Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2003
Publication Date: 8/8/2003
Citation: Cavagnaro, P., Masuelli, R., Simon, P.W. 2003. Molecular data suggest multiple members comprising the alliinase gene family in garlic [abstract]. HortScience. 38:804-805. Interpretive Summary:
Technical Abstract: The enzyme alliinase (S-alk(en)yl-L-cysteine sulfoxide lyase) found in Allium plants is involved in the production of organosulfur compounds responsible for odor, pungency, health benefits, and plant pathogen resistance. It catalyzes the degradative conversion of S-alk(en)yl-Lcysteine sulfoxides (ACSOs) to their corresponding thiosulfinates and has been suggested to be a family of isozymes differing in their substrate specificity and accounting, therefore, for the variable thiosulfinates composition observed among Allium species. We are currently studying the genomic structure and expression patterns of the alliinase gene -family in garlic. Two approaches were carried out to estimate the number of gene copies and identify different sequence variants. Southern Blot analysis suggests at least 4-8 copies depending on the garlic clone, whereas PCR amplification and sequencing of an intron-bearing fragment revealed 27 sequence variants. The possibility that alliinase genes are arranged in tandem in the genome may account for underestimates of the copy number suggested by Southern blot data. Alliinase sequences were most variable in the intron region, while the coding regions were more conserved. However a 17 by deletion was observed in the coding region of several, probably not functional, variants. An intron-less copy was also identified. Our results suggest multiple and diverse copies comprising the alliinase gene family in garlic. Several genes could be functional and contribute to the high alliinase content in garlic bulbs. Transcribed copies are being analyzed. Multiple copies of this gene in the garlic genome may play an important role in the development, adaptiveness and evolution of this species.