• Molecules and Cells
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• v.23 no.2
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• pp.161-169
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• 2007

We identified two alternatively spliced variants of the peroxisomal targeting signal 1 (PTS1) receptor protein Pex5ps in monocot (rice, wheat, and barley) but not in dicot (Arabidopsis and tobacco) plants. We characterized the molecular and functional differences between the rice (Oryza sativa) Pex5 splicing variants OsPex5pL and OsPex5pS. There is only a single-copy of OsPEX5 in the rice genome and RT-PCR analysis points to alternative splicing of the transcripts. Putative light-responsive cis-elements were identified in the 5' region flanking OsPEX5L and Northern blot analysis demonstrated that this region affected light-dependent expression of OsPEX5 transcription. Using the pex5-deficient yeast mutant Scpex5, we showed that OsPex5pL and OsPex5pS are able to restore translocation of a model PTS1 protein (GFP-SKL) into peroxisomes. OsPex5pL and OsPex5pS formed homo-complexes via specific interaction domains, and interacted with each other and OsPex14p to form hetero-complexes. Although overexpression of OsPex5pL in the Arabidopsis pex5 mutant (Atpex5) rescued the mutant phenotype, overexpression of OsPex5pS only resulted in partial recovery.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.343-348
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• 2007

Starch contents play important roles in determining the fruit quality. Stawberry accumulates starch in the early stages and then mobilized into soluble sugars during fruit ripening. To date the molecular studies on the ADP-glucose pyrophosphorylase (AGPase), a key enzyme of starch biosynthesis, were not reported. cDNAs encoding small (FagpS) and large (FagpL1 and FaspL2) AGPase subunits were isolated from strawberry (Fragaria ${\times}$ ananassa Duch. cv. Niyobou). Both FagpS and FagpL1 cDNAs have open reading frames deriving 55-58 kDa polypeptides, where FagpL2 contains a partial fragment. Sequence analyses showed that FagpS has a glutamate-threonine-cysteine-leucine (ETCL) instead of a glutamine-threonine-cysteine-leucine (QTCL) motif found in all the dicot plants except for Citrus. In fruits, FagpS and FagpL1 were expressed in all stages with a little change in the amounts of transcripts. In the case of FagpL2, we were not able to detect any signal from all stages of fruit development and all tissues except for very a weak signal from the leaf. The results indicate that FagpL1 and FagpL2 show ubiquitous and leaf-specific expression patterns, respectively. The studies suggest that the starch contents in strawberry might be controlled by the expression of AGPase gene at both the transcriptional and post-transcriptional levels during fruit development.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.422-431
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• 2016

Plants utilize cytochrome P450, a large superfamily of heme-containing mono-oxygenases, in the synthesis of lignins, UV protectants, pigments, defense compounds, fatty acids, hormones, and signaling molecules. Despite the overwhelming assortment of rice P450 accession numbers in the database, their functional studies are lacking. So far, there is no evidence involving rice P450 in disease immunity. Most of our understanding has been based on other plant systems that are mostly dicot. In this study, we isolated the cytochrome P450 (OsCYP71) in rice, and screened the gene using gain-of-function technique. The full-length cDNA of OsCYP71 was constitutively overexpressed using the 35S promoter. We then explored the functions of OsCYP71 in the rice - Xanthomonas oryzae pv. oryzae pathosystem. Using the gene expression assays, we demonstrate the interesting correlation of PR gene activation and the magnitude of resistance in P450-mediated immunity.

• Asian Journal of Turfgrass Science
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• v.10 no.2
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• pp.125-142
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• 1996

Crassulacean acid metaholism (CAM) was investigated in leaves and stems of the succulent $C_4$dicot Portulaca oleracea L. Under 14-hour days, stem tissues showed much greater fluctuation of acidity than leaf tissues. But leaf and stem tissues showed almost same CAM-like pattern of acid fluctuation under 8-hour days. Stem tissues of R oleracea grown under the naturai environment showed high CAM activity, but no CAM activity was seen in leaves of those plants. In the naturally growing plants, the rapid acidification was seen in intact stems at dawn, but defoliated stems showed only a gradual increase. RuBP carlboxylase activity was very high at 2:00 P.M. in both leaves and stems. However, its activity at 1:00 A.M. and 5:30 AM. was hardly detected. particularly, activity of PEP carboxylase in leaves was very high in the early morning, though that in stem tissues was little. These results indicate that $CO_2$ passed through open stomata at dawn may be assimilated by PEP carboxylase in leaves, and then $C_4$ products move to stems. The levels of nitrate concentration and of nitrate reductase were higher in stems than in leaves. The levels were also higher in the light than in the dark. It would be suggested that considerable amount of nitrate absorbed from roots ho assimilated in stems, and nitrate transferred to leaves via stem tissues be reduced there. Key words: Portalaca oleracea, Cactus, Photosynthesis, Nitrogen assimilation, Crassulacean acid metabolism (CAM).

• Journal of Environmental Science International
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• v.25 no.9
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• pp.1289-1297
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• 2016

The walls of guard cells have many specialized features. Guard cells are present in the leaves of bryophytes, ferns, and almost all vascular plants. However, they exhibit considerable morphological diversities. There are two types of guard cells: the first type is found in a few monocots, such as palms and corn, and the other is found in most dicots, many monocots, mosses, ferns, and gymnosperms. In corns, guard cells have a characteristic dumbbell shape with bulbous ends. Most dicot and monocot species have kidney-shaped guard cells that have an elliptical contour with a pore at its center. Although subsidiary cells are common in species with kidney-shaped stomata, they are almost always absent in most of the other plants. In this study, there were many different stomatal features that were associated with kidney-shaped guard cells, but not dumbbell shaped guard cells, which are present in most grasses, such as cereals. Each plant investigated exhibited different characteristic features and most of these plants had kidney-shaped guard cells. However, the guard cells of Chamaesyce supina Mold, were often more rectangular than kidney-shaped. In contrast, Sedum sarmentosum guard cells were of the sink ensiform type and in Trifolium repens, the guard cells exhibited a more rhombic shape. Therefore, kidney-shaped guard cells could be divided into a number of subtypes that need to be investigated further.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.59-65
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• 2002

ADP-glucose pyrophosphorylase (AGPase) catalyzes the key regulatory step in starch biosynthesis. Two cDNA clones encoding AGPase subunits were isolated from the leaf cDNA library of Chinese cabbage (Brassica campestris L. spp. pekinensis). One was designated as BCAGPS for the small subunit and the other as BCAGPL for the large subunit. Both cDNAs have uninterrupted open reading frames deriving 57 kDa and 63 kDa polypeptides for BCAGPS and BCAGPL, respectively, which showed significant similarity to those of other dicot plants. Also, However, the deduced amino acid sequence of BCAGPL has a unique feature. That is, it contains two regions (Rl and R2) lacking in all other plant enzymes. This is the first report of BCAGPL containing Rl and R2 among plant large subunits as well as small subunits. From the genomic Southern analysis and BAC library screening, we inferred the genomic status of BCAGPS and BCAGPL gene.

• Journal of Plant Biology
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• v.37 no.3
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• pp.371-380
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• 1994

To determine the patterns and the levels of expression of the cauliflower mosaic virus (CaMV 35S) promoter and the rice actin 1 (Act1) promoter in rice, transgenic rice plants containing CaMV 35S-$\beta$-glucuronidase (GUS) and Act1-GUS constructs were generated and examined by fluorometric and histochemical analyses. The fluorometric analysis of stably transformed calluses showed that the activity of the rice Act1 promoter was stronger than that of the CaMV 35S promoter in rice cells. In a histochemcial study of the transgenic rices, it was shown that the GUS activity directed by the CaMV 35S promoter was localized mainly in parenchymal cells of vascular tissues of leaves and roots and mesophyll cells of leaves. These results are similar to those of potato, a dicot plant. In contrast, rice plant transformed with Act1-GUS fusion construct revealed strong GUS activity in parenchymal cells of vascular tissue, mesophyll cells, epidermal cells, bulliform cells, guard subsidiary cells of leaves and most cells of the root, suggesting that the rice Act1 promoter is more constitutive than the CaMV 35S promoter. It was also confirmed that in both types of transgenic rice little or no staining was localized in metaxylen tracheary elements of vascular tissue from leaves or roots. These results indicate that the rice Act1 promoter can be utilized more successfully for expression of a variety of foreign gene in rice than the CaMV 35S promoter.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.318-324
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• 2017

With the development of next-generation sequencing (NGS), a cutting-edge technology, genotype-by-sequencing (GBS) became available at a low cost per sample. GBS makes it possible to customize the process of library preparation to obtain high-quality single nucleotide polymorphisms (SNPs) in the most efficient way. However, a GBS library is hard to construct due to fine-tuning of concentration of each reagent and set-up. The major reason for this is the presence of undigested genomic DNA (gDNA) owing to the efficiency of different restriction enzymes for different species with unknown reasons. Therefore, this proof-concept study is to demonstrate the unpredictable patterns of enzyme digestion from various plants in order to make the reader aware of the caution needed when choosing restriction enzymes for their GBS library preparations. Indeed, no pattern was found for the digestibility of gDNA samples and restriction enzymes in the current study. We suggest that more data should be accumulated on this matter to help researchers who want to apply GBS technologies in a variety of genetic approaches.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.461-468
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• 2008

An endophytic bacterial strain YC5480 producing antifungal and phytotoxic compounds simultaneously was isolated from the surface sterilized root of Artemisia sp. collected at Jinju area, Korea. The bacterial strain was identified as a species of Pseudomonas brassicacearum based on its 16S rRNA gene sequence analysis and physiological and biochemical characteristics. The seed germination and growth of monocot and dicot plants were inhibited by culture filtrate (1/10-strength Tryptic Soy Broth) of the strain. The germination rate of radish seeds in the culture filtrate differed in various culture media. Only 20% of radish seeds germinated in the culture media of 1/2 TSB for 5 days incubation. Mycelial growth of fungal pathogens, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora capsici was also inhibited by the culture filtrate of the strain YC5480. An antifungal compound, KS-1 with slight inhibitory activity of radish seed germination at 1,000 ppm and a seed germination inhibitory compound, KS-2 without suppression of fungal growth were produced simultaneously in TSB. The compounds KS-1 and KS-2 were identified to be 2,4-diacetylphloroglucinol (DAPG) and 2,4,6-trihydroxyacetophenone (THA), respectively.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.52-58
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• 2007

ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide and insecticide by the action of the protoporphyrinogen IX oxidase (Protox IX). The present study was conducted to determine growth responses of plant and insects to ALA, biodegradable biopesticidal substance. In the paddy condition experiment, plant height and shoot fresh weight of barnyardgrass (Echinochloa crus-galli) was more reduced by ALA than rice plants, even though both plant species show great phytotoxicity. Hairy crabgrass (Digitaria sanguinalis), a monocot weed, was more sensitive to ALA at 5mM under upland condition when ALA applied on the foliage, compared with soybean (Glycine max) as a dicot crop. ALA solutions were tested for their insecticidal and larvicidal activities against Spodaptera exigua (Hubner) and Tetranychus urticae Koch. by foliar application and leaf-dipping method. The result showed higher insecticidal activity of ALA at 10mM and its mixture with insecticide luferon against S. exigua. Strongest insecticidal activity against T. urticae was observed from the ALA solution at 10mM 72 days after application. This results show that ALA solution had potent herbicidal and insecticidal activities against agricultural pests even though their activities were lower than those of synthetic pesticides.