• Horticultural Science & Technology
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• v.29 no.6
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• pp.511-522
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• 2011

Flower color is one of the main target traits in the flower breeding. Recently, technological advances in genetic engineering have been successfully reported the flower colors, such as blue roses and blue carnations that are impossible to develop by traditional breeding. Accumulated knowledge-based approaches for flavonoid biosynthesis enabled to introduce novel and unique colors into flowers. These flower color modifications have been made through the regulation of flavonoid metabolic pathway - control of endogenous gene expression and introduction of foreign genes to produce novel and specific flavonoids - and the introduction of transcription factors that are known to regulate sets of genes being involving in the flavonoid biosynthetic pathway. More empirical regulation of the flavonoids metabolism requires the understanding for regulatory mechanism of intrinsic flavonoids depending on the flower crops and the very sophisticated control of flavonoid metabolic flow. In this review, we summarized successful examples of flower color modification. It might be useful to deduce the strategy for the creation of exquisite colors in flower plants.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.141-141
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• 2003

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1442-1448
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• 2015

The flavonoid apigenin and its O-methyl derivative, genkwanin, have various biological activities and can be sourced from some vegetables and fruits. Microorganisms are an alternative for the synthesis of flavonoids. Here, to synthesize genkwanin from tyrosine, we first synthesized apigenin from p-coumaric acid using four genes (4CL, CHS, CHI, and FNS) in Escherichia coli. After optimization of different combinations of constructs, the yield of apigenin was increased from 13 mg/l to 30 mg/l. By introducing two additional genes (TAL and POMT7) into an apigenin-producing E. coli strain, we were able to synthesize 7-O-methyl apigenin (genkwanin) from tyrosine. In addition, the tyrosine content in E. coli was modulated by overexpressing aroG and tyrA. The engineered E. coli strain synthesized approximately 41 mg/l genkwanin.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.365-366
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• 2007

• Journal of Life Science
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• v.20 no.2
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• pp.292-297
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• 2010

Anthocyanin, a phenolic compound, is a pigment that shows blue or red color in the fruit, petal and other tissues. It is an important factor in grape berry skin pigment and accumulates only in the skin. This skin-specific accumulation of anthocyanin has been reported to be regulated by the ufgt gene which encodes UDP-glucose: flavonoid 3-O-glucosyltransferase that participates in the biosynthesis of anthocyanin. The ufgt gene is expressed only in berry skin, while the other genes involved in the biosynthetic pathway are expressed in both skin and flesh tissues. In order to determine whether anthocyanin accumulation is primarily regulated by compartment of UFGT, a ufgt cDNA clone was isolated from grape berry, its open reading frame was ligated in pBI121 vector in either a sense or an antisense orientation under the control of the CaMV35S promoter and the recombinant constructs were incorporated into tobacco plants. Several transgenic lines were selected and characterized to determine the level of expression of the grapevine ufgt transcript and endogenous homologs of tobacco. Compared to the wild-type, the amount of anthocyanins in sense transgenic plants increased by 44%, while the amount of anthocyanins in antisense transgenic plants decreased by 88%. In addition, the color of flowers became intense in the sense transgenic plants. These results suggest that over-expression or repression of the ufgt gene affected the accumulation of anthocyanin in flowers of tobacco.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1737-1746
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• 2013

IbMYB1, a transcription factor (TF) for R2R3-type MYB TFs, is a key regulator of anthocyanin biosynthesis during storage of sweet potatoes. Anthocyanins provide important antioxidants of nutritional value to humans, and also protect plants from oxidative stress. This study aimed to increase transgenic potatoes' (Solanum tuberosum cv. LongShu No.3) tolerance to environmental stress and enhance their nutritional value. Transgenic potato plants expressing IbMYB1 genes under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter (referred to as SM plants) were successfully generated through Agrobacterium-mediated transformation. Two representative transgenic SM5 and SM12 lines were evaluated for enhanced tolerance to salinity, UV-B rays, and drought conditions. Following treatment of 100 mM NaCl, seedlings of SM5 and SM12 lines showed less root damage and more shoot growth than control lines expressing only an empty vector. Transgenic potato plants in pots treated with 400 mM NaCl showed high amounts of secondary metabolites, including phenols, anthocyanins, and flavonoids, compared with control plants. After treatment of 400 mM NaCl, transgenic potato plants also showed high DDPH radical scavenging activity and high PS II photochemical efficiency compared with the control line. Furthermore, following treatment of NaCl, UV-B, and drought stress, the expression levels of IbMYB1 and several structural genes in the flavonoid biosynthesis such as CHS, DFR, and ANS in transgenic plants were found to be correlated with plant phenotype. The results suggest that enhanced IbMYB1 expression affects secondary metabolism, which leads to improved tolerance ability in transgenic potatoes.

• KSBB Journal
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• v.28 no.2
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• pp.106-114
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• 2013

Ponciri fructus, the unripe fruits of Poncirus trifoliata, are widely used in oriental traditional medicine as a remedy for inflammation, gastritis, emesis, digestive ulcers, allergy, and dysentery. To study the anti-wrinkle effects of Ponciri fructus extract (PFE) containing flavanone glycosides, PFE was fermented with Ganoderma lucidum mycelia and its biological activities were investigated. In Ponciri fructus extracts fermented with G. lucidum (G-PFE), polyphenol content was $1,021.00{\pm}0.50{\mu}g/mL$ and flavonoid content was $589.41{\pm}0.21{\mu}g/mL$. G-PFE was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and superoxide anion radical by a dose dependent manner, respectively. G-PFE showed higher antioxidant activity than that of PFE. In addition, the photoprotective properties of G-PFE was tested in human dermal fibroblasts (HDF) exposed to UVA radiation. G-PFE inhibited the activity of matrix metalloproteinase-1 (MMP-1) and showed a dose dependent decrease in the expression level of MMP-1. G-PFE also increased collagen biosynthesis in HDF. These results demonstrate that G-PFE could be useful as a potential cosmetic ingredient for anti-wrinkle.

• The Korean Journal of Mycology
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• v.47 no.2
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• pp.153-163
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• 2019

This study was carried out to investigate the feasibility of Salix gracilistyla production for cosmetic use through mycelial fermentation. The efficacy of this method was confirmed by fermentation using the mycelia of Ganoderma lucidum (a representative medicinal mushroom). Total polyphenol and flavonoid content and DPPH radical scavenging activity of S. gracilistyla extract (SGE) were found to be higher than those of G. lucidum fermented S. gracilistyla extract (GLSGE). GLSGE had relatively lower collagenase activity than SGE. However, GLSGE increased HDFn cell viability more potently than SGE, and increased the biosynthesis of type I procollagen. Thus, GLSGE could be used as an anti-aging cosmetic active ingredient. These results indicate that extract fermentation using G. lucidum mycelia can effectively enhance some beneficial effects of functional materials.

• Journal of Applied Biological Chemistry
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• v.52 no.1
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• pp.15-20
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• 2009

Poplar contains various flavonoids including naringenin, kaempferol, myricetin, apigenin, luteolin, rhamnetin, and quercetin. These flavonoids are synthesized from naringenin with various enzymes. However, none of genes from poplar involved in flavonoid biosynthesis have been biochemically characterized. We cloned PFNS I-1 from Populus deltoids by RT-PCR method. The open reading frame of PFNS I-1 consisted of 1,017-bp and it showed high similarity with other FNS genes. The purified recombinant PFNS I-1, expressed in Escherichia coli, catalyzed the reaction from flavanone (naringenin) to flavone (apigenin). The reaction of PFNS I-1 was enhanced by cofactors such as oxoglutarate, $Fe^{2+}$, ascorbate and catalase. Thus, it is concluded that PFNS N-1 encodes a flavone synthase I.

• Molecules and Cells
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• v.41 no.4
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• pp.351-361
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• 2018

Sucrose is a crucial compound for the growth and development of plants, and the regulation of multiple genes depends on the amount of soluble sugars present. Sucrose acts as a signaling molecule that regulates a proton-sucrose symporter, with its sensor being the sucrose transporter. Flavonoid and anthocyanin biosynthesis are regulated by sucrose, and sucrose signaling can affect flavonoid and anthocyanin accumulation. In the present study, we found a Myb transcription factor affecting accumulation of anthocyanin. AtMyb56 showed an increase in its expression in response to sucrose treatment. Under normal conditions, anthocyanin accumulation was similar between Col-0 (wild type) and atmyb56 mutant seedlings; however, under sucrose treatment, the level of anthocyanin accumulation was lower in the atmyb56 mutant plants than in Col-0 plants. Preliminary microarray analysis led to the investigation of the expression of one candidate gene, AtGPT2, in the atmyb56 mutant. The phosphate translocator, which is a plastidial phosphate antiporter family, catalyzes the import of glucose-6-phosphate (G-6-P) into the chloroplast. AtGPT2 gene expression was altered in atmyb56 seedlings in a sucrose-dependent manner in response to circadian cycle. Furthermore, the lack of AtMyb56 resulted in altered accumulation of maltose in a sucrose-dependent manner. Therefore, the sucrose responsive AtMyb56 regulates AtGPT2 gene expression in a sucrose-dependent manner to modulate maltose and anthocyanin accumulations in response to the circadian cycle.