초록 ▼

Ⅴ. 연구개발결과
고온하에서 화색이 안정적으로 발현되는 국화품종을 육성하기 위해 35S::RsMYB와 pInMYB::RsMYB을 이용해 국화 스프레이 품종 피치엔디에서 9개체, 피치레드 9개체,비비드스칼렛 21개체, 국화 스탠다드 품종 신마 3개체의 형질전환체를 육성하였고,내열성 발현유전자가 도입된 국화 형질전환체를 육성하여 고온하에서의 생리특성을 살펴본 결과 비형질체 전환에 비해 높은 수준의 내열성을 나타낸 내열성 유전자가 도입된 국화 형질전환체를 육성하였다.
고온적응성이 우수한 신품종 개발을 위해 여름 개화용 국화인

Ⅴ. 연구개발결과
고온하에서 화색이 안정적으로 발현되는 국화품종을 육성하기 위해 35S::RsMYB와 pInMYB::RsMYB을 이용해 국화 스프레이 품종 피치엔디에서 9개체, 피치레드 9개체,비비드스칼렛 21개체, 국화 스탠다드 품종 신마 3개체의 형질전환체를 육성하였고,내열성 발현유전자가 도입된 국화 형질전환체를 육성하여 고온하에서의 생리특성을 살펴본 결과 비형질체 전환에 비해 높은 수준의 내열성을 나타낸 내열성 유전자가 도입된 국화 형질전환체를 육성하였다.
고온적응성이 우수한 신품종 개발을 위해 여름 개화용 국화인 하추국 계통의 유전자원 15품종을 수집하여 교배하여 생육 및 화색과 화형이 우수한 163계통을 1차 선발하였다. 1차 선발한 계통은 촉성재배, 자연재배, 억제재배 등 3회에 걸쳐 특성검정을 실시하여 생육과 절화품질이 우수한 화이트썸머, 써니썸머, 핑크썸머, 옐로우썸머 등 4품종을 육성하였다.

Abstract ▼

Discoloration of chrysanthemum flowers was found to be serious in summer season, resulting in declination of ornamental value in the market. Hence, enhancement of flower color by genetic engineering to overcome extreme temperature during summer season is necessary. In this study, we produced transge

Discoloration of chrysanthemum flowers was found to be serious in summer season, resulting in declination of ornamental value in the market. Hence, enhancement of flower color by genetic engineering to overcome extreme temperature during summer season is necessary. In this study, we produced transgenic chrysanthemums (cvs. Peach Red, Peach ND, and Vivid Scarlet)using Agrobacterium-mediated transformation system, which contains anthocyanin regulatory RsMYB1 gene isolated from radish (Raphanus sativus L.)by placing under the control of either cauliflower mosaic virus 35S or petal specific promoter InMYB. In order to consider the copy number of target gene(RsMYB1), transgenic plants confirmed by PCR were further analyzed by southern hybridization, In addition, expression level of anthocyanin biosynthetic genes was also confirmed by reverse-transcription(RT) PCR. Furthermore, expression level of anthocyanin in the transgenic plants were examined in the greenhouse.
Background: Several MYB genes belonging to R2R3 MYB transcription factors have been used in several plant species to enhance anthocyanin production, and have shown various expression or regulation patterns. This study focused on the effect of ectopic expression of an RsMYB1 isolated from radish(Raphanus sativa) on chrysanthemum cv. ‘Shinma’. Results: The RT-PCR results confirmed that RsMYB1 regulated the expression of three key biosynthetic genes(CmF3H, CmDFR, and CmANS) that are responsible for anthocyanin production in transgenic chrysanthemum, but were not detected in the non-transgenic line. In all transgenic plants, higher expression levels of key biosynthetic genes were observed in flowers than in leaves. However, the presence of RsMYB1 in chrysanthemum did not affect any morphological characteristics, such as plant height, leaf shape or size, and number of flowers.Furthermore, no anthocyanin accumulation was visually observed in the leaves and floral tissue of any of the transgenic lines, which was further confirmed by anthocyanin content estimation. Conclusion: To our knowledge, this is the first time the role of an MYB transcription factor in anthocyanin production has been investigated in chrysanthemum.
This research was conducted to develop genetic transformation of the recalcitrant chrysanthemum cv. Shinma by application of appropriate antibiotics and selective agents. Clavamox had the least inhibitory effect on shoot regeneration compared to timentin, carbenicillin, and cefotaxime. Clavamox, at a concentration of 125 mg L−1, was found to be the most suitable for shoot regeneration and production of quality shoots, suppressing the growth of Agrobacterium in explants infected with strains GV3101 or C58C1 for 3 and 4 weeks, respectively. The concentration of phosphinothricin (PPT) was found to be 1.0 mg L−1 for screening of putative transgenic shoots. Moreover, transgenic chrysanthemums were obtained by culturing explants co-cultivated with A. tumefaciens strain GV3101 harboring an anthocyanin regulatory gene RsMYB1 isolated from radish (Raphanus sativus), which was placed under the control of cauliflower mosaic virus promoter (CaMV) 35S and petalspecific promoter InMYB1 isolated from the morning glory (Ipomoea nil), on shoot regeneration medium supplemented with recommended concentration of antibiotic and selective agent. Flow cytometry analysis revealed that there was no variation in ploidy level between transgenic plants and donor plants(non-transformants). To our knowledge, this is the first report of the use of Clavamox and MYB transcription factor for genetic transformation of this chrysanthemum.
When encounter harsh environmental conditions such as drought, salinity, low temperature and high temperature, plants constantly monitor the environmental signals. Therefore, severe abiotic stresses cause adverse effects on the growth, development and productivity followed by generating morphological, physiological, biochemical and molecular changes in plants. Of abiotic stresses, high temperature especially emerged in vigorously growing season can have dramatic impacts on the productivity and quality of crops resulting in farmers’ low income. Many of researches using the Arabidopsis as a model plant have clarified responses to heat stress, though these findings still remain to be obscure to crops.
Chrysanthemum is one of the most important commercial cut flowers in the world. In summer, heat stress by high temperature has effects on chrysanthemum like low productivity, flowering delay and discoloration. Monothiol glutaredoxins play important roles in maintaining redox homeostasis in living cells and share some conserved function across species. Arabidopsis thaliana monothiol glutaredoxin AtGRX3 is critical for protection from oxidative stress in cytosol and/or nucleus. Collectively, we here report that over-expression of AtGRX3 in chrysanthemum plants confers tolerance to heat stress. To improve the tolerance to heat stress in chrysanthemum, independent fourteen lines constitutively over-expressing AtGRX3 that isolated from A. thaliana were generated via Agrobacterium-mediated genetic transformation technology. All lines were characterized by polymerase chain reaction, Southern hybridization, semi-quantitative reverse transcription-PCR, and bioassays.Over-expression of AtGRX3 in Chrysanthemum plants enhanced photosynthetic performance and insistence of cell membrane permeability, and decreased oxidative damage in addition to promotion of plant growth under heat stresses.These findings suggest a specific protective role of the redox protein against high temperature stress, and provide a genetic engineering strategy to improve crop thermotolerance.