• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.309-315
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• 2000

Panax ginseng is an important medicinal plant that has been used worldwide for geriatric, tonic, stomachic, and aphrodisiac treatments. Ginsenosides contained in the ginseng root are the main substances having active functions for human body. The price of ginseng is very expensive due to a complex process of cultivation, and the yield of ginseng is limited, which cannot meet the demand of the increasing market. Researchers have applied plant biotechnology to solve the problems but there are still things to be determined towards ginsenoside production by large-scale adventitious root culture. In this experiment, 5 to 20 liter bioreactors were employed to determine optimal conditions for adventitious root culture and ginsenoside production of Panax gineng. Callus was induced from the ginseng root on MS agar medium containing 1.0 mg. $L^{-1}$ 2,4-D and 0.1 mg. $L^{-1}$ kinetin. Then the callus was cultured on MS agar medium supplemented with 2.0 mg. $L^{-1}$ IBA, 0.1 mg. $L^{-1}$ kinetin, and 30 g. $L^{-1}$ to induce adventitious roots. The maximum root growth and ginsenoside production were obtained in 1/2 MS medium. 2.0 mg. $L^{-1}$ naphthalene acetic acid resulted in greater root growth than 2.0 mg $L^{-1}$ indole-3-butyric acid. Ginsenoside content increased with 2.0 mg. $L^{-1}$ benzyl adenin or kinetin. High concentrations of benzyl adenin (above 3.0 mg. $L^{-1}$ ) decreased the adventitious root growth and ginsenoside productivity. N $H_{4}$$^{+}$ inhibited the ginsenoside accumulation, while high concentrations of $K^{+}$, $Mg_{2}$$^{+}$, and $Ca_{2}$$^{+}$ increased it. N $H_{4}$$^{+}$ at 0.5 and 1.0 times of the normal amount in 3/4 SH medium resulted in the greatest biomass increase, but the highest ginsenoside productivity was obtained when N $O_{3}$$^{-}$ was used as the sole nitrogen source in the medium. Most microelements at high concentrations in the medium inhibited the root growth, but high concentrations of MnS $O_4$enhanced the root growth. Root dry weight increased with increasing sucrose concentrations up to 50 g. $L^{-1}$ , but decreased from 70 g $L^{-1}$ Ginsenoside productivity was maximized at the range of 20 to 30 g. $L^{-1}$ sucrose. In the experiment on bioreactor types, cone and balloon types were determined to be favorable for both adventitious root growth and ginsenoside production. Jasmonic acid was effective for increasing ginsenoside contents and Rb group ginsenosides mainly increased. These results could be employed in commercial scale bioreactor cultures of Panax ginseng.x ginseng.

• The Plant Pathology Journal
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• v.19 no.1
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• pp.19-23
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• 2003

Turnip crinkle vims (TCV) inoculation onto resistant Arabidopsis ecotype Dijon（Di-17) leads to a hypersensitive response (HR) on the inoculated leaves. A dominant gene, HRT, which confers an HR to TCV, has been cloned from Di-17 plants by map-based cloning. HRT is a LZ-NBS-LRR class resistance gene and it belongs to a small gene family that includes RPP8, which confers resistance to Peronospora parasitica Emco5. Outside of the LRR region, HRT and RPP8 proteins share 98% amino acid identity while their LRR regions are less conserved (87% identity). HRT-transformed Arabidopsis plants developed an HR but generally remained susceptible to TCV due to a dominant RRT allele, which is not compatible with resistance. However, several transgenic plants that over-expressed HRT much higher than Di-l7 showed micro-HR or no HR when inoculated with TCV and were resistant to infection. Both the HR and resistance are dependent on salicylic acid but independent of NPRI, ethylene, or jasmonic acid. Arabidopsis plants containing both TCV coat protein gene and HRT developed massive necrosis and death in seedlings, indicating that the TCV coat protein is an avirulence factor detected by the HRT.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.28-38
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• 2023

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positivesense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host's machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins' role in replicating plant (+)ss RNA viruses.

• Natural Product Sciences
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• v.7 no.4
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• pp.120-123
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• 2001

To develop systems for economic production of useful essential oil compounds, callus was induced from the seedlings of Agastache rugosa and cultured on MS medium. The volatile oil fraction was extracted from the callus and investigated by mean of GC-MS. The composition of the oil was compared with that of the mother plant. As a result, sixty five compounds including ferruginol were identified in the essential oil fraction. The main component of the oil from the leaves of Agastache rugosa was methyl chavichol (53.6%). Methyl jasmonate and jasmonic acid were added to the culturing cell suspension, separately and the composition of induced oil were compared. The oils from cultured cells treated with jasmonates showed considerably different patterns. Especially, the peak of estragole was found in callus oil after treatment with methyl jasmonate as though the amount was limited to 0.58%. In general, the TIC pattern of GC-MS of the callus oil became more similar to the oil from the leaves after elicitation.

• Molecules and Cells
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• v.26 no.1
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• pp.1-4
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• 2008

A gene's influence on an organism's Darwinian fitness ultimately determines whether it will be lost, maintained or modified by natural selection, yet biologists have few gene expression systems in which to measure whole-organism gene function. In the Department of Molecular Ecology at the Max Planck Institute for Chemical Ecology we are training "molecularly enabled field biologists" to use transformed plants silenced in the expression of environmentally regulated genes and the plant's native habitats as "laboratories." Research done in these natural laboratories will, we hope, increase our understanding of the function of genes at the level of the organism. Examples of the role of threonine deaminase and RNA-directed RNA polymerases illustrate the process.

• BMB Reports
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• v.42 no.7
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• pp.439-443
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• 2009

Dehydrins are group II, late embryogenesis abundant proteins that act putatively as chaperones in stressed plants. To elucidate the function of dehydrins in poplar, we isolated the $SK_2$-type dehydrin gene Podhn from Populus alba $\times$ P. tremula var. glandulosa suspension cells and analyzed its expression following treatments of abiotic stress, wounding and plant growth regulator. Sequence homology and phylogenetic analyses indicate Podhn encodes an acidic dehydrin (pI 5.14, 277 amino acids, predicted size 25.6 kDa) containing two lysine-rich "K-segments" and a 7-serine residue "S-segment", both characteristic of $SK_2$-type dehydrins. Southern blots show Podhn genes form a small gene family in poplar. Podhn was expressed in all tissues examined under unstressed conditions, but most strongly in cell suspensions (especially in the stationary phase). Drought, salt, cold and exogenous abscisic acid (ABA) treatments enhanced Podhn expression, while wounding and jasmonic acid caused its reduction. Therefore, Podhn might be involved in ABA or stress response.

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

• Plant Biotechnology Reports
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• v.2 no.4
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• pp.253-258
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• 2008

The cDNA of the touch-induced genes (TCH) of the sweet potato [Ipomoea batatas (L.) Lam.] has been cloned and analyzed. IbTCH1, which exists as at least two-copy genes in the genome of the sweet potato, encodes for 148-amino acid polypeptides, and harbors four conversed $Ca^{2+}-binding$ motif EF-hands. IbTCH1 was shown to be expressed in the flower, leaf, thick pigmented root, and particularly in the white fibrous root, but expressed only weakly in the petiole. IbTCH1 is upregulated upon exposure to environmental stresses, dehydration, and jasmonic acid. Furthermore, IbTCH1 is developmentally regulated in the leaf and root. These results strongly indicate that the gene performs functions in both plant development and in defense/stress-signaling pathways.

• Molecules and Cells
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• v.22 no.1
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• pp.58-64
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• 2006

WRKY family proteins are a class of plant-specific transcription factors involved in stress response signaling pathways. In this study a gene encoding a putative WRKY protein was isolated from a pepper EST database (http://genepool.kribb.re.kr). The cDNA, named Capsicum annuum WRKY2 (CaWRKY2), encodes a putative polypeptide of 548 amino acids, containing two WRKY domains with zinc finger motifs and two potential nuclear localization signals. Northern blot analyses showed that CaWRKY2 mRNA was preferentially induced during incompatible interactions of pepper plants with PMMoV, Pseudomonas syringae pv. syringae 61, and Xanthomonas axonopodis pv. vesicatoria race 3. Furthermore, CaWRKY2 transcripts were strongly induced by wounding and ethephon treatment, whereas only moderate expression was detected following treatment with salicylic acid and jasmonic acid. CaWRKY2 was translocated to the nucleus when a CaWRKY2-smGFP fusion construct was expressed in onion epidermal cells. CaWRKY2 also had transcriptional activation activity in yeast. Taken together our data suggest that CaWRKY2 is a pathogen-inducible transcription factor that may have a role in early defense responses to biotic and abiotic stresses.

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.955-963
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• 2023

Chlorella is a eukaryotic organism that can be used as an industrial host to produce recombinant proteins. In this study, a salt-inducible promoter (SIP) was isolated from the freshwater species Chlorella vulgaris PKVL7422 from the screening of genes that were upregulated after salt treatment. Several cis-acting elements, including stress response elements, were identified in the isolated SIP. Moreover, the Gaussia luciferase gene was cloned after the SIP and transformed into C. vulgaris to test the inducibility of this promoter. Reexamination of transcriptome of C. vulgaris revealed that genes involved in the synthesis of methyl jasmonic acid (MeJA), gibberellin (GA), and abscisic acid (ABA) were upregulated when C. vulgaris was treated with salt. Furthermore, the expression level of recombinant luciferase increased when the transformed C. vulgaris was treated with salt and MeJA, GA, and ABA. This study represents the first report of the C. vulgaris SIP and highlights how transformed microalgae could be used for robust expression of recombinant proteins.