• Horticultural Science & Technology
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• v.35 no.2
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• pp.252-264
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• 2017

Tea is one of the most consumed beverages worldwide and the relatively high levels polyphenols is benefit for health. In this study, we developed an efficient system for proliferation of callus from 'Anji Baicha', a cultivar of tea (Camellia sinensis). Callus tissue was initially induced by culturing leaf explants on medium containing different plant growth regulators. For callus induction, thidiazuron (TDZ) was more effective than 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}-naphthalene$ acetic acid (NAA), and $N^6-benzyladenine$ (BA). The frequency of callus induction from leaf explants reached 90.21% on $1.0mg{\cdot}L^{-1}$ TDZ and the developed callus was reddish and friable. We also tested the effect of different concentrations of NAA, 2,4-D, indole 3-acetic acid (IAA), BA, and TDZ, alone and in combinations, on callus proliferation. Medium supplemented with TDZ in combination with IAA was suitable for callus proliferation and accumulation of tea polyphenols. The growth index value and tea polyphenol content of callus cultured on MS medium containing $0.5mg{\cdot}L^{-1}$ TDZ and $1.0mg{\cdot}L^{-1}$ IAA was maximally 1,351% and 23.24%, respectively, and the relative abundance of epicatechin was as high as 17.449%. We also measured the antioxidant activity of all samples and the callus with the highest tea polyphenol content also exhibited high potential radical scavenging activity.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.291-296
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• 2019

This study was conducted to determine the effect of a light-emitting diode (LED) on in vitro shoot growth and rooting in teak (Tectona grandis L.). In the experiments with apical bud explants, the greatest shoot elongation (3.2 cm) occurred when they were cultured on DKW medium under 50% blue and 50% red LED mixture (BR), whereas no differences in growth were observed in different light sources (florescent light [F] or BR) or media (MS or DKW). The highest number of shoot multiplication (2.4/explant) or elongation (4.94 cm) was achieved with 0.5 or 1.0 mg/L 6-Benzyladenine (BA) treatment under BR. In addition, the best rooting rate (93.8%) or root length (1.3 cm) was recorded with 0.5 mg/L indole-3-butyric acid (IBA) treatment under BR, and the highest root induction (3.1/explant) was observed in 0.2 mg/L IBA under BR. The in vitro rooted plantlets were hardened and survived well on soil.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.261-267
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• 2010

We describe culture conditions for a high-efficiency in vitro regeneration system of Papaver nudicaule through somatic embryogenesis and secondary somatic embryogenesis. The embryogenic callus induction rate was highest when petiole explants were cultured on Murashige and Skoog (MS) medium containing 1.0 mg $1^{-1}$ ${\alpha}$-naphthaleneacetic acid (NAA) and 0.1 mg $1^{-1}$ 6-benzyladenine (BA) (36.7%). When transferred to plant growth regulator (PGR)-free medium, 430 somatic embryos formed asynchronously from 90 mg of embryogenic callus in each 100-ml flask. Early-stage somatic embryos were transferred to MS medium containing 1.0 mg $1^{-1}$ BA and 1.0 mg $1^{-1}$ NAA to germinate at high frequency (97.6%). One-third-strength MS medium with 1.0% sucrose and 1.0 mg $1^{-1}$ $GA_3$ had the highest frequency of plantlet conversion from somatic embryos (91.2%). Over 90% of regenerated plantlets were successfully acclimated in the greenhouse. Secondary somatic embryos were frequently induced directly when the excised hypocotyls of the primary somatic embryos were cultured on MS medium without PGRs. Sucrose concentration significantly affected the induction of secondary embryos. The highest induction rate (89.5) and number of secondary somatic embryos per explant (9.3) were obtained by 1% sucrose. Most secondary embryos (87.2-94.3%) developed into the cotyledonary stage on induction medium. All cotyledonary secondary embryos were converted into plantlets both in liquid and on semisolid 1/3-strength MS medium with 1.0% sucrose.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.293-298
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• 2007

Robinia pseudoacacia var. umbraculifera, commonly called umbrella black locust were regenerated after co-cultivation of internode segments with Agrobacterium tumefaciens which included yeast cadmium factor 1 (YCF 1) gene. The tolerance to cadmium and lead for plants can be increased by the YCF1 gene expression. Moreover, the recent studies have shown that YCF1 gene transgenic plants increase the accumulation of cadmium and lead into plant vacuoles. The effect of plant growth regulator such as 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}$-naphthaleneacetic acid (NAA), 6-benzyladenine (BA), and thidiazuron (TDZ) were studied to evaluate the propagation of plants through internode explants. The efficient induction of multiple adventitious shoots and callus were observed on a medium supplemented with 0.1 mg/L TDZ + 0.2 mg/L BA. To induce shoot elongation and rooting, regenerated shoots were transferred into basal MS medium without any plant growth regulator. Successful Agrobacterium tumefaciens mediated transformation was obtained by 20 min vacuum-infiltration with $50{\mu}M$ acetosyringone on the optimal multiple shoot induction medium with 30 mg/L hygromycin and 300 mg/L cefotaxime. To confirm the integration and expression of transgene, Polymerase Chain Reaction (PCR) and Reverse Transcriptase PCR (RT-PCR) were performed with specific primers. The frequency of transformation was approximately 18.94%. This study can be used to genetic engineering of phytoremediator.

• 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.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.213-237
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• 1987

In vitro flowering system may minimize the confounded influence of non-floral meristem parts of plants in studying the relationship of a given treatment and flowering responses. We have induced flower buds from plantlets regenerated from zygotic embryo-derived somatic embryos of ginseng, which circumvented the normal 2-year juvenile period before flowering. The result suggests that the adulthood of ginseng root explants in the experiment previously conducted by Chang and Hsing (1980; Nature 284: 341-342) is not prerequired to flowering of plantlets regenerated through somatic embryogenesis. We have also induced flower buds from elongated axillary brandches from cotyledonary nodes by culturing ginseng zygotic embryos, seedlings, and excised cotyledonary nodes. It was found that 6-benzyladenine (BA) supplemented to the medium was essential for flowering, whereas abscisic acid (ABA) was inhibitory. Gibberellic acid(GA3) was also required for flowering when ABA was present with BA in the medium. The results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respective-ly, in the induction of flowering of ginseng. Tran Thanh Van (1980; Int. Rev. Cytol., Suppl. IIA: 175-194) has developed the "thin cell layer system" in which the induction of shoots, roots, or flower buds from epidermal layer explants were controlled by culture conditions and exogenous growth regulators in the medium, Utilizing the thin cell layer system, Meeks-Wagner et al. (1989; The Plant Cell 1: 25-35) have cloned genes specifically expressed during floral evocation. However, the system is too tedious for obtaining a sufficient amount of plant materials for biochmical and molecular biological studies of flowering. We have developed a garlic callus culture system and one obvious advantaging over the thin cell layer system is that an abundant cells committed to develope into flower buds proliferate. When the above cells were compared by two-dimensional gel electrophoresis with those which have just lost the competence for developing into flower buds, a few putative proteins specific to floral evocation were detected. The garlic callus culture system can be further explored for elucidation of the molecular biological mechanism of floral evocation and morphogenesis.hogenesis.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.690-696
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• 2015

We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 mg/L N⁶-benzyladenine (BA) and 0.1 mg/L gibberellic acid (GA₃). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 mg/L BA and 0.2 mg/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 mg/L NAA and 0.2 mg/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 mg/L phloroglucinol. Most rooted plants were acclimatized successfully.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.178-184
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• 2019

Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.43-50
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• 2006

The goal of this research was to develop an efficient cryopreservation protocol for germplasms of yam (Diosorea batatas), that were cultivated in Korea. Comparative studies with four other cryogenic techniques and subsequent experiments for shoot regrowth were conducted. in vitro-grown shoot-apices of the D. batatas were successfully cryopreserved by encapsulation-dehydration. The maximum survival of shoot-apices could be achieved when the precultured (with 0.3 M of sucrose for one day) and encapsulated (with a 3%(w/v) Na-alginate solution) apices were dehydrated for $3.5{\sim}4\;h$ prior to direct immersion in LN (liquid nitrogen). The frequency of regrowth rate of cryopreserved apices was not decreased during 3-month storage period. The thawing method markedly affected survival of the cryopreserved apices, and thawing at $40^{\circ}C$ for 3 min produced the best results. When cryopreserved apices were post-cultured on the post-culture medium (MS), supplemented with $0.2mgl^{-1}$ of BA ($N_6$-benzyladenine) and $0.2mgl^{-1}$ of kinetin, they showed direct shooting without callusing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.349-353
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• 2004

Mature embryo and leaf base segment of Korean oat were used as materials in an experiment to check plant regeneration efficiency. MS media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, and picloram were used for callus induction from mature embryos and leaf base segments. Three mg/l of 2,4­D and 3 mg/l of picloram in callus induction medium showed high frequency for plant regeneration from mature embryos. Leaf base segments were transferred to callus induction medium and incubated at $25^{\circ}C$ in 16/8 hr light/dark cycle for 3 weeks. Callus induction from leaf base segments of Malgwiri showed high efficiency in medium containing 3 mg/l of 2,4-D and 1 mg/l of kinetin $(91.8\%)$. In case of Samhangwiri, the combinations of phytohormones did not show significant difference. Regeneration from leaf base segments showed high frequency in shoot medium containing 1 mg/l of antiauxin, tri-iodobenzoic acid (TIBA) and 1 mg/l of 6-benzyladenine (BA). Calli induced from leaf base segments of Samhangwiri and Malgwiri in media containing 3 mg/l of 2,4-D and 3 mg/l of picloram showed high regeneration frequency. It appears that the callus initiation medium may be an important factor for subsequent plant regeneration.