• 한국식물학회:학술대회논문집
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• 한국식물학회 1993년도 제7회 식물생명공학 심포지움 식물 세포 분화의 분자적 접근 Seventh Symposium on Plant Biotechnology -Approach to Plant Cell Differentiation-
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• pp.37-50
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• 1993

• 한국식물학회:학술대회논문집
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• 한국식물학회 1985년도 워크샵 및 심포지엄 북한산국립공원의 식생
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• pp.7-18
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• 1985

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• The Plant Pathology Journal
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• 제30권1호
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• pp.58-67
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• 2014

The multifunctional triple gene block protein 1 (TGB1) of the Potexvirus Alternanthera mosaic virus (AltMV) has been reported to have silencing suppressor, cell-to-cell movement, and helicase functions. Yeast two hybrid screening using an Arabidopsis thaliana cDNA library with TGB1 as bait, and co-purification with TGB1 inclusion bodies identified several host proteins which interact with AltMV TGB1. Host protein interactions with TGB1 were confirmed by biomolecular fluorescence complementation, which showed positive TGB1 interaction with mitochondrial ATP synthase delta' chain subunit (ATP synthase delta'), light harvesting chlorophyll-protein complex I subunit A4 (LHCA4), chlorophyll a/b binding protein 1 (LHB1B2), chloroplast-localized IscA-like protein (ATCPISCA), and chloroplast ${\beta}$-ATPase. However, chloroplast ${\beta}$-ATPase interacts only with $TGB1_{L88}$, and not with weak silencing suppressor $TGB1_{L88}$. This selective interaction indicates that chloroplast ${\beta}$-ATPase is not required for AltMV movement and replication; however, TRV silencing of chloroplast ${\beta}$-ATPase in Nicotiana benthamiana induced severe tissue necrosis when plants were infected by AltMV $TGB1_{L88}$ but not AltMV $TGB1_{L88}$, suggesting that ${\beta}$-ATPase selectively responded to $TGB1_{L88}$ to induce defense responses.

• Molecules and Cells
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• 제20권1호
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• pp.112-118
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• 2005

It was previously shown that AtNAP1 is a plastidic SufB protein involved in Fe-S cluster assembly in Arabidopsis. In this study, we investigated the effects of depleting SufB protein from plant cells using virus-induced gene silencing (VIGS). VIGS of NbNAP1 encoding a Nicotiana benthamiana homolog of AtNAP1 resulted in a leaf yellowing phenotype. NbNAP1 was expressed ubiquitously in plant tissues with the highest level in roots. A GFP fusion protein of the N-terminal region (M1-V103) of NbNAP1 was targeted to chloroplasts. Depletion of NbNAP1 resulted in reduced numbers of chloroplasts of reduced size. Mitochondria also seemed to be affected. Despite the reduced number and size of the chloroplasts in the NbNAP1 VIGS lines, the expression of many nuclear genes encoding chloroplast-targeted proteins and chlorophyll biosynthesis genes remained unchanged.

• Journal of Plant Biotechnology
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• 제33권3호
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• pp.185-194
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• 2006

엽록체는 숙주세포에 잡아먹힌 (식균작용) 남세균이 숙주세포와 공생관계를 형성하여 온 것으로 간주된다. 엽록체 게놈은 정적이라고 이해하고 있지만 형질전환을 통하여 상동염기가 도입되면 이와는 반대로 intramolecular homologous recombination에 의해 subgenomic circle을 만드는 등 매우 다이나믹하다는 것이 최근에 증명되고 있다. 고등식물의 엽록체 형질전환은 핵 형질전환에서 기대할 수 없는 여러 이점을 제공한다. 예컨대, transgene의 발현율을 높일 수 있고, transgene들을 polycistronic하게 발현할 수 있으며, 도입된 transgene이 모계유전을 하게 된다는 것 등이다. 담배는 엽록체 형질전환의 모델 식물로 사용되어 왔으나 최근에는 벼, 대두, 면화 등 다른 주요 작물의 형질전환도 가능하게 되었다. 엽록체 형질전환된 작물은 미생물을 이용하여 고부가가치 단백질을 생산하는 생물반응기를 향후 대체할 수 있게 될 것이다.

• Journal of Plant Biotechnology
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• 제44권2호
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• pp.115-124
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• 2017

Cytoplasmic male sterility (CMS) is a maternally inherited trait leading to loss of the ability to produce fertile pollen and is extensively used in hybrid crop breeding. Ogura-CMS was originally generated by insertion of orf138 upstream of atp8 in the radish mitochondrial genome and transferred to Brassica crops for hybrid breeding. Gene expression changes by dysfunctional mitochondria in Ogura-CMS result in pollen developmental defects, but little is known about gene expression patterns in vegetative tissue. To examine the interaction between nuclear and organellar regulation of gene expression, microarray and subsequent gene expression experiments were conducted with leaves of $F_1$ hybrid Chinese cabbage derived from self-incompatible (SI) or Ogura-CMS parents (Brassica rapa ssp. pekinensis). Out of 24,000 genes deposited on a KBGP24K microarray, 66 genes were up-regulated and 26 genes were down-regulated by over 2.5 fold in the CMS leaves. Up-regulated genes included stress-response genes and mitochondrial protein genes, while genes for ascorbic acid biosynthesis and thylakoid proteins were down-regulated. Most of the major component genes for light reactions of photosynthesis were highly expressed in leaves of both SI and CMS plants, but most of the corresponding proteins were found to be greatly reduced in leaves of CMS plants, indicating posttranscriptional regulation. Reduction in thylakoid proteins and chlorophylls led to reduction in photosynthetic efficiency and chlorosis of Ogura-CMS at low temperatures. This research provides a foundation for studying chloroplast function regulated by mitochondrial signal and for using organelle genome introgression in molecular breeding.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권3호
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• pp.177-188
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• 1999

The effect of ABA on the chloroplast disassembly of Zea mays was investigated by measuring the changes in the relative distribution of chlorophyll(Chl) between the Chl-protein complexes in ABA treated and untreated sensecting leaves. The reaction center(RC)-light harvesting complex(LHC) regions were rapidly disassembled in the late stage of dark-induced senescence. Plus, during dark-induced senescence, the disassembly of a reaction center of P700 apoproteins containing mainly Chl a was faster than that of a reaction center of LHCI apoproteins containing both Chl a and Chl b. The increase in the relative distribution of Chl-protein complexes in the RC-Core2 in the late stage of senescence was due to the accumulation of core complexes such as CP47/43 and reaction centers including D1/D2 apoproteins disassembled from the RC-Corel containing the dimer of D1/D2 apoproteins. The LHCII region was more stable than the other Chl-protein complexes throughout leaf senscence. Accordingly, it is suggested that the preferential breakdown of Chl a gives rise to the disassembly of Chl a-binding proteins, particularly reaction centers and core complexes during dark-induced senescence, plus the primary target of the photosynthetic apparatus in sensecing leaves would seem to be Chl a along with the proteins associated with Chl a. The application of ABA promoted the disassembly of the P700 apoproteins in the PSI reaction center and the dimer of D1/D2 apoproteins, and the conversion of the trimeric LHCII apoprotein to the monometirc LHCII apoprotein during the middle stage of leaf senescence, thereby suggesting that ABA accelerates the disassembly of both Chl a-binding and Chl a+b-binding proteins, particularly Chl a-binding proteins during the middle stage of leaf senescence.

• 식물조직배양학회지
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• 제27권5호
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• pp.407-409
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• 2000

Outer envelope membrane proteins of chloroplasts encoded by the nuclear genome are transported without the N-terminal transit peptide. Here, we investigated the targeting mechanism of AtOEP7, an Arabidopsis homolog of small outer envelope membrane proteins in vivo. AtOEP7 was expressed transiently in protoplasts or stably in transgenic plants as fusion proteins with GFP. In both cases AtOEP7:GFP was targeted to the outer envelope membrane when assayed under a fluorescent microscope or by Western blot analysis. Except the transmembrane domain, deletions of the N- or C-terminal regions of AtOEP7 did not affect targeting although a region closed to the C-terminal side of the transmembrane domain affected the targeting efficiency. Targeting experiments with various hybrid transmembrane mutants revealed that the amino acid sequence of the transmembrane domain determines the targeting specificity The targeting mechanism was further studied using a fusion protein, AtOEP7：NLS：GFP, that had a nuclear localization signal. AtOEP7：NLS：GFP was efficiently targeted to the chloroplast envelope despite the presence of the nuclear localization signal. Taken together, these results suggest that the transmembrane domain of AtOEP7 functions as the sole determinant of targeting specificity and that AtOEP7 may be associated with a cytosolic component during translocation to the chloroplast envelope membrane.

• Current Research on Agriculture and Life Sciences
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• 제17권
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• pp.59-63
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• 1999

벼의 엽록체 small HSP의 고온 스트레스 하에서의 기능을 밝히기 위하여 Oshsp21 cDNA를 pET 발현 vector에 도입하였다. 형질전환된 대장균 배양액에 IPTG를 첨가하여 단백질 발현을 유도시킨 다음 고온 stress 하에서의 생존율을 대조구와 비교하였다. 그 결과 대조균주의 경우 $50^{\circ}C$에서의 생존율이 크게 감소하였으나 Oshsp21이 발현된 대장균의 경우 70% 이상의 생존율을 나타내었다. 또한 대장균 단백질을 $55^{\circ}C$에서 30분간 열처리한 후, 대장균 단백질을 가용성과 비가용성 단백질로 분획한 다음, 각각의 비율을 조사한 결과, 대조균주의 경우 총 단백질의 약 60%가 비가용성 단백질로 변성되었으나, Oshsp21을 발현시킨 대장균의 경우 총 단백질의 약 35%만이 비가용성 단백질로 나타났다. 이러한 결과는 벼의 엽록체 small HSP는 세포내에서 분자 chaperone으로 기능하여 고온내성을 부여할 수 있음을 나타낸다.

• Journal of Plant Biotechnology
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• 제46권4호
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• pp.323-330
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• 2019

The high expression level of industrial and metabolically important proteins in plants can be achieved by plastid transformation. The CaIA vector, a Capsicum-specific vector harboring aadA (spectinomycin resistance), is a selectable marker controlled by the PsbA promoter, and the terminator is flanked by the trnA and trnI regions of the inverted repeat (IR) region of the plastid. The CaIA vector can introduce foreign genes into the IR region of the plastid genome. The biolistic method was used for chloroplast transformation in Scoparia dulcis with leaf explants followed by antibiotic selection on regeneration medium. Transplastomes were successfully screened, and the transformation efficiency of 3 transgenic lines from 25 bombarded leaf explants was determined. Transplastomic lines were evaluated by PCR and Southern blotting for the confirmation of aadA insertion and its integration into the chloroplast genome. Seeds collected from transplastomes were analyzed on spectinomycin medium with wild types to determine genetic stability. The increased chloroplast transformation efficiency (3 transplastomic lines from 25 bombarded explants) would be useful for expressing therapeutically and industrially important genes in Scoparia dulcis L.