• Plant Biotechnology Reports
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• v.4 no.1
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• pp.53-59
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• 2010

A specific deleted version of ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) lacking the signal receiver domain (1.152 amino acids)-coding sequence, referred to as $ARR1{\Delta}DDK$, was amplified using Arabidopsis thaliana cDNA prepared from adult leaves and transferred into the genome of Nicotiana tabacum cv. Samsun under the transcriptional control of a ${\beta}$-estradiol-inducible expression system. The ectopic expression of $ARR1{\Delta}DDK$ affected the morphology of transgenic seedlings and their segments in vitro. In the presence of an inducer, ${\beta}$-estradiol, ectopic expression of $ARR1{\Delta}DDK$ induced only the formation of soft, pseudo-bulbous tissue in the root tip region of intact seedlings, which appeared similar to callus generated on a hypocotyl segment in the presence of 2,4-D and 6-benzyladenine (BA), both at $1\;{\mu}M$. Those callus tissues on the root tip region could not generate shoots unless $1\;{\mu}M$ BA was supplied. In segment culture, ectopic expression of $ARR1{\Delta}DDK$ induced calluslike tissue around the cut-end of cotyledon and hypocotyl segments with occasional shoot formation, suggesting that the expression of $ARR1{\Delta}DDK$ could substitute for the effects of cytokinin on these segments. Additionally, treatment with only ${\beta}$-estradiol induced NtWUS, a WUS ortholog in tobacco, which was detected during the process of callus tissue formation in the root tip region and also in cotyledon or hypocotyl segments. These findings suggest that the NtWUS might be associated in the transdifferentiation process caused by the functional regulation of $ARR1{\Delta}DDK$ in transgenic tobacco seedlings.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.189-194
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• 1995

Calli were successfully induced from immature embryos of Citrus junos SIEB. cultured on 1/2 MS medium supplemented with 40.4 BA. Plant were regenerated from immature embryo derived callus on MS medium with 5 $\mu$M BA. The calli were morphologically characterized by two types: one was whitish and the other was yellowish. After 16 weeks of culture, shoots and root were formed on calli. Plantlets were transplanted to soil and successfully grown to a whole plant Also, the arrangement of the cells showed many differences according to developmental stages of callus and organogenesis. The small cells were compact in callus cultured for 6 weeks and the extended cells which divided actively appeared in it after 8 weeks of culture. The globular protrusion of compacted cells occurred in callus after 10 weeks of culture, and the neighboring cells were liquefied. Oil sac surrounded by the liquefied cell was observed in the leaf and was formed by rupture of liquefied cells.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.161-166
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• 1994

Since garlics (Allium sativum L.) are propagated through cloves, infection by virus or other pathogens may become severe problem if not using high quality seed bulbs every year resulting in the reduction of yield and bulb quality, In order to solve this problem, the establishment of virus-free bulb production and its supply system have been required because no chemicals were found to eliminate viruses from seed bulbs. This experiment was conducted to develop an effective production technique of high quality seed bulbs using shoot-tip culture. Over 90% of shoot-tips explanted on January L 1990 were survived at constant temperature of either 20, 24 or 28$^{\circ}C$, wheres 88% at alternate temperature (28/20$^{\circ}C$). The growth of shoot and root was most vigorous at constant 24$^{\circ}C$, and least at alternate temperature (28/20$^{\circ}C$) condition. When shoot-tips were explanted June 21 to August 1,1991, survival and growth of shoot-tips was most vigorous on MS medium supplymented with 0.1 mg/L NAA and 2 mg/L kinetin and least 1 mg/L Gh$_3$. The shoot-tips taken from the seed bulbs stored at 4$^{\circ}C$ for 15 to 60 days were placed on MS medium, shoot growth and in vitro bulblet formation increased slightly as affected by the increase of told treatment period at 4$^{\circ}C$.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.137-143
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• 1994

In an attempt to optimize the in vitro-regeneration conditions necessary for the genetic manipulation of tomato species, we examined several hybrid lines and wild species (peruvianum, pimpinellifolium, glandulosum) of Lycopersicon for. their, different regeneration ability. The basal medium used for callus growth and organogenesis was MSB (MS + B5) supplemented with three combinations of TDZ (Thidiazuron) 0.5mg/L+NAA 0.5mg/L, BA 2.0mg/L+NAA0.05 mg/L, and zeatin 3.0 mg/L + IAA 0.02 mg/L. In the genotype of Lycopenicon grandulosum, combination of TDZ and NAA was more effective in inducing shoot and root differentiation than those of BA and NAA or zeatin and IAA. When all genotypes tested were considered, however combination of zeatin and IAA was shown to be the best in shoot regeneration. Result indicate that callus and organogenesis of Lycopenicon species are dependent upon the hormone types and plant genotypes, but MSB medium with zeatin 3.0 mg/L + IAA 0.02 mg/L maybe appropriate for genotype-independent plant regeneration system of Lycopercicon species. We also tried TDZ as a cytokinin source in tomato tissue culture and found it highly significant in tomato regeneration system.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.43-50
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• 2014

This study was carried out to determine the optimal medium composition and growth regulators for the micropropagation of Platycodon grandiflorum (Jacq.) A. DC. Nodes containing yellow green petals were used as plant materials to execute the study. The best performance of adventitious root development was found in 1/4 strength of MS basal salt and the growth was satisfactory in the concentration of 1/2 MS medium. The best condition for adventitious root development and growth was observed in the higher concentration (5%) of sucrose and activated charcoal free 1/4MS medium respectively. Adventitious roots were developed at the controlled culture medium at pH 4.8 with a tendency of suppression with higher levels of pH. However, it was prevailed that the development and growth depended on the concentration of agar. The lower concentration of agar (0.4%) was performed better than that of higher concentration (1.2%), whereas the agar concentration (0.4%) showed the best performance for the development and growth of adventitious roots. For the development of shoots containing node, BA combined with IAA was more effective than kinetin with IAA or NAA. The highest shoot development (3.9 shoots per explant) was performed on MS medium supplemented with 0.1 mg/L BA and 0.5 mg/L IAA.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.304-308
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• 2021

Iris koreana (Iridaceae) is an endangered plant native to Korea. In order to develop an in vitro propagation method, we investigated the effect of 2,4-dichlorophenoxy acetic acid (2,4-D) and a-naphthalene acetic acid (NAA) on callus induction in different I. koreana tissues. In addition, we also investigated the effect of 2,4-D and Benzyl aminopurine (BA) treatments on adventitious shoot induction in viable calli and the effect of indole-3-butyric acid (IBA) on root formation in viable shoots. We found that callus production was highest with 1.0 mg/L NAA (94.4% cultured rhizome explants), and adding low concentrations of 2,4-D to BA containing media significantly increased the frequency of shoot primordial formation. The best rooting results were obtained with 1.0 mg/L IBA, on which 98% of regenerated shoots developed roots and produced an average of 7.4 roots within 45 days. This in vitro propagation protocol will be useful for conservation, as well as for mass propagation.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.1-6
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• 1999

In order to obtain plantlet derived by anthers, the anthers of Lilium asiatic hybrid 'Gran Paradiso' were cultured on Murashige and Skoog's medium supplemented with various combinations of auxin and cytokinin. The most suitable pollen stage of anther culture for the callus induction was 3 days before anthesis at the early to late binucleate stage. Organogenic calli were induced on MS medium supplemented with 5.0 mg/L 2,4-D alone and the combination of 1.0 mg/L 2,4-D and 1.0 mg/L kinetin, however, the combination of NAA and BA was more effective than that of 2,4-D and kinetin on plant regeneration through organogenesis. Shoots were formed from the induced callus on the medium with 0.5 mg/L NAA and 1.0 mg/L BA after 180 days of culture. Multiple shoots with 3-4 leaves, roots, and bulblets were formed on the medium with the combination of 2.0 mg/L NAA and 2.0 mg/L BA after 250 days of culture. The chromosome from root tip of the regenerated plantlet showed the diploid (2n=2x=24). Diploid plants were transferred to the pots and all plants were flowered in two years.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.634-639
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• 2006

In order to develop a disease-resistant root stock for the growth of watermelon, an efficient regeneration system of the gourd(Lagenaria leucantha Duch.) inbred line GO701-2 via organogenesis was established in this experiment. Using proximal parts of cotyledon explant excised from germinated seedling in vitro, maximum adventitious shoot formation (39%) was achieved on MS medium where cytokinin (BA) and auxin (IAA) were added at a concentration of 3mg/L and 0.1mg/L, respectively. Roots of the elongated shoots were successfully formed on MS medium without adding any plant growth regulators. The cucumber CsGolS1 gene known as a resistance gene against biotic and abiotic stresses, was constructed into the binary vector pBI121 under the control of CaMV 35S promoter. When the gene was introduced into the genome of gourd by Agrobacterium-mediated transformation, putative transgenic plants were obtained with the transformation efficiency of approximately 20 percent.