Abstract: Two 215 bp myb gene fragments,LeMYB1 and LeMYB2 with GenBank accession No. AY131230 and AY131231 respectively , were cloned through RT - PCR. The primers were designed in accordance with tobacco myb1 at the DNA-binding domain conserved in MYB , and the template was the RNA isolated from tomato seedlings showing hypersensitive responses (HR) . Only nucleotide 63 was different between the two fragments , of which LeMYB1 was A and LeMYB2 was G. Three nucleotides within the primers for cloning of LeMYB1 were different between LeMYB1 and counterpart of THM18,whereas 90.7% nucleotide sequence of LeMYB1 was identical to corresponding parts of tobacco myb1. Northern assay revealed that expression of LeMYB1-related genes were
induced upon occurrence of hypersensitive necrosis in tomato seedlings and enhanced henceforth. Their coincident expression with HR development in tomato indicated that LeMYB1-related genes might be involved in regulation of
HR and disease resistance conferred by tomato fungal resistance gene Cf-9.

Key words: Tomato, LeMYB, Transcription factor, Gene expression, Cf-9, Hypersensitive response