• BMB Reports
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• v.32 no.2
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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.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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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.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.318-321
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• 2009

The Efficacy of PSB-2061, was investigated in comparision with predinisolone in acetic acid and Picrylsulfonic acid solution (TNBS)-induced rat inflammatory bowel disease (IBD) for 5 days. 5 % TNBS solution were administered with polyethylene (P.E) tube inserted to rats intracolon, which causing colitis to the rats. The TNBS control group (the saline treated colitic rat) exhibited ulceration and inflammation of the distal colon with formation of granuloma and pathologic connections. We checked the inflammatory parameters like rat's weight, food intake quantity change during administration. After 5 days, we sacrificed the rats and checked the colon's length, ulcer and pathologic condition. Oral treatment with PSB-2061 resulted in significant recovery of macroscopic parameters like weight and diet intake change. Especially, PSB-2061 extract had a more potent effect than $mesalazine^{(R)}$ on macroscopic colonic damage score. We can suggest that PSB extract could be a promising drug in the treatment of IBD.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.318-326
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• 2016

Two phosphate solubilizing bacteria, Pantoea rodasii PSB-11and Enterobacter aerogenes PSB-12, were isolated from button mushroom compost and employed to assess their synergistic effect in liquid medium and on growth of green gram plants by single and co-inoculation of the strains. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($521{\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of Pantoea strain ($485{\mu}g\;ml^{-1}$) and Enterobacter strain ($470{\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production and glucose consumption was observed in the E. aerogenes PSB-12 single inoculated culture medium rather than those of co-inoculation. According to the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 10.6% and 10.7% higher shoot and root growth respectively compared to the control. Therefore, in concluding, co-inoculation of the strains P. rodasii and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, being short assessment period of the present study, we recommend in engaging further works under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.401-414
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• 2016

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia anthina PSB-15 and Enterobacter aerogenes PSB-16, was assessed in liquid medium and green gram plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($519{\mu}g\;mL^{-1}$) into the medium, followed by single inoculation of Burkholderia strain ($492{\mu}g\;mL^{-1}$) and Enterobacter strain ($483{\mu}g\;mL^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production, and glucose consumption were observed in the culture medium co-inoculated with PSB-15 and PSB-16 strains rather than that of single inoculation. Based on the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 9% and 8% higher shoot and root growth, respectively, compared to the control. Therefore, in conclusion, co-inoculation of the strains B. anthina and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, considering the short assessment period of the present study, we recommend engaging in further work under field conditions in order to test the suitability of these strains as bio-inoculants.

• Journal of Photoscience
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• v.12 no.3
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• pp.175-183
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• 2005

Plants dissipate excess excitation energy from their photosynthetic apparatus by a process called non-photochemical quenching (NPQ). The major part of NPQ is energy dependent quenching (qE) which is dependent on the thylakoid pH and regulated by xanthophyll cycle carotenoids associated with photosystem (PS) II of higher plants. The acidification of the lumen leads to protonation and thus conformational change of light harvesting complex (LHC) proteins as well as PsbS protein of PSII, which results in the induction of qE. Although physiological importance of qE has been well established, the mechanistic understanding is rather insufficient. However, recent finding of crystal structure of LHCII trimer and identification of qE mutants in higher plants and algae enrich and sharpen our understanding of this process. This review summarizes our current knowledge on the qE mechanism. The nature of quenching sites and components involved in this process, and their contribution and interaction for the generation of qE appeared in the proposed models for the qE mechanism are discussed.

• Korean Journal of Weed Science
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• v.15 no.3
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• pp.206-213
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• 1995

Glyphosate(N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves(i.e. third old leaf) of tomato(Lycopersicon esculentum Mil var. Moneymaker). Herbicide binding protein, QB protein(D1), has been immunoblotted using the antibodies raised against the hybrid-protein expressed by a part of spinach psb A gene cloned in frame with the 3'end of lac Z gene to allow expression of the ${\beta}$-galactosidase(EC 3.21.23) in Escherichia coli. Glyphosate has an effect on a turnover of D1 within photosystem II of thylakoid membrane. The dysfunction of D1 protein within light harvesting complex(LHC-II) seems to be a pleiotropic effect of glyphosate.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.259-266
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• 2011

Elsholtzia hallasanensis, E. springia, and E. splendens var. fasciflora (Lamiaceae) were reported recently as new species or new varieties of E. splendens according to their morphological characteristics. To reappraise the taxonomic status of these additional taxa and to determine the relationships between all Korean Elsholtzia taxa except E. saxatilis, which is distributed in North Korea, molecular studies based on the nrDNA (ITS) and cpDNA (rpl16, and trnH-psbA) sequences of seven taxa of Elsholtzia and one outgroup were carried out. The molecular data support that E. angustifolia and E. minima are distinct species from E. splendens and E. ciliata, respectively, because they have several private marker genes and show monophyly. The molecular data also support that E. splendens has a very close taxonomic relationship with both E. hallasanensis and E. springia. We found that E. splendens var. fasciflora, with multiple inflorescence, was based on several private marker genes and on the monophyly of its trees, suggesting that it can be considered as a variety. Elsholtzia springia, with the same sequences and the same morphological characteristics with E. hallasanensis after transplanting, should be treated as a synonym of E. hallasanensis. Moreover, we consider the taxonomic status of E. hallasanensis as E. splendens var. hallasanensis (Y. Lee) N.S. Lee & C.S. Lee, stat. nov.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.189-195
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• 1997

A phosphate solubilizing bacterium (PSB) possessing a high ability to solubilize hydroxyapatite (HA) was isolated from the rhizosphere of wheat. The PSB markedly developed clear zones after inoculating for 36 hours at $30^{\circ}C$. This bacterium was identified as Enterobacter agglomerans through API 20E system and Biolog$^{TM}$ analysis. The values of similarity and distance coefficient from authentication trial of the strain were 0.656 and 4.79 respectively. High performance liquid chromatography (HPLC) of the products of this strain indicated that this strain excretes maily oxalic acid with som other organic acids. During the incubation period of E. agglomerans, the pH values showed an inverse correlation ($r^2=0.933^{**}$) with solubilization of inorganic phosphate. Acid phosphatase activity of the strain was 10-15 times greater than alkaline phosphatase activity. Alkaline phosphatase activity had almost constant near zero activity across time. The population of E. agglomerans greatly increased during the first day of inoculation ; however, it drastically decreased thereafter.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.29-36
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• 2009

Fourteen bacterial strains were isolated from crop rhizosphere and identified as phosphate solubilizing bacteria (PSB) by 16S rRNA analysis. Only 3 strains exhibited a strong ability to solubilize insoluble phosphate in agar medium containing a hydroxyapatite. The rates of P solubilization by isolates were ranged from 200 and $2300\;mg\;L^{-1}$, which are inversely correlated with pH in culture medium. Furthermore, HPLC analyses reveal the production of organic acid from the culture filtrates of PSB. Among these, strain Acinetobacter sp. released only gluconic acid, Pseudomonas orientalis produced gluconic acid which was subsequently converted into 2-ketogluconic acid, and Enterobacter asburiae released acetic acid and succinic acid. On the other hand, P. orientalis and E. asburiae released $372\;mg\;L^{-1}$ and $191\;mg\;L^{-1}$ of IAA into broth culture, respectively, while Acinetobacter sp. did not produce IAA. Furthermore, in vivo study showed that plant growth promoting effect by bacteria generally seemed to be increased IAA production and phosphate solubilization.