Effect of different factors on induction of hairy roots in Iranian garlic

Garlic (Allium sativum( is one of the most important pharmaceutical and industrial plants with medicinal properties such as lowering blood pressure and cholesterol, fighting against infectious diseases, cancer prevention, anti-diabetic properties, antioxidant and anti-fungal properties. It is a rich source of organosulphur compounds such as allicin (diallyl disulphide oxide) which is produced enzymatically from alliin (S-2- propenyl-L-cystiene sulfoxide) if cells are damaged. Hairy root culture using Agrobactrium rhizogenes is one of the practical methods for studying secondary metabolite pathway. These hairy roots are genetically stable and grow rapidly. In this study, the hairy root induction is studied in two separate experiments which were run in a factorial completely randomized design with three replications. In the first experiment, the effects of bacterial strain (ATCC15834 and A4), variety (Gorgon and Ramhormoz), inoculation medium (MS, MS containing 3% sucrose and MS containing 6% sucrose) and bacterial densities (OD600 = 0.6 to 0.9 and 1.2 to 1.5) were examined. In the second experiment, the effects of co-culture medium (MS, MS containing acetosyringone, B5 and B5 containing acetosyringone) and co-culture time (24, 48 and 72 hours) were studied. A systematic study using two strains and densities of Agrobactrium rhizogenes was carried out to determine the best condition for hairy root induction in two varieties of garlic in different inoculation and co-culture media. Results showed that bacterial strain A4, MS inoculation medium containing 6% sucrose, OD between 0.5 and 1, MS co-culture medium containing acetosyringone, and co-culture time 72 hours had the highest percentage of hairy root induction. Hairy roots were approved using polymerase chain reaction for gene rol B. Amplification of the specific gene was noted in the transformant at 780 bp. Hairy root cultures have received more attention in recent years and were extensively used to produce important secondary metabolites and also as experimental systems for secondary metabolic pathway elucidation studies. The results of this studymay be very helpfulfor hairy root induction in garlic which could further be useful for studying gene function and consequently, production of secondary metabolites in this plant.