Project Number: 1275-21220-222-02
Project Type: Trust

Start Date: Nov 04, 2002
End Date: Nov 03, 2007

Objective:
Clone and characterize genes that are specifically expressed in sugar beet taproots in response to insect and pathogen attack using root maggot resistant plant varieties. Clone and characterize the promoters of taproot specific genes.

Approach:
A sugar beet cDNA library that was prepared from taproot tissues of a root-maggot resistant line at 0, 24 and 48 hours after infestation will be screened using differential hybridization with subtracted probes enriched for 1) resistance-associated and 2) taproot-specific genes. Subtracted probes will be prepared by hybridization of the taproot mRNA of resistant varieties with susceptible varieties and/or leaf mRNA. An unsubtracted probe will be used as a control. Sequences of clones that specifically hybridize with the subtracted probe will be compared against GenBank sequences for identification purposes. Molecular techniques (Northern and/or realtime PCR analysis) will be used to characterize the expression patterns of the cloned genes in the developing taproots . Genomic clones for the most interesting genes will be isolated from a sugar beet DNA library we have already prepared. The isolated clones will be sequenced and the promoter regions identified. Cloned promoters will be fused with reporter genes, such as GUS or GFP, for analysis of expression in sugar beet and spinach (a model plant system for sugar beet). BL-1; recertified May 19, 2006.