Genetic engineering of carotenoid pigments to modify flower color in Oncidium

• Main Authors: Shu-Fang Cheng, 鄭淑芳
• Other Authors: Pei-Fang Lee
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/q52zsh

碩士 === 輔英科技大學 === 生物科技系碩士班 === 102 === Oncidium is one of the most important orchids used for cut flowers in Taiwan. The creation of new cultivars with novel traits is important for Oncidium to enhance the competitiveness of orchid industry. However, traditional breeding processes are limited by the long life cycle and self-incompatibility. In this study, we attempted to suppress chromoplast-specific carotenoid-associated protein ( CHRC ) gene isolated from Oncidium (Gower Ramsey) to develop innovative flower color in Oncidium by using the RNA interference (RNAi) approach. We introduced the RNAi expression vectors driven by Arabidopsis AP1 promoter or CaMV 35S promoter into Arabidopsis and Oncidium mediation by Agrobacterium tumefaciens to inhibit CHRC gene expression. The transgenic plants were confirmed with PCR, RT-PCR analysis and GUS activity assay. Chlorophyll fluorescence parameter ( Fv/Fm ) and carotenoid content were measured in leaves of transformants. Seven independent 35S-CHRCIA and eleven AP1-CHRCIA transgenic Arabidopsis plants were produced. The transgenic Arabidopsis showed a decrease in Fv/Fm values and carotenoid content and no phenotype change were observed. In addition, we established an efficient propagation system of Oncidium protocorm-like bodies (PLBs) and used as explants materials for genetic transformation. Eleven independent 35S-CHRCIO and eleven AP1-CHRCIO transgenic Oncidium were obtained. The 35S-CHRCIO plants showed lower Fv/Fm values and carotenoid content and no significant change were observed in AP1-CHRCIO. These results suggest that CHRC related genes were inhibited and caused decline in Fv/Fm values and carotenoid content of transgenic plants.