5' sequence characterization of alliinase gene family members in garlic

CAVAGNARO, P. F.; GALMARINI, C. R.; MASUELLI, R. W.; SIMON, P. W.

San Diego

Conferencia; Plant & Animal Genomes XII Conference; 2004

The alliinase enzymes found in Allium plants are involved in the production of organosulfur compounds responsible for their odor, pungency, therapeutical properties and for resistance to certain plant pathogens. This enzyme is encoded by a family of related genes. It is probable that subfunctionalization of duplicated alliinase copies may result in variants with specific activities so that isozymes differing in substrate specificity may account for the relative content of thiosulfinates found in onion bulbs. A root-specific alliinase copy has also been reported. Comparing heterologous sequences with known alliinase genes could help to predict the diversity or conservation of functions for these new variants. We have characterized an intron-bearing fragment of the 5’ end of 12 alliinase genes in garlic. Pairwise overall sequence similarities ranged from 72.3 – 99.5%with exons more conserved (88.6-99.8%) than introns (28-99%). Intron size ranged from 33 to 203 bp with highly conserved insertion sites. At the protein level similarity ranged from 88 – 100%. Genomic sequence similarity with onion ranged from 69-84% and 83-91% at the DNA and protein levels, respectively. The characterization of alliinase members in garlic and related species will contribute to the understanding of the structure and function of this gene family.