• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.441-449
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• 2005

Photo system II (PSII) is one of the two photosynthetic reaction centers in the chloroplast of higher plants. The chlorophyll a/b-light harvesting complex serves primarily as an antenna for PSII. We isolated a cDNA that encodes a chlorophyll a/b-binding protein (Cab) from Panax ginseng. The small subunit consists of 935 nucleotides long and has an open reading frame of 795 bp with the deduced amino acid of 265 residues (pI 5.63), 28.6 kDa. The deduced amino acid sequence matched to the previously reported Cab genes. Their degree of amino acid identity ranged from 68 to $92\%$. Phylogenetic analysis based on the amino acid residues was showed that the ginseng Cab gene was grouped with P. persica (AAC34983), A. thaliana (AAD28771), G. hirsutum (CAA38025), G. max (AAL29886), and V. radiate (AAF89205).

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.63-79
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• 1987

Light regulates a variety of genes in higher plants. The expression of light-induced plant genes is regulated at the level of transcription via red- light photomorphogenic receptor, phytochrome, as well as unknown blue light photoreceptor(s). Ribulose-5-phosphate carboxylase/oxygenase (Rubisco) small subunit (SSB) and light harvesting chlorophyll a/b (Cab) protein are those of the best understood genes regulated by light. 5'-upstream flanking sequence (- -400) of Rubisco SSB and Cab genes sis known as a light responsive, enhance-like element. It responses to red and blue light in transgenic plant system as a tissue specific manner. Phytochrome gene is also regulated by light. In contrast to most of the light regulated plant genes, it is negatively controlled by red light. Search for the cis- and trans-acting factors responsible for the light signal is in progress to understant photomorphogenesis and development in higher plants.

• Journal of Photoscience
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• v.9 no.2
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• pp.332-334
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• 2002

We examined the effects of supplementary ultraviolet-B (UV-B) radiation on the changes in synthesis and degradation of ribulose-I, 5-biphosphate carboxylase /oxygenase (Rubisco) and light-harvesting chlorophyll a/b binding protein of PSII (LHCII), as well as mRNA levels for small and large subunits of Rubisco (rbcS and rbcL, respectively) and LHCII (cab) with leaf age in UV-sensitive rice (Norin I) and UV-resistant rice (Sasanishiki). Both Rubisco and LHCII were actively synthesized until the leaf had fully expanded, and then decreased with leaf age. Synthesis of Rubisco, but not LHCII, was significantly suppressed by UV-B in Norin 1. The degradation of Rubisco was enhanced by UV-B around the time of the leaf maturation in the two cultivars. The levels of rbcS and rbcL were reduced by UV-B at the early leaf stages after emergence in both cultivars. The level of cab was first present at the highest level in the two cultivars, but drastically decreased due to UV-B treatment immediately after leaf emergence in Norin 1. It was proved that synthesis and degradation of Rubisco and LHCII greatly changed with leaf age: Rubisco synthesis was significantly suppressed by supplementary UV-B radiation at the transcription step during the early leaf stages. It was also suggested that the difference between the two rice cultivars in sensitivity to UV-B in the synthesis of Rubisco might be due to the specific suppression not only after transcription but also at transcription.

• Journal of Photoscience
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• v.5 no.4
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• pp.149-152
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• 1998

Expression of light-harvesting chlorophyll a/b-binding protein gene(cab) is repressed in the dark and activited by light. However, the detail of its regulatory mechanism is not characterized so far. To identify the interactions of cis-acting elements and trans-acting factors involvedin this regulation, nuclear extracts from the light-grown and dark-adapted Arabidopsis thaliana leaves were anlayzed for mobility shift assay against 134bp fragments had two retarded bands and one retardation band, respectively, both in light-grown and dark-adapted bands in the dark-adapted tissues. A new retardation the cab 3 expression in the dark. Several light regulatory motifs are scattered in the 146 bp region of cab 3 promoter. One of the light-regulatory motifs could be the binding site for the negative regulatory factor.

• BMB Reports
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• v.34 no.6
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• pp.496-501
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• 2001

Lincomycin, an inhibitor of plastid protein synthesis, was found to block the synthesis of apoprotein P700 with a molecular mass of 72 kDa and the assembly of the Chl a-protein of PS I. Synthesis of the polypeptides of 48, 43.5, and 32 kDa of the PS II complex is also suppressed. This process is accompanied by the disappearance of the PS Two reaction center Chl a at 683 nm, and of the PS One reaction center Chl a at 690, 696, and 705 nm on the fourth derivative of the absorption spectra at 77K. Lincomycin does not affect the synthesis of LHC subunits. It increases the content of the two main Chl forms of LHC at 648 nm (Chl b) and 676 nm (Chl a). The low-temperature fluorescence ratio F736/F685 is also increased. However, the effect of cycloheximide (an inhibitor of cytoplasmic protein synthesis) leads to the reduction of polypeptides of the light-harvesting Chl a/b-protein complex in the range of 29.5-22 kDa. Under these conditions, the relative amount of Chl b and the F736/ F685 fluorescence ratio decrease significantly. This is obviously the result of blocking the LHC I and LHC II synthesis. At the same time rifampicin and actinomycin D (inhibitors which block transcription in chloroplast and nuclear genome, respectively) inessentially affect the characteristics of these complexes.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.522-530
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• 2018

Brachypodium distachyon has been developed as a monocot model plant for temperate grasses and bioenergy crops. Although B. distachyon research is moving forward rapidly, the study of photoresponses has not been explored. To extend our knowledge of responses to light in monocots, we performed photoresponse analysis of B. distachyon using two inbred lines, Bd21 and Bd21-3. In this study, we first compared growing phenotypes between the two lines and investigated coleoptile and primary leaf growths under dark, far-red, red, and white light conditions. The results showed that the growth of the two lines were similar until tillering stage, but other developmental stages from heading to senescence were much delayed in Bd21-3, which resulted in increased height and tiller numbers. Under different light conditions, primary leaf lengths were kept increasing during the growth period, whereas the coleoptile extension was inhibited 4 to 7 days after growth depending on the light conditions applied. These results suggest that the responses to light in B. distachyon can be examined by measuring coleoptile lengths approximately 7 days after seedling growth. Moreover, we selected light-responsive genes known in Arabidopsis thaliana, such as chlorophyll A/B binding protein (CAB), light-harvesting chlorophyll binding protein (Lhcb) and chalcone synthase (CHS), and confirmed their light-induced gene expression in B. distachyon. Therefore, the present study suggests that the inhibition of coleoptile growth can be used as the parameter to analyze photoresponses in the monocot model plant, and also provide the reference genes whose expression is induced by far-red and red light treatment.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.204-212
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• 2016

To understand the responses of grapevines in response to cold stress causing the limited growth and development, differentially expressed genes (DEGs) were screened through transcriptome analysis of shoots from 2 grapevine cultivars ('Campbell Early' and 'Muscat Baily A') kept at -$2^{\circ}C$ for 4 days. In gene ontology analysis of DEGs from 'Campbell Early', there were 17,424 clones related with biological process, 28,954 with cellular component, and 6,972 with molecular function genes in response to freezing temperature. The major induced genes included dehydrin xero 1, K-box region and MADS-box transcription factor family protein, and MYB domain protein 36, and inhibited genes included light-harvesting chlorophyll B-binding protein 3, FASCICLIN-like arabinoogalactan 9, and pectin methylesterase 61 in 'Campbell Early' grapevines. In gene ontology analysis of DEGs from 'Muscat Baily A', there were 1,157 clones related with biological process, 1,350 with cellular component, and 431 with molecular function gene. The major induced genes of 'Muscat Baily A' included NB-ARC domain-containing disease resistance protein, fatty acid hydrozylase superfamily, and isopentenyltransferase 3, and inhibited genes included binding, IAP-like protein 1, and pentatricopeptide repeat superfamily protein. All major DEGs were shown to be expressed differentially by freezing temperature in real time-PCR analysis. Protein domain analysis using InterPro Scan revealed that ubiquitin-protein ligase was redundant in both tested grapevines. Transcriptome profile of shoots exposed to cold can provide new insights into the molecular basis of tolerance to low-temperature in grapevines, and can be used as resources for development new grapevines tolerant to coldness.

• Journal of Plant Biology
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• v.39 no.4
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• pp.301-307
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• 1996

The disassembly of Chl-protein complexes during dark-induced senescence (DIS) was investigated using detached third and fourthleaves of 21$\pm$1 day-old Arabidopsis thaliana. Although Chl content decreased linearly after 1 d, a significant decrease of photochemical effeciency (Fv/Fm) was observed after 2 d. In experiments using native green gel electrophoresis of Chl-protein complexes combined with additional two-dimensional SDS-PAGE analysis, we could observe the degradation of both photosystems after 2 d. Although light-harvesting complex(LHC) for PSI (LHCI) was degraded first in PSI complex, small PSII apoproteins including CP47/CP43 and D1/D2 apoproteins were degraded first in PSII complexes. LHC for PSII (LHCII) trimers were stable until 4 d. The level of LHCII monomers was increased until 3 and decreased thereafter, resulting in the increase of free pigments. These results suggest that the disassembly process of PSI is different from that of PSII.

• Journal of Plant Biology
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• v.36 no.1
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• pp.97-104
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• 1993

The lipid composition of thylakoid membranes was compared between mesophyll and bundle sheath chloroplasts of maize. According to mild-denaturing gel electrophoresis, mesophyll thylakoids contained both PS I complex and PS II light-harvesting chlorophyll-protein complex(LHCP), while those of bundle sheath cells contained mainly PS I complex. The amount of lipids per mg chlorophyll was higher in bundle sheath thylakoids than in mesophyll. The major polar lipid classes were monogalactosyldiacylglycerol(MGDG), digalactosyldiacylglycreol, sulfolipid and phosphatidylglycerol (PG) in both tissues. Linolenic acid(18 : 3), linoleic acid(18 : 2) and palmitic acid(16 : 0) were the main fatty acyl components, with higher ratio of unsaturated to saturated fatty acids in bundle sheath thylakoids, suggesting these membranes are more fluid. The most striking difference in lipid composition between the two kinds of tissues was the practical absence of trans- 3-hexadecenoic acid(16 : 1t) in PG of bundle sheath thylakoids. This fatty acid is known to be involved in the association of LHCP as oligomeric form. More than 80% of MGDG molecular species was 18 : 3, 18 : 3, demonstrating that maize is a typical 18 : 3 plant. Therefore, the possibility of the functional relationships between the lamella structure, and thus the distribution of photosystems, and MGDG molecular species was excluded.

• BMB Reports
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• v.38 no.4
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• pp.481-485
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• 2005

The response of Spirulina (Arthrospira) platensis to high salt stress was investigated by incubating the cells in light of moderate intensity in the presence of 0.8 M NaCl. NaCl caused a decrease in photosystem II (PSII) mediated oxygen evolution activity and increase in photosystem I (PSI) activity and the amount of P700. Similarly maximal efficiency of PSII (Fv/Fm) and variable fluorescence (Fv/Fo) were also declined in salt-stressed cells. Western blot analysis reveal that the inhibition in PSII activity is due to a 40% loss of a thylakoid membrane protein, known as D1, which is located in PSII reaction center. NaCl treatment of cells also resulted in the alterations of other thylakoid membrane proteins: most prominently, a dramatic diminishment of the 47-kDa chlorophyll protein (CP) and 94-kDa protein, and accumulation of a 17-kDa protein band were observed in SDS-PAGE. The changes in 47-kDa and 94-kDa proteins lead to the decreased energy transfer from light harvesting antenna to PSII, which was accompanied by alterations in the chlorophyll fluorescence emission spectra of whole cells and isolated thylakoids. Therefore we conclude that salt stress has various effects on photosynthetic electron transport activities due to the marked alterations in the composition of thylakoid membrane proteins.