Regulatory - English

The Florigene carnation varieties are genetically modified to alter the flower colour. They are intended for ornamental use only. Florigene has approval to market these flowers in the European Union, and we provide here additional information for those customers interested in more technical and background detail.

Genetic modification of flower colour in carnation

Flower colour is generally the result of the relative concentration and type of two pigment types - carotenoids and flavonoids. Carotenoids are responsible for yellow through orange colours Anthocyanins are flavonoid based coloured pigments. There are three groups of anthocyanins, the delphinidins that generally produce blue flower colour, cyanidins that produce red or pink flower colour, and pelargonidins that produce orange or brick red flower colour. The relevant biochemical pathway is shown in the Figure below.

Carnations lack the part of the anthocyanin biosynthetic pathway that is responsible for the production of delphinidin, as they lack a gene encoding the enzyme flavonoid 3'5' hydroxylase (F3''5'H in the diagram) that converts dihydrokaempferol (DHK) to dihydroquercetin (DHQ) and then to dihydromyricetin (DHM). In the genetically modified carnations commercialized by Florigene a gene encoding flavonoid 3'5' hydroxylase has been isolated from other plant species and transferred to carnation. Delphinidin is thus produced as a result of the combined expression of the introduced genes together with endogenous genes in the anthocyanin biosynthetic pathway. The production of delphinidin results in a change in flower colour. The transgenic plants also contain an ALS gene (SuRB), coding for an acetolactate synthase protein (ALS), derived from tobacco. Expression of this gene confers resistance to sufonylurea herbicides and allows selection of the transgenic carnation at early stages of development, when they are in tissue culture.

Environmental safety

Florigene flowers are imported into the EU from farms in South America. The flowers pose no greater risk to the environment in either Europe or South America than any other carnation variety grown for cut flower production. This is because there are three theoretical avenues of gene dispersal, none of which are possible for imported carnation flowers;

• 1. Vegetative spread of the imported cut flowers, leading to the formation of wild populations.

• 2. Formation and dispersal of seed from the imported cut flower as a result of self fertilization or fertilization with pollen from an external source.

• 3. Formation of seed by a recipient plant, fertilized by pollen dispersed from the imported cut flower.

1. Vegetative spread.

Carnation does not spread vegetatively, i.e. the plant does not produce organs such as stolons, rhizomes, root-borne shoots, tubers, bulbs, corms or runners and roots will not form on discarded or old cut-flowers. Florigene has experience of large scale production of carnation in Australia, Japan, Colombia and Ecuador and carnation has never been found growing wild, even in the immediate vicinity of carnation growing areas where waste material has been discarded or has been left for composting.

2. Formation of seed on a cut flower.

For gene dispersal by seed formation to occur from a cut carnation flower, the following events would all need to occur successfully; arrival of viable pollen on the stigma of the carnation, pollen germination, pollen tube growth to the ovule of the carnation, fertilization, seed formation and seed dispersal. Notwithstanding the fact that successful pollination of a carnation flower in a vase is highly unlikely, no seed set could occur. This is because the process of seed development takes at least 5 weeks on a plant – where the growth of any developing embryo can be sustained. A cut flower will survive for less time than this.

3. Pollen dispersal from a cut flower leading to a successful hybridization event.

There are several mutually exclusive facts that, in combination, indicate that potential pollen spread is not a feasible avenue for gene dispersal.

Firstly, the potential for pollen spread from a cut flower is only theoretically possible;

• In general, production of viable pollen by carnation is much lower than that of wild Dianthus species.

• Hybridization of Dianthus in nature is facilitated by insect pollination and is only effectively achieved by the Lepidoptera (butterflies, moths). Pollen is not spread by wind.

• The only point in the chain where insects could be reasonably expected to access flowers is when on display or in the hands of the consumer. The physical barrier of the multiple petals presents a significant obstacle to any potential pollinating insects in less open flowers.

Safety to human health

There are no potential harmful effects from handling the transgenic carnation flowers, and the flower produce no wind borne pollen. Carnation has been used safely by humans for ornamental purposes for centuries. The production of delphinidin is novel for carnation, but there are many flowers and other ornamental species that produce delphinidin and delphinidin is also present in many raw foods, such as grapes, blueberry and many others. Accidental consumption of the flowers would therefore pose no risk to human health.

The regulatory process

Florigene's carnation varieties are genetically modified, and after detailed evaluation have been approved for sale in Europe. The main legislation regulating the marketing of genetically modified products in the European Union is EU directive 2001/18/EC, regulations 1946/2003, 64/2004 and 1830/2003, and decisions 2004/204/EC, 2002/812/EC, 2002/623/EC and 2002/811/EC. Each of Florigene varieties has been given a unique identifier. The details of the varieties currently approved on the market in the EU are: