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.
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.
3. Pollen dispersal from a cut flower leading to a successful hybridization event.
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.
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
The regulatory process
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.
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;
||EU approval & registration No.|
For more information on the regulatory system in the EU we recommend;
A public information website provided by the European commission which tracks all applications for
marketing approval and deliberate release in the EU, and is located at
http://gmoinfo.jrc.it/. A link to a copy of Directive 2001/18/EC is also located there.|
|• ||A very useful document, with questions and answers
about the European regulatory system is located at http://www.gmo-compass.org|
Another important link is to the Biosafety Clearing House, a portal coordinating International
trade in GMO’s, located at http://bch.biodiv.org.
We welcome feedback and encourage any comments, either through the email portal
provided at this website, or at firstname.lastname@example.org.