• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.192-196
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• 2011

Microbial induction of rusty-root was proved in this study. The enzymes hydrolyzing plant structural materials, including pectinase, pectolyase, ligninase, and cellulase, caused the rusty-root in ginseng. Pectinase and pectolyase produced the highest rusty-color formation. Ferrous ion ($Fe^{+++}$) caused the synergistic effect on rusty-root formation in ginseng when it was used with pectinase. The effect of ferric ion ($Fe^{++}$) on rusty-root formation was slow, compared with $Fe^{+++}$, probably due to gradual oxidation to $Fe^{+++}$. Other metal ions including the ferric ion ($Fe^{++}$) did not affect rusty-root formation. The endophytic bacteria Agrobacterium tumefaciens, Lysobacter gummosus, Pseudomonas veronii, Pseudomonas marginalis, Rhodococcus erythropolis, and Rhodococcus globerulus, and the rotten-root forming phytophathogenic fungus Cylindrocarpon destructans, caused rusty-root. The polyphenol formation (rusty color) was not significantly different between microorganisms. The rotten-root-forming C. destructans produced large quantities of external cellulase activity (${\approx}2.3$ U[${\mu}m$/min/mg protein]), which indicated the pathogenecity of the fungus, whereas the bacteria produced 0.1-0.7 U. The fungal external pectinase activities (0.05 U) and rusty-root formation activity were similar to those of the bacteria. In this report, we proved that microbial hydrolyzing enzymes caused rusty-root (Hue value $15^{\circ}$) of ginseng, and ferrous ion worsened the symptom.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.213-218
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• 1999

Fructans are polyfructose molecules that function as nonstructural storage carbohydrates in several plants. In addition, it has been suggested that, due to their solubility, they can play an important role in helping plants survive periods of osmotic stress. In order to study the effect of levan synthesis on plant growth, the coding region of the levansucrase gene, which was isolated from Zymomonas mobilis, was introduced into tobacco plants using Agrobacterium tumefaciens-mediated transformation. The presence of the levansucrase gene in transgenic plants was verified by genomic DNA gel blot analysis. RNA gel blot and immunoblot analyses showed an accumulation of the corresponding transcript and protein product of the bacterial levansucrase gene in transgenic plants. Furthermore, a thin layer chromatography analysis revealed that fructans were synthesized and deposited in transgenic tobacco plants. When $T_1$ seeds were germinated and grown under polyethylene glycol-mediated drought stress or cold stress, the transgenic seedlings displayed a substantially higher level of growth than that of untransformed plants. These results suggest that fructans may playa significant role in the tolerance of plants under osmotic stress.

• Journal of Plant Biotechnology
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• 제1권1호
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• pp.46-55
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• 1999

The expressed sequence tags(ESTs) from immature seed of rice, Oryza sativa cv Milyang 23, were partially sequenced and analyzed by homology. As of 1998, the partial sequences of about 6,600 cDNA clones were analyzed from normal and normalized immature seed cDNA libraries. About 2,200 ESTs were putatively identified by BLASTX deduced amino acid sequence homology analysis. About 20% of them were putatively identified as storage proteins. Also the clones were highly homologous to genes involved particularly in starch biosynthesis, glycolysis, signal transduction and defenses. Compared to 35% of redundancy in the ESTs of normal cDNA library, that from the substracted library was 15%. The Korea Rice Genome Network is maintained to provide the updated information of sequences, their homologies and sequence alignments of ESTs. For the stable expression of transgene in rice, diverse vectors were developed for overexpression, targeting and gene dosage effect with transit peptides (Tp) and matrix attachment region (MAR) sequence from chicken lysozyme locus. The rice calli were transformed via Agrobacterium tumefaciens LBA4404(pSB1) with the triparental mating technique and selected by herbicide resistance. The green fluorescent protein(GFP) gene in expression vector under the control of rbcS promoter-Tp was overexpressed upto 10 % of the total soluble protein. In addition, the Tp-sGFP fusion protein was properly processed during translocation into chloroplast. The expression of sGFP in the presence of MAR sequences was analyzed with Northern and immunoblot analysis. All the lines in which sGFP transgene with MAR sequence, showed position independent and copy number-dependent expression, while the lines without MAR showed the varied level of expression with the integration site. Thus the MAR sequence significantly reduced the variation in transgene expression between independent transformants.

• 식물조직배양학회지
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• 제28권1호
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• pp.41-45
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• 2001

CAB 유전자로 형질전환된 담배 2세대 식물체의 도입된 CAB 유전자 존재여부를 genomic PCR 방법으로 각계통에서 확인하였다. CAB유전자로 형질전환된 2세대 식물체를 자연 광 조건과 90% 차광된 온실에서 각각 생육시킨 결과 형질전환 식물체의 광합성능 정도는 정상 식물체와 유사하거나 약간 높은 경향이었으며, 광포화점은 형질전환 담배 식물체나 정상 식물체 모두 500$\mu$mol m$^{-2}$ s$^{-1}$로 차이가 없었다. 조사한 7계통 중 C7, C11, C14 계통의 광합성 정도가 조사된 모든 광량에서 정상 담배 식물체보다 높게 나타났다. 차광된 조건에서 생육한 담배 식물체의 광합성능 정도는 조사된 7계통 중 C2, C11, C14 계통이 90% 차광된 온실조건에서도 광합성 능이 우수하게 나타났다. 형질전환 담배 식물체의 chlorophyll 함량은 정상 NC82와 차이가 없었으며, 양지에서 생육한 조건과 90% 차광된 조건 모두에서 차이점이 없었으며 광합성능과 chlorophyll 함량과의 유의성은 없었다. 형질전환 담배 식물체 수확엽의 건물률은 정상 식물체와 비교하여 차이점이 나타나지 않았으며, 내용성분도 nicotine, 전당, 전질소에서 차이가 없었다.

• Journal of Ginseng Research
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• 제33권3호
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• pp.212-218
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• 2009

인삼으로부터 뽑은 PgCYP 유전자와 표지유전자인 NPTII 유전자를 함유하고 있는 Agrobacterium tumefaciens GV3101균주를 이용하여 담배 잎절편과 공동배양한 후 MS 기본배지에 kanamycin 100 $\mu$g/ml, cefotaxime 500 $\mu$g/l, BA 2 mg/l와 NAA 0.2 mg/l가 첨가된 선발배지에 치상하여 4주 후 항생제가 첨가된 기본배지에서 발근시켰다. 생존한 선발체의 잎을 이용하여 PCR 반응으로 도입유전자의 삽입여부를 확인하였다. 또한 선발된 형질전환체를 이용하여 RT-PCR을 실시하여 PgCYP 유전자가 담배식물에 안정적으로 도입되어 전사되고 있음을 확인하였다.

• 식물조직배양학회지
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• 제22권2호
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• pp.71-76
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• 1995

자리공 모상근에서 광처리에 따른 항산화효소의 활성을 조사하였다. Catalasa superoxide dismutasae, ascorbate oxidase (AO)의 활성은 광도가 2,000 lx까지 증가할수록 감소하였으며, 특히 AO활성은 2,000 lx에서 암상태보다 92% 감소하였다. Glutathione reductase, glutathione peroxidase (GPO), ascorbate peroxidase 그리고 peroxidase의 활성도는 500 lx까지는 광도가 높아질수록 증가하였으나 그 이상의 높은 광도에서는 현저하게 감소하였다. GPO의 활성은 AO처럼 2,000 lx에서 암상태보다 85%감소하였다. 광파장에 따른 항산화효소의 활성은 청색광의 파장에서 가장 많이 억제되었으며, AO의 활성은 25%까지 감소하였다. 청색광 파장의 광도에 따른 항산화효소의 활성도는 30 lx까지는 증가하다가 200 lx에서는 암상태보다 21-71%까지 감소하는 경향을 나타내었다. AO의 활성은 청색 파장의 광도(300-200 lx)가 증가할수록 급격히 감소하여 200 lx에서는 70%까지 억제되었다. 자리공 모상근의 항산화효소 활성은 청색광 파장의 높은 광도에서 주로 생성된 유해산소 의하여 억제되고 있음을 확인하였다. 광상태하에서 모상근의 생장과 betalain 합성을 향상시키기 위해서는 모상근에서 생성되는 산화제의 효율적인 제거가 요구됨이 시사되었다.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.71-77
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• 2011

Drought and salinity are the most important abiotic stresses that affect the normal growth and development of plants. Glycine betaine is one of the most important osmolytes present in higher plants that enable them to cope with environmental stresses through osmotic adjustment. In this study, a betaine aldehyde dehydrogenase (BADH) gene from spinach under the control of the stress-induced promoter rd29A from Arabidopsis thaliana was introduced into potato cultivar Gannongshu 2 by the Agrobacterium tumefaciens system. Putative transgenic plants were confirmed by Southern blot analysis. Northern hybridization analysis demonstrated that expression of BADH gene was induced by drought and NaCl stress in the transgenic potato plants. The BADH activity in the transgenic potato plants was between 10.8 and 11.7 U. There was a negative relationship (y = -2.2083x + 43.329, r = 0.9495) between BADH activity and the relative electrical conductivity of the transgenic potato plant leaves. Plant height increased by 0.4-0.9 cm and fresh weight per plant increased by 17-29% for the transgenic potato plants under NaCl and polyethylene glycol stresses compared with the control potato plants. These results indicated that the ability of transgenic plants to tolerate drought and salt was increased when their BADH activity was increased.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.268-274
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• 2009

Porphyromonas gingivalis, the gram-negative anaerobic oral bacterium, initiates periodontal disease by binding to saliva-coated oral surface. The cholera toxin B subunit (CTB) genetically linked to FimA1 (1-200 aa) or FimA2 (201-337 aa) of the P. gingivalis fimbrial antigen were introduced into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated transformation method. The integration of CTB-FimA1 or CTB-FimA2 fusion genes were confirmed in the chromosome of transformed leaves by genomic DNA PCR amplification method. Synthesis and assembly of the CTB-FimA fusion proteins into oligomeric structures with pentamer size was detected in transformed tuber extracts by immunoblot analysis. The binding activities of CTB-FimA fusion proteins to intestinal epithelial cell membrane receptors were confirmed by GM1-ganglioside enzyme-linked immunosorbent assay (GM1-ELISA). The ELISA showed that the expression levels of the CTB-FimA1 or CTB-FimA2 fusion proteins were 0.0019, 0.002% of the total soluble protein in transgenic tuber tissues, respectively The synthesis of CTB-FimA monomers and their assembly into biologically active oligomers in transformed potato tuber tissues demonstrates the feasibility of using edible plants for the production of enterocyte targeted fimbrial antigens that could elicit mucosal immune responses.

• 한국연초학회지
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• 제20권1호
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• pp.57-65
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• 1998

This study was conducted to develop a resistant tobarro against Potato virus Y (PVY) by transformation of the plants with genetically engineered viral genes. The complimentary DNAs (cDNAS) of potato virus Y-necrosis strain (PVY-Vn) replicase mutant genes (3'-deleted, 5'-deleted and ADD-mutant Nlbs) were synthesized through RT-PCR by using purified PVY-VN RNA and synthesized primers, and cloned in the sense orientation into a plant expression vector (pMBPI), The cDNAS of the genes were transferred into Agrobacterium tumefaciens LBA 4404, and then transformed into tobacco (Nicotiana tabacum cv. Burley 21) plants. Regenerated plants were tested for PVY resistance by inoculation test; 13 transgenic plants including 7 for 3'-deleted Nlb, 3 for 5'-deleted Nlb, and 3 for ADD-mutant Nlb appeared to be resistant at 4 weeks after inoculation with PVY-VN. Among the 13 transgenic tobacco plants, 8 plants had no symptom up to 14 weeks after inoculation. The progenies ($T_1$) from self-fertilization of the transgenic lines varied 0.0% to 81.2% in their resistance (% of resistant plants). The analysis of Nlb-31deleted, -5'deleted and -ADD mutant in the $T_1$ plants by polymerase chain reaction (PCR) showed that Nlb-3'deleted, -5'deleted and -ADD mutants were detected in all of the resistant plants. These results suggest that the PVY resistance was inherited in the $T_1$ generation.

• Molecules and Cells
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• 제28권4호
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• pp.331-339
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• 2009

Capsaicin is a very important secondary metabolite that is unique to Capsicum. Capsaicin biosynthesis is regulated developmentally and environmentally in the placenta of hot pepper. To investigate regulation of capsaicin biosynthesis, the promoter (1,537 bp) of pepper capsaicin synthase (CS) was fused to GUS and introduced into Arabidopsis thaliana (Col-0) via Agrobacterium tumefaciens to produce CSPRO::GUS transgenic plants. The CS was specifically expressed in the placenta tissue of immature green fruit. However, the transgenic Arabidopsis showed ectopic GUS expressions in the leaves, flowers and roots, but not in the stems. The CSPRO activity was relatively high under light conditions and was induced by both heat shock and wounding, as CS transcripts were increased by wounding. Exogenous capsaicin caused strong suppression of the CSPRO activity in transgenic Arabidopsis, as demonstrated by suppression of CS expression in the placenta after capsaicin treatment. Furthermore, the differential expression levels of Kas, Pal and pAmt, which are associated with the capsaicinoid biosynthetic pathway, were also suppressed in the placenta by capsaicin treatment. These results support that capsaicin, a feedback inhibitor, plays a pivotal role in regulating gene expression which is involved in the biosynthesis of capsaicinoids.