ISOLATION AND CHARACTERIZATION OF DROUGHT TOLERANCE-RELATED GENE (S) IN BARLEY

Abstract

Differential display-polymerase chain reaction (DD-PCR) technique was used to analyze differentially expressed sequence tags (ESTs) in barley (Hordeum vulgare L.) cultivar Giza 126 under drought stress. An array of 66 differentially expressed EST and 74 EST fragments were obtained from roots and shoots, respectively. The sequences of these fragments were identified and determined using a bioinformatics approach; BLAST. Results of the database sequence alignment for roots identified 28 (42%) fragments showed homology with some predicted proteins, 12 (18%) fragments showed homology with predicted proteins under abscisic acid (ABA), 7 (11%) fragments showed homology with predicted proteins under low temperature, 10 (15%) fragments showed homology with transcription factors, 5 (8%) fragments showed homology with different enzymes, 3 (5%) fragments showed homology with un-identifying clones and one (1%) fragment showed homology with LEA protein. With regard to shoots, 34 (46%) fragments showed homology with some predicted proteins, 13 (18%) fragments showed homology with predicted proteins under abscisic acid (ABA), 4 (5%) fragments showed homology with predicted proteins under low temperature, 4 (5%) fragments showed homology with transcription factors, 7 (10%) fragments showed homology with different enzymes, 8 (11%) fragments showed homology with un-identified clones, 3 (4%) fragments showed homology to different genes and one (1%) fragment showed homology with 14-3-3 protein. These results could be used to improve abiotic stress tolerance of economic crops. It is therefore evident from the aforementioned discussion that this study has revealed some important aspects associated closely with environmental tolerance (drought) in barley which could be used for the elucidation of mechanisms underlying environmental molecular stress responses in other major strategic cereal crops. Key Words: Drought stress, Differential Display-Polymerase Chain Reaction (DD-PCR), EST, Gene expression, Hordeum vulgare L.