Abstract: The DNA and cDNA fragments of the THL1 were amp lified from genomic DNA and stigma cDNA of Brassica oleracea ‘E1’by PCR and RT2PCR methods. Their lengths were 732 bp and 455 bp re
spectively. Sequence analysis indicated that the identities of DNA and cDNA with those cloned from Brassica oleracea ‘Xiyuan 4’ previously were 97.9% and 98.3% respectively, the introns of the two sequences were
different in size. Moreover, the second intron of THL1 from Brassica oleracea ‘E1’was not comp ly with the
typ ical GT-AG rule: AT existed in the 3′end of the second intron. The cDNA of THL1 was cloned into vector pET-43.1a ( + ) to be pET43.1a ( + ) -THL1, transferred into E1coli BL21 and exp ressed as a 74 kD fusion p rotein when induced with IPTG. Thioredoxin activitywasmeasured by ability of the THL1 to reduce insulin. The result showed the THL1 gene had been correctly exp ressed.

Key words: Brassica oleracea, Thioredoxin-like protein, Gene clone, Sequence analysis