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Bundoora, Australia

Tanaka Y.,Suntory Business Expert Ltd | Brugliera F.,Florigene Pty Ltd
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2013

Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 30-hydroxylase (F30H) and flavonoid 30,50-hydroxylase (F3050H) and thus they play a crucial role in the determination of flower colour. F30H and F3050H mostly belong to CYP75B and CYP75A, respectively, except for the F3050Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3050H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3050H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3050H and F30H in delphinidinproducing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Nakamura N.,Suntory Holdings Ltd | Tems U.,Florigene Pty Ltd | Fukuchi-Mizutani M.,Suntory Holdings Ltd | Chandler S.,Florigene Pty Ltd | And 4 more authors.
Plant Biotechnology | Year: 2011

An important part of the assessment of the potential environmental impact from the introduction of a genetically modified (GM) plant is an evaluation of the potential for gene flow from the GM plant to related wild species. This information is needed as part of the risk-assessment process, in the context of whether gene flow to wild species is possible. One method for evaluating gene flow is to use molecular techniques to identify genes in wild species populations that may have originated from a cultivated species. An advantage of this method is that a phenotypic marker or trait is not required to measure gene flow. In the present study we analyzed the seedlings of seeds from three wild native Rosa species (R. multiflora Thunb., R. luciae Rochebr. et Franch. ex Crép. and R. rugosa Thunb.) selected from several locations across Japan where the wild rose was growing in close proximity to cultivated rose plants (Rosxhybrida). To determine whether gene flow from cultivated rose had occurred, young leaves of 1,296 seedlings from the wild Rosa plants were analyzed by PCR for the presence of the KSN locus. This locus originated from a sport of R. chinensis Jacq. var. spontanea (Rehd. Et Wils.) Yu et Ku and is involved in the recurrent flowering phenotype observed for cultivated rose hybrids, but is absent in Japanese species roses. The KSN locus was absent in all seedlings sampled, indicating no gene flow to wild Rosa species from the cultivated rose had occurred, and providing evidence that the probability of gene flow from cultivated to wild Rosa species in Japan is low or non-existent.

Nakamura N.,Suntory Holdings Ltd | Fukuchi-Mizutani M.,Suntory Holdings Ltd | Katsumoto Y.,Suntory Holdings Ltd | Togami J.,Suntory Holdings Ltd | And 12 more authors.
Plant Biotechnology | Year: 2011

The release of genetically modified plants into the environment can only occur after permission is obtained from the relevant regulatory authorities. This permission will only be obtained after extensive risk assessment shows comparable risk of impact to the environment and biodiversity as compared to non-transgenic host plants. Two transgenic rose (Rosa×hybrida) lines, whose flowers were modified to a bluer colour as a result of accumulation of delphinidin-based anthocyanins, have been trialed in greenhouses and the field in both Japan and Australia. Flower colour modification was due to expression of genes of a viola flavonoid 3',5'-hydroxylase and a torenia anthocyanin 5-acyltransferase. In all trials it was shown that the performance of the two transgenic lines, as measured by their growth characters, was comparable to the host untransformed variety. Biological assay showed that the transgenic lines did not produce allelopathic compounds. In Japan, seeds from wild rose species that had grown in close proximity to the transgenic roses did not carry either a Rosa×hybrida specific marker gene or the transgenes. In hybridization experiments using transgenic rose pollen and wild rose female parents, the transgenes were not detected in the seed obtained, though there was a low frequency of seed set. The transgene was also not transmitted when Rosa×hybrida cultivars were used as females. In in situ hybridization analysis transgene transcripts were only detected in the epidermal cells in the petals of the transgenic roses. In combination, the breeding and in situ analysis results show that the transgenic roses contain the transgene only in the L1 layer cells and not in the L2 layer cells that generate reproductive cells. General release permissions have been granted for both transgenic lines in Japan and one is now commercially produced.

Chandler S.F.,Florigene Pty Ltd | Brugliera F.,Florigene Pty Ltd
Biotechnology Letters | Year: 2011

Micro-propagation, embryo rescue, mutagenesis via chemical or irradiation means and in vitro inter-specific hybridisation methods have been used by breeders in the floriculture industry for many years. In the past 20 years these enabling technologies have been supplemented by genetic modification methods. Though many genes of potential utility to the floricultural industry have been identified, and much has been learnt of the genetic factors and molecular mechanisms underlying phenotypes of great importance to the industry, there are only flower colour modified varieties of carnation and rose in the marketplace. To a large extent this is due to unique financial barriers to market entry for genetically modified varieties of flower crops, including use of technology fees and costs of regulatory approval. © 2010 Springer Science+Business Media B.V.

Gion K.,Suntory Business Expert Ltd | Suzuri R.,Suntory Business Expert Ltd | Ishiguro K.,Suntory Business Expert Ltd | Katsumoto Y.,Suntory Business Expert Ltd | And 5 more authors.
Acta Horticulturae | Year: 2012

We have been using genetic engineering to develop and commercialize new floricultural cultivars focusing on novel flower colour. Rose, carnation and chrysanthemum do not have violet or blue flowers due to their lack of ability to synthesize the delphinidin-based anthocyanins which most violet/blue flowers contain. Flavonoid 3', 5'-hydroxylase (F3'5'H) is the key enzyme on the biosynthesis pathway leading to delphinidin. Transgenic rose, carnation and chrysanthemum expressing a heterologous F3'5'H gene produced flowers with a novel violet/blue flower colour for these species, not possible by hybridization breeding. Transgenic carnations are sold in USA, EU and Japan and a transgenic rose in Japan. Rose, carnation and chrysanthemum expressing an Arabidopsis FT (a gene that promotes flowering) exhibited very early flowering phenotypes. Expressing dominant chimeric repressors of various transcriptional factors in transgenic rose resulted in various novel flower morphologies. These technologies will be useful for development of novel floricultural crops in future.

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