Study on induction of Allium sativum L. hairy roots with antibacterial activity against Vibrio

Allium sativum L. has long been used to improve the health of humans and other species due to its antibacterial activity. Applying biotechnology to create a stable and large-scale production process for Allium sativum L., medicinal herbs by hairy root culture technology are essential. However, Allium sativum L. is a monocotyledonous plant, so its ability to induce hairy roots is lower than that of dicotyledonous plants, which requires more research investment. In this study, we succeeded in inducing hairy roots in monocotyledonous plants Allium sativum L, by evaluating parameters impacting hairy root induction such as plant organs, acetosyringone concentration, infection time and co-culture time. The results showed that the optimal procedure for induction of Allium sativum L. hairy roots by Agrobacterium rhizogenes ATCC 15834 was as follows: 10 day old in vitro Allium sativum L. sprouts were wound and soaked in 100 μM acetosyringone solution for 10 min, infection time was 5 minutes, co-culture time was 48 hours cultured on B5 medium (Gamborg B5 medium) having the induction rate of hairy roots reaching 64.4% after 14 days of culture. Allium sativum L. hairy roots had good antibacterial effect against all three strains of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus because the MBC/MIC ratios are all less than or equal to 2. Especially, for V. cholerae (MIC = 1.84 mg/ml, MBC = 2.11 mg/ml), hairy roots have antibacterial activity equivalent to tetracycline antibiotics and better than non-infectious roots.