The laboratories participating in the NSF Potato Genome Project are producing comprehensive structural and functional genomic information and resources freely available to the research community. The data generated are aiding in the development of tangible products, such as disease resistance traits and genetic markers, for growers, breeders and communities interested in potato and plant biology and environmentally friendly agricultural practices.

Key achievements:

• Late Blight resistance gene, RB, has been isolated. RB is unlike any P. infestans resistance gene isolated to date in that it confers resistance to all strains of P. infestans.
• More than 180 resistance gene candidates and several active resistance genes, conferring resistance to viral, oomycete and bacterial pathogens, as well as genes for general resistance, have been identified. Knowledge of the sequence of these regions is being used to identify corresponding disease resistance traits from related Solanaceae such as tomato and pepper, as resources for natural plant disease resistance.
• Physical and genetic maps of resistance "hot spots" on potato chromosome 5 and chromosome 11, conferring resistance to viral, bacterial, nematode, and 10 different strains of oomycete pathogens ( P. infestans ) have been assembled and characterized.
• Analysis of the R1 resistance gene "hot spot" on potato chromosome 5 of Solanum demissum has given insight into the functional and evolutionary significance of resistance gene clustering. We determined that the R1 homologues at this cluster form three independent groups of fast-evolving Type I resistance genes. The sub-categorization of Type I resistance genes has not been reported elsewhere. Such genes were first identified among clustered RGC2 genes in lettuce, where they were distinguished from slow-evolving Type II R-genes. Our findings suggest that a common or similar mechanism underlies differentiation of Type I and Type II R-genes and differentiation of Type I R-genes into distinct groups.
• Five core and two P. infestans challenged potato cDNA libraries have been completed. 130,000 ESTs (Expressed Sequence Tags) have been generated from these libraries and released to the Genbank public database. Using these ESTs, a 10,000 cDNA potato microarray has been generated and distributed, including information on microarray methods and a list of control and validated clones.
• Analysis of potato genome-wide expression patterns has been conducted, identifying many resistance genes and providing a valuable public resource for understanding potato biology on a genome-wide level.
• An expression profiling service run by TIGR for the Solanaceae community has been established allowing researchers to submit mRNA for their choice of microarray hybridization experiments.
• Conserved Ortholog Set (COS) markers have been identified, tying the potato and tomato genomes to the Arabidopsis genome.
• A number of databases have been established to house project data, including Solanaceae resistance gene sequences, non-redundant ESTs, microarray expression profiles, COS markers and cDNA and BAC clones.