• The Plant Pathology Journal
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• v.34 no.6
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• pp.499-505
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• 2018

Huanglongbing (HLB, Citrus greening disease) is one of the most devastating diseases that threaten citrus production worldwide. Although HLB presents systemically, low titer and uneven distribution of these bacteria within infected plants can make reliable detection difficult. It was known loop-mediated isothermal amplification (LAMP) method has the advantages of being highly specific, rapid, efficient, and laborsaving for detection of plant pathogens. We developed a new LAMP method targeting gene contained tandem repeat for more rapid and sensitive detection of Candidatus Liberibacter asiaticus (CLas), putative causal agent of the citrus huanglongbing. This new LAMP method was 10 folds more sensitive than conventional PCR in detecting the HLB pathogen and similar to that of real-time PCR in visual detection assay by adding SYBR Green I to mixture and 1% agarose gel electrophoresis. Positive reactions were achieved in reaction temperature 57, 60 and $62^{\circ}C$ but not $65^{\circ}C$. Although this LAMP method was not more sensitive than real-time PCR, it does not require a thermocycler for amplification or agarose gel electrophoresis for resolution. Thus, we expect that this LAMP method shows strong promise as a reliable, rapid, and cost-effective method of detecting the CLas in citrus and can be applied for rapid diagnosis is needed.

• Research in Plant Disease
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• v.24 no.4
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• pp.342-347
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• 2018

Bacterial canker caused by Clavibacter michiganensis is considered to be one of the most serious diseases, leading to economic damage to tomato worldwide. Diagnosis of the bacterial canker on tomato is known to be difficult because the causal pathogen is slow-growing on artificial media as well as causes latent infection in tomato. In this study, as a less time-consuming method, a specific primer set was newly designed for rapid detection of C. michiganensis. The method presented here is so simple, easy, and fast that it can be useful and practical in direct detection of the bacterial canker pathogen from tomato plants.

• Ecology and Resilient Infrastructure
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• v.6 no.2
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• pp.128-135
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• 2019

This study evaluates the effect of dissolved effluent organic matter (SE-dEfOM) from sewage wastewater treatment plants on the adsorption and estrogenic activity of bisphenol A (BPA). Specific ultraviolet absorbance and fluorescence index analyses indicated that SE-dEfOM was mainly microbially derived non-humic substances differed from Suwannee River natural organic matter (SR-NOM) as reference. Both Langmuir and Freundlich models successfully explained the adsorption of BPA onto both SE-dEfOM and SR-NOM. Additionally, the SE-dEfOM showed higher binding capacities and affinities for BPA than those of SR-NOM, resulting in better reduction of the estrogenic activity of BPA. These findings suggest that the binding and toxicity of BPA are largely dependent on the source of organic matters.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.645-653
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• 2019

Background: Cytochrome P450 enzymes catalyze a wide range of reactions in plant metabolism. Besides their physiological functions on primary and secondary metabolites, P450s are also involved in herbicide detoxification via hydroxylation or dealkylation. Ginseng as a perennial plant offers more sustainable solutions to herbicide resistance. Methods: Tissue-specific gene expression and differentially modulated transcripts were monitored by quantitative real-time polymerase chain reaction. As a tool to evaluate the function of PgCYP736A12, the 35S promoter was used to overexpress the gene in Arabidopsis. Protein localization was visualized using confocal microscopy by tagging the fluorescent protein. Tolerance to herbicides was analyzed by growing seeds and seedlings on Murashige and Skoog medium containing chlorotoluron. Results: The expression of PgCYP736A12 was three-fold more in leaves compared with other tissues from two-year-old ginseng plants. Transcript levels were similarly upregulated by treatment with abscisic acid, hydrogen peroxide, and NaCl, the highest being with salicylic acid. Jasmonic acid treatment did not alter the mRNA levels of PgCYP736A12. Transgenic lines displayed slightly reduced plant height and were able to tolerate the herbicide chlorotoluron. Reduced stem elongation might be correlated with increased expression of genes involved in bioconversion of gibberellin to inactive forms. PgCYP736A12 protein localized to the cytoplasm and nucleus. Conclusion: PgCYP736A12 does not respond to the well-known secondary metabolite elicitor jasmonic acid, which suggests that it may not function in ginsenoside biosynthesis. Heterologous overexpression of PgCYP736A12 reveals that this gene is actually involved in herbicide metabolism.

• Journal of the Korean Society of Safety
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• v.34 no.3
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• pp.96-101
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• 2019

Chemicals Control Act have been strengthened to control more safely hazardous chemicals from 2015. In particular, the standards for the installation and management of handling facilities was enhanced with specific regulations depending on type of the facilities and the hazardous chemicals. However, some standards for handling facilities caused difficulties in implementing the strengthened standards due to various field conditions, such as lack of physical space. The Ministry of Environment is implementing Safety Assessment System (SAS) to solve these problems since 2018. However, many plants have difficulties in preparing alternative methods to pass the safety evaluation. The purpose of this study was to review and analyze the SAS and to suggest alternative measures in terms of management and technical aspects through the case study of hydrochloric acid storage tanks. The following safety solutions were suggested for handling facilities that had insufficient the space and capacity for the retaining wall due to physical space. Firstly, insufficient space was resolved by introducing equipment relocation or demolition, and retaining wall expansion. Secondly, the wall of the surrounding buildings was used as an alternative to the retaining wall with additional chemical resistant treatment. Finally, sensor installation and facility inspection were suggested as ways to improve chemical safety. Therefore, improvement of chemical accident prevention system is required not only in terms of facilities supplementation but also management aspect. The results of this study are expected to be available for similar facilities and will be based on the preparation of additional safety assessment as alternatives measures in the future.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.320-331
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• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• Entomological Research
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• v.48 no.5
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• pp.384-389
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• 2018

Aphis gossypii Glover is an important insect pest that functions as a viral vector and mediates approximately 45 different viral diseases. As part of a strategy for control of A. gossypii, we investigated the functions of genes using RNAi. To this end, a cDNA library was constructed for various genes and for selecting appropriate targets for RNAi mediated silencing. The cDNA library was constructed using the Gateway cloning system with site-specific recombination of bacteriophage ${\lambda}$. It was used to carry out single step cloning of A. gossypii cDNAs. As a result, a cDNA library with a titer of $8.4{\times}10^6$ was constructed. Since the sequences in this library carry att sites, they can be cloned into various binary vectors. This library will be of value for various studies. For later screening of selected genes, it is planned to clone the library into virus-induced gene silencing (VIGS) vectors, which makes it possible to analyze gene function and allow subsequent transfection of plants. Such transfection experiments will allow testing of RNAi-induced insecticidal activity or repellent activity to A. gossypii, and result in the identification of target genes. It is also expected that the constructed cDNA library will be useful for analysis of gene functions in A. gossypii.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.909-917
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• 2018

Quercetin and its glycoside derivatives were identified and quantified using high-performance liquid chromatograph (HPLC) and liquid chromatograph/mass spectrometer/mass spectrometer (LC/MS/MS) in the leaves, flowers, and fruits of 22 Malus genotypes. In all genotypes, small amounts of quercetin aglycone were present, with water-soluble glycoside forms were the most abundant in different Malus plant tissues, including quercetin-3-galactoside, quercetin-3-rutinoside, quercetin-3-glucoside, quercetin-3-xyloside, quercetin-3-arabinoside, and quercetin-3-rhamnoside. Among these six quercetin glycosides, quercetin-3-galactoside was the common form in Malus plants, except in the leaves and flowers of M. ceracifolia and M. magdeburgensis, and in the fruits of M. micromalus 'Haihong Fruit', where there was a higher concentration of quercetin3-glucoside. Among the different tissues tested, leaves contained the highest concentration of quercetin and its glycosides, while fruits contained the lowest concentrations of these compounds. Among the genotypes we analyzed, no specific genotype consistently contained the highest concentration of quercetin and its glycoside derivatives. M. domestica 'Honeycrisp' had the highest total compound concentration (approximately $1600mg\;kg^{-1}$), whereas M. hupehensis contained the lowest in its fruits. In contrast, the concentration of total quercetin and its glycosides was more than $5000mg\;kg^{-1}$ in the leaves of eight genotypes and greater than $2500mg\;kg^{-1}$ in the flowers of seven species. In general, the concentration of quercetin and its glycoside derivatives depended on the species and tissue type. These results may provide useful information for the evaluation and selection of edible Malus fruits and the materials for quercetin glycoside extraction.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.22-22
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• 2019

Green stem disorder (GSD) of soybean (Glycine max (L.) Merr.) is characterized by delayed senescence of stems with normal pod ripening and seed maturation (Hobbs, 2006). GSD complicates harvesting of soybeans by significantly increasing the difficulty in cutting the affected plants. There is also the potential for moisture in the stems to be scattered on the seed, reducing the grade and storability of the seed. Not only the cause of GSD is yet unknown, but also GSD cannot be evaluated until maturity, therefore the method to evaluate GSD in early growth stage with high sensitivity is necessary. In previous studies, it has been reported that vegetative storage protein (VSP) accumulates and the syndrome of GSD appears in soybean after depod treatment (Fischer, 1999). Soybean VSP is a storage protein which is abundant in young sink leaves and degraded during seed fill (Wittenbach, 1982). Hence, we have established a system to quantify VSP of high sensitivity by using standard protein made by genetically transformed E. coli and specific antibody against VSP, and studied the relationship between VSP and GSD, by depod experiment and drought/excess wet experiments. The result of depod experiment with the cultivar 'Yukihomare' was the same with the previous studies, VSP accumulated much more than control and the syndrome of GSD appeared in soybean in depod treatment. Drought and excess wet had different impact on GSD. Excess wet caused GSD of the cultivar 'Tachinagaha (GSD susceptible)', while drought caused a little syndrome of GSD in the cultivar 'Touhoku 129 (GSD resistant)'. The accumulation of VSP differed between the two cultivars over time. In conclusion, the accumulation of VSP came along with the emergence of GSD. Different cultivars showed different response to drought and excess wet. In the future, it is expected that the dynamics of VSP will be elucidated in detail, leading to the development of early diagnosis technology for green stem disorder and the elucidation of mechanism of soybean GSD.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.12-17
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• 2021

Saponarin found in young barley sprouts has a variety of beneficial biological and pharmacological properties, including antioxidant, hypoglycemic, antimicrobial, and hepatoprotective activities. Our previous work demonstrated that saponarin content was correlated with the expression levels of three biosynthetic pathway genes [chalcone synthase (HvCHS1), chalcone isomerase (HvCHI), and UDP-Glc:isovitexin 7-O-glucosyltransferase (HvOGT1)] in young barley seedlings under various abiotic stress conditions. In this study, we investigated the saponarin content and expression levels of three saponarin biosynthetic pathway genes in hulled and hulless domestic barley cultivars. In the early developmental stages, some hulled barley cultivars (Kunalbori1 and Heukdahyang) had much higher saponarin contents than did the hulless barley cultivars. An RNA expression analysis showed that in most barley cultivars, decreased saponarin content correlated with reduced expression of HvCHS1 and HvCHI, but not HvOGT1. Heat map analysis revealed both specific increases in HvCHS1 expression in certain hulled and hulless barley cultivars, as well as general changes that occurred during the different developmental stages of each barley cultivar. In summary, our results provide a molecular genetic basis for the metabolic engineering of barley plants to enhance their saponarin content.