Breeders gerbera collections contain large numbers of cultivars with variable anthocyanin pigmentation patterns that follow the anatomy of the complex inflorescence. Along with isolating the anthocyanin pathway genes for genetic engineering purposes, we have used them as markers for inflorescence development. Our early studies demonstrated that the expression of chalcone synthase (GCHS1), an enzyme acting early in the anthocyanin pathway, was regulated in a similar way in all varieties while the expression of the late anthocyanin pathway gene, dihydroflavonol-4-reductase (GDFR) was very precisely correlating with the presence of colour in different cultivars. Later on, our studies have identified regulatory genes that are required for organ and tissue specific activation of biosynthetic genes. GMYC1 encodes a bHLH protein that has a major role in regulating GDFR expression in petals and carpels, however, not in pappus bristles or stamens. We have also identified an R2R3-type MYB factor, GMYB10, that induced anthocyanin pigmentation in transgenic plants. Identification of candidate targets for GMYB10 using microarray analysis revealed two new MYB factors whose exact functions are not yet clear.

Our current work focuses on metabolic channeling with the aim at characterizing multienzyme complexes (metabolons) involved in biosynthesis of diverse flavonoid compouds.

PUBLICATIONS

Elomaa et al., Bio/Technology 11:508-511 (1993)
Helariutta et al., Plant Mol Biol 22: 183-193 (1993)
Helariutta et al., Plant Mol Biol 28: 47-60 (1995)
Helariutta et al., Plant Mol Biol 28: 935-941 (1995)
Elomaa et al., Plant J 16: 93-99 (1998)
Elomaa et al., Plant Phys 133: 1831-1842 (2003)
Laitinen et al., J Exp Bot 59: 3691-3703 (2008), doi:10.1093/jxb/ern216