• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.143-149
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• 2000

An Efficient in vitro regeneration system and an optimized Agrobacterium mediated transformation protocol are described, based on the use of young seedling cotyledons of Capsicum annuum L. Optimal regeneration efficiency can be obtained by cultivating cotyledon explants on media containing 4 mg/L benzyladenine and 0.1 mg/L indolacetic acid. The effect of antibiotics used to eliminate Agrobacteria, as well as the toxic level of some generally used selection agents (kanamycin, geneticin, hygromycin, phosphinotricin and methotrexate) in regenerating pepper tissues were determined. To enable the comparison of different selection markers in identical vector background, a set of binary vectors containing the marker genes for NPTII, HPT, DHFR and BAR respectively, as well as the CaMV 35S promoter/enhancer-GUS chimaeric gene was constructed and introduced into four different Agrobacterium host strains.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.6-9
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• 2005

Plant biotechnology involving genetic modification has been rather controversial. However, the major issues related to safety are being addressed by continued improvements in technology. Some of the related facts will be highlighted to set the tone for a scientific discussion on the possibilities of using the technology for crop improvement. Our main research interest is to understand the molecular regulation of shoot bud regeneration in plant tissue culture, which is essential for crop improvement by biotechnology. We have isolated and characterized some genes that are associated with adventitious shoot regeneration. These include a MADS-box cDNA (PkMADS1) from paulownia kawakamii, which regulates vegetative shoot development and in vitro shoot regeneration from leaf explants. Another gene we have characterized from petunia codesfor a cytokinin binding protein (PETCBP). Preliminary functional analysis of this gene indicated that this also affects adventitious shoot bud initiation. Also, the antisense suppression of this gene in petunia causedexcessive branching. Results from our work and selected other publications will be used to highlight the possibilities of manipulation of such genes to improve crop species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.49-52
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• 2001

conditions for callus induction and plant regeneratin from seeds of lawngrass (Zoysia japonica Steud.) were confirmed in this study. MS (Murashige and Skoog) medium containg 2,4-D 3 or 5mg/l was used for callus induction, and MS medium with different volumes of BA, NAA and kinetin hormones was used to regenerate the plants from induced calli. MS basic medium containing agar with no hormones or kinetin 1.0mg/l and MS basic medium containing gelite and NAA 1.0mg/l were higher for green callus induction. MS medium containing agar and kinetin 1.0mg/l ws highest degree of efficiency for plant regeneration.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.175-177
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• 2014

This is the first report describing the seasonal conditions affecting shoot regeneration by the chrysanthemum cv. Baeksun. The shoot regeneration from petal explants was found to be more favorable from September to December, reaching the highest values in December. In addition, the quality of the shoots was also influenced according to the season of the explant collection, where healthy and uniform plants were derived from the explants collected in December. Choosing the proper season for explant collection affected the successive plant growth parameters (i.e., plant height and fresh weight). Thus, the current results strongly suggest that season plays an important role in plant tissue culturing, which is an essential tool for micropropagation and Agro-bacterium-mediated genetic transformation studies.

• Plant Resources
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• v.2 no.1
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• pp.16-21
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• 1999

An efficient regeneration system was established by using in vitro plantlets of germinated seedlings from different cultivars of lettuce (Lactuca sativa cv. Chongchima, Chongchuckmyun, Jeokchima, Jeokchuckmyun). Shoot formation were observed from all cultivars on MS medium supplemented with 0.1 mg/L NAA and 0.5 mg/L BA. In all cultivars, when cotyledon was cultured, the number of shoot per explant was more greater than that hypocotyl and leaf disc were cultured. Shoot formation rate (91.7%) was high in a cotyledon culture of cultivar, Chongchukmyun. The growth of multiple shoots derived from the cultivar, Chongchukmyun, was most effective on medium containing 0.5 mg/L BA and 1.0 mg/L GA$_3$. When shoots were transferred on MS medium without plant growth regulators, roots were effectively differentiated. Rooted plantlets were acclimated on pots for further propagation.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.51-54
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• 2004

This study was conducted to examine differences in shoot regeneration among chrysanthemum cultivars. Leaf explants of chrysanthemum cultivars 'Sulhwa', 'Puma', 'Geummokseo' and 'Sulpoong' were used. Explants cultured on the medium for 2 weeks formed calli at the cut surfaces. Shoots regenerated on MS basal medium supplemented with various concentration combinations of NAA and BAP. Explants were cultured under cool-white fluorescent lamps with a light intensity of $40\mu{Mm}^{-2}$.$s^{-1}$ for 16 $hday^{-1}$, at $25^{\circ}c$ and 70-80% relative humidity. 'Geummokseo' and 'Sulpoong' were the most responsive cultivars in shoot regeneration. Most effective medium for 'Sulhwa' and 'Puma' was MS basal medium supplemented with 10.0 $\mu{M}$ NAA and 5.0 $\mu{M}$ BAP and for 'Geummokseo' MS supplemented with 10.0$\mu{M}$ NAA and 20.0$\mu{M}$ BAP. Regeneration of multiple shoots was observed on MS basal medium supplemented with 1.0$\mu{M}$ or 10.0 $\mu{M}$ NAA and 5.0$\mu{M}$ BAP. High frequency regeneration of adventitious shoots from leaf explants and efficient induction of root from these regenerated shoots were obtained.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.229-235
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• 2010

In this study, we established an in vitro regeneration system to maximize the recovery of leafy perilla (Perilla frutescens L. Britton) plantlets as part of developing a molecular biotechnology-based metabolic engineering program for this crop plant. Hypocotyl segments including the apical buds were used as explants for the direct production of shoots without an interim callus phase. The number of shoots produced from the apical buds peaked within 3-4 weeks, and the shoots were subsequently cultured on Murashige and Skoog (MS) media supplemented with 2 mg $1^{-1}$ benzylaminopurine (BA). Spontaneous rhizogenesis was observed after 7-10 days of culture on MS media without hormonal additives. The rooted shoots developed into normal plants in soil after hardening on distilled water for 3-4 days. The average plantlet regeneration frequency was higher for the apical buds (64.33%) than for the top (15.66%), middle (4%), and basal (1.33%) segments of the hypocotyls. This regeneration system demonstrates a capacity for high-frequency plantlet recovery and thus should be considered for use in the genetic manipulation of leafy perilla.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.49-55
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• 2017

We investigated the callus induction and plant regeneration ability of 16 maize genotypes, including the Korean inbred lines, using 9 to 15 day-old immature zygotic embryos from maize grown in pots and from field cultures. Immature zygotic embryos placed on MS medium supplemented with L-proline 0.7 g/L, MES 0.5 g/L, Dicamba 1.5 mg/L, 2,4-D 0.5 mg/L, $AgNO_3$ 4 mg/L, and sucrose 20 g/L, showed the highest frequency of callus induction. The highest number of shoots regenerated when the embryogenic callus were transferred to MS medium supplemented with 5 mg/L zeatin. The root formation was observed when shoots were grown on MS medium supplemented with 0.2 mg/L indole-3-butyric acid (IBA). Additionally, under the same culture conditions, immature zygotic embryos from maize grown in the field also had a high frequency of plant regeneration. Except one genotype, 15 genotypes showed callus induction and shoot regeneration. Among the 16 genotypes tested, H99, B98, HW3, and B73 yielded the best plant regeneration. H99 showed maximum shoot formation from the primary embryogenic callus. The results suggest that genotypes and growth conditions of the maize plant plays very important roles for enhancing the embryogenesis competence of immature zygotic embryos. The successful regeneration from immature zygotic embryos of maize inbred lines provides a basis for molecular breeding of new cultivars by genetic transformation.

• Journal of Plant Biotechnology
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• v.50
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• pp.176-182
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• 2023

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica 'Fuji') leaf explants were developed in the present study. The effects of dark incubation periods in the early stages of culture, pre-treatment methods, the number of explants per culture container, the type of culture containers, and the orientation of the explants on culture media were evaluated to determine the optimal shoot regeneration conditions for 'Fuji' apple leaf explants. Light incubation of explants produced minimal response. However, dark incubation of explants for 4 weeks during the initial culture period enhanced shoot regeneration frequency. Comparing the number of explants per container, a higher percentage of shoot regeneration was obtained with nine explants per container compared with four explants per container. Pre-treatment, before culture, by dipping explants in a liquid regeneration medium containing 40 g/L of sorbitol for 2 hours produced the highest shoot formation rate, and the time of shoot formation was accelerated. The percentage of shoot regeneration and number of shoots per regenerating explant reached a maximum of 87.5% and 4.7, respectively. The regenerated shoots were elongated and rooted on a rooting medium of 1/4 MS with 0.2 mg/L IBA. The plantlets were successfully acclimatized, and the regenerated plants produced normal phenotypes.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.192-197
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• 2009

Camptotheca acuminata, a native of South China is a well known natural source of monoterpene-indole alkaloid camptothecin(CPT), one of the most promising anti-tumoural compounds. This study was conducted to optimize plant growth regulators and culture conditions on plantlets regeneration through organogenesis from callus of Camptotheca acuminta. Callus were induced from various explants of in vitro germinated plantlets of C. acuminta using WPM medium containing 0.2 ㎎/L 2,4-D. Hypocotyl segments were exhibited higher embryogenic callus than the other explants. Shoot buds formation from embryogenic callus was affected by plant growth regulators, pre-treated dark condition and liquid culture. Organogenesis was optimal in WPM liquid medium containing 0.5 ㎎/L BA. The dark pre-treatment for 2 weeks before the solid culture was effective for organogenesis. The regenerated shoots were rooted in WPM medium with 0.2 ㎎/L NAA and successfully acclimated in green-house conditions.