• Journal of Plant Biotechnology
• /
• v.34 no.2
• /
• pp.153-159
• /
• 2007

Plant regeneration of Pulsatilla koreana was achieved via adventitious shoot formation indirectly from callus and directly from adventitious root segments. For the callus induction from leaf or petiole explants, combination of 2,4- dichlorophenoxyaceticacid (2,4-D) with $2.22\;{\mu}M$ 6-benzyladenine (BA) was effective. Adventitious shoot induction from callus was enhanced by the combined treatment with $0.1\;{\mu}M$ polyvinylpyrrolidone (PVP) compared to cytokinin treatment alone. Adventitious roots were induced from the petiole segments on 1/2 MS medium with $4.93\;{\mu}M$ IBA. High frequency direct adventitious shoot formation from the segments of adventitious roots was achieved on medium with $4.92\;{\mu}M$ 2-isopentenyladenine (2-ip). Elongated shoots were rooted on half-strength MS medium containing $5.71\;{\mu}M$ indole acetic acid (IAA). Regenerated plantlets with well-developed shoots and roots were successfully transferred to soil. This in vitro propagation protocol might be useful for mass propagation as well as conservation of this plant.

• Molecules and Cells
• /
• v.39 no.6
• /
• pp.484-494
• /
• 2016

Plant cells have a remarkable ability to induce pluripotent cell masses and regenerate whole plant organs under the appropriate culture conditions. Although the in vitro regeneration system is widely applied to manipulate agronomic traits, an understanding of the molecular mechanisms underlying callus formation is starting to emerge. Here, we performed genome-wide transcriptome profiling of wild-type leaves and leaf explant-derived calli for comparison and identified 10,405 differentially expressed genes (> two-fold change). In addition to the well-defined signaling pathways involved in callus formation, we uncovered additional biological processes that may contribute to robust cellular dedifferentiation. Particular emphasis is placed on molecular components involved in leaf development, circadian clock, stress and hormone signaling, carbohydrate metabolism, and chromatin organization. Genetic and pharmacological analyses further supported that homeostasis of clock activity and stress signaling is crucial for proper callus induction. In addition, gibberellic acid (GA) and brassinosteroid (BR) signaling also participates in intricate cellular reprogramming. Collectively, our findings indicate that multiple signaling pathways are intertwined to allow reversible transition of cellular differentiation and dedifferentiation.

• Plant Resources
• /
• v.7 no.1
• /
• pp.39-46
• /
• 2004

To demonstrate the importance of transformation efficiency in independent event, molecular and cytogenetic analysis were conducted with genomic DNA and chromosome of transgenic plants produced by Agrobacterium tumefeciens LBA4404 (pSBM-PPGN: gusA and bar). Selection ratios of putative transgenic calli were similar in independent experiments, however, transformation efficiencies were critically influenced by the type of regeneration media. MSRK5SS-Pr regeneration mediun, which contains 5 mgL$^{-1}$ kinetin, 2% (w/v) sucrose in combination with 3% (w/v) sorbitol, and 500 mgL$^{-1}$ proline, was efficient to produce transgenic plant of rice from putative transgenic callus in the presence of L-phosphinotricin (PPT). With MSRK5SS-Pr medium, transformation efficincies of Nagdongbyeo were significantly enhanced from 3.7% to 6.3% in independent callus lines arid from 7.3% to 19.7% in plants produced, respectively. Stable integration and expression of bar gene were confirmed by basta herbicide assay, PCR amplification and Southern blotting of bar gene, and fluorescence in situ hybridization (FISH) analysis using pSBM-PPGN as a probe. In Southern blot analysis, diverse band patterns were observed in total 44 transgenic plants regenerated from 20 independent PPT resistant calli showing from one to five copies of T-DNA segments, however, the transformants obtained from one callus line showed the same copy numbers with the same fractionized band patterns.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.53-53
• /
• 2023

Abeliophyllum distichum, one of the Korean endemic plant, is a significant pharmaceutical plant resource. A. distichum with phenylethanoid glycoside can use to regulate the development of cancer, DNA damage with radicals, and the generation of inflammatory mediators. In this study, we investigated whether the biomass, content of phenylethanoid glycoside, and growth rate of callus derived from A. distichum (cultivar Okhwang1, CAD) change in the absence or presence of plant hormones (2,4-Dichlorophenoxyacetic acid; 2, 4-D and 1-Naphthaleneacetic acid; NAA). The results showed that the best biomass, the growth rate of callus, and the contents of phenylethanoid glycoside were cultivated on Murashige and Skoog (MS) growth medium fortified with 1 ppm 2,4-D + 2 ppm NAA after 4 weeks. In a further study, CAD was cultivated on MS growth medium fortified with an elicitor (Methyl Jasmonate, MeJA). The results showed that CAD turned to brown color and fragile form with the elicitor. HPLC-PDA analysis revealed that the contents of phenylethanoid glycoside in the elicitor-treated group were higher than in the elicitor-non-treated group. These results are consistent with the findings of Arano-Varela H et al.,'s study which is that acteoside production can increase after the treatment of MeJA. Therefore, this study can be used to develop an effective and sustainable production of useful substances as an alternative to plant cultivation.

• Journal of Plant Biotechnology
• /
• v.37 no.3
• /
• pp.313-318
• /
• 2010

To develop edible vaccines for swine, the embryogenic calli (type II) derived from HiII genotype were inoculated with A. tumefaciens strain C58C1 containing the binary vector pMYV611, 613, 616, and V621, 622 and 623 respectively. Six of those vectors carry nptII gene which confers resistance to paromomycin and apxIIA gene producing ApxII toxin which is generated in various serum types of A. pleuropneumoniae as a target gene. The 4,120 callus clones for pMYV611, 5,959 callus clones for pMYV613, 7,581 callus clones for pMYV616, 52,329 callus clones for V621, 48,948 callus clones for V622, and 56,188 callus clones for V623 were inoculated. The frequency of positive response clone was confirmed into range of 2.3% - 4.4% for each vectors by NPTII ELISA kit assay, and the selected callus clones of them were finally 3 callus clones from pMYV611 (0.07%), 4 callus clones from pMYV613 (0.07%), 2 callus clones from pMYV616 (0.03%), 51 callus clones from V621 (0.1%), 72 callus clones from V622 (0.15%), and 102 callus clones from V623 (0.18%) respectively. From the selected callus clones of each binary vector, the integration of the apxIIA gene into maize genome was detected from 2 plants of pMYV613 and 2 plants of V623 by Southern blot analysis.

• The Plant Pathology Journal
• /
• v.15 no.1
• /
• pp.38-43
• /
• 1999

Mutants of the monopartite geminivirus beet curly top virus (BCTV) have been screened for infectivity, systemic movement, replication and symptom development in Arabidopsis thaliana. As known by coding for coat protein, R1 mutant was not infectious and did not move systemically. R2, R3 and L2/L3 mutants produced milder symptoms compared to wild type BCTV but the infectivity was reduced by 40% to 60%. R2 ORF is thought to be involved in the regulation of ssDNA and dsDNA accumulation because only dsDNA was accumulated on R2-infected organs. Disruption of ORF L4 resulted in reduced infections, but the viral DNA was accumulated in infected organs from roots to shoot tips as much as wild type BCTV on Sei-O. In addition, 4 mutants did not produce callus-like tissues on infected organs, suggesting that L4 ORF may play a role in the induction of host cell divisions by virus infection. This result was supported by the patterns of mRNA expression and promoter analysis of the cell cycle marker gene, cycl, on Arabidopsis. cycl mRNA was accumulated on symptomatic organs by wild type BCTV infections but not by L4 mutant. We conclude that the BCTV L4 ORF is essential for symptom developments, specially callus-like formation on infected organs.

• Proceedings of the Zoological Society Korea Conference
• /
• 2001.10a
• /
• pp.198.1-198
• /
• 2001

• Journal of Plant Biology
• /
• v.37 no.3
• /
• pp.381-385
• /
• 1994

The highest degree of callus formation was obtained from the shoot tips of Dianthus superbus when cultured on the MS medium supplemented with 2.0 mg/L NAA and 0.5 mg/L BAP. Embryogenic calluses were obtained from the seperated friable calluses on MS medium containing 2.0 mg/L 2,4-D after 7-8 wk of culture. For plant regeneration, embryogenic calluses were selected and cultured on te proliferation medium. After 3 wk, somatic embryos appeared on MSK medium (0.5 mg/L NAA, 2.0 mg/L kinetin) and N6 medium (2.0 mg/L kinetin, 0.1 mg/LNAA, 0.1 mg/L 2,4-D and 2.0 g/L casein hydrolysate). When these somatic embryos were kept under continuous illumination, shoots were successfully regenerated on the both media. The shoots were rooted on MS medium supplemented with 2.0 mg/L NAA.

• Journal of Plant Biology
• /
• v.39 no.4
• /
• pp.249-256
• /
• 1996

Beet curly top virus is the DNA virus that is providing useful for basic studies of the infection of Arabidopsis thaliana with viral host and provides a system for studying both resistance and the molecular basis of symptom development. An importnat aspect of symptom development observed in BCTV-infected A. thaliana (ecotype Sei-O) was the induction of cell division on phloem and surrounding cortex cells. Analysis of the expression of GUS reporter gene activity in transgenic plants containing constructs with promoter of the auxin-inducible saur gene showed that saur promoter activity was induced concomitantly in symptomatic tissues at the inflorescence shoot tips of the transgenic lines. The auxin sensitivity tests showed that hypersusceptible ecotype, Sei-O produced more amounts of callus than susceptible ecotype, Col-O. These studies indicated that changes in auxin concentration were involved in the induction of cell division in BCTV-infected plants and clearly demonstrated that there was a strong correlation between auxin-induced gene expression and the activation of cell division.

• Journal of Plant Biotechnology
• /
• v.29 no.4
• /
• pp.259-264
• /
• 2002

Induction of embryogenic callus from Allium wakegi Araki explants was promoted on medium containing 2,4-D, and production of abnormal embryos from the embryogenic callus increased as 2,4-D concentration was raised. Shoot tip was found to be the best explant source for embryogenic callus formation followed in the order by bulb scale and leaf section. Medium containing 0.09 M sucrose was effective for embryogenic callus production. The regenerants from embryogenic callus on medium containing 2,4-D and BA at different concentrations was consisted of diploids, tetraploids and a few mixaploids of 2n＋4n, and their chromosomal aberration rate ranged from 8.0 to 33.3%. Frequency of chromosomal aberrants was the highest (18.7%) in the regenerants obtained from bulb scale-derived embryogenic callus among others. Plant regeneration rate was high (33.5%) from the shoot tip-derived embryogenic callus and the frequency of chromosomal aberrants was very low (7.0%). The plantlets regenerated on medium containing 0.26 M sucrose resulted in high chromosomal aberrants. The regenerants on medium containing sucrose at 0.09∼0.20 M produced chromosomal aberrants at around 15.2∼16.6%.