Molecular analysis of lipoxygenase (LOX) genes in common wheat and phylogenetic investigation of LOX proteins from model and crop plants

Lipoxygenase (LOX) proteins constitute an important class of lipid-hydrolyzing enzymes in cellular organisms. Here, we report a molecular analysis of LOX genes in common wheat (Triticum aestivum L.) and a more comprehensive phylogenetic investigation of the LOX proteins from higher plants. The full-length nucleotide sequences of two LOX genes (TaLOX1 and TaLOX2) from common wheat were isolated. TaLOX1 and TaLOX2 were assigned to the short arm of chromosome 4D and the long arm of chromosome 5D, respectively. TaLOX1 and TaLOX2 were both expressed in the developing grains of two common wheat varieties, indicating that they may contribute to the total LOX activity in common wheat seeds. A more extensive phylogenetic analysis conducted with 143 unique LOXs from model and crop plants revealed that plant LOXs could be classified into two subfamilies, which correlated with the absence (subfamily I) or presence (subfamily II) of a predicted chloroplast targeting peptide in the deduced LOX proteins. Our work provides new information on the LOX genes in common wheat and the phylogenetic relationships of higher plant LOXs, which may aid further functional and evolutionary studies of plant LOXs.