• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.325-334
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• 1995

The early senescence mutant induced from Gihobyeo by $\gamma-ray$ irradiation was determined. The mutated gene expression was identified with comparing the characteristic of original cultivar. The mutant had so similar the morphological characteristics to original cultivar that it couldn't be distinguished until senescence occurred at about 20 days after heading. Suddenly yellow leaves were observed within a few days due to great decreases in total chlorophyll and various carotenoid contents. Transmission electron microscopy showed the formation of starch granules, distortion of fine structure of leaf cell organelles, especially grana structures, and the decrease in grain filled after senescence occurred. But banding patterns of total proteins and isozymes have not show any differences, The early senescence mutant will be very useful for study material not only on physiological and biochemical properties of plant senescence but also on gene expression regulating senescence which gives great influence on yield potential and its stability.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.349-353
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• 2009

We developed a new barley cultivar "Dami" (Hordeum vulgare L.) with the auricleless gene lig (al, li, aur-a). The characteristic of auricleless is a spontaneous mutant type which has known as a monogenic recessive gene. The plant with the gene has erect leaf blades because of no auricle. The cultivar was derived from a cross between 'BGS60' and 'Kangbori'. 'BGS60' has the auricleless gene (li), while 'Kangbori' showed a high biomass with winter hardiness and resistance to BaYMV (Barley Yellow Mosaic Virus). Subsequent generations were handled by the bulk method in a pedigree selection program. A promising line showed both high yield and lodging resistance in the yield trials at Iksan in 2003 to 2004, and designated as Iksan414. The line was subsequently evaluated for winter hardiness, earliness, and yield in the seven locations around Korea for three years from 2005 to 2007 and was designated as "Dami" and released. It has the growth habit of III, erect plant type, green leaf and stem similar to the check cultivar 'Sunwoo' Its heading date was April 30, and maturing date May 31 in paddy field conditions, which were similar to those of 'Sunwoo' respectively. The cultivar Dami was 97 cm in culm length, had 643 spikes per $m^2$ and higher leaf dry weight, and better adaptability to dense planting, winter hardiness, and resistance to BaYMV than the check cultivar did. The average forage yield of "Dami" was about 12 ton $ha^{-1}$ in dry matter (33 ton $ha^{-1}$ in fresh matter) in paddy field. "Dami" also showed 7.5% of crude protein content, 28.5% of ADF (Acid Detergent Fiber), 50.1% of NDF (Neutral Detergent Fiber), and 66.4% of TDN (Total Digestible Nutrients), including higher grade of silage quality for whole crop barley. This cultivar would be suitable for the area where the daily minimum temperature of January is above $-8^{\circ}C$ in Korean peninsula.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.666-670
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• 2008

Lovastatin (Mevinolin, Monacolin K) is a well-known drug for the therapy of hypercholesterolemia. It is an important fungal secondary metabolite as it inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, EC 1.1.1.34) which catalyzes a major rate-limiting step in the biosynthesis of cholesterol. Both soybeans and black soybeans with Aspergillus terreus ATCC 20542 mutant were used as the seed culture for the mass production of lovastatin. The production of lovastatin in soybean seed culture of Asp. terreus was twofold compared to that of black soybean seed culture. The effect of two different vessels (petri dish and Erlenmeyer flask) on lovastatin production was also studied. The production of lovastatin on petri dish was tenfold to that of Erlenmeyer flask. Furthermore, the most lovastatin production on rice bran was achieved when the soybean seed culture was treated by heat shock at $30^{\circ}C$ for 1 hour, representing 82% of HMG-CoA reductase inhibition in the koji extract. We estimated that the heat treated soybean seed culture could be a new method for the mass production of lovastatin.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.89-96
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• 2000

For large DNA fragment transformation in dicots and monocots, BIBAC2 vector system was applied to Arabidopsis thaliana and Oryza sativa L. cv. Jinmi as a model plant, respectively. For Arabidopsis, the Th1 gene in T23L3 BAC clone whose size is about 90 kb was used as the target gene source for transformation. Because T23L3 BAC clone was originally constructed in pBelloBAC11, the target gene was reconstructed into BIBAC2. As the results of reconstruction, 476 colonies were survived in selection medium containing 40 mg/L kanamycin. In colony hybridization analysis, 24 out of 476 colonies exhibited positive signals. In the pulsed-field gel electrophoresis analysis, 11 out of 24 positive clones exhibited the band at the location of 90 kb. In Southern hybridization, positive signal band at the location of 90 kb was observed in all 11 transformants. Using these verified clones, Agrobacterium-mediated transformation was applied to Arabidopsis thaliana th1-201 mutant for genetic complementation test. Twelve thousands T$_1$ seeds were harvested, and antibiotic selection test is being analyzed to verify whether these seeds were transformed. for rice, COR356 that contains 150 kb human genomic DNA in a BIBAC2 vector was used as the target gene. As the results of transformation, 151 out of 210 co-cultivated calli were survived in selection medium containing 5 mg/L hygromycin, and 45 out of 151 survived calli were regenerated into plants. Transformation efficiency was 21.6%. Progeny test using 71 seeds is being analyzed now. These results provide the potential that large DNA fragments can be transferred into both dicots and monocot by Agrobacterium-mediate d transformation system.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.564-574
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• 2019

Like many fungal pathogens, the conidium and appressorium play key roles during polycyclic dissemination and infection of Magnaporthe oryzae. Ran-binding protein microtubule-organizing center (RanBPM) is a highly conserved nucleocytoplasmic protein. In animalia, RanBPM has been implicated in apoptosis, cell morphology, and transcription. However, the functional roles of RanBPM, encoded by MGG_00753 (named MoRBP9) in M. oryzae, have not been elucidated. Here, the deletion mutant ΔMorbp9 for MoRBP9 was generated via homologous recombination to investigate the functions of this gene. The ΔMorbp9 exhibited normal conidial germination and vegetative growth but dramatically reduced conidiation compared with the wild type, suggesting that MoRBP9 is involved in conidial production. ΔMorbp9 conidia failed to produce appressoria on hydrophobic surfaces, whereas ΔMorbp9 still developed aberrantly shaped appressorium-like structures at hyphal tips on the same surface, suggesting that MoRBP9 is involved in the morphology of appressorium-like structures from hyphal tips and is critical for development of appressorium from germ tubes. Taken together, our results indicated that MoRBP9 played a pleiotropic role in polycyclic dissemination and infection-related morphogenesis of M. oryzae.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.106-112
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• 2014

Very few plant growth-promoting rhizobacteria (PGPR) are known to produce gibberellins (GAs). The current study aimed to isolate a phytohormone-producing PGP rhizobacterium from soil and assess its potential to enhance plant growth. The newly isolated bacterium was identified as Leifsonia soli sp. SE134 on the basis of partial 16S ribosomal RNA gene sequence. Application of L. soli culture filtrate significantly increased the biomass, hypocotyl, and root lengths of cucumber seeds as compared with non-inoculated sole medium and distilled water treated controls. Furthermore, the PGPR culture was applied to the GA-deficient mutant rice cultivar Waito-C. Treatment with L. soli SE134 significantly increased the growth of Waito-C rice seedlings as compared with controls. Upon chromatographic analysis of L. soli culture, we isolated, detected and quantified different GAs; namely, $GA_1$ ($0.61{\pm}0.15$), $GA_4$ ($1.58{\pm}0.26$), $GA_7$ ($0.54{\pm}0.18$), $GA_8$ ($0.98{\pm}0.15$), $GA_9$ ($0.45{\pm}0.17$), $GA_{12}$ ($0.64{\pm}0.21$), $GA_{19}$ ($0.18{\pm}0.09$), $GA_{20}$ ($0.78{\pm}0.15$), $GA_{24}$ ($0.38{\pm}0.09$), $GA_{34}$ ($0.35{\pm}0.10$), and $GA_{53}$ ($0.17{\pm}0.05$). Plant growth promotion in cucumber, tomato, and young radish plants further evidenced the potential of this strain as a PGP bacterium. The results suggest that GA secretion by L. soli SE134 might prove advantageous for its ameliorative role in crop growth. These findings can be extended for improving the productivity of different crops under diverse environmental conditions.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.389-397
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• 2007

Using the active-increment of Tos17 copies in the genome of Oryza sativa L., there were many studies about induction and selection of new mutants. This study mainly focuses on the induction for retrotransposon(Tos17) activity in the callus of Ilpumbyeo(Oryza sativa L.) according to varied culture period and condition. The objectives of this study are obtaining various mutants($M_1$) through plant regeneration, identification of the mutation relation with Tos17, and subsequent phenotyping of the mutants($M_2,\;M_3$). A total of 371 $M_1$ mutants was obtained. The degree of Tos17 activity obtained regeneration plants with each different culture period was evaluated by Southern blot analysis. The result showed that control Ilpumbyeo rice has 5 numbers of copies and the band numbers obtained 7, 8, 9.5, 12, 6, 13.5, 17.5 from culture period of 1, 2, 3, 5, 6, 7, 8 month, respectively. In this study, the result showed that most effectual culture period for activity of Tos17 in Ilpumbyeo rice is 5 month. Hereafter, collections and analysis of various recombination plants will act on an important factor in multiplication and preservation of $M_2$ and $M_3$ generation. And an urgent and important subject is a development of screening method for selection of diverse mutants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.187-194
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• 2010

The soybean stay green mutant genotype (SSG) derived from the nuclear gene, d1d2, and cytoplasmic gene, cytG, inhibit the breakdown of chloroplast in the leaves, pod walls, seed coats, and embryos during maturity. Soybean seed with black seed coat and green cotyledon (SBG) are preferred than black seed coat with yellow cotyledon (SBY) especially for cooking with rice and as source of traditional food in Korea. The researchers evaluated the seed's chlorophyll content of SSG and introduced SSG to the SBG variety breeding program. The seed chlorophyll content of SSG with d1d2 was $39.93{\sim}60.80\;{\mu}g/g$ and SSG with cytG $38.08{\sim}39.89\;{\mu}g/g$. The Korean SBG variety which was derived from SSG with cytG, contains $16.35{\sim}37.73\;{\mu}g/g$. The composition of seed chlorophyll differs according to the genetic background of SSG genotype. Inheritance study showed that cotyledon color was segregated 15:1 (yellow:green) at $F_2$ seed indicating two recessive genes control green cotyledon as revealed by previous study. Only less than 3% soybean lines showed black seed coat with green cotyledon among crosses SBY and SSG (d1d2). Results showed that SSG with d1d2 can be used as a good source for SBG with high chlorophyll content in the seed cotyledon, but due to the complex genetic behavior, breeding resource of SBG with d1d2 should be prepared to improve the breeding efficiency for development SBG variety.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.893-902
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• 2011

Endophytic fungi are little known for their role in gibberellins (GAs) synthesis and abiotic stress resistance in crop plants. We isolated 10 endophytes from the roots of field-grown soybean and screened their culture filtrates (CF) on the GAs biosynthesis mutant rice line - Waito-C. CF bioassay showed that endophyte GMH-1B significantly promoted the growth of Waito-C compared with controls. GMH-1B was identified as Penicillium minioluteum LHL09 on the basis of ITS regions rDNA sequence homology and phylogenetic analyses. GC/MS-SIM analysis of CF of P. minioluteum revealed the presence of bioactive $GA_4$ and $GA_7$. In endophyte-soybean plant interaction, P. minioluteum association significantly promoted growth characteristics (shoot length, shoot fresh and dry biomasses, chlorophyll content, and leaf area) and nitrogen assimilation, with and without sodium chloride (NaCl)-induced salinity (70 and 140 mM) stress, as compared with control. Field-emission scanning electron microcopy showed active colonization of endophyte with host plants before and after stress treatments. In response to salinity stress, low endogenous abscisic acid and high salicylic acid accumulation in endophyte-associated plants elucidated the stress mitigation by P. minioluteum. The endophytic fungal symbiosis of P. minioluteum also increased the daidzein and genistein contents in the soybean as compared with control plants, under salt stress. Thus, P. minioluteum ameliorated the adverse effects of abiotic salinity stress and rescued soybean plant growth by influencing biosynthesis of the plant's hormones and flavonoids.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.32-39
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• 1981

In order to study the genetic system of the blast resistant varieties, the conidial suspension of mutant races of T-2$^{+t}$, N-2$^{+t}$, C-8$^{+t}$ was inoculated at 4-5 leaf stage by injector for F_2 seedlings from the crosses between seven resistant varieties and four maker lines easily detectable at seedling stage. The results are summarized as follows; 1. The fertility of cross between Semi-dwaf testers and Indica resistant varieties except Carreon was about 74 percents. 2. The segregation modes of resistance varied with varieties and blast races. However, the resistance was expressed as dominance in all cases. Tetep, Tadukan and Carreon showed more complicated segregation for resistance than that of the bred lines. 3. For blast races used, four segregation ratios such as 3:1, 9:7, 13:3 and 37:27 were found in the Tatukan, Tetep, and IR747, and three segregation ratios such as 3:1, 13:3 and 15:1 in the Carreon, and two segregation ratios of 3:1 and 13:3 with Suweon 287, Suweon 288, and Iri342. 4. In the segregation of the resistance to the each races, the ratios of 3:1, 13:3, 15:1 were fitted to T-2$^{+t}$, and the ratios of 3:1, 13:3, 9:7 and 37:27 to N-2$^{+t}$ and C-8$^{+t}$. 5. Suweon 287, Suweon 288 and Iri342 carried one simple dominant gene and inhibitor gene was considered in some cross combinations. Meanwhile Tadukan, Tetep and IR747 seemed to carry one to three resistant genes, and in some cross combinations, the expression of these genes were simple dominant, inhibiting, duplicating and complimentary action. 6. Resistance genes to blast races, T-2$^{+t}$, N-2$^{+t}$ and C-8$^{+t}$ in the Tadukan, Tetep, Carreon, Suweon 287, Suweon 288 and Iri342 were found to be independent with the linkage group of II(lg), VIII(la), XI(bc), and XII(gl).bc), and XII(gl).