• Journal of Life Science
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• v.16 no.3 s.76
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• pp.527-533
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• 2006

The purpose of this study is to improve the culturability of a indica type rice cultivar, IR 36, using DNA marker associated with the ability of plant regeneration in anther and seed culture. The varietal difference of ability of callus formation and plant regeneration was investigated in anther and seed culture of 8 rice cultivars. Three japonica rice cultivars showed to have better culturability than those of tongil and indica type genotypes. But two indica/japonica lines, 'MGRI 079' and 'MGRI 036', which were selected to have good culturability in previous study showed the highest regenerability (20%) in anther culture of 8 rice cultivars. Thirty four $BC_2F_4$ lines were selected by marker screening using RZ400 for 100 $BC_2F_4$ lines derived from a cross $'MGRI\;079/IR\;36^{^*3}'$. The frequency of callus formation of 30 $BC_2F_4$ lines was higher than those of 'IR 36' in anther culture of the selected $BC_2F_4$ lines. The ability of plant regeneration of 15 lines was higher than that of 'IR 36' in the seed culture of 34 $BC_2F_4$ lines. A promising line, $BC_2F_4-28$, was selected to have better culturability in the anther and seed culture of the $BC_2F_4$ lines. The heading date and grain shape of the $BC_2F_4-28$ was similar to 'IR 36'. In seed culture of 50 $BC_4F_3$ lines derived from a rice cross $'MGRI\;079/IR\;36^{^*5}'$, 11 lines including $BC_4F_3-3$ showed to have higher regenerability compared with 'IR 36'. The highest frequency of plant regeneration (11%) was obtained from $BC_4F_3-46$ in seed culture of the $BC_4F_3$ lines.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.195-200
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• 1998

Callus induction from leaf and stem explants of Arabidopsis thaliana was successfully obtained when leaf explants were cultured on MS medium containing 2.0 mg/L 2,4-D in the dark and also, when stem explants were cultured on CP medium containing 0.5 mg/L 2,4-D and 0.1 mg/L BAP. Explant-derived sliced calli were suspension-subcultured every week in CP liquid medium with 0.5 mg/L 2,4-D and 0.1 mg/L BAP in the dark, and shoot-forming cell clusters of nodular, pale yellow and knobby type were selected after 7-8 weeks of culture. Shoots were initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium containing 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for four weeks. Shoot regeneration frequency (calli regenerating at least one shoot) was more than 50%. For plant regeneration, excised shoots were trnasferred to hormone free medium for root initiation after 4 weeks of culture. The regenerants were bolting after 2 weeks of culture and formed in vitro flowering buds within bracts after 4 weeks of culture.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.53-62
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• 2019

The purpose of this study was to establish the in vitro propagation system by shoot tip culture of six Hosta species native to Korea (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) for mass proliferation and a new cultivar development. The shoot tips of each Hosta species were cultured on MS medium containing eight combinations of 0.5, 1.0, 2.0, 4.0 mg/L BA with 0.1 mg/L NAA, 0.1, 0.5, 1.0, 2.0 mg/L TDZ with 0.1 mg/L NAA, and without any PGRs (control). They were investigated on callus, somatic embryo, crown bud, differentiation and growth of shoot and root, total fresh weight after 8 weeks of culture. In all six Hosta species, callus and somatic embryo induction rate and multiple shooting rate of the PGRs treatment group were higher than that of the control group. The highest number of differentiated shoots were obtained on medium supplemented with 2.0 ㎎/L TDZ in H. capitata (5.4), 1.0 mg/L TDZ in H. clausa and H. jonesii (3.3 and 5.8, respectively), 0.5 mg/L BA in H. minor (11.1), 1.0 mg/L BA and 0.1 mg/L TDZ in H. venusta (8.1), and 0.5 mg/L TDZ in H. yingeri (9.8). In somatic embryo formation, the PGRs treatment group of H. jonesii and H. yingeri were more effective than the control group, and the effects were relatively less in H. capitata, H. clausa Nakai, H. minor, H. venusta. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. H. clausa showed no significant effect on callus and shoot differentiation regardless of the type and concentration of cytokinin, but slightly increased in formation of crown bud in TDZ.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.140-146
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• 2000

This study was conducted to determine the effect of cutting type, growth regulators and propagation media on the rooting and root growth of Roea davurica $P_{ALL}$. Three type of cutting, hardwood, half-softwood, softwood cutting and root cutting of Rosa davurica $P_{ALL}$, were used to study the rooting ability. There was no rooting in hardwood cutting while root cutting was appeared 100% of callus formation and rooting. The optimum conditions of softwood cutting for rooting were IAA 100ppm and rooton-F at vermiculite+perlite. The rate of rooting in treatment of rooton-F ranged from 10 to 60%, but such a good effect was not appeared in other growth regulators, IAA, NAA and IBA.

• Proceedings of the Botanical Society of Korea Conference
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• 1996.07a
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• pp.61-74
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• 1996

Human and monogastric animals can not synthesize 10 out of the 20 amino asids and therefor need to obtain these from their diet. The plant seed is a major source of dietary protein. It is particular important in their study to increase nutritional quality of the seed storage proteins. The low contents of lysine, asparagine and threonenein various cereal seeds and of cystein and methionine. In legume seeds is due to the low proportions of these amino acids in the major storage proteins, we have tried to apply the three strategies; (1) mutagenesis and selection of specific amino acid analogue resistance, (2) cloning and expression study of lysine biosynthesis related gene, (3) transfomation of lysine rich soybean glycinin gene. The 5-methyltryptophan (5MT) resistant cell lines, SAR1, SAR2 and SAR3 were selected from anther derived callus of rice (Oryza sativa L. "Sasanishiki"). Among these selected cell lines, two (SAR1 and SAR3) were able to grow stably at 200 mg/L of 5MT. Analysis of the freed amino acids in callus shows that 5MT resistant cells (SAR3) accumulated free tryptophan at least up to 50 times higher than those that of the higher than of SAS. These results indicated that the 5MT resistant cell lines are useful in studies of amino acid biosynthesis. Tr75, a rice (Oryza sativa L., var. Sasanishiki) mutant resistant to 5MT was segregated from the progenies of its initial mutant line, TR1. The 5MT resistant of TR75 was inherited in the M8 generations as a single dominant nuclear gene. The content of free amino acids in the TR75 homozygous seeds increased approximately 1.5 to 2.0 fold compared to wild-type seeds. Especially, the contents of tryptophan, phenylalanine and aspartic acid were 5.0, 5.3 and 2.7 times higher than those of wild-type seeds, respectively. The content of lysine is significantly low in rice. The lysine is synthesized by a complex pathway that is predominantly regulated by feedback inhibition of several enzymes including asparginase, aspatate kinase, dihydrodipicolinat synthase, etc. For understanding the regulation mechanism of lysine synthesis in rice, we try to clone the lysine biosynthetic metabolism related gene, DHPS and asparaginase, from rice. We have isolated a rice DHPS genomic clone which contains an ORF of 1044 nucleotides (347 amino acids, Mr. 38, 381 daltons), an intron of 587 nucleotides and 5'and 3'-flanking regions by screening of rice genomic DNA library. Deduced amino acid sequence of mature peptide domain of GDHPS clone is highly conserved in monocot and dicot plants whereas that of transit peptide domain is extremely different depending on plant specie. Southern blot analysis indicated that GDHPS is located two copy gene in rice genome. The transcripts of a rice GDHPS were expressed in leaves and roots but not detected in callus tissues. The transcription level of GDHPS is much higher in leaves indicating enormous chloroplast development than roots. Genomic DNA clones for asparaginase genes were screened from the rice genomic library by using plaque hybridization technique. Twelve different genomic clones were isolated from first and second screening, and 8 of 12 clones were analyzed by restriction patterns and identified by Southern Blotting, Restriction enzyme digestion patterns and Southern blot analysis of 8 clones show the different pattern for asparaginase gene. Genomic Southern blot analysis from rice were done. It is estimated that rice has at least 2-3 copy of asparaginase gene. One of 8 positive clones was subcloned into the pBluescript SK(+) vector, and was constructed the physical map. For transformation of lysine rich storage protein into tobacco, soybean glycinin genes are transformed into tobacco. To examine whether glycinin could be stably accumulated in endosperm tissue, the glycinin cDNA was transcriptionally fused to an endosperm-specific promotor of the rice storage protein glutelin gene and then introduced into tobacco genomic via Agrobacterium-mediated transformation. Consequently the glycinin gene was expressed in a seed-and developmentally-specific manner in transgenic tobacco seeds. Glycinin were targeted to vacuole-derived protein bodies in the endosperm tissue and highly accumulated in the matrix region of many transgenic plant (1-4% of total seed proteins). Synthesized glycinin was processed into mature form, and assembled into a hexamer in a similar manner as the glycinin in soybean seed. Modified glycinin, in which 4 contiguous methionine residues were inserted at the variable regions corresponding to the C - teminal regions of the acidic and basic polypeptides, were also found to be accumulated similarly as in the normal glycinin. There was no apparent difference in the expression level, processing and targeting to protein bodies, or accumulation level between normal and modified glycinin. glycinin.

• Journal of Plant Biotechnology
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• v.6 no.3
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• pp.157-163
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• 2004

An efficient system for the regeneration of adventitious shoots from in vitro cultured leaf sections of Lycium chinense Miller was developed and silent somaclones from the regenerants detected with RAPD method. Among the eight media tested (B5, SH, N&N, 1/2MS, MS, 3/2MS, GD and WPM), and four cytokinins (BA, kinetin, 2ip and zeatin) with different concentrations (1, 5, 10, 20, 30 and 40 $\mu{M}$), 1/2 MS medium supplemented with 20 and 30 $\mu{M}$ zeatin showed the best regeneration frequency (100% and 93.7%) and higher average number of shoots (9.0 and 9.4). All regenerants easily elongated after subculturing on 1/4MS without growth stimulants and produced spontaneous adventitious roots from their basal parts. With phenotypically normal 40 regenerants, RAPD analysis with 15 different random primers was performed to examine the cryptic somaclonal variants. No substantial differences in banding patterns were found in the amplified polymorphic DNAs implying no DNA changes during dedifferentiation into adventitious shoots. However, one (OPF-4) of the 15 primers detected silent somaclonal variation in one regenerant in which two different polymorphic bands did not appear when compared with the rest regenerants. The results indicate that regenerantion via intervening callus phase can be used to establish true-to-type planting stocks for homogeneous population.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.174-178
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• 1999

An anthocyanin-deficient tomato (Lycopersicon esculentum Mill.) strain, H957, shows an unusual tolerance to low phosphorus (P). To investigate whether the tolerance originates from a tissue/cellular strength, plant tissue culture procedure was employed which facilitate to characterize the tolerance independent of morphological features. The tolerance was analyzed by comparing H957 against H883, its maternal wild type, while each explant was co-cultured on minimal P media. Comparisons were made in fresh weight, dry weight, callus and shoot formation, mineral contents, and P utilization ratios at $0-400{\cdot}\bar{I}MP$, . Growth of the two strains was severely impaired at 0 and $12.5{\cdot}\bar{I}MP.\;At\;25-200{\cdot}\bar{I}MP$, however, H957 consistently showed a greater fresh and dry weight than H883. Shoot onset of H957 was less delayed than H883 compared to optimal P conditions. H957 tissue contains an overall lower P concentration than H883. These observations indicate that H957 may tolerate to low P by its tissue or cellular strength in P utilization side from its morphology.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.291-299
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• 2006

During long bone lengthening, there are many disadvantages including axial deviation, malalignment and re-fracture which are commonly encountered inspite of its proven abilities. To study the effects of intramedullary K-wire application on the lengthening of long bone, ten skeletally mature mongrel dogs were separated into two groups(Group I, II). Right femurs of group I(5 dogs) were fixed with only monolateral external fixator after subperiosteal osteotomy. Right femurs of group II(5 dogs) were fixed with mono lateral external fixator and intramedullary K-wire after subperiosteal osteotomy. Lengthening was started at 7 days after the surgery with the rate of 0.5 mm per day for 5 weeks and the dogs were sacrificed after 15 weeks postoperatively to examine histologic differences and evaluate bone mineral density. Radiographic examination at an interval of two weeks was done to evaluate the type of callus formed and to analyze complications including instability of external skeletal fixation and axial deviation. Bone mineral density at the lengthened area and contralateral nonlengthened area were measured using quantitative computerized tomography. Histological examination of regenerated bone was performed using Masson's trichrome stain method. The radiographs demonstrated poor callus formation, higher incidence of axial deviation and screw loosening in the group I compared to the group II. The bone mineral density at the lengthened area in the group II was higher than that of the group I(P<0.05). Histological examination showed that the new bone trabeculae in the group II were greater than that of the group I. In conclusion, the combination of monolateral external fixator and intramedullary K-wire can prevent pin loosening, axial deviation and reduce healing period in dogs.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.149-156
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• 1999

In order to investigate the effect of low temperature pretreatment on pollen dimorphism and embryo formation in anther culture of Platycodon grandiflorum, the anthers with microspore at the uninucleate stage were cultured on Murashige and Skoog medium supplemented with 0.5mg/L NAA and 1.0 mg/L BA. The low temperature pretreatment have clear effect on the frequencies of S pollen grains, symmetrical binucleate microspores (B type of S pollen), multinucleate and multicelled pollen grains. Especially, after low temperature pretreatment at 8$^{\circ}C$ for 5 days increased the frequency of S pollen grain (20.6%) in vivo. In addition, the highest frequency of callus induction (54.9%) and embryo formation (9.9%) were obtained from the anther pretreatment at 8$^{\circ}C$ or 5 days. Three distinct pathways could be recognized in the androgenesis, one involving mainly the vegetative cell, the second starting with the vegetative and the generative cell, respectively, and the third accompaning with two equal vegetative type cells in the pollen grains.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.7-14
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• 1994

Immature zygotic embryos of five Korean soybean cultivars cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) produced somatic embryos without forming an intervening callus. The highest frequency (up to 90%) of somatic embryo formation was obtained when zygotic embryos were cultlued on medium containing 1 to 2 mga 2, 0-D in four cultivars. However the frequency was highly variable to the cultivars. Transversely sliced primary somatic embryo halves were also capable of forming secondary embryos at frequencies of up to 70% when cultured on medium containing 0.1 to 1 mg/L 2,4-D. Somatic embryos formed on zygotic embryos cultured on medium containing 0.1 to 0.2 mg/L 2,4-D had two cotyledons more frequently than one horn-type cotyledon and those on medium containing 0.5 to 4mg/L 2,4-LD had a horm-type cotyledon at a prominently higher freequency. However somatic embryos on medium containing 10mg/L or higher concentrations of 2,4-D were usually shunted at the globular stage even after transfer to medium containing lower concentrations of 2,4-D or other growth regulators. non somatic embryos with one or two cotyledons or a hem-type cotyledon were transferred to medium containing $GA_3$, those with two cotyledons converted to plantlets at a higher frequency (25%) than the others.