Flavonoids, common to all land plants, are synthesized via the phenylpropanoid pathway. Phenylala... more Flavonoids, common to all land plants, are synthesized via the phenylpropanoid pathway. Phenylalanine ammonia lyase catalyzes the first reaction of this pathway (conversion of phenylalanine to cinnamate), which is followed by a set of about ten enzymes catalyzing reactions to flavones, flavonols and anthocyanins (Fig.1). Anthocyanin pigments are responsible for pink, orange and purple to blue colors in petals. Flavonoids in our model ornamental plant Gerbera hybrida consist of three subgroups, flavones, flavonols and anthocyanins. Most of the anthocyanins accumulate in the adaxial epidermi of petals and give the different cultivars their different color. Both pelargonidin and cyanidin derivatives are found in gerbera, but none of the cultivars contain delphinidin. According to chromatographic and MS analysis for ray flowers of more than 22 cultivars in different developmental stages, we observed that pelargonidin-type Gerbera cultivars accumulated only the favone apigenin, while cya...
The formation of protein complexes, metabolons, and the channeling of intermediates of secondary ... more The formation of protein complexes, metabolons, and the channeling of intermediates of secondary metabolism has been discussed for at least 30 years. Metabolons and channeling enable plants to perform a highly effective synthesis of specific natural products without or with reduced metabolic interference and avoiding accumulation of toxic intermediates. In spite of a long tradition of the concept, precise examples of complete metabolons are very scarce. Our aim is to define flavone and anthocyanidin specific metabolons in the ornamental plant Gerbera hybrida. Our earlier data shows that specific genes are expressed early in development (PAL and CHS3) and others late (PAL, CHS1 and DFR), possibly correlating with flavone and anthocyanin biosynthesis. Furthermore, transformation of the pelargonidin type Gerbera cultivar Terra Regina with a MYB-type regulatory gene induces cyanidin biosynthesis without interfering with the background pelargonidin biosynthesis. Using our large set of ES...
... (B) Variety Terra Regina, which is the nontransformed reference for all GM lines derived from... more ... (B) Variety Terra Regina, which is the nontransformed reference for all GM lines derived from the variety. (C) GM Regina, transformed with antisense GCHS1, which encodes chalcone synthase. Flowers are white since anthocyanin biosynthesis is blocked (Elomaa et al., 1993). ...
Proceedings of the National Academy of Sciences, 2008
Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-... more Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-like (CYC-like) TCP domain proteins have been shown to control flower symmetry in distantly related plant lineages. Gerbera hybrida , a member of one of the largest clades of angiosperms, the sunflower family (Asteraceae), is an interesting model for developmental studies because its elaborate inflorescence comprises different types of flowers that have specialized structures and functions. The morphological differentiation of flower types involves gradual changes in flower size and symmetry that follow the radial organization of the densely packed inflorescence. Differences in the degree of petal fusion further define the distinct shapes of the Gerbera flower types. To study the role of TCP transcription factors during specification of this complex inflorescence organization, we characterized the CYC-like homolog GhCYC2 from Gerbera . The expression of GhCYC2 follows a gradient along th...
We have identified an R2R3-type MYB factor, GMYB10, from Gerbera hybrida (Asteraceae) that shares... more We have identified an R2R3-type MYB factor, GMYB10, from Gerbera hybrida (Asteraceae) that shares high sequence homology to and is phylogenetically grouped together with the previously characterized regulators of anthocyanin pigmentation in petunia (Petunia hybrida) and Arabidopsis. GMYB10 is able to induce anthocyanin pigmentation in transgenic tobacco (Nicotiana tabacum), especially in vegetative parts and anthers. In G. hybrida, GMYB10 is involved in activation of anthocyanin biosynthesis in leaves, floral stems, and flowers. In flowers, its expression is restricted to petal epidermal cell layers in correlation with the anthocyanin accumulation pattern. We have shown, using yeast (Saccharomyces cerevisiae) two-hybrid assay, that GMYB10 interacts with the previously isolated bHLH factor GMYC1. Particle bombardment analysis was used to show that GMYB10 is required for activation of a late anthocyanin biosynthetic gene promoter, PGDFR2. cis-Analysis of the target PGDFR2 revealed a s...
Tobacco rattle virus (TRV) has a bipartite, positive-sense single-stranded RNA genome and is wide... more Tobacco rattle virus (TRV) has a bipartite, positive-sense single-stranded RNA genome and is widely used for virus-induced gene silencing (VIGS) in plants. RNA1 of TRV that lacks the gene for the cysteine-rich 16K silencing-suppression protein infects plants systemically in the absence of RNA2. Here, we attempted to engineer RNA1 for use as a VIGS vector by inserting heterologous gene fragments to replace 16K. The RNA1 vector systemically silenced the phytoene desaturase (PDS) gene, although less efficiently than when the original VIGS vector system was used, which consists of wild-type RNA1 and engineered RNA2 carrying the heterologous gene. Infectious RNA1 mutants with a dysfunctional 16K suppressed silencing and enhanced transgene expression in green fluorescent protein-transgenic Nicotiana benthamiana following inoculation by agroinfiltration, unlike mutants that also lacked 29K, a movement protein (MP) gene. The 30K MP gene of Tobacco mosaic virus complemented in cis the moveme...
Background The flowering process in plants proceeds through the induction of an inflorescence mer... more Background The flowering process in plants proceeds through the induction of an inflorescence meristem triggered by several pathways. Many of the genes associated with both the flowering process and floral architecture encode transcription factors of the MADS domain family. Gerbera, a member of the sunflower family, Asteraceae, bears compressed inflorescence heads (capitula) with three different flower types characterized by differences in both sexuality and floral symmetry. To understand how such a complex inflorescence structure is achieved at the molecular level, we have characterized the array of Gerbera MADS box genes. The high number of SQUAMOSA-like genes in Gerbera compared to other model species raised the question as to whether they may relate to Gerbera's complex inflorescence structure and whether or not a homeotic A function is present. Results In this paper we describe six Gerbera genes related to the SQUAMOSA/APETALA1/FRUITFULL genes of snapdragon and Arabidopsis....
Plants bind solar energy to organic matter via photosynthesis and assimilation of carbon dioxide ... more Plants bind solar energy to organic matter via photosynthesis and assimilation of carbon dioxide from the atmosphere and comprise the major source of nutrition and bioenergy. Plant biotechnology contributes to solution of important constraints in food and feed production and creates new technologies and applications for the sustainable use of plant resources. Genome-wide approaches such as massive parallel sequencing and microarrays to study gene expression, molecular markers for selection of important traits in breeding, characterization of genetic diversity with the aforementioned approaches, and somatic hybridization and genetic transformation are important tools in plant biotechnology. In this paper, studies carried out on enhanced resistance to viruses and tolerance of cold stress in potato, genetic modification of flower pigmentation and morphology in gerbera, production of edible vaccines in transgenic barley seeds, and expression of heterologous proteins for pharmaceutical p...
We have developed a regeneration method and an Agrobacterium-mediated transformation protocol for... more We have developed a regeneration method and an Agrobacterium-mediated transformation protocol for the commercially important ornamental plant Gerbera hybrida. Pieces of petioles of the red variety Terra Regina were cocultivated with a disarmed Agrobacterium ...
Lignin biosynthesis is a major carbon sink in gymnosperms and woody angiosperms. Many of the enzy... more Lignin biosynthesis is a major carbon sink in gymnosperms and woody angiosperms. Many of the enzymes involved are encoded for by several genes, some of which are also related to the biosynthesis of other phenylpropanoids. In this study, we aimed at the identification of those gene family members that are responsible for developmental lignification in Norway spruce (Picea abies (L.) Karst.). Gene expression across the whole lignin biosynthetic pathway was profiled using EST sequencing and quantitative real-time ...
We cloned and sequenced a rat cDNA encoding the 2'-5' oligoadenylate synthetase, ... more We cloned and sequenced a rat cDNA encoding the 2'-5' oligoadenylate synthetase, a component of the mammalian interferon-induced antiviral response, and used Agrobacterium-mediated transformation to generate transgenic potato clones expressing this mammalian enzyme. In transgenic plants infected with potato virus X and followed under field conditions, virus concentrations in leaves and in tubers were significantly lower than in nontransgenic controls. Additionally, virus concentration in the leaves of five transgenic clones and in tubers of one clone was also lower than in transgenic potatoes expressing potato virus X coat protein.
The effects of the transformation of a 4-coumarate:coenzyme A ligase (4CL) gene involved in ligni... more The effects of the transformation of a 4-coumarate:coenzyme A ligase (4CL) gene involved in lignin biosynthesis on the interactions between transgenic plants and soil microbiota were studied in silver birch (Betula pendula Roth). Although the genetic transformation did not lead to expected changes in wood chemistry, it had significant influence on root biomass and morphology. The transgenic lines had less
Flavonoids, common to all land plants, are synthesized via the phenylpropanoid pathway. Phenylala... more Flavonoids, common to all land plants, are synthesized via the phenylpropanoid pathway. Phenylalanine ammonia lyase catalyzes the first reaction of this pathway (conversion of phenylalanine to cinnamate), which is followed by a set of about ten enzymes catalyzing reactions to flavones, flavonols and anthocyanins (Fig.1). Anthocyanin pigments are responsible for pink, orange and purple to blue colors in petals. Flavonoids in our model ornamental plant Gerbera hybrida consist of three subgroups, flavones, flavonols and anthocyanins. Most of the anthocyanins accumulate in the adaxial epidermi of petals and give the different cultivars their different color. Both pelargonidin and cyanidin derivatives are found in gerbera, but none of the cultivars contain delphinidin. According to chromatographic and MS analysis for ray flowers of more than 22 cultivars in different developmental stages, we observed that pelargonidin-type Gerbera cultivars accumulated only the favone apigenin, while cya...
The formation of protein complexes, metabolons, and the channeling of intermediates of secondary ... more The formation of protein complexes, metabolons, and the channeling of intermediates of secondary metabolism has been discussed for at least 30 years. Metabolons and channeling enable plants to perform a highly effective synthesis of specific natural products without or with reduced metabolic interference and avoiding accumulation of toxic intermediates. In spite of a long tradition of the concept, precise examples of complete metabolons are very scarce. Our aim is to define flavone and anthocyanidin specific metabolons in the ornamental plant Gerbera hybrida. Our earlier data shows that specific genes are expressed early in development (PAL and CHS3) and others late (PAL, CHS1 and DFR), possibly correlating with flavone and anthocyanin biosynthesis. Furthermore, transformation of the pelargonidin type Gerbera cultivar Terra Regina with a MYB-type regulatory gene induces cyanidin biosynthesis without interfering with the background pelargonidin biosynthesis. Using our large set of ES...
... (B) Variety Terra Regina, which is the nontransformed reference for all GM lines derived from... more ... (B) Variety Terra Regina, which is the nontransformed reference for all GM lines derived from the variety. (C) GM Regina, transformed with antisense GCHS1, which encodes chalcone synthase. Flowers are white since anthocyanin biosynthesis is blocked (Elomaa et al., 1993). ...
Proceedings of the National Academy of Sciences, 2008
Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-... more Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-like (CYC-like) TCP domain proteins have been shown to control flower symmetry in distantly related plant lineages. Gerbera hybrida , a member of one of the largest clades of angiosperms, the sunflower family (Asteraceae), is an interesting model for developmental studies because its elaborate inflorescence comprises different types of flowers that have specialized structures and functions. The morphological differentiation of flower types involves gradual changes in flower size and symmetry that follow the radial organization of the densely packed inflorescence. Differences in the degree of petal fusion further define the distinct shapes of the Gerbera flower types. To study the role of TCP transcription factors during specification of this complex inflorescence organization, we characterized the CYC-like homolog GhCYC2 from Gerbera . The expression of GhCYC2 follows a gradient along th...
We have identified an R2R3-type MYB factor, GMYB10, from Gerbera hybrida (Asteraceae) that shares... more We have identified an R2R3-type MYB factor, GMYB10, from Gerbera hybrida (Asteraceae) that shares high sequence homology to and is phylogenetically grouped together with the previously characterized regulators of anthocyanin pigmentation in petunia (Petunia hybrida) and Arabidopsis. GMYB10 is able to induce anthocyanin pigmentation in transgenic tobacco (Nicotiana tabacum), especially in vegetative parts and anthers. In G. hybrida, GMYB10 is involved in activation of anthocyanin biosynthesis in leaves, floral stems, and flowers. In flowers, its expression is restricted to petal epidermal cell layers in correlation with the anthocyanin accumulation pattern. We have shown, using yeast (Saccharomyces cerevisiae) two-hybrid assay, that GMYB10 interacts with the previously isolated bHLH factor GMYC1. Particle bombardment analysis was used to show that GMYB10 is required for activation of a late anthocyanin biosynthetic gene promoter, PGDFR2. cis-Analysis of the target PGDFR2 revealed a s...
Tobacco rattle virus (TRV) has a bipartite, positive-sense single-stranded RNA genome and is wide... more Tobacco rattle virus (TRV) has a bipartite, positive-sense single-stranded RNA genome and is widely used for virus-induced gene silencing (VIGS) in plants. RNA1 of TRV that lacks the gene for the cysteine-rich 16K silencing-suppression protein infects plants systemically in the absence of RNA2. Here, we attempted to engineer RNA1 for use as a VIGS vector by inserting heterologous gene fragments to replace 16K. The RNA1 vector systemically silenced the phytoene desaturase (PDS) gene, although less efficiently than when the original VIGS vector system was used, which consists of wild-type RNA1 and engineered RNA2 carrying the heterologous gene. Infectious RNA1 mutants with a dysfunctional 16K suppressed silencing and enhanced transgene expression in green fluorescent protein-transgenic Nicotiana benthamiana following inoculation by agroinfiltration, unlike mutants that also lacked 29K, a movement protein (MP) gene. The 30K MP gene of Tobacco mosaic virus complemented in cis the moveme...
Background The flowering process in plants proceeds through the induction of an inflorescence mer... more Background The flowering process in plants proceeds through the induction of an inflorescence meristem triggered by several pathways. Many of the genes associated with both the flowering process and floral architecture encode transcription factors of the MADS domain family. Gerbera, a member of the sunflower family, Asteraceae, bears compressed inflorescence heads (capitula) with three different flower types characterized by differences in both sexuality and floral symmetry. To understand how such a complex inflorescence structure is achieved at the molecular level, we have characterized the array of Gerbera MADS box genes. The high number of SQUAMOSA-like genes in Gerbera compared to other model species raised the question as to whether they may relate to Gerbera's complex inflorescence structure and whether or not a homeotic A function is present. Results In this paper we describe six Gerbera genes related to the SQUAMOSA/APETALA1/FRUITFULL genes of snapdragon and Arabidopsis....
Plants bind solar energy to organic matter via photosynthesis and assimilation of carbon dioxide ... more Plants bind solar energy to organic matter via photosynthesis and assimilation of carbon dioxide from the atmosphere and comprise the major source of nutrition and bioenergy. Plant biotechnology contributes to solution of important constraints in food and feed production and creates new technologies and applications for the sustainable use of plant resources. Genome-wide approaches such as massive parallel sequencing and microarrays to study gene expression, molecular markers for selection of important traits in breeding, characterization of genetic diversity with the aforementioned approaches, and somatic hybridization and genetic transformation are important tools in plant biotechnology. In this paper, studies carried out on enhanced resistance to viruses and tolerance of cold stress in potato, genetic modification of flower pigmentation and morphology in gerbera, production of edible vaccines in transgenic barley seeds, and expression of heterologous proteins for pharmaceutical p...
We have developed a regeneration method and an Agrobacterium-mediated transformation protocol for... more We have developed a regeneration method and an Agrobacterium-mediated transformation protocol for the commercially important ornamental plant Gerbera hybrida. Pieces of petioles of the red variety Terra Regina were cocultivated with a disarmed Agrobacterium ...
Lignin biosynthesis is a major carbon sink in gymnosperms and woody angiosperms. Many of the enzy... more Lignin biosynthesis is a major carbon sink in gymnosperms and woody angiosperms. Many of the enzymes involved are encoded for by several genes, some of which are also related to the biosynthesis of other phenylpropanoids. In this study, we aimed at the identification of those gene family members that are responsible for developmental lignification in Norway spruce (Picea abies (L.) Karst.). Gene expression across the whole lignin biosynthetic pathway was profiled using EST sequencing and quantitative real-time ...
We cloned and sequenced a rat cDNA encoding the 2'-5' oligoadenylate synthetase, ... more We cloned and sequenced a rat cDNA encoding the 2'-5' oligoadenylate synthetase, a component of the mammalian interferon-induced antiviral response, and used Agrobacterium-mediated transformation to generate transgenic potato clones expressing this mammalian enzyme. In transgenic plants infected with potato virus X and followed under field conditions, virus concentrations in leaves and in tubers were significantly lower than in nontransgenic controls. Additionally, virus concentration in the leaves of five transgenic clones and in tubers of one clone was also lower than in transgenic potatoes expressing potato virus X coat protein.
The effects of the transformation of a 4-coumarate:coenzyme A ligase (4CL) gene involved in ligni... more The effects of the transformation of a 4-coumarate:coenzyme A ligase (4CL) gene involved in lignin biosynthesis on the interactions between transgenic plants and soil microbiota were studied in silver birch (Betula pendula Roth). Although the genetic transformation did not lead to expected changes in wood chemistry, it had significant influence on root biomass and morphology. The transgenic lines had less
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Papers by T. Teeri