Abstract: Reverse transcription-polymerase chain reaction (RT-PCR) was performed to isolate a cDNA clone using specific primers designed based on the barley (Hordeum vulgare L.) Mlo gene cDNA sequence. A full-length cDNA encoding an Mlo-like protein was isolated and characterized in a Triticum aestivum L.-Haynaldia villosa L. 6VS/6AL translocation line. The putative protein consists of 534 amino acid residues, which contain a nuclear localization motif (NLS), nine casein kinase II motifs (S/T-X-X-D/E) and seven protein kinase C motifs (S/T-X-R/K). It is highly homologous to other plant Mlo proteins. Thus, this clone was designated as Ta-Mlo (GenBank accession No. AF384144). Northern blotting analysis showed that the transcription of Ta-Mlo was enhanced slightly by Blumeria graminis (DC) EO Speer f. sp. tritici. Western blotting analysis showed that the protein expression product of the Ta-Mlo gene in wheat seedling leaves is a membrane-bound protein. The protein could be induced by B. graminis. Southern blotting analysis indicated that there is one copy of the Ta-Mlo gene in each wheat genome. Ta-Mlo was localized on specific chromosomal regions of 2AL, 2BL, and 2DL in wheat.

Key words: cloning, expression, Mlo-like gene, RT-PCR, Triticum aestivum-Haynaldia villosa 6VS/6AL translocation line.