Identification and expression analysis of S-alk(en)yl-L-cysteine sulfoxide lyase isoform genes and determination of allicin contents in Allium species

• Published in: PloS one 2020-02, Vol.15 (2), p.e0228747-e0228747
• Main Authors: Sayadi, Vahid, Karimzadeh, Ghasem, Rashidi Monfared, Sajad, Naghavi, Mohammad Reza
• Format: Article
• Language: English
• Subjects: Agricultural biotechnology; Agriculture; Alliin lyase; Alliinase; Allium; Allium - genetics; Allium - metabolism; Amino Acid Sequence; Binding sites; Biology and Life Sciences; Biosynthesis; Bulbs; Cysteine - metabolism; Endemic species; Enzymes; Garlic; Gene expression; Gene Expression Regulation, Plant; Gene sequencing; Genes; Genetics; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - metabolism; Isoforms; Lyases - chemistry; Lyases - genetics; Lyases - metabolism; Maximum likelihood method; Phylogenetics; Proteins; Research and Analysis Methods; Researchers; Roots; Sulfinic Acids - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0228747

Alliinase is the key enzyme in allicin biosynthesis pathway. In the current study, the identification and sequencing of alliinase genes along with determination of allicin contents were reported for Allium species with a novel report for Iranian endemic species. The presence of different isoforms in the Allium being discovered for the first time. In bulbs tissue, the highest allicin concentration was in Allium sativum, A. umbilicatum, and A. fistolosum (1.185%, 0.367%, and 0.34%, respectively), followed by A. spititatum (0.072%), A. lenkoranicum (0.055%), A. atroviolaseum (0.36%), A. rubellum (0.041%), and A. stamineum (0.007%). The highest allicin content in the leaves and roots were in A. sativum (0.13%), and A. stamineum (0.195%), respectively. The ORFs length ranged from 1416 in A. sativum (iso-alliinase2; ISA2) to 1523 bp in A. sativum (alliinase); the identity with A. sativum (alliinase) varies from 95% to 68% for A. ampeloprasum, and A. sativum (iso-alliinase1, ISA1) respectively. These data suggested that both ISA1 and ISA2 had a high expression in the roots and bulbs compared to A. sativum as the control in all species. Note that ISA1 and ISA2 were not expressed in the leaves. The results showed that isoforms expression patterns among different tissues in Allium species were variable. The presence of various isoforms is a possible explanation for the difference between the species in terms of obtained results, especially the amount of allicin.