DNA construct to confer multiple traits on plants

Abstract

The present invention is directed to a DNA construct formed from a fusion gene which includes a trait DNA molecule and a silencer DNA molecule. The trait DNA molecule has a length that is insufficient to impart a desired trait to plants transformed with the trait DNA molecule. The silencer DNA molecule is operatively coupled to the trait DNA molecule with the trait and silencer DNA molecules collectively having sufficient length to impart the trait to plants transformed with the DNA construct. Expression systems, host cells, plants, and plant seeds containing the DNA construct are disclosed. The present invention is also directed to imparting multiple traits to a plant.

Description

[0001] This application is a divisional of U.S. patent application Ser. No. 09 / 025,635, filed Feb. 18, 1998, which is hereby incorporated by reference in its entirety and claims the benefit of U.S. Provisional Application Ser. No. 60 / 035,350, filed Feb. 19, 1997, and 60 / 062,870, filed Oct. 21, 1997, which are hereby incorporated by reference.FIELD OF THE INVENTION [0002] The present invention is directed to a DNA construct to confer multiple traits on plants. BACKGROUND OF THE INVENTION [0003] Control of plant virus diseases took a major step forward in the last decade when it was shown in 1986 that the tobacco mosaic virus (“TMV”) coat protein gene that was expressed in transgenic tobacco conferred resistance to TMV (Powell-Abel, P., et al., “Delay of Disease Development in Transgenic Plants that Express the Tobacco Mosaic Virus Coat Protein Gene,”Science, 232: 738-43 (1986)). The concept of pathogen-derived resistance (“PDR”), which states that pathogen genes that are expressed in...

AI Technical Summary

Benefits of technology

[0015] Rather than attempting to incorporate full length viral genes in a plant, the present invention uses short fragments of such genes to impart resistance to the plant against a plurality of viral pathogens. These short fragments, which each by themselves have insufficient length to impart such resistance, are more easily and cost effectively produced than full length genes. There is no need to include in the plant separate promoters for each of the fragments; only a single promoter is required. Moreover, such viral gene fragments can preferably be incorporated in a single expression system to produce transgenic plants with a single transformation event.

[0017] Another use of the present invention involves imparting resistance against a plurality of different viruses. For example, in potato, the present invention can be employed to impart resistance against potato leaf roll virus, potato virus Y, and potato virus X. To effect such resistance, in accordance with the present invention, a DNA construct, driven by a single promoter, and containing a portion of the potato leafroll virus replicase encoding gene, a portion of the potato virus Y coat protein encoding gene, and a portion of the gene encoding the movement protein of potato virus X can be produced and transformed into potato. As a result, transgenic potato with resistance to potato leafroll virus, potato virus Y, and potato virus X can be produced by a single transformation event. This constitutes a significant advance beyond incorporating full length versions of each of the genes with separate promoters together in a single expression vector or in separate vectors.

Problems solved by technology

It is well known that particular plant types are often susceptible to more than one virus.

Although PDR is an excellent approach to controlling the damaging effects of plant viruses, incorporating multiple virus resistance in a given plant can be challenging.

For example, identifying and producing full length viral genes to transform plants can be expensive and time consuming.

Further, such genes may be so large that they need to be incorporated in different expression systems which must be separately incorporated in plants.

Images