NOTE: Dr Michael Antoniou is reader in medical and molecular genetics at King's College London. See his recent article 'Economics, not common sense, drives GM crops'
COMMENT from Dr Antoniou: We have always said that the development of GM crops is a purely commercially motivated enterprise. The attached article which reviews progress in the generation and marketing of GM ornamental plants just proves this point since there is absolutely no benefit to humanity from this exercise. What a total waste of time and resources with potentially dangerous environmental consequences.
EXTRACT: Navigating the regulatory process particularly cuts into profit margins. "We estimated that it would take about two years and cost $250,000 each year," says Dobres, to conduct the molecular analysis experiments and field tests required by the US Department of Agriculture (USDA). Dobres adds, however, that the situation is "not totally bleak." As a member of the steering committee for a private-public coalition coordinated by the USDA, the Specialty Crops Regulatory Initiative, he is working with others to bring regulatory relief to specialty GM crops and save companies and regulatory agencies time and money.
Nature Biotechnology 25, 963 - 965 (2007)
3 September 2007
1.Great Falls, Montana
Recombinant technology has not yet taken root in ornamental plant breeding, but if some early genetically modified products succeed in the marketplace, might this change?
Suntory, Osaka, Japan
Roses are red, or maybe not. Genetic modification can do what nature cannot - make a blue rose.
A collaboration between US biotech firm Mendel Biotechnology, of Hayward, California, and the large German plant breeder Selecta Klemm, of Stuttgart, Germany, aims to exploit the power of plant functional genomics to create a new range of products for the worldwide ornamental plant, or floriculture, market. Focused on developing flowering plants that can adapt to changing environmental conditions, joint venture Ornamental Biosciences, is a rare foray for biotech into modern floriculture. Whether there is room for more than a scattering of such ventures in a field dominated by work on food crops, only time will tell.
Hot and dry
In 2006, US consumers spent $20.8 billion on ornamental plants, according to the Society of American Florists in Alexandria, Virginia, and global sales rang up billions more. Yet just two companies are dedicated to applying biotech tools in floriculture, a business that sells cut flowers like roses and carnations, potted plants like poinsettias, and bedding plants like petunias and geraniums (Table 1). "There are not many companies in the space, because there were not many relevant technologies for people to use until [recently]" says James Zhang, vice president of business development at Mendel Biotechnology. However, now that information has become available on genes and pathways that affect traits such as stress tolerance and color creation in plants, floriculture researchers finally have some of the tools they need to create hardier and more unusual plants.
The ten-year-old Mendel Biotechnology holds patents on key genetic engineering methods for making field crops such as corn and soybeans drought tolerant. "We were the first company to develop drought-tolerant technologies for plants," says Zhang. The firm focuses on making genetically modified (GM) plants that resist biotic stress, such as insects and fungal diseases, and abiotic stress, such as drought and low temperatures.
Their 'Weatherguard' technology covers the C-box, or CRT binding factor (CBF), family of transcription factors, isolated originally from Arabidopsis thaliana. This family of regulatory factors binds to a genetic element called C-repeat/dehydration responsive element (CRT/DRE) found in the promoters of dozens of cold- and drought-responsive genes.
Unlike agriculture, where the same GM corn is planted year after year, traditionally floriculture is dynamic, and consumers covet new plant varieties.
Drought and cold tolerance share common molecular response pathways. Three members of the family (CBF1, CBF2 and CBF3) are induced within 15 minutes after plants are transferred to cold temperatures, and a fourth one (CBF4) is induced by drought. And both cold and drought stress induce the expression of the response to dehydration gene, RD29A, through activation of CBF proteins.
Because so many aspects of cold and drought tolerance are under transcriptional control, transcription factors are excellent tools for engineering plants to withstand these stresses. When overexpressed, heterologous CBF transcription factors switch on a plant's own defense systems. In rice, for example, the overexpression of a calcium-dependent protein kinase via an introduced CBF gene improves cold and drought tolerance1. CBF transcription factors have been successfully engineered into soybeans, canola, tomatoes, alfalfa, cherries, strawberries, rice and other crops by researchers at Mendel and elsewhere2. Now, Ornamental Bioscience is extending the technology to petunias and other bedding plants.
Ornamental Bioscience "is going after drought tolerance first," says plant molecular biologist Joche Bog, technical manager of the research facility in Stuttgart. Bog is starting with petunias, which are easy to transform and have a relatively short life cycle, to examine how transcription factors control drought tolerance. Once transformation protocols are worked out, they'll be transferred to impatiens, geraniums and poinsettias, he says.
Drought-tolerant plants fit right in with the environmentally friendly trend of 'xeriscaping', a type of landscaping that strives to reduce water use (see http://en.wikipedia.org/wiki/Xeriscaping). In fast-growing areas of the western United States, up to half of residential water usage ends up on landscape plants and lawns. With drought-tolerant plants, "people don't have to worry about plants dying if they forget to water them or while [they are] on vacation," says Zhang.
Another project is investigating transcription factors that stop fungal pathogens such as powdery mildew, botrytis and sclerotinia from attacking plants. Reducing the need for insecticide use on plants protects the environment, a goal Ornamental Bioscience calls "ecological genetic support."
Once in a blue rose
The only floriculture company currently marketing a GM ornamental plant is Melbourne, Australia based Florigene. Founded in 1986 by the Australian government and private investors, to apply biotech to floriculture and forestry, Florigene originally partnered with the US based Calgene (now owned by St. Louis, Missouri based Monsanto). Today, Florigene is a subsidiary of Suntory, a beverage and food company headquartered in Osaka, Japan that has expanded into health foods and flowers. Eleven years ago, Florigene introduced a GM carnation, some 75 million of which have been sold in Australia, Japan and the US as Florigene-Moondust, -Moonshadow, -Moonlite and -Moonshade, in shades ranging from blue-violet to deep purple. These so-called 'blue' carnations embody Florigene's 'Blue Gene Technology', which currently is being used to fashion a blue rose that the company expects to hit the market sometime in 2008.
Three major groups of pigments, the betalains, the carotenoids and the flavonoids, are responsible for natural flower color. Florigene's Blue Gene Technology focuses on, among other things, the use of a recombinant cytochrome P450 enzyme, flavonoid 3',5'-hydroxylase (F3',5'H)3, to manipulate the concentration of the flavonoid anthocyanin delphinidin (named after delphiniums), which imparts blue-to-purple hues. Some flowers, such as forget-me-nots, larkspur, petunias and delphiniums, naturally contain delphinidin. However, the top-selling cut flowers, including roses, carnations and chrysanthemums, lack F3',5'H and hence delphinidin. Historically, cross-breeding has generated thousands of varieties of red, white, pink and yellow roses, but traditional breeding can never compensate for the total absence of the gene responsible for blue color.
The genes involved with flavonoid biosynthesis, as well as transformation methods to insert them into ornamental plants and propagate color traits, are at the center of Florigene's intellectual property portfolio. Public documents filed with the Australian government to obtain permission to carry out greenhouse trials of the blue rose give some insights into Florigene's transformation methods. Florigene researchers transfer the gene encoding F3',5'H from petunias into the hybrid tea rose (Rosa x hybrida) using the vector Agrobacterium tumefaciens, along with marker genes for antibiotic resistance or sulfonylurea-type herbicide resistance. Vegetative tops of the plants bearing shoots and flowers are grafted onto nontransgenic Rosa multiflora or Rosa canina rootstock growing in greenhouses. However, the remaining details of the transformation and regeneration process "are company secrets," according to Steve Chandler, Florigene's general manager.
Even after the company achieved success with blue carnations ten years ago, the route to a blue rose has been thorny. The initial cloning of the blue gene from petunias took three years to achieve because it is expressed only at certain times during flower development and has high homology with other cytochrome P450 genes. Once isolated, simply inserting the blue gene is not sufficient to ensure blue-violet pigments will be present. The pH of the petal vacuoles and the presence of other flavonoids and metal ions contribute to blue coloration and must be regulated. "Flower color is not simply a result of pigment concentration," says Chandler, "physiological issues complicate it all."
Achieving a desired color in roses or other flowers requires downregulation of competing pathways and overexpression of others through the use of antisense RNA or RNA interference or the insertion of genes from other plants, according to Chandler. Orange petunias, for example, are made by starting with a red petunia, then downregulating an endogenous flavonoid 3'-hydroxylase gene and overexpressing an inserted dihydroflavonol 4-reductase (DFR) gene from a rose. Depending on the plant tissue, DFR can contribute to blue, red or orange pigments. In Florigene's GM blue rose, more than 90% of all the pigment in the petals consists of delphinidin, yet the flower is not truly blue, but rather lavender to mauve. Florigene researchers continue to tinker with genes and related factors to improve the color to attract consumers (Box 1).
Smelling just as sweet
Today's roses may come in myriads of colors, sizes and shapes, but most have little to no fragrance. Like tomatoes, where breeding for commercial use has reduced the flavor, breeding has made roses brighter and more colorful with bigger blooms, but forced out genes for fragrance. "Flower breeders put so much emphasis on creating varieties with eye-popping blooms that scent got sacrificed along the way," says Harry Klee, a horticulturist at the University of Florida, Gainesville.
Klee and colleagues at the Max Planck Institute in Golm-Potsdam, Germany, made a discovery that could one day lead to sweeter-smelling roses, as well as tastier tomatoes. They identified and cloned a set of genes from tomatoes that are responsible for both flavor (in tomatoes) and fragrance (in roses)””a family of decarboxylases that convert phenylalanine to 2-phenylethanol, commonly known as rose oil4. This volatile compound, which gives roses their heavenly scent, is used by the flavor and fragrance industry. Klee and Dave Clark, also at the University of Florida, Gainesville, cloned the last gene in the rose oil pathway, LePAR (encoding 2-phenylacetaldehyde reductase; details will appear in an upcoming issue of Phytochemistry). Klee's laboratory is reconstituting the entire pathway in bacteria to produce large quantities of natural rose oil, which is preferred by the perfume and food industry over chemically synthesized versions.
Clark, an environmental horticulturist, is engineering LePAR into roses to resurrect fragrance. His molecular model, the petunia, belongs to the Solanaceae family, as do tomatoes. "When we overexpress the tomato gene in petunias, it makes ten times more rose oil" than plants not spiked with the gene, says Clark. The Solanaceae family also includes tobacco, peppers, eggplants and potatoes, all valuable horticultural plants of economic importance. Lessons learned in the petunia model could be transferred to edible members of the family to improve taste.
Clark has met with several rose-breeding companies, who are watching his progress, but none has cut a deal. If none signs on, the University of Florida may support the commercialization of fragrant roses. "We can do it in house if we have to, but it will take a few years longer," says Clark. His quest is based on more than rose petals in the sky””consumer surveys indicate that people will pay more for roses with loftier scents.
About 80% of US agriculture depends on GM crops, but floriculture lags behind for several reasons. Although floriculture researchers at Mendel Biotechnology, Ornamental Bioscience, Florigene and universities use standard genomics methods such as antisense RNA and RNA interference to silence or overexpress genes, there are few floriculture-specific tools. This has led molecular biologist Michelle Jones at Ohio State University in Wooster to create her own; she developed a petunia DNA microarray in collaboration with Anthony Stead at the University of London, Royal Holloway. Each microarray contains 4,500 unique cDNAs largely related to floral development, based on expressed sequence tags identified by Clark's laboratory. "We hope other researchers will contribute gene sequences for roots, vegetative tissues and other plant features," says Jones, to make the microarrays more comprehensive.
Jones' goal is to use petunias as a molecular model system to improve knowledge about floriculture. "We need to convince the industry that genetically engineered ornamentals are better and cheaper than traditional breeding," Jones says. For some traits, such as blue flowers, genetic engineering offers the only option. If knowledge gained in GM petunias can be translated to other species, the floriculture industry may dig up money for basic research that could lead to licensing deals or more floriculture biotech startups.
Jones' focus is on finding genes that slow the senescence of flowers in vases and gardens, a consumer-desirable trait that could boost sales of ornamentals. Although she works in Ohio, the sixth-largest producer of floriculture crops in the US, she receives no funding from floriculture companies. To explore ways to control senescence, Jones uses transformed petunias created by Klee and Clark that overexpress a mutant ethylene receptor gene (etr1-1) from Arabidopsis, which, when inserted into petunias, extends the life of the flowers5.
Like all GM organisms, GM ornamentals face government regulation before marketing. The standards, enforced by the US Department of Agriculture in Washington, DC, are less stringent than those for GM food crops. Yet the paperwork and field trials extend costs and timelines, and even prompted one floriculture company to close its GM program (Box 2). GM agricultural crops offset these costs because farmers grow thousands of acres of one variety of corn or soybeans. But at a fraction of the size, the ornamental plant business cannot spread costs over enough plants to ensure a profit. Moreover, within a flower category, hundreds of varieties are marketed, so a GM trait in one type of flower garners a small market share.
Unlike agriculture, where the same GM corn is planted year after year, traditionally floriculture is dynamic, and consumers covet new plant varieties. Classical plant breeding adeptly provides new blooms and colors. In the five to ten years that it would take biotech to perfect a GM plant, something entirely different may come into vogue. "It's like trying to hit a running target," says University of Florida's Clark.
"You have to think differently about how to apply biotechnology to floriculture than to row crops or vegetables," says Alan Blowers, biotech project manager at Ball Helix, the internal biotech division of the 100-year-old Ball Horticultural Company in West Chicago, Illinois. Just 15 years ago, sweet peas were the number-one crop in acreage grown by Ball Horticultural Company, but today the company grows zero acres of this out-of-fashion plant.
Ball Horticultural, a family-owned business in operation since 1905, set up Ball Helix in 1998 to provide its breeders with analytical technologies to improve traits such as flower color and disease resistance, and to troubleshoot problems. Ball Helix's genetic-engineering capabilities are a trade secret intended exclusively for in-house purposes. Nonetheless, Blowers dreams of making a pine-scented poinsettia to replace the lost scent in homes with artificial Christmas trees. Nothing is in the works, and it will take years of investment in molecular biology methods to insert the relevant genes encoding enzymes involved in scent production.
Yet over 15 years, the market for corn and soybean varieties holds strong and steady and is not affected by consumer whimsy. In contrast to most GM crops in use today, in which recombinant traits such as herbicide or pesticide resistance appeal mainly to farmers, floriculturists must design plants with consumer appeal to add value. Traits that lure consumers are especially important because ornamentals are a purely discretionary purchase.
But, somewhat intriguingly, fragrant roses or drought-resistant petunias do not seem to meet with the same resistance as GM food crops. "I give talks to master gardener groups with 600 people, and I hardly ever hear of anyone who is apprehensive about bioengineered ornamentals," says Clark.
For its part, Florigene has been selling GM carnations in three countries for ten years. "We've sold millions and millions of them, and once every three or four years a single individual will protest against them," says Chandler. Ultimately, perhaps fragrant roses could even improve the public's perception of agbiotech in general. "GM roses will not save the earth," admits Klee, but they may prove more palatable and less threatening to Western consumers than GM crops.
For 5,000 years, people have cultivated roses, the most loved of cut flowers. But will people buy blue roses? Florigene, the Melbourne, Australia based company that is genetically engineering a blue rose, is banking on the novelty of the color to drive sales, as well as on color psychology. "Color choice in flowers is an interesting psychological area," says Florigene's Steve Chandler, and motivated by the same reasons people buy cars, paint and other consumer items in certain colors. Blue is the color of the sky, oceans and computer screens. About 20% of people rank blue as their favorite color overall. The soothing color creates feelings of calmness and makes people more productive. Spiritual - and, in the US, Italy and France, patriotic - feelings are encapsulated in the color, too, and blue celebrates baby boys. "Inevitably, there will be people who will buy blue roses," Chandler predicts. And as blue is the color most preferred by men, it is possible that males who would never dream of buying roses of any other color may finally visit a florist shop.
The high cost of licenses, patents, research and development, and deregulation of genetically modified (GM) ornamentals "is a significant financial burden," says Michael Dobres, CEO at NovaFlora in West Grove, Pennsylvania. The genes and enabling technologies such as transformation methods and selectable markers are owned by agricultural giants such as Monsanto, of St. Louis, Missouri; Syngenta, of Basel, Switzerland; and DuPont, of Wilmington, Delaware, according to Dobres. About two years ago, NovaFlora dropped its genetic engineering program in lieu of cell biology methods such as customized mutagenesis, used to scramble natural genes to design new flower varieties. Navigating the regulatory process particularly cuts into profit margins. "We estimated that it would take about two years and cost $250,000 each year," says Dobres, to conduct the molecular analysis experiments and field tests required by the US Department of Agriculture (USDA). Dobres adds, however, that the situation is "not totally bleak." As a member of the steering committee for a private-public coalition coordinated by the USDA, the Specialty Crops Regulatory Initiative, he is working with others to bring regulatory relief to specialty GM crops and save companies and regulatory agencies time and money. If the regulatory climate loosens up, he even suggests that NovaFlora may re-enter the GM plant business.
Oh, S.J., et al. Plant Physiology. 138, 341 351 (2005).
Zhang, J.Z., Creelman, R.A.& Zhu, J. Plant Physiol. 135, 615 621 (2004).
Tanaka, Y. Phytochem. Rev. 5, 283 291 (2006).
Tieman, D. et al. Proc. Natl. Acad. Sci. USA 103, 8287 8292 (2006).
Jones, M.L. et al. J. Exp. Bot. 56, 2733 2744 (2005).