• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.217-221
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• 2002

Callus induction and embryogenesis were studied in three different genotypes of Acanthopanax senticosus, to develop a protocol for somatic embryogenesis and acclimatization. Young leaf, stem, node, petiole, peduncle, flower and root explants were collected from 3-year old trees of A. senticosus accessions (Korea, Russia and Japan). Callus was obtained from all cultured explants but showed the higher rate of callus formation in flower cultured. For the three A. senticosus accessions, callus was well formd on MS media containing 2mg/ l of 2,4-D and 2mg/ l of TDZ, 4mg/ l of 2,4-D and 1mg/ l of TDZ than other treatments. For three A. senticosus accessions, when callus transferred to MS medium with 2,4-D, embryogenic cell formed. For A. senticosus accessions Korea, embryogenic cells were obtained on callus induced from petiole, stem, node and root explants, and induction rate was lower than 3%. 200mg of embryogenic callus was transferred to MS free liquid medium and somatic embryos of heart stage were obtained after 45days of culture. When somatic embryo of germination stage were transferred to solid medium, most of the embryos were regenerated into plantlets on 1/4 MS medium. Normal plants with both shoots and roots were transferred to greenhouse soil and were successfully acclimatized.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.275-280
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• 1999

In order to find optimum conditions for somatic embryogenesis from different individual (2-year-old) in Aralia elata were cultured on MS medium supplemented with 1.0 mg/L 2,4-D, 3% sucrose, and 0.3% gelrite. We also investigated the effect of MS medium salt concentration, BA and ABA on the embryo germination and plant regeneration. While noticeable difference was observed on somatic embryo induction among different individual tree, no apparent difference was seen in both germination and regeneration frequencies. Compared with nonembryogenic calli, embryogenic calli tended to look yellow and/or pale brown in color, slowly growing and soft in their texture. Regardless of BA or ABA treatment, half-strength MS salt medium proved to be better than full strength MS medium in both embryo germination and plant regeneration. Both hypocotyl and cotyledon developments were slightly promoted by adding 0.1 mg/L BA. However, its effect on germination and regeneration seemed inferior to control. ABA treatment on somatic embryos at their torpedo and early cotyledonary stages resulted in poor response in germination and regeneration. Although most regenerated plantlets varied greatly in cotyledon number and shape, they could be developed into normal plants after 4 weeks in culture. More than 95% plantlets were acclimatized in an artificial soil mixture, successfully transplanted to nursery bed and grew normally without any phenotypic abnormalty.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.693-697
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• 2011

This study was conducted to examine effects of concentrations of abscisic acid (ABA) or /kinds of osmotica on induction of somatic embryos (SEs), germination and plantlet regeneration in Japanese larch (Larix kaempferi). In comparison of duration of culture, concentrations of ABA and osmoticum, the highest induction number (191/g tissue) of the SE was showed in $60{\mu}M$ ABA+0.2 M sucrose for 4 weeks culture. However, the lowest number (3.5~23.5) of SEs was induced from $4{\mu}M$ ABA+0.1 M sucrose, regardless of culture duration for SEs induction. In comparison of germination efficiency of SEs, the highest induction frequencies of cotyledon (90.9%), hypocotyl (95.8%) and root (96.5%), respectively, were obtained from the SEs that cultured from the treatment of $60{\mu}M$ ABA+0.2 M sucrose with 5 weeks culture. In contrast, the lowest germination response was showed in SEs that induced from the treatment of $4{\mu}M$ ABA+0.1 M sucrose. In comparison of effect of different kinds/concentrations of osmotica for germination and plantlet regeneration, the best response was obtained from the treatment of 0.2 M sucrose with induction of cotyledon (98.3%), hypocotyl (78.4%), root (57.5%) and plantlet regeneration (54.8%), respectively.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.323-330
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• 2021

Zygotic embryo culture was performed to propagate evergreen oak, Quercus myrsinifolia, which has recalcitrant seeds and is difficult to propagate by cuttings. Zygotic embryos appeared in WPM medium after 14 days, and after 56 days, they developed into complete plants with cotyledons and roots. The medium suitable for zygotic embryo culture was 1/4 WPM medium, showing a shoot growth of 2.43 cm and root growth of 8.7 cm after 8 weeks of culture. As a result of investigating the effect of GA₃ on the growth of plants germinated from zygotic embryos through GA₃ treatment, the best growth was shown in 0.5 mg/l GA₃ treatment. The in vitro rooting and growth of IBA-treated zygotic embryo-derived plants were good in the 0.5 mg/l IBA treatment and rooting and shoot growth were not observed at higher concentrations. And the callus induction rate also increased as the concentration of IBA increased. Plants grown in vitro were transferred to a plastic pot containing artificial soil and acclimatized in a greenhouse for about 4 weeks, resulting in more than 90% survival. As a result of this study, the zygotic embryo culture method was confirmed to be effective for mass propagation of Q. myrsinifolia. The results of this study are expected to contribute significantly to the mass propagation of elite Q. myrsinifolia.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.347-353
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• 2009

Procedures that induce microspore embryogenesis have been described for a range of Brassica species, but embryo yield remains low for a number of genotypes. We have carried out experiments with the microspores from a weakly responsive line of B. napus to determine the culture conditions that optimize their in vitro embryogenesis by treating them with effectors of ethylene synthesis and action. The results revealed that isolated microspores subjected to an initial heat stress in a medium supplemented with inhibitors of ethylene synthesis such as AVG and $CoCl_2$ exhibited significantly increased embryo yields. This suggested that regulatory effects are exerted by the ethylene produced by the isolated microspores on the early processes of gametogenesis. As a consequence, treatment of microspores with SAM, an ethylene synthesis precursor, or with the ethylene-releasing agent ethephon, led to decreases in embryo yield. A special response to ethylene during the early stages of microspore development was finally shown to occur through experiments where isolated microspores were treated for increasing periods of time with $CoCl_2$. Collectively, our data demonstrated that the induction of embryogenesis induced by heat stress can be enhanced by inhibitors of ethylene biosynthesis.

• Journal of Embryo Transfer
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• v.14 no.2
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• pp.93-97
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• 1999

The development potential of bovine somatic cells was evaluated using nuclear transfer. A single donor cell derived from fetus of HanWoo(Korean Native Cattle) was selected and deposited into perivitelline space of each enucleated oocyte before electrical fusion and activation. Nuclei of donor cells starved for 7 days (37%) tended to support the development of reconstitute embryo the blastocyst stage better than those of donor cells starved 3, 14 and 30 days. The cleavage rate was significantly lower(P<0.05) in reconstitute embryos derived from large size donor cells(51.2%), than those from small medium size donor cells(76.6 and 73.5, respectively). The developmental rate to blastocyst of reconstructed embryos from medium size donor cells was higher than those from small and medium size donor cells. This study demonstrates that an appropriate culture period for induction into quiescent stage and the size of donor cells effect on the efficiency of nuclear transfer using cultured bovine cells.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.253-258
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• 1997

토끼에서는 수정란 이식과 같은 기본적인 번식공학적 방법의 효율성이 아직 생쥐와 같은 실험동물에 비해 떨어지고 있어 생물공학적인 기술을 응용하는데 큰 어려움이 있다. 특히 유전자 이식에 의한 형질전환 토끼의 생산과 같은 생물공학적인 기술을 실용화하는데 효율이 높은 수정란이식 기술의 개발이 필수적이라고 할 수 있다. 본 연구에서는 토끼에서 수정란 이식 기술의 첫 단계인 과배란 유도를 효율적으로 이용할 수 있는 방법을 정립하기 위해 반복적인 과배란 유도가 배란율 및 수정란의 질적인 면과 양적인 면에 미치는 영향을 조사하였다. 연구방법으로는 FSH와 HCG를 사용하여 과배란을 유도하였고 2.5 개월의 반복처리간격으로 3번의 반복적인 과배란 처리를 한 후 반복처리에 따른 배란율과 배란된 난자의 형태학적 상태, 배양에 의한 발생 능력 상태 등을 감소하였으며 배란수의 변이도 커지는 경향을 나타내었다(첫번째, 32.6(+-)2.5; 두번째 28.7(+-)3.7; 세번째 20.99(+-)3.8). 제 2극체의 돌출, 전핵의 형성, cummulus cell의 존재등에 의한 회수된 난자의 형태학적 관찰에 의한 방법으로 난자를 분류한 결과 과배란의 반복수가 증가함에 따라 다양한 모양의 난자가 회수되어 배란이 광범위한 시간대에 일어나고 있음을 나타내었다. 또한 과배란의 반복적인 유도에 의해 난소의 혈포수는 증가하였으나 채란된 난자의 채외배양에 의한 발육율에는 차이가 없었다. 그러므로 과배란의 반복적인 유도는 공란토의 난소반응에는 영향을 미쳤으나 난자의 질에는 영향을 미치지 않았음을 나타낸다.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.1-6
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• 2008

The covalent conjugation of SUMO(Small Ubiquitin-related MOdifier) protein to its substrates regulates numerous cellular processes, including protein stability and activity in eukaryotes as well as in plants. In this present review, we summarize biochemical aspects of SUMO conjugation and deconjugation and the functions of SUMO and sumoylation-related proteins in Arabidopsis and other plants. In particular, we provide an overview of the roles of the SUMO in widely different biological processes including the ABA response, floral induction, pathogen defense, abiotic stresses and hormone signaling. Furthermore, we explore the possible roles of SUMO in embryo and seed development.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.62-63
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• 2005

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.411-413
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• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.