We have isolated and sequenced the Arabidopsis thaliana LOX1 gene which encodes a lipoxygenase. The 5255 bp sequence includes 763 bp upstream from the start codon, 4345 bp spanning the coding region and 147 bp downstream from the stop codon. The coding region of the LOX1 gene consists of 8 exons separated by 7 introns. The introns in the LOX1 gene are located in sites predicted by the closely related soybean seed LOX3 gene sequence. With the exception of intron 1, the LOX1 introns are smaller in size than the LOX3 introns. Furthermore the Arabidopsis gene contains 7 introns, while the soybean gene contains 8. Four putative TATA box elements were identified in the 763 bp sequence upstream from the coding region, however only one is followed by a cap site which is located in a position appropriate for it to act as the initiation site for transcription.