Project Number: 5325-21000-002-00
Project Type: Appropriated

Start Date: Mar 01, 2006
End Date: Feb 28, 2011

Objective:
Design and test molecular tools to better control transgene expression and integration. Identify, characterize, and demonstrate the utility of novel gene promoter elements for control of transgene expression in cereal crops. Emphasis is to be placed on promoters that provide developmental or environmental specificity to transgene expression, but are not active in the grains harvested for food or feed. Develop new recombination systems for plants that allow precise integration of DNA into targeted locations and selective removal of unwanted transgenic DNA from the genome. Make promoters and site-specific recombination systems with proven utility available to researchers in the public and private sectors.

Approach:
Use microarray and computer analyses from in-house and collaborative studies to identify rice, barley and wheat genes that exhibit organ-specific-, pathogen- or abiotic stress-responsive expression patterns. Isolate the corresponding promoters and examine and document their ability to control expression in transgenic cereal plants. Design and build transformation vectors incorporating site-specific recombination systems designed to target predetermined integration sites in cereal genomes and to allow excision of plasmid backbone and marker genes no longer needed after transformants are identified. Optimize codons and protein targeting signals as needed for better functionality in plant cells. Transform plants with recombinase-encoding constructs and target constructs. Demonstrate site-specific excision and/or integration reactions in plant cells. (Replaces 5325-21000-008-00D, 2/06.)