1. Sterility. The goal is to produce reliable systems to provide high level genetic containment when this is needed. Production and field-testing of trees with engineered sterility genes based on diverse methods, but with a focus on suppression of native genes essential for flowering (via “RNAi” forms of floral regulatory genes).
2. Stability. Are transgenes expressed in a sufficiently stable and predictable manner over years in the field to enable useful and safe applications? We have studied stability of expression in hundreds of transgenic trees, some over nearly a decade in the field.
3. Domestication. Genetic modification of tree form, flowering, chemistry, and carbon allocation via changes in the plant hormone gibberellic acid. We have field-tested hundreds of different genotypes, and are currently producing hundreds more for testing.
4. Microarrays. Analysis of genome-scale gene expression, and mapping genes for growth based on tens of thousands of SNPs (single nucleotide polymorphisms), using microarrays based on entire genome sequences. We have described the expression for thousands of genes new to sci-ence in wood forming tissues, and many other tissues are under study.
5. Gene discovery. We use “activation tagging,” where single-gene mutations are created and marked to aid recovery, using gene transfer methods. This enables the genes that control impor-tant traits to be rapidly and precisely identified for the first time. We have tested thousands of trees in the in lab and field, and discovered more than 40 novel gene:trait linkages.
6. Gene validation. We work with biotechnology companies and other research laboratories to rigorously test new genes that control wood chemistry, stress tolerance, and yield. A new field trial of lignin-reduced trees was planted in fall 2005.