Generation of Novel Floral Traits Using a Combination of Floral Organ-Specific Promoters and a Chimeric Repressor in Torenia fournieri Lind.
In this study, we attempted to develop a new biotechnological method for the efficient modification of floral traits. Because transcription factors play an important role in determining floral traits, chimeric repressors, which are generated by attaching a short transcriptional repressor domain to transcription factors, have been widely used as effective tools for modifying floral traits in many plant species. However, the overexpression of these chimeric repressors by the Cauliflower mosaic virus 35S promoter sometimes causes undesirable morphological alterations to other organs. We attempted simultaneously to generate new floral traits and avoid such quality loss by examining five additional floral organ-specific promoters, one Arabidopsis thaliana promoter and four Torenia fournieri promoters, for the expression of the chimeric repressor of Arabidopsis TCP3 (AtTCP3), whose overexpression drastically alters floral traits but also generates dwarf phenotypes and deformed leaves. We found that the four torenia promoters exhibited particularly strong activity in the petals but not in the leaves, and that the combination of these floral organ-specific promoters with the chimeric repressor of AtTCP3 caused changes in the color, color patterns and cell shapes of petals, whilst avoiding other unfavorable phenotypes. Interestingly, each promoter that we used in this study generated characteristic and distinguishable floral traits. Thus, the use of different floral organ-specific promoters with different properties enables us to generate diverse floral traits using a single chimeric repressor without changing the phenotypes of other organs.
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519 Japan kattu@affrc.go.jp nohtsubo@kpu.ac.jp.
Katsutomo
K
Sasaki
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519 Japan.
Hiroyasu
H
Yamaguchi
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519 Japan.
Ichiro
I
Kasajima
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519 Japan Graduate School of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0795 Japan.
Takako
T
Narumi
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519 Japan Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-8522 Japan kattu@affrc.go.jp nohtsubo@kpu.ac.jp.
Norihiro
N
Ohtsubo
D000872:Anthocyanins / Q000096:biosynthesis; D053898:Biosynthetic Pathways / Q000235:genetics; D048430:Cell Shape; D019175:DNA Methylation / Q000235:genetics; D035264:Flowers / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005966:Glucuronidase / Q000378:metabolism; D019684:Magnoliopsida / Q000166:cytology / Q000235:genetics*; D009928:Organ Specificity / Q000235:genetics; D010641:Phenotype; D019441:Plant Epidermis / Q000166:cytology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D019655:Quantitative Trait, Heritable; D012097:Repressor Proteins / Q000378:metabolism*; D013997:Time Factors
D000872:Anthocyanins; D012097:Repressor Proteins; D005966:Glucuronidase
GUS; Ornamental flower; Promoter; TCP3; Torenia; Transcription factor