Characterization of nematode resistance gene analogs in tetraploid wheat

Using a PCR-based approach we have isolated and characterized a putative plant resistance gene from Triticum turgidum whose corresponding resistance gene has been identified in Triticum aestivum. Furthermore, the partial sequences of four new resistance gene analogs (RGA), were used to study their expression profiles in leaves and in roots of two different varieties of T turgidum. The analysis of the conserved motifs clearly indicates that the sequences we have isolated belong to the NBS-LRR class of plant resistance genes. Expression studies in healthy plants, using the varieties Creso and Latino of T turgidum, indicate different localizations of RGA transcripts and suggest that they function in the general mechanism of plant surveillance against pathogens. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.