Abstract
In which cells of the flower volatile biosynthesis takes place is unclear. In rose and snapdragon, some enzymes of the volatile phenylpropanoid/benzenoid pathway have been shown to be present in the epidermal cells of petals. It is therefore generally believed that the production of these compounds occurs in these cells. However, whether the entire pathway is active in these cells and whether it is exclusively active in these cells remains to be proven. Cell-specific transcription factors activating these genes will determine in which cells they are expressed. In petunia, the transcription factor EMISSION OF BENZENOIDS II (EOBII) activates the ODORANT1 (ODO1) promoter and the promoter of the biosynthetic gene isoeugenol synthase (IGS). The regulator ODO1 in turn activates the promoter of the shikimate gene 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Here the identification of a new target gene of ODO1, encoding an ABC transporter localized on the plasma membrane, PhABCG1, which is co-expressed with ODO1, is described. PhABCG1 expression is up-regulated in petals overexpressing ODO1 through activation of the PhABCG1 promoter. Interestingly, the ODO1, PhABCG1, and IGS promoters were active in petunia protoplasts originating from both epidermal and mesophyll cell layers of the petal, suggesting that the volatile phenylpropanoid/benzenoid pathway in petunia is active in these different cell types. Since volatile release occurs from epidermal cells, trafficking of (volatile) compounds between cell layers must be involved, but the exact function of PhABCG1 remains to be resolved.
Original language | English |
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Pages (from-to) | 3157-71 |
Number of pages | 15 |
Journal | Journal of Experimental Botany |
Volume | 63 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2012 May |
Externally published | Yes |
Subject classification (UKÄ)
- Biochemistry and Molecular Biology
- Cell Biology
Free keywords
- ATP-Binding Cassette Transporters
- Amino Acid Sequence
- Cell Membrane
- Flowers
- Gene Expression Regulation, Plant
- Genes, Plant
- Intracellular Space
- Molecular Sequence Data
- Molecular Weight
- Odorants
- Organ Specificity
- Petunia
- Plant Epidermis
- Plant Proteins
- Promoter Regions, Genetic
- Protein Transport
- Protoplasts
- RNA, Messenger
- Subcellular Fractions