• Journal of Photoscience
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• 제10권3호
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• pp.245-249
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• 2003

The psbA gene of photo system II was cloned and characterized from the P. ginseng chloroplast. The psbA gene is composed of 1,062 nucleotides. The overall amino acid sequence shows 99% and 98% identities to dicots and monocots of higher plants, respectively. Southern blot analysis revealed that a single copy of the psbA gene existed in the chloroplast genome. Northern blot analysis of the in vivo accumulation of the psbA transcript, after being grown under the different intensities (5%, 10%, 20%, and 100%) of daylight, indicated that the steady-state level of the psbA transcript was not significantly affected by light intensity.

• Journal of Ginseng Research
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• 제27권3호
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• pp.146-150
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• 2003

본 연구는 DNA수준에서 인삼의 종내 및 종간 개체간의 유전변이를 확인할 수 있는 새로운 방법인 PCR-aided RFLP를 사용하여 품종육성의 기초자료로 삼고자 수행하였다. 인삼의 엽록체 DNA중 psbA gene과 rbcL gene을 제한효소처리하여 그 band 양상을 조사하고자 하였다. Chloroplast DNA 중 psbA gene과 rbcL gene을 분리하기 위하여 각각 psbA-N, psbA-C primer 및 rbcL-N, PX-1 primer를 사용한 결과 적정 분자량인 psbA gene은 1,008bp에서, rbcL gene은 1,336 bp에서 band가 나타났다. 또한 atpB gene, rpoB gene, trn gene을 분리하기 위한 primer를 사용한 결과 역시 예상 대로 1,366bp, 900bp, 1,500bp, 1,008bp에서 band가 나타났다. PCR에 의하여 분리한 psbA gene과 rbcL gene을 sau3A, Taq1, Alu1, HaeIII 등의 제한효소로 절단하여 RFLP양상을 조사한 결과 모든 인삼에서 TaqI 제한효소 처리구에서 KG Line 과 종 및 변종간 모두 절단이 되었으며 800bp에서 band가 위치하고 있다. AluI의 제한효소 처리구에서도 KG Line과 유전자원에서 800bp인 동일한 band를 보였다. 제한효소 HaeIII에서는 KG Line의 경우 500bp의 위치에서 희미하게 band를 동일하게 보였다. 그러나 유전자원에 있어 HaeIII 제한효소처리구에서는 band가 관찰되지 않아 KG Line과 차이를 보였다. 모든 chloroplast gene은 PCR 증폭에 의하여 밴드를 형성하였으나 제한효소 처리후 각 인삼 종내 또는 종간 식별이 용이하지 않아서 좀 더 많은 제한효소를 사용하거나 증폭된 DNA를 염기서열을 분석하여 비교하는 방법이 고려 되어야 할 것으로 사료된다.

• Journal of Photoscience
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• 제12권3호
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• pp.129-133
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• 2005

The psbC gene, encoding the intrinsic chlorophyll-binding protein of CP43, one of the PS core complex polypeptides, was cloned from the Panax ginseng chloroplast, which is composed of 1,422 nucleotides and the overall nucleotide sequence shows more than 84% identity to those of eukaryotic photosynthetic organisms. The predicted topology of CP43, based on hydropathy analysis, includes six membrane-spanning ${\alpha}-helices$ resulting in three lumenal and four stromal loops. The putative translation start codon for the psbC gene is located at 48 nucleotides upstream from the stop codon of the psbD gene whose product is also a component of the PSII reaction center, implying that the promoter of the psbC gene is possibly located in the middle of the structural gene of the psbD gene. Northern blot analysis of the in vivo accumulation of the psbC transcript from the plants grown under the various growth light intensities (5%, 10%, 20%, and 100%) of daylight indicated that the steady-state level of the psbC transcript was not significantly affected by light intensity.

• 대한약침학회지
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• 제15권1호
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• pp.18-22
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• 2012

Panax ginseng is a well-known herbal medicine in traditional Asian medicine. Although wild ginseng is widely accepted to be more active than cultivated ginseng in chemoprevention, little has actually been reported on the difference between wild ginseng and cultivated ginseng. Using suppressive subtraction hybridization, we cloned the p-psbB gene as a candidate target gene for a wild ginseng-specific gene. Here, we report that one of the clones isolated in this screen was the chloroplast p-psbB gene, a chlorophyll a-binding inner antenna protein in the photosystem II complex, located in the lipid matrix of the thylakoid membrane. Real-time results showed that the expression of the p-psbB gene was significantly up-regulated in wild ginseng as compared to cultivated ginseng. Thus, the p-psbB gene may be one of the important markers of wild ginseng.

• BMB Reports
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• 제32권2호
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• pp.189-195
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• 1999

From the Panax ginseng chloroplast, the psbE and psbF genes, encoding the $\alpha$- and $\beta$-subunits of cytochrome b-559 of the photosystem II reaction center, respectively, were cloned and characterized. The psbE and psbF genes were composed of 252 and 117 nucleotides, respectively. The deduced amino acid sequence of the $\alpha$-subunits showed 95%, 93%, and 91% homology to monocots, dicots, and liverwort, respectively, whereas the $\beta$-subunits showed approximately 98% to 95% homology to the same species. Southern blot analysis revealed that a single copy of the psbEF gene exists in the chloroplast plastid. Northern blot analysis indicated that the psbE and psbF genes are cotranscribed as a polycistron.

• 한국환경과학회지
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• 제13권4호
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• pp.359-365
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• 2004

The change of chlorophyll fluorescence parameters, O-J-I-P transients and psbA gene expression were investigated in the leaves of Crinum asiaticum var. japonicum on the natural condition in winter, in order to elucidate physiological responses of photosystem II (PS II) activity to winter stresses. The photochemical efficiencies of PS II, Fv/Fm, were significantly low in winter, contrary to its high value in summer. The values of I -qN and I-qP were lower in midday than at dawn or night both in summer and winter, although their decrease in midday was less in winter than in summer. In the O-J-I-P transients, the fluorescence intensity of J, I, P-step decreased remarkably depending on temperature drop in winter. And the D I reaction center protein of PS II decreased in late winter more than in early winter, concomitantly with relatively high content of description products of psbA gene in midday. These results indicate that low temperature in winter causes irreversible damage to PS II and subsequently leads to cell death.

• ALGAE
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• 제27권4호
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• ALGAE
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• 제17권1호
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• pp.53-58
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• 2002

The transition of plant life from aquatic algae to land to land plants was one of the major events in the history of life. However, in hypothesizing the exact evolutionary path of the transition, limited shared phenotypic characters in aquatic algae and land plants (embryophytes) have been a major hinderance. Chloroplast genomes contain characters useful in tracing evolutionary histories. Embryophyte chloroplast genomes are distinguished from algal cpDNAs by having over 20 group Ⅱ introns, some of which were gained during the transition from algae to embryophytes (Manhart and Palmer 1990; Lew and Manhart 1993;Lee and Manhart 2002). Here we examine a gene cluster that, in land plants, contains psbB, psbT, psbH, petB and petD with introns found in petB and petD (petB.i and petD.i). In addition the presence/absence of introns in trnA and trnI (trnA.i and trnI.i) were determined in all five major lineages of charophytes. We found that the psbB gene cluster occurs in most surveyed charophytes and embryophytes except Spirogyra (Zygnematales) which lacks it due to intra-genomic rearrangement. All four introns are absent in Chlorokybus but present in some or all of the other four charophyte lineages (Klebsormidiales, Zygnematales, Coleochaetales, and Charales). In addition, Chlorokybus is distinguished from other charophytes and embryophytes by having an unusually long spacer (over 2 kb) between psbH-petB. The results indicate that Chlorokybus diverged before the intron gains but after psbB gene cluster formation, placing the other charophyte lineages closer to embryophytes.

• 한국잡초학회지
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• 제15권3호
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• pp.206-213
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• 1995

Glyphosate를 토마토의 동화산물 공급부위에 처리하였을 때, 제초제결합 단백질인 QB 단백질을 Escherichia coli 내에서 ${\alpha}$-galactosidase가 발현되기 위해 lac Z 유전자의 3' 말단에 cloning된 시금치 psb A 유전자에 의해 발현되는 hybrid 단백질에 대한 항체를 형성시킨 후 이것을 이용하여 immunoblotting을 실시하였다. G1yphosate는 thylakoid 막의 Photosystem II내에 있는 D1 단백질의 붕괴에 영향을 주었다. LHC II 복합체내의 D1 단백질의 기능 이상은 glyphosate 의 다면발현적 효과였다.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1479-1484
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• 2010

Photosynthesis uses light energy to drive the oxidation of water at an oxygen-evolving catalytic site within photosystem II (PSII). Chlorophyll binding by the photosystem II subunit S protein, PsbS, was found to be necessary for energy-dependent quenching (qE), the major energy-dependent component of non-photochemical quenching (NPQ) in Arabidopsis thaliana. It is proposed that PsbS acts as a trigger of the conformational change that leads to the establishment of nonphotochemical quenching. However, the exact structure and function of PsbS in PSII are still unknown. Here, we clone and express the recombinant PsbS gene from Arabidopsis thaliana in E. coli and purify the resulting homogeneous protein. We used various biochemical and biophysical techniques to elucidate PsbS structure and function, including circular dichroism (CD), fluorescence, and DSC. The protein shows optimal stability at $4^{\circ}C$ and pH 7.5. The CD spectra of PsbS show that the conformational changes of the protein were strongly dependent on pH conditions. The CD curve for PsbS at pH 10.5 curve had the deepest negative peak and the peak of PsbS at pH 4.5 was the least negative. The fluorescence emission spectrum of the purified PsbS protein was also measured, and the ${\lambda}_{max}$ was found to be at 328 nm. PsbS revealed some structural changes under varying temperature and oxygen gas condition.