAR genes as biological induction, providing further evidence for BTH as a signal. Presumably, BTH is bound by a receptor and the binding triggers a signal transduction cascade that has an ultimate effect on transcription factors that regulate SAR gene expression. Thus OsNDR1 may act as a transducer of pathogen signals and/or interact with the pathogen and is indeed another important step in clarifying the component participating in the defense response pathways in rice.

• The Plant Pathology Journal
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• 제27권1호
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• pp.53-58
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• 2011

Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages) than that of the control group. JA followed by SA (JA${\rightarrow}$SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.

• Journal of Microbiology and Biotechnology
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• 제19권2호
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• pp.194-203
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• 2009

$HpaG_{Xooc}$, from rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola, is a member of the harpin group of proteins, eliciting hypersensitive cell death in non-host plants, inducing disease and insect resistance in plants, and enhancing plant growth. To express and secret the $HpaG_{Xooc}$ protein in Bacillus subtilis, we constructed a recombinant expression vector pM43HF with stronger promoter P43 and signal peptide element nprB. The SDS-PAGE and Western blot analysis demonstrated the expression of the protein $HpaG_{Xooc}$ in B. subtilis. The ELISA analysis determined the optimum condition for $HpaG_{Xooc}$ expression in B. subtilis WBHF. The biological function analysis indicated that the protein $HpaG_{Xooc}$ from B. subtilis WBHF elicits hypersensitive response(HR) and enhances the growth of tobacco. The results of RT-PCR analysis revealed that $HpaG_{Xooc}$ induces expression of the pathogenesis-related genes PR-1a and PR-1b in plant defense response.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.67.1-67
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• 2003

Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

• 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.

• 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.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.36-36
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• 2022

The molecular understanding of resistance and susceptibility of host plants to scab, a most threatful disease to pome fruit production worldwide, is very limited. Comparing resistant line '93-3-98' to susceptible one 'Sweet Skin' at seven time points of 0, 0.5, 1, 2, 3, 4, 8 days post inoculation, RNA-sequencing data derived from infected and mock-inoculated young leaves were analyzed to evaluate the tolerant response and to mine candidate genes of pear to the scab pathogen Venturia nashicola. Analysis of the mapped reads showed that the infection of V. nashicola led to significant differential expression of 17,827 transcripts with more than 3-fold change in the seven pairs of libraries, of which 9,672 (54%) are up- and 8,155(46%) are down-regulated. These included mainly receptor (NB-ARC domains-containing, CC-NBS-LRR, TIR-NBS-LRR, seven transmembrane MLO family protein) and transcription factor (ethylene responsive element binding, WRKY DNA-binding protein) related gene. An arsenal of defense response of highly resistant pear accessions derived from European pear was probably supposed no sooner had V. nashicola infected its host than host genes related to disease suppression like Polyketide cyclase/dehydrase and lipid transport protein, WRKY family transcription factor, lectin protein kinase, cystein-rich RLK, calcium-dependent phospholipid-binding copine protein were greatly boosted and eradicated cascade reaction induced by pathogen within 24 hours. To identify transcripts specifically expressed in response to V. nashicola, RT-PCRs were conducted and compare to the expression patterns of seven cultivars with a range of highly resistant to highly susceptible symptom. A DEG belonging to the PR protein family genes that were higher expressed in response to V. nashicola suggesting extraordinary role in the resistance response were led to the identification. This study provides the first transcriptional profile by RNA-seq of the host plant during scab disease and insights into the response of tolerant pear plants to V. nashicola.