Plant & Animal Genomes XIII Conference

January 15-19, 2005
Town & Country Convention Center
San Diego, CA

Citrus EST Sequencing And High-Density Microarrays

Mikeal L. Roose , Claire T. Federici , Matthew P. Lyon , Raymond D. Fenton , Steve Wanamaker , Timothy J. Close

  Dept. of Botany and Plant Sciences, University of California, Riverside, CA 92521, U. S. A.

To improve the publicly available database of ESTs for citrus, we are sequencing clones from 16 cDNA libraries. Most libraries have been prepared from tissue of Washington navel orange, but some were prepared from other sweet oranges or other varieties more appropriate for particular traits. By January 2005 we expect to have sequenced, trimmed, and assembled at least 100,000 ESTs from libraries that contain genes expressed in a range of organs and environmental conditions. Libraries sequenced include vegetative shoot tips, phloem tissue challenged by citrus tristeza virus (CTV), bark exposed to CTV isolates that induce quick decline, tissues of plants exposed to various pathogens, fruit rind after cold acclimation, rind and pulp after postharvest treatment and cold storage, rind of young fruit after thrip feeding, rind of fruit infested with red scale, rind of Clementine at separation stage, roots exposed to citrus nematode, roots exposed to low available iron conditions, flowers, ovaries, developing seeds, and embryogenic callus. We continue to develop a microcomputer EST browser program, "HarvEST:Citrus" to facilitate distribution and use of these and all other public citrus EST sequences. Analyses to be presented include the number and annotation of EST sequences and unigenes available for citrus and the proportion of sequences expressed in various libraries. A high-density Affymetrix microarray containing multiple alleles of all available citrus sequences is expected to be available by May 2005. Funding is from the California Citrus Research Board and University of California Discovery Grant Program.