Over-expression of Arabidopsis FT gene reduces juvenile phase and induces early flowering in ornamental gentian plants
Ornamental gentian plants are perennial and have a juvenile period of over 1 year before flowering. We transformed gentian plants with a construct comprising the Arabidopsis FLOWERING LOCUS T (FT) gene (encoding a major component protein of the flowering hormone ‘florigen’) under the control of the rolC promoter from Agrobacterium rhizogenes, which is known to induce vascular-specific expression. The resultant rolCpro-FT transgenic gentian plants showed early flowering in vitro and the earliest line formed floral buds within 4 months after transformation. Regeneration experiments from leaf explants of these rolCpro-FT transgenic plants also confirmed the early flowering phenotype. After acclimatization, these transgenic plants showed normal floral development in a closed greenhouse. There is no effective method to induce early flowering by cultivation management in gentian, therefore these lines might be very useful as annual early season cultivars.
KeywordsEarly flowering FT Gentian In vitro flowering Transgenic plant
We thank J. Kuzuo, C. Yoshida and R. Takahashi, Iwate Biotechnology Research Center, for technical assistance. We also thank J. Abe and H. Kawamura, Iwate Agriculture Research Center, for their helpful suggestions. The authors thank Dr. M. Takagi, Advanced Industrial Science and Technology, for providing a vector harboring the Arabidopsis FT gene. This study was supported in part by a Programme for Promotion of Basic and Applied Researches for Innovations in Bio-oriented Industry (Japan).
- Corbesier L, Vincent C, Jang S, Fornara F, Fan Q, Searle I, Giakountis A, Farrona S, Gissot L, Turnbull C, Coupland G (2007) FT protein movement contributes to long-distance signaling in floral induction of Arabidopsis. Science 316:1030–1033. doi: 10.1126/science.1141752 PubMedCrossRefGoogle Scholar
- Hikage T, Saitoh Y, Tanaka-Saito C, Hagami H, Satou F, Shimotai Y, Nakano Y, Takahashi M, Takahata Y, Tsutsumi K (2007) Structure and allele-specific expression variation of novel alpha/beta hydrolase fold proteins in gentian plants. Mol Genet Genomics 278:95–104. doi: 10.1007/s00438-007-0230-4 PubMedCrossRefGoogle Scholar
- Kodama K (2006) Gentian. In: The Japanese Society for Horticultural Science (ed) Horticulture in Japan 2006. Nakanishi Printing Co., Kyoto, pp 248–253Google Scholar
- Lifschitz E, Eviatar T, Rozman A, Shalit A, Goldshmidt A, Amsellem Z, Alvarez JP, Eshed Y (2006) The tomato FT ortholog triggers systemic signals that regulate growth and flowering and substitute for diverse environmental stimuli. Proc Natl Acad Sci USA 103:6398–6403. doi: 10.1073/pnas.0601620103 PubMedCrossRefGoogle Scholar
- Mishiba K, Nishihara M, Abe Y, Nakatsuka T, Kawamura K, Kodama K, Takesawa K, Abe J, Yamamura S (2006) Production of dwarf potted gentian using wild-type Agrobacteriun rhizogenes. Plant Biotechnol 23:33–38Google Scholar
- Nishihara M, Nakatsuka T, Hosokawa K, Yokoi T, Abe Y, Mishiba K, Yamamura S (2006) Dominant inheritance of white-flowered and herbicide-resistant traits in transgenic gentian plants. Plant Biotechnol 23:25–31Google Scholar
- Nishihara M, Nakatsuka T, Mizutani-Fukuchi M, Tanaka Y, Yamamura S (2008) Gentians: from gene cloning to molecular breeding. In: Jaime A, da Silva T (eds) Floricultural and ornamental biotechnology, vol V. Global Science Books, UK, pp 57–67Google Scholar