• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.85-89
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• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Journal of Plant Biotechnology
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• 제6권3호
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• pp.193-197
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• 2004

In vitro multiplication of Curculigo orchioides was achieved by direct somatic embryogenesis in young leaf segments. Immature leaf segments of about 0.5 cm in length were cultured on MS medium supplemented with different concentrations of BAP (2-10 $\mu{M}$) or Kin (2-10 $\mu{M}$). Optimum response in terms of per cent cultures responding (89%) and the number of embryos per explant (16) were observed on MS medium supplemented with 8 $\mu$M BAP. The emergence of several somatic embryos on the adaxial side of the leaf segments was observed one month after the culture. Germinated somatic embryos were grown up to about 1.5 cm length before transferring to maturation medium. For maturation, the individual embryos were isolated and transferred to MS medium supplemented with BAP (5 $\mu{M}$) and NAA (0.5 $\mu{M}$). The plantlets emerged from the embryos were transferred to soil containing 1 peat: 1 sand with 90% success. The embryos were formed directly on the leaf segments without any callus phase. Direct regeneration of somatic embryos is important for the conservation of this endangered species, as rare somaclonal variants are likely to arise than from indirect regeneration.

• 한국약용작물학회지
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• 제6권4호
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• pp.294-298
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• 1998

생물반응기를 이용한 대량 번식 방법 개발의 기반을 마련하고자 현삼 조직의 액체배양에서 직접 체세포배 발생에 미치는 치상조직과 식물 생장조절제의 상호영향을 조사하였다. 식물체의 부위에 따라 전혀 다른 양상을 보였는데, 잎, 줄기 및 엽병조직을 치상한후 체세포배 발생 정도를 살펴본 결과 줄기 절편을 배양하였을 때 체세포배 발생율이 가장 높았다. 또한 유식물체로 발달되기까지 약 3주의 기간이 소요되어 빠른 속도로 성장이 이루어진 반면, 뿌리의 형성은 이루어지지 않았다. 엽병을 접종 재료로 하여 3주간 배양하였을 때는 직접체 세포배를 통한 shoot는 형성은 되었으나 줄기 절편에 비해 체세포배 발생율은 낮았으며, 뿌리 발생도 이루어지지 못하였다. 잎조직을 액체 배지에 치상하였을 경우 체세포배 발생에 소요되는 기간이 줄기와 엽병에 비해 상대적으로 길었으며 , 배양 8주 후에는 완전한 식물체로 발달하였다. 액체배양에서 체세포배 형성에 영향하는 생장조절제로는 BA효과가 컸으혀, BA에 옥신류인 IAA와 NAA를 첨가함에 따라 탈분화가 진행되어 체세포배 발생을 감소시키는 경향을 보였다. 짧은 배양 시간 동안 많은 유식물체를 얻을 수 있는 최적의 조건은 BA 05 mg/ l 나 1.0 mg/ l 로 첨가시킨 NS 액체배지에 줄기 부위를 치상 조직으로 이 용하는 것이 가장 효과적 이었다.

• Journal of Ginseng Research
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• 제36권4호
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• pp.442-448
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• 2012

Somatic embryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somatic embryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal.

• Journal of Plant Biology
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• 제39권2호
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• pp.127-135
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• 1996

An efficient system of somatic embryogenesis was established for the red pepper plant (Capsicum annuum L. cv. Nokkwang) usign immature zygotic embryos. The size of the immature zygotic embryos and the concentrations of 2, 4-D and sucrose were found to be critical. Somatic embryos were induced via callus or directly from explants and regenerated into plantlets successfully. When zygotic embryos 1~2 mm long were cultured on the modified Murashige-Skoong (MS) medium supplemented with 2 mg/L 2, 4-D for 3 weeks in the dark, somatic embryos were induced directly from the apical region of zygotic embryos with the highest frequency being approximately 90%. To mature the somatic embryos, ABA and an ethylene inhibitor AgNO3 were used. The highest frequency of shoot regeneration (25% in each) resulted at 2$\mu$M ABA or 20$\mu$M AgNO3 treatment at rates 3.7 and 1.6 times control, respectively. Shoots developed mainly from the cotyledonary node on CoCl2-containing medium, and from the upper side of cotyledon on medium containing AgNO3 while the embryos on the control medium produced shoots from both the cotyledonary node and the upper region of cotyledons both at frequencies of 50%. Indirect somatic embryogenesis via callus was induced at an efficiency of approximately 10% with zygotic embryos 3~4 mm long cultured on MS medium containing 5~10 mg/L, 2, 4-D for 5~7 weeks under a continuous light condition. The plants regenerated from the somatic embryos were morphologically normal. Using scanning electron microscopy, the direct and indirect somatic embryogeneses were observed to follow the globular, heart and torpedo stages, similar to zygotic embryogenesis. Also, suspensors appeared in the early globular and ovoid-shaped late globular embryos during indirect somatic embryogenesis.

• 식물조직배양학회지
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• 제25권2호
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• pp.115-118
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• 1998

작약의 종자로부터 절취한 배를 기내 발아시켜 획득한 자엽조직으로부터 체세포배발생에 적합한 배지내의 식물생장 조절제 조성을 밝히기 위하여 전배양배지와 배유도배지의 식물생장조절제 조성별 체세포배 발생율과 접합자배의 구조와 동일한 정상 체세포배 발생 정도를 조사한 결과를 요약하면 다음과 같다. 자엽으로부터 체세포배발생을 위한 식물생장조절제로 ABA가 첨가된 배지에서 체세포배 발생율이 높았으며, 특히 ABA가 0.5 mg/L 첨가된 배지에서 59.9%의 높은 체세포배 발생율을 나타내었다. ABA가 첨가된 배지에서 접합자배를 배양할 경우 발아가 저해되고 발아한 식물체가 비정상적인 형태로 발달하는 현상이 나타났으나 이들 비정상적인 형태의 자엽으로부터 체세포배 발생이 효과적이었으며, ABA가 0.5 mg/L 첨가된 배지에서 자엽으로부터 발생된 체세포배의 형태는 2개의 자엽을 갖는 정상체세포배가 22.6%, 3개 19.5%, 1개 9.8%로 나타났으며 볼링핀 또는 나팔모양의 비정상적인 배는 1.3%로 낮게 나타났다.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.107-110
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• 2008

A high-efficiency, reproducible somatic embryogenesis system for strawberry cultivar Chandler was developed. Thirty-one somatic embryos per explant(max no.) were recorded in leaf discs which were cultured on medium containing MS salts+$B_5$ vitamins+2% glucose+4.0 mg $1^{-1}$TDZ(Thidiazuron) and incubated at $10{\pm}1^{\circ}C$ under darkness for one week followed by three weeks under 16-h photoperiod. The scanning electron microscopic(SEM) ontogeny revealed the normal development of somatic embryos from globular to heart-shaped and dissection microscopy from torpedo-shaped to cotyledonary-stage embryos. The maximum germination percentage of 48% could be obtained on MS medium containing kinetin(1.0 mg $1^{-1}$) and the maximum survival percentage(79%) of plantlets after four weeks was found to be in the mixture of vermiculite, peatmoss, and soilrite(1:1:1).

• 한국약용작물학회지
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• 제5권4호
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• pp.289-293
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• 1997

지황 (Rehmannia glutinosa) 에서 종근 저장시 나타나는 병원균의 오염율을 없애면서 종묘를 대량 증식시키기 위한 방법의 하나로 조직을 액체 배양하여 직접 체세포배를 형성하고자 할 때 효과적인 생장조절제의 종류와 농도 및 이들의 혼용 효과와 직접 체세포배 형성 효율이 높온 최적 치상 조직을 찾고자 실험 한 결과는 다음과 같다. 1. MS고체배지에 잎 절편을 치상한 결과 BA를 1.0 mg/l 이상처리 한 경우에는 직접적으로 체세포배가 형성되었으나 BA 1.0 mg/1에 NNA를 혼용한 경우에는 캘러스만 형성되었고, BA 2.0 mg/l에 NAA를 혼용한 경우에는 캘러스 과정을 거쳐 체세포배가 형성되었다. 2. MS 액체배지에 잎 절편을 배양한 결과 IAA와 NAA를 각각 0.5 mg/l로 처리하거나, IAA와 IBA를 각각 2.0 mg/l로 처리한 경우 직접 체세포배가 형성 되었다. 3. 잎 절편을 MS 액체배지에 치상하였을 때 BA, zeatin 및 kinetin을 각각 2.0 mg/l로 처리한 경우 직접체세포배가 효과적으로 형성되 었다. 4. IAA 1.0 mg/l에 BA, zeatin및 kinetin을 혼용처리한 MS 액체배지에 잎 절편을 배양한 결과, zeatin 2.0mg/l을 혼용 처리한 구에서 직접 체세포배 형성율이 가장 높았고 다음이 kinetin 2.0 mg/l 와 zeatin 5.0mg/l을 조합한 경우이었다. 5. 치상 6주 후부터 줄기, 엽병 및 잎 절편에서 직접 체세포배가 형성되었으나, 8주 후 치상 조직별 체세포배 형성율은 잎 절편에서 가장 높았다.

• Journal of Plant Biotechnology
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• 제31권1호
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• pp.67-72
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• 2004

고구마의 정단배양에 의한 배발생 캘러스로부터 대량증식 체계가 개발되어져 왔다. 고구마 정단분열조직은 1mg/L 2,4-D가 첨가된 MS배지에서 배양 4주 경에 최적의 배발생 캘러스가 형성되었다. 또한 2,4-D가 첨가된 배지에 casein을 첨가함으로써 고구마 신천미 품종의 배발생 효율을 최고 90%이상으로 2.4-D단독처리보다 현저하게 증가시켰다. 배발생 캘러스로부터 체세포배의 유도는 식물생장조절제가 제거된 MS 기본배지에서 효과적으로 형성되었으며 300∼500mg/L casein을 첨가한 배지에서는 더 높은 형성 빈도와 녹색의 단단한 체세포배가 발달하였다. 한편, 2mm이하의 체세포배로부터 이차 배발생 캘러스 형성 및 체세포배의 발달이 100∼300mg/L casein의 첨가에 의해 증가하였다 배발생 캘러스에서 얻어진 체세포배는 직접 MS기본배지에서 쉽게 각 기관이 형성되었으며, 발근과 shoot를 발달시켜 정상적인 식물체로 하여 토양에 성공적으로 옮겨 심을 수 있었다.

• Plant Biotechnology Reports
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• 제3권4호
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• pp.333-340
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• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.