• The Plant Pathology Journal
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• 제32권4호
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• pp.300-310
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• 2016

Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants according to disease severity, we inoculated plants with different cell densities of P. cichorii using dipping and syringe infiltration methods. High-dose inocula (${\geq}10^6cfu/ml$) induced evident necrotic lesions within one day that corresponded to bacterial growth in the infected tissues. Among the chlorophyll fluorescence parameters analyzed, changes in quantum yield of PSII (${\Phi}PSII$) and non-photochemical quenching (NPQ) preceded the appearance of visible symptoms, but maximum quantum efficiency of PSII ($F_v/F_m$) was altered well after symptom development. Visible/near infrared and chlorophyll fluorescence hyperspectral images detected changes before symptom appearance at low-density inoculation. The results of this study indicate that the P. cichorii infection severity can be detected by chlorophyll fluorescence assay and hyperspectral images prior to the onset of visible symptoms, indicating the feasibility of early detection of diseases. However, to detect disease development by hyperspectral imaging, more detailed protocols and analyses are necessary. Taken together, change in chlorophyll fluorescence is a good parameter for early detection of P. cichorii infection in tomato plants. In addition, image-based visualization of infection severity before visual damage appearance will contribute to effective management of plant diseases.

• The Plant Pathology Journal
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• 제35권2호
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• pp.112-124
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• 2019

Barley worldwide is affected seriously by Fusarium seedling blight (FSB) and Fusarium head blight (FHB) diseases caused by the Fusarium species. The objective of this study was to facilitate the resistance of hulled and hull-less barley at different growth stages to F. culmorum according to direct parameters: disease rating (DR), fresh weight of leaves and roots, kernel weight per spike, kernel number per spike, plump kernels, and indirect parameters - chlorophyll a fluorescence (CF). Plate assay, greenhouse and field tests were performed on 30 spring barley doubled haploid (DH) lines and their parents infected with Fusarium culmorum. Direct parameters proved that hulled genotypes show less symptoms. Most studied chlorophyll a fluorescence (CF) parameters (apart from DIo/CS - amount of energy dissipated from PSII for laboratory test, TRo/CS - amount of excitation energy trapped in PSII reaction centers, ETo/CS - amount of energy used for electron transport and RC/CS - number of active reaction centres in the state of fully reduced PSII reaction center in field experiment) were significantly affected by F. culmorum infection. In all experiments, hulled genotypes had higher values of CF parameters compared to hull-less ones. Significant correlations were detected between direct and indirect parameters and also between various environments. It was revealed that ABS/CS, TRo/CS, and RC/CS have significant positive correlation in greenhouse test and field experiment. Significant correlations suggest the possibility of applying the CF parameters in selection of barley DH lines resistant to F. culmorum infection.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• 한국작물학회지
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• 제65권2호
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• pp.113-123
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• 2020

본 논문은 과산화수소 엽면 처리를 통해 수수에서 한발 스트레스 완화 효과가 있는지 알아보기 위하여 과산화수소 처리에 따른 생육 및 생리적 특성 변화와 단백질 변화를 분석하였다. 1. 포장 실험에서 한발 스트레스는 수수 생장을 감소시켰으나, 과산화수소 처리구에서는 과산화수소 무처리구보다 생육이 우수하였다. 또한 한발 조건에서 과산화수소 처리는 무처리에 비해 수량 관련 형질들의저하를 막는 효과를 보였다. 2. 엽 녹색도(SPAD) 및 엽록소 형광(Fv/Fm), 광합성 형질 조사에서 과산화수소 처리가 과산화수소 무처리보다 높았고, 포장 실험에서 엽내 과산화수소 함량은 적습+H₂O₂ 처리가 적습+H₂O 처리보다 과산화수소 함량이 227.8 µmol·g^-1 높았고, 한발 조건에서 엽내 과산화수소 함량은 한발+H₂O₂ 처리가 한발+H₂O 처리보다 16.7 µmol·g^-1으로 낮았다. 3. 한발 조건에서 과산화수소 처리는 여러 단백질의 발현을 변화시켰으며, 특히 광합성 관련 단백질인 ATP synthase deltal chain, cytochrome b6-f complex iron-sulfur subunit, ATP synthase subunit gamma, putative uncharacterized protein Sb02g002690, Sb07g027500와 Superoxide 라디칼을 제거해주는 superoxide dismutase가 증가한 것을 확인하였다. 그리고 단백질 보호와 복원에 관련된 heat shock protein의 발현 증가도 확인되었다. 종합적으로 과산화수소 엽면 처리가 한발 하에서 광합성 관련 단백질의 발현을 증가와 기공 개도를 높여 광합성 능력을 향상시켰다. 특히 엽내에 축적될 수 있는 활성산소종을 제거하는 항산화 능력이 높아져 한발 스트레스 대한 내성을 높여 수수의 생육과 수량성 저하가 억제되는 것을 확인할 수 있었다.