• The Plant Pathology Journal
• /
• 제17권6호
• /
• pp.384.1-384
• /
• 2001

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2000년도 추계 학술발표회
• /
• pp.25.2-25
• /
• 2000

• 한국식물생명공학회:학술대회논문집
• /
• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
• /
• pp.243-243
• /
• 2005

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 1999년도 임시총회 및 추계 학술발표회
• /
• pp.47.1-47
• /
• 1999

• The Plant Pathology Journal
• /
• 제28권2호
• /
• pp.164-171
• /
• 2012

Rice blast disease caused by Magnaporthe grisea (Hebert) Barr [teleomorph] is one of the most devastating diseases in rice plantation areas. Silicon is considered as a useful element for a large variety of plants. Rice variety MR219 was grown in the glasshouse to investigate the function of silicon in conferring resistance against blast. Silica gel was applied to soil while sodium silicate was used as foliar spray at the rates of 0, 60, 120, 180 g/5 kg soil and 0, 1, 2, 3 ml/l respectively. The treatments were arranged in a completely randomized design. Disease severity and silicon content of leaves were compared between the non-amended controls and rice plants receiving the different rates and sources of silicon. Silicon at all rates of application significantly (${\alpha}$ = 0.05) reduced the severity of disease with highest reduction (75%) recorded in treatments receiving 120 g of silica gel. SEM/EDX observations demonstrated a significant difference in weight concentration of silicon in silica cells on the leaf epidermis between silicon treated (25.79%) and non treated plants (7.87%) indicating that Si-fertilization resulted in higher deposition of Si in silica cells in comparison with non-treated plants. Application of silicon also led to a significant increase in Si contents of leaves. Contrast procedures indicated higher efficiency of silica gel in comparison to sodium silicate in almost all parameters assessed. The results suggest that mitigated levels of disease were associated with silicification and fortification of leaf epidermal cells through silicon fertilization.

• Journal of Microbiology and Biotechnology
• /
• 제13권6호
• /
• pp.984-988
• /
• 2003

The actinomycete strain KH-6l4 possessed strong antifungal activity, especially antagonistic to the rice blast fungus, Pyricularia oryzae. Diaminopimelic acid (DAP) type and morphological and physiological characteristics, examined by scanning electron microscopy (SEM), indicated that KH-614 belonged to the genus Streptomyces. Antifungal agent produced by this strain was found to be most active, when the strain was cultured in the presence of glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. Based on the spectral report data, MS and NMR, the antifungal agent was identified as cyclo(L-leucyl-L-prolyl). According to the antimicrobial activity test measured by minimal inhibitory concentration (MIC), the cyclo(1eu-pro) exhibited the activity against Candida albicans IAM 4905, Mucor ramannianus IAM6218, Rhizoctonia solani IFO 6218, Aspergilus fumigatus ATCC 42202, Glomerella cingulata IFO 9767, Trichophton mentagrophytes ATCC 18749, and Trichophyton rubrum ATCC 44766, the order of MIC values were 50, 12.5, 5, 50, 25, 5, $5\;\mu\textrm{g}/ml$, respectively. Specifically, cyclo(1eu-pro) was one of the most effective elements against Pyricularia oryzae IFO 5994 with the MIC value of $2.5\;\mu\textrm{g}/ml$, thus indicating that cyclo(leu-pro) is a potential antifungal agent.

• Mycobiology
• /
• 제51권5호
• /
• pp.273-280
• /
• 2023

The nucleolus is the largest, membrane-less organelle within the nucleus of eukaryotic cell that plays a critical role in rRNA transcription and assembly of ribosomes. Recently, the nucleolus has been shown to be implicated in an array of processes including the formation of signal recognition particles and response to cellular stress. Such diverse functions of nucleolus are mediated by nucleolar proteins. In this study, we characterized a gene coding a putative protein containing a nucleolar localization sequence (NoLS) in the rice blast fungus, Magnaporthe oryzae. Phylogenetic and domain analysis suggested that the protein is orthologous to Rrp8 in Saccharomyces cerevisiae. MoRRP8-GFP (translational fusion of MoRRP8 with green fluorescence protein) co-localizes with a nucleolar marker protein, MoNOP1 fused to red fluorescence protein (RFP), indicating that MoRRP8 is a nucleolar protein. Deletion of the MoRRP8 gene caused a reduction in vegetative growth and impinged largely on asexual sporulation. Although the asexual spores of DMorrp8 were morphologically indistinguishable from those of wild-type, they showed delay in germination and reduction in appressorium formation. Our pathogenicity assay revealed that the MoRRP8 is required for full virulence and growth within host plants. Taken together, these results suggest that nucleolar processes mediated by MoRRP8 is pivotal for fungal development and pathogenesis.

• Journal of Microbiology and Biotechnology
• /
• 제19권1호
• /
• pp.11-16
• /
• 2009

Magnaporthe oryzae, the causal agent of rice blast, forms a specialized infection structure, called an appressorium, which is crucial for penetration and infection of the host plant. Pharmacological data suggest that calcium/calmodulindependent signaling is involved in appressorium formation in this fungus. To understand the role of the calcium/calmodulin-activated protein phosphatase on appressorium formation at the molecular level, MCNA, a gene encoding the catalytic subunit of calcineurin, was functionally characterized in M. oryzae. Transformants expressing sense/antisense RNA of MCNA exhibited significant reductions in mycelial growth, conidiation, appressorium formation, and pathogenicity. cDNA of MCNA functionally complemented a calcineurin disruptant strain (cmp1::LEU2 cmp2::HIS3) of Saccharomyces cerevisiae. These data suggest that calcineurin A plays important roles in signal transduction pathways involved in the infection-related morphogenesis and pathogenicity of M. oryzae.

• 농업과학연구
• /
• 제6권2호
• /
• pp.97-104
• /
• 1979

새로운 도열병균의 생태형에 대하여 감수성이 높은 수도 통일계 품종 밀양 23호의 도열병의 발생경과와 발생양상에 미치는 시비수준의 영향을 구명하기 위하여 이 연구를 시도하였다. 그 동안에 얻은 연구 결과는 다음과 같다. 대체로 시비수준이 높아짐에 따라 밀양 23호는 도열병에 대하여 감수성이 더욱 높아지며 발병과 시비 수준사이에 밀접한 관계가 인정되었다. 이와 같은 관계는 마디도열병이나 이삭목도열병의 발생보다도 잎도열병 발생에 있어서 더욱 뚜렷하게 나타난다. 시비수준이 낮은 경우에도 마디도열병이냐 목도열병이 상당히 많이 발생하며 시비수준이 높은 경우의 마디 또는 이삭목도열병의 발생과 차이가 크지 않았다. 따라서 시비수준을 조절하므로서 마디 또는 목도열병을 회피시킨다는 것은 불가능할지 모르며 또한 잎도열병의 발생상으로부터 목도열병을 예찰한다는 것도 곤란한 일이라 생각된다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2000년도 추계 학술발표회
• /
• pp.29.2-29
• /
• 2000