Abstract: Sequences of DNA and cDNA of SDIR1 gene in Arabidopsis thaliana were isolated by using PCR and RTPCR. The alignment result showed that there were three different transcripts in Arabidopsis thaliana, which indicated that there were alternative splicing pneumonia in the transcription of SDIR1 gene. The length of three transcripts were 822 bp, 691 bp and 666 bp, respectively, and were named as SDIR1822, SDIR1691 and SDIR1666 subsequently. Compared with the reported sequences of DNA and cDNA in Arabidopsis thaliana, SDIR1822 contained intact coding domain, while the others missed some nucleotides in coding domain. SDIR1691 missed 131 bp which contained 33 bp in the 3′ end of the second exon, 53 bp of all the third exon and 45 bp in the 5′ end of the fourth exon. SDIR1666 missed 156 bp which contained 18 bp in the 3′ end of the third exon and 138 bp in the 5′ end of the fourth exon. The expression ratio of three different transcripts SDIR1822, SDIR1691 and SDIR1666 was 2600∶133∶100 analyzed by selecting 101 clones, which might indicate the relative content of different transcripts of SDIR1 gene in Arabidopsis thaliana.

Key words: SDIR1 gene