• Journal of Photoscience
• /
• v.7 no.2
• /
• pp.53-58
• /
• 2000

We performed the cloning of a chalcone synthase (CHS) gene, the key enzyme in the anthocyanin biosynthesis, from the cDNA library constructed with grape suspension cells irradiated UV-B. The PCR fragment was used to cloning the CHS gene. One CHS cDNA clone containing an open reading frame and a partial stilbene synthase (STS)cDNA, the stilbene-type phytoalexin, were isolated. The CHS cDNA clone (VCHS) showed 87% sequence homology with VvCHS (V.vinifea) and 72.3% identity with VSTSY(V.vinifea). its amino acid sequences were longer than any other CHS genes as 454 residues. Two genes were weakly expressed in white light irradiated cells, but highly induced in UV-B irradiated condition during 32 hours. Interestingly, the STS was quickly and abundantly expressed from 2 hours when supplemented with jasmonic acid (JA) and the maximum expression was observed at 4 hours and then gradually decreased. But, the additional UV-B or white light quickly degraded the STS expression than only JA treated grape suspension cells. The CHS also was rapidly induced with JA and the synergistical effect was observed at the addigional light treatment of UV-B or white light. These results are indicated that CHS and STS have different response mechanisms against the environmental stresses.

• Korean Journal of Breeding Science
• /
• v.40 no.4
• /
• pp.422-429
• /
• 2008

In this work, we analyzed the activity of control enzymes of flower color biosynthesis, chalcone synthase (CHS) and flavanone 3-hydroxylase (FHT) using biochemical and enzymological methods in Lilium longiflorum and 11 Lilium cultivars. The results obtained are as follows ; Naringenin (NAR) was synthesized in all Lilium cultivars tested by the catalytic activity of CHS which used malonyl-CoA and 4-coumaryol-CoA as substrates. Substrate-specific activity of CHS was observed because eridictiol (ERI), which uses caffeoyl-CoA as a substrate, was not detected in tested cultivars. In next step, dihydroflavone product was synthesized by FHT using flavanones as a substrate. FHT synthesized dihydrokaempferol (DHK) by using NAR as substrates. A remarkable activity of FHT was observed in other 11 cultivars.

• Journal of Plant Biotechnology
• /
• v.46 no.4
• /
• pp.247-254
• /
• 2019

Flavonoids are widely distributed secondary metabolites in plants that have a variety biological functions, as well as beneficial biological and pharmacological activities. In barley (Hordeum vulgare L.), for example, high levels of saponarin accumulate during primary leaf development. However, the effect of saponarin biosynthetic pathway genes on the accumulation of saponarin in barley is poorly understood. Accordingly, the aim of the present study was to examine the saponarin contents and expression levels of saponarin biosynthetic pathway genes [chalcone synthase (CHS), chalcone isomerase (CHI), and UDP-Glc:isovitexin 7-O-glucosyltransferase (OGT)] during early seedling developmental and under several abiotic stress conditions. Interestingly, the upregulation of HvCHS, HvCHI, and HvOGT during early development was associated with saponarin accumulation during later stages. In addition, exposure to abiotic stress conditions (e.g., light/dark transition, drought, and low or high temperature) significantly affected the expression of HvCHS and HvCHI but failed to affect either HvOGT expression or saponarin accumulation. These findings suggested that the expression of HvOGT, which encodes an enzyme that catalyzes the final step of saponarin biosynthesis, is required for saponarin accumulation. Taken together, the results of the present study provide a basis for metabolic engineering in barley plants, especially in regards to enhancing the contents of useful secondary metabolites, such as saponarin.

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

• Journal of Microbiology
• /
• v.43 no.6
• /
• pp.475-486
• /
• 2005

Fungal secondary metabolites constitute a wide variety of compounds which either playa vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. Owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. A majority of the fungal secondary metabolic genes are classified as type I polyketide synthases (PKS) which are often clustered with other secondary metabolism related genes. In this review we discuss on the significance of our recent discovery of chalcone synthase (CHS) genes belonging to the type III PKS superfamily in an industrially important fungus, Aspergillus oryzae. CHS genes are known to playa vital role in the biosynthesis of flavonoids in plants. A comparative genome analyses revealed the unique character of A. oryzae with four CHS-like genes (csyA, csyB, csyC and csyD) amongst other Aspergilli (Aspergillus nidulans and Aspergillus fumigatus) which contained none of the CHS-like genes. Some other fungi such as Neurospora crassa, Fusarium graminearum, Magnaporthe grisea, Podospora anserina and Phanerochaete chrysosporium also contained putative type III PKSs, with a phylogenic distinction from bacteria and plants. The enzymatically active nature of these newly discovered homologues is expected owing to the conservation in the catalytic residues across the different species of plants and fungi, and also by the fact that a majority of these genes (csyA, csyB and csyD) were expressed in A. oryzae. While this finding brings filamentous fungi closer to plants and bacteria which until recently were the only ones considered to possess the type III PKSs, the presence of putative genes encoding other principal enzymes involved in the phenylpropanoid and flavonoid biosynthesis (viz., phenylalanine ammonia-lyase, cinnamic acid hydroxylase and p-coumarate CoA ligase) in the A. oryzae genome undoubtedly prove the extent of its metabolic diversity. Since many of these genes have not been identified earlier, knowledge on their corresponding products or activities remain undeciphered. In future, it is anticipated that these enzymes may be reasonable targets for metabolic engineering in fungi to produce agriculturally and nutritionally important metabolites.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1998.07a
• /
• pp.79-82
• /
• 1998

White and blue/white varieties of Torenia hybrida cv. Summerwave (SWB) were successfully obtained from the blue variety of by cosuppressing gene expression of two of the enzymes involved in anthocyanin biosynthesis; chalcone synthase (CHS) and dihydroflavonol 4-reductase (DFR). Such molecular brceding is the only precise and efficient way to widen the flower color variation of SWB due to its male and female sterility. Flower color and the degree of suppression varies depending on the transgenic lines. The dorsal and ventral petal lobes and corolla tube consistently lose anthocyanins prior to lateral petal lobes. A pink variety was also obtained by cosuppressing the flavonoid 3`5`-hydroxylase (F3`5`H) gene. Yellow torenia was obtained from T-33, an in-house cultivar that contained both carotenoids and anthocyanins, by blockage of anthocyanin biosynthesis with cosuppressing CHS or DFR genes.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.11
• /
• pp.1536-1541
• /
• 2014

Pinocembrin is a flavonoid that exhibits diverse biological properties. Although the major source of pinocembrin is propolis, it can be synthesized biologically using microorganisms such as Escherichia coli, which has been used to synthesize diverse natural compounds. Pinocembrin is synthesized from phenylalanine by the action of three enzymes; phenylalanine ammonia lyase (PAL), 4-coumarate:CoA ligase (4CL), and chalcone synthase (CHS). In order to synthesize pinocembrin from glucose in Escherichia coli, the PAL, 4CL, and CHS genes from three different plants were introduced into an E. coli strain. Next, we tested the different constructs containing 4CL and CHS. In addition, the malonyl-CoA level was increased by overexpressing acetyl-CoA carboxylase. Through these strategies, a high production yield (97 mg/l) of pinocembrin was achieved.

• Journal of Plant Biotechnology
• /
• v.36 no.4
• /
• pp.415-422
• /
• 2009

This study aimed to develop carnation cultivars with new coloring system. We used four genes of Petunia hybrida - chalcone synthase (CHS), flavanone 3-hydroxylase (FHT), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) - as probes, in order to isolate four genes from carnations (Dianthus Caryophyllus). The isolated genes were used as probes in order to select mutants out of collected carnations, using Northern blot analysis. The Northern blot analysis revealed 10 DFR mutants - Gumbyul, Eunbyul, Ballatyne, Crystal, Eugenia, Koreno, Imp. White Sim, West Crystal, White Alpine, and White Charotte. Six among the selected 10 cultivarswere excluded from the target cultivars, because Eugenia, Imp. White Sim, and White Alpine were proved to be double mutants of DFR and ANS, Koreno was considered to be a double mutant of DFR and CHS, and Gumbyul and Ballatyne were proved to be double mutants of DFR and CHI (Chalcone isomerase). Consequently, we selected five DFR mutants, including Virginie, which was already selected as a DFR mutant. Finally, we measured DFR activities in order to confirm the selection, and the results showed that all of the five cultivars - Eunbyul, Crystal, West Crystal, White Charotte, and Virginie - had got no DFR activity.

• Journal of Life Science
• /
• v.29 no.10
• /
• pp.1055-1061
• /
• 2019

Sarracenia purpurea as a carnivorous plant in the family Sarraceniaceae is known to require strong light for its growth and to absorb nutrients from the decomposed molecules of insects that are attracted by color, sweet juice, and the like. S. purpurea grew greenish in whole body under weak light conditions, while the whole of the insectivorous sac including leaves, is changed to dark red under strong light conditions. The phenomenon of reddish S. purpurea is thought to be related to the flavonoid pigment anthocyanin. Interestingly, the color change was not observed when S. purpurea was grown in a growth condition with abundant nitrogen fertilizer. The expression levels of anthocyanin contents and biosynthesis-related genes were strongly correlated with light intensity and nitrogen fertilizer. The anthocyanin content in the strong light condition ($240{\mu}mol\;m^{-2}s^{-1}$) was 6.15 times higher than that in the weak light ($40{\mu}mol\;m^{-2}s^{-1}$). In contrast, the anthocyanin contents were not significantly changed when 0.8% urea solution was supplied as nitrogen fertilizer. Consistently, CHALCONE SYNTHASE (CHS) gene was up-regulated by strong light and down-regulated by nitrogen fertilizer. These results suggest that the environmental changes of light and nitrogen in soil regulate the anthocyanin content in S. purpurea.

• Journal of Life Science
• /
• v.18 no.2
• /
• pp.234-240
• /
• 2008

Anthocyanin synthesis in strawberry (Fragaria x ananassa cv Maehyang) begins approximately 26 days postflowering and continued throughout fruit ripening. A set of cDNA clones encoding the anthocyanin biosynthetic enzymes were isolated from strawberry. A pair of primers were designed for polymerase chain reaction (PCR) through the comparison of the nucleotide sequences of homologous genes from diverse plants. Reverse transcriptase-PCRs were performed using cDNA synthesized from ripe fruit total RNA and the primers corresponding to each gene. Eight genes of the anthocyanin pathway were cloned and confirmed by sequencing to code for phenylalanine ammonia lyase (PAL), 4-cummarate CoA ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidine synthase (ANS), UDP-glucose:flavonoid-3-O-glucosyl-transferase (UFGT). Northern analyses showed that the corresponding genes were differentially expressed during the fruit development process. All genes except PAL were predominantly expressed in fruit. Expression of PAL, DFR and ANS was detected 10 days postflowering at the early stage of fruit development, declined for a while and sharply increased 22 days postflowering then showed a peak 34 days postflowering. The other genes, however, were not expressed up to 22 or 30 days postflowering when the initial fruit ripening events occur at the time of initiation of anthocyanin accumulation. The onset of anthocyanin synthesis in ripening strawberry coincides with a coordinated induction of the anthocyanin pathway genes, suggesting the involvement of regulatory genes. We propose that at least two different regulatory mechanisms playa role in the biosynthesis of anthocyanin during color development of strawberry.