Isolation and characterization of some drought-related ESTs from barley

Drought is one of the main constraints facing crops and affecting their production. In a trial to investigate and understand drought effect, differential display experiments were performed where; about 107 DD-fragments have been isolated from wild barley plants subjected to drought treatment. These fragments were categorized according to their gene expression into four categories: 1) up regulated genes; 2) up and down regulated; 3) down regulated and 4) down and up regulated genes. The isolated fragments were cloned and sequenced. Sequence analysis using GeneBank database revealed that some fragments have significant similarities with starch branching enzyme I (sbeI) gene; glycosyl transferase family 1 gene; Retrotransposons Ty3-gypsy subclass; gag-polypeptide of LTR copia-type retroelement gene; IMP cyclohydrolase/phosphoribosylaminoimidazolecarboxamide formyltransferase and unknown proteins. Some other fragments have significant similarity with Triticum aestivum gene for TaAP2-B, complete cds and 3B chromosome, clone BAC TA3B63N2. These results indicate that starch metabolism, transposon elements and purine metabolism might have been affected by drought stress. Key words: Wild barley, differential display, drought; starch metabolism, purine metabolism