SBIR-STTR Award

Ornamentals are one of the most valuable sectors of the nations specialty crop industry. They not only provide an essential source of income and jobs for those involved in the industry but also serve to enrich the quality of life for gardeners and the general public alike. Although the tools of biotechnology have been successfully used for the development of commodity grain and fiber crops they have not yet found wide commercial application in ornamentals and other specialty crops. This is in large part due to strict regulatory requirements related to the use of selectable markers. Although selectable markers are needed to facilitate the introduction and retention of genes into plant cells, once introduced they are no longer needed and their presence represents and unnecessary regulatory burden. An urgent need therefore exists for a plant transformation technology that allows the development of biotechnology derived specialty crops that are free of selectable markers. Addressing this need will facilitate regulatory approval, marketplace entry, and consumer acceptance of biotechnology derived ornamentals and other specialty crops. In this Phase I proposal we propose to initiate development of a transposon based marker removal system in roses that will, in Phase II, allow the development of roses with improved consumer and grower traits that are free of selectable markers and other superfluous DNA sequences. Once developed this technology will be tested and developed in other economically valuable specialty crops. This should lead to improved grower, consumer and market acceptance of genetically engineered specialty crops. OBJECTIVES: The general objective of this proposal is to test and validate components of a selectable marker removal system in roses. Proof-of-concept research proposed in this SBIR Phase I application will lead to development of a fully tested marker removal system in a subsequent SBIR Phase II proposal. The primary specific objective of Phase I is to demonstrate the accurate and efficient molecular activity of our technique in tissue cultured rose material. APPROACH: To simulate the removal of selectable markers in transformed plant tissues, short-term transformation and selection assays using DNA constructs described in the application will be performed in cultured rose leaf explants. The proposed technology includes novel DNA molecules designed to allow the real time monitoring of marker excision events in cell cultures of rose.

There is an urgent need for an effective chemical-free control measure for crown gall. Crown gall is a major disease of many perennial crops. It is especially a problem in long-lived woody crops such as roses, where galls on rose bushes render plants unsalable. In the case of woody fruit and nut producing crops such as walnut, grapes, pears and apples, galled trees and vines are less productive. Losses of 10 to 30% have been reported and control with chemicals has both an environmental cost and a significant business costs, estimated at more than a $1000 per acre for roses alone. Rose and other nursery crop growers currently work under an EPA Critical Exemption for the use of such chemicals. This exemption could be lifted at anytime. OBJECTIVES: Germplasm created in this project will help reduce the dependency of farmers on ozone depleting chemicals traditionally used to combat crown gall in roses and many other woody plants. The specific objective of this USDA-SBIR Phase II proposal is to develop roses that are resistant to crown gall disease. We propose to achieve this goal using a novel disease resistance technology that specifically targets gall forming genes in rose rootstock. APPROACH: We will use a novel trait gene that blocks crown gall formation in a broad range of plants. The trait gene technology works by interfering with the gall forming genes of the crown gall bacterium (Agrobacterium) as it invades the plant cell. This approach neutralizes the bacterial genes, within the plant cell, by creating a complimentary copy of bacterial gall forming genes. These gall forming genes would otherwise produce hormones that trigger gall formation There is no other technology that allows for the creation of such resistance to crown gall bacteria. We will deliver this technology using an approach that allows separation of trait genes from unwanted genes needed to transfer trait genes to a plant. The technology uses a "jumping gene" to separate and move a trait gene (such as crown gall resistance) away from unwanted foreign DNA, only used for the gene transfer process, but not required for functioning of the delivered trait gene. This genetic clean up technology has the added benefit of reducing the regulatory burden that such plants will be subjected to prior to commecialization