• Journal of Plant Biotechnology
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• 제41권4호
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• pp.236-241
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• 2014

An efficient regeneration protocol for stem disc culture of Populus euramericana, which is important species for bioenergy resource in agroforestry, was established. The number of explants that were obtained and the number of explants that regenerated varied with the genotypes. However, in all the genotypes, stem disc culture produced more regenerated shoots than did in axillary bud culture. A comparison of the effects of cytokinin type and concentration on shoot regeneration in different explants (i.e., petiole, leaf, and root segments of P. euramericana) revealed that a concentration of $0.002mg\;l^{-1}$ thidiazuron (TDZ) used on petiole segments resulted in the greatest shoot regeneration (95.83%). The hormonal requirements for the greatest shoot regeneration in the three explant types varied. Different concentrations of $AgNO_3$ and $CoCl_2$ were added separately to the medium to stop the yellowing and subsequent necrosis of the regenerated shoots. Lower concentrations (3 and $5mg\;l^{-1}$) of these compounds improved shoot regeneration and elongation, compared with the control. The in vitro-regenerated shoots were transferred to rooting medium and subsequently acclimatized. The highly efficient regeneration system of P. euramericana reported here can be used for mass propagation of this recalcitrant for regeneration, economically important tree species.

• Journal of Plant Biotechnology
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• 제47권1호
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• pp.26-39
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• 2020

In maize, immature embryos (IEs) are highly regenerative explants most suitable for producing high frequencies of plantlet regeneration in vitro. Apart from media, explants, and hormones, genotypic variation also influences in vitro characters to a great extent. In the present study, IEs were used to study the distinctive effect of variation of size/stage and hormones in different genotypes on five in vitro characters viz., frequency of callus induction, growth rate of total callus, frequency of E. callus induction, and volume and number of regenerated plantlets. LS medium with different concentrations of 2,4-D (0.5, 1.5, 2.5, 4.0 and 5.0 mg/L) were used to study the former four in vitro characters, and medium with 6-benzylaminopurine and kinetin (0.5 mg/L, each) was used for plantlet regeneration. IEs of 1.0, 1.5, 2.0, 2.5 and 3.0 mm in size were isolated from four inbred lines viz., NM74C, NM81A, NM5883 and NM5884. Two-way ANOVA revealed that explant size and genotypes, as well as hormonal concentrations showed significant effects on in vitro characters. Two millimeter IEs were found to be suitable for in vitro cultures. LS medium with 1.5 mg/L 2,4-D and LS with BAP and Kn (0.5 mg/L, each) were found to be the best hormonal concentrations for callus induction, maintenance, and regeneration, respectively. Among the four genotypes, NM81A and NM5883 yielded more non-embryogenic and Type I E. calli. In contrast, NM74C and NM5884 yielded more highly regenerative Type II calli. Inbred line NM5884 was found to be the best among these four genotypes.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.15-15
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• 2019

The walnut (Juglans regia L.), a member of the Juglandaceae, is native to the mountain ranges of central Asia. This species of walnut is valued commercially for its nuts and in some areas for its timber. The seeds of walnut are recalcitrant and it has strong integument dormancy and their germination is irregular, making its natural propagation difficult. Low percentage of seed germination and long propagation cycle are the main problems of propagation. This study was conducted medium composition on in vitro plantlet regeneration from axillary buds of walnut. It has proved to be the most generally applicable and reliable method of in vitro propagation. Micropropagation culture that axillary buds are excised aseptically enables faster multiplication of plants. The axillary buds of walnut new cultivar "Sinlyeong" were cultured on two basal media which contained the different plant growth regulators depending on the respective shooting and rooting stage. After 12 weeks, the shoot generation rate was 85.3%, the shoot number and its length were 1.9/explant and 2.7 cm in the most favorable medium composition. The percentage of rooting was 25.4%. From these results, it was found the optimum basal medium and plant growth regulator for in vitro plant regeneration from axillary buds of walnut new cultivar "Sinlyeong". However, we have continued to search the other medium additives to enhance the rate of walnut root.

• 한국자원식물학회지
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• 제17권3호
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• pp.331-338
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• 2004

본 연구에서는 카네이션과 고구마의 무병 종묘를 생산하고자 정단분열조직배양을 실시하였으며, 생산된 배양종묘의 바이러스 감염여부를 진단하기 위해 ELISA방법을 이용하여 주요 바이러스를 검정하였다. 카네이션의 정단분열조직 배양에 공시 한 'Roland' 등 4품종 중 투명화 현상이 없이 가장 정상적인 잎이 발생하고 절간신장이 이루어지며 뿌리의 발생도 양호한 생장반응을 보인 품종은 석죽계통인 'Giant Gipsy' 이었으며 MS기본배지에 NAA 0.05 ㎎/L와 BA 0.1㎎/L 혹은 kinetin 1.0㎎/L와 조합한 구에서 shoot의 재생이 양호하였다. 배양7주일 후에는 explant 1개체에서 평균 5-6개, 많은 것은 10개체 이상의 multiple shoot가 형성되었고 기내 마디삽목법에 의하여 대량증식할 수 있었다. 투명화현상이 심한 품종은 'Casha'와 'Desio'로 나타났는데 투명화 현상은 kinetin 첨가보다는 BA첨가구에서 현저하게 증가하였다. 카네이션 기내 배양종묘의 바이러스 감염여부는 ELISA방법을 이용하여 CarMV와 CarRSV를 신속하게 다량의 시료를 진단할 수 있었다. 그 결과 정단분열조직의 배양을 통해 65.2%에서 무병 주가 생산되었음을 확인할 수 있었다.

• Molecules and Cells
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• 제44권10호
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• pp.723-735
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• 2021

Spemann organizer is a center of dorsal mesoderm and itself retains the mesoderm character, but it has a stimulatory role for neighboring ectoderm cells in becoming neuroectoderm in gastrula embryos. Goosecoid (Gsc) overexpression in ventral region promotes secondary axis formation including neural tissues, but the role of gsc in neural specification could be indirect. We examined the neural inhibitory and stimulatory roles of gsc in the same cell and neighboring cells contexts. In the animal cap explant system, Gsc overexpression inhibited expression of neural specific genes including foxd4l1.1, zic3, ncam, and neurod. Genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) and promoter analysis of early neural genes of foxd4l1.1 and zic3 were performed to show that the neural inhibitory mode of gsc was direct. Site-directed mutagenesis and serially deleted construct studies of foxd4l1.1 promoter revealed that Gsc directly binds within the foxd4l1.1 promoter to repress its expression. Conjugation assay of animal cap explants was also performed to demonstrate an indirect neural stimulatory role for gsc. The genes for secretory molecules, Chordin and Noggin, were up-regulated in gsc injected cells with the neural fate only achieved in gsc uninjected neighboring cells. These experiments suggested that gsc regulates neuroectoderm formation negatively when expressed in the same cell and positively in neighboring cells via soluble factors. One is a direct suppressive circuit of neural genes in gsc expressing mesoderm cells and the other is an indirect stimulatory circuit for neurogenesis in neighboring ectoderm cells via secreted BMP antagonizers.

• 문화기술의 융합
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• 제5권1호
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• pp.409-412
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• 2019

본 실험은 칼라 'Gagsi' 품종의 줄기를 절편체로 사용하여 칼라의 대량증식 시스템을 확립하고자 진행이 되었다. 실험은 cefotaxime 항생제 (25, 50, 100 mg/L)가 포함된 Murashige와 Skoog (MS) 기본 배지를 사용하였다. 캘러스 유도는 MS 기본 배지에 NAA 0.5 mg/L, BA 1.0 mg/L 등의 식물 호르몬을 첨가한 배지가 사용되었다. 기본 MS 배지에 cefotaxime 25, 50, 100 mg/L 농도가 첨가 된 배지에서 비교한 결과 캘러스 유도율은 25 mg/L 농도에서 10.5 %가 나와 가장 효율이 높았고 갈변율은 10.5 %로 가장 낮았다. 캘러스 유도 배지인 MNB에 cefotaxime 25 mg/L을 첨가한 배지에서 캘러스 유도율은 34.5 %, 갈변율은 27.0 %가 나타났다. 항생제인 cefotaxime은 이전에 식물 조직 배양 실험에서도 사용되었고, 실험 결과 칼라 식물 생장을 촉진시키는 효과와 오염 및 갈변을 억제하는 긍정적인 영향을 준다는 것을 입증하였다. 이를 토대로 대량 증식 시스템 개발에 기여를 할 수 있고 농가 소득 향상에 도움이 될 것으로 판단된다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.16-16
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• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• Journal of Plant Biotechnology
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• 제48권1호
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• pp.54-61
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• 2021

This work describe an efficient method for the shoot induction and plant regeneration of seedling-derived apical bud explants of Tilia mandshurica Rupr. & Maxim. The highest rate of shoot induction (82.2%) was obtained when apical bud explants from juvenile seedlings (5 months old) were cultured on Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP). However, apical bud explants obtained from mature trees (12 years old) did not produce any shoots, even with BAP supplementation. Among the three cytokinins tested for shoot multiplication (BAP, zeatin, and kinetin), BAP was the most effective; the highest number of shoots per explant (2.1) was observed on MS medium supplemented with 1.0 mg/L BAP. In contrast, the longest average shoot length (3.0 cm) was observed after growth on MS medium with 2.0 mg/L zeatin. No multiplication occurred when apical bud explants were cultured with kinetin-supplemented media. During rooting of in vitro-elongated shoots, the highest rooting rate (100%) was observed in half-strength MS medium supplemented with 0.5 ~ 1.0 mg/L indole-3-butyric acid (IBA) or 3.0 mg/L 1-naphthaleneacetic acid (NAA). During the acclimatization process, plantlets that were rooted on the IBA (0.5 mg/L)-supplemented medium had the highest survival rate (100%) and maximum root length (18.5 cm). These findings suggest that a low concentration (0.5 mg/L) of IBA is appropriate for the rooting and acclimatization of T. mandshurica. Plants were successfully transferred to the greenhouse with a 100% survival rate. This protocol will be useful for the large-scale propagation of Tilia species.

• Animal Bioscience
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• 제35권4호
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• pp.533-543
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• 2022

Objective: Caspase-mediated apoptosis plays a crucial role in the regulation of endometrial and placental function in females. Caspase activity is tightly controlled by members of the inhibitors of apoptosis proteins (IAPs) family. However, the expression and regulation of IAPs at the maternal-conceptus interface has not been studied in pigs. Therefore, we determined the expression of IAP family members baculovirus IAP repeat-containing 1 (BIRC1) to BIRC6 at the maternal-conceptus interface in pigs. Methods: We obtained endometrial tissues from pigs at various stages of the estrous cycle and pregnancy, conceptus tissues during early pregnancy, and chorioallantoic tissues during mid- to late pregnancy and analyzed the expression of IAPs. Furthermore, we determined the effects of the steroid hormones estradiol-17β (E2) and progesterone on the expression of IAPs in endometrial explant tissue cultures. Results: During the estrous cycle, BIRC2 and BIRC5 expression varied cyclically, and during pregnancy, endometrial BIRC1, BIRC2, BIRC3, BIRC4, and BIRC5 expression varied in a stage-specific manner. Conceptus and chorioallantoic tissues also expressed IAPs during pregnancy. The BIRC2 and BIR3 mRNAs were localized to luminal epithelial cells, and BIRC4 proteins to glandular epithelial cells in the endometrium. Exposure of endometrial tissues to E2 increased the expression of BIRC6, while progesterone increased the expression of BIRC1, BIRC4, and BIRC6 in a dose-dependent manner. Conclusion: These results indicated that IAPs were expressed in the endometrium during the estrous cycle and at the maternal-conceptus interface during pregnancy in a stage-specific manner. In addition, steroid hormones were found to be responsible for the expression of some IAPs in pigs. Together, the results suggested that IAPs may play important roles in endometrial and placental functions by regulating caspase action and apoptosis at the maternal-conceptus interface.

• 한국동물생명공학회지
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• 제37권4호
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• pp.255-265
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• 2022

The cellular communication network factor (CCN) family proteins regulate many biological events such as angiogenesis, tumor growth, placentation, implantation, and embryogenesis. The expression and function of CCN1, CCN2, and CCN3 at the maternal-conceptus interface are established in humans and rodents, but little is known about the role of CCN4 to CCN6 in the reproductive organs in any other species. Several studies in transcriptome analysis in pigs have shown that the expression of CCN4 and CCN6 increases in the endometrium during early pregnancy. However, their expression, regulation, and function in the endometrium throughout the estrous cycle and pregnancy have not been fully understood in pigs. Thus, we determined the expression, localization, and regulation of CCN4 and CCN6 during the estrous cycle and at the maternal-conceptus interface in pigs. We found that the levels of CCN4, but not CCN6, changed during the estrous cycle. The levels of CCN4 were greater during mid- to late pregnancy than in the early stage, and the levels of CCN6 were greatest on Day 15 of pregnancy. CCN4 and CCN6 were detected in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. CCN4 mRNA was mainly localized to epithelial cells, CCN6 mRNAs to epithelial and stromal cells in the endometrium. In endometrial explant cultures, CCN4 expression was increased by progesterone, and CCN6 expression by interferon-𝛾. These results suggest that CCN4 and CCN6 may play roles in the establishment and maintenance of pregnancy by regulating the endometrial epithelial cell functions in pigs.