IMPROVEMNET OF HAIRY ROOT INDUCTION IN Artemisia annua BY VARIOUS STRAINS OF Agrobacterium rhizogenes

Abstract

Plants have been considered as a significant source of drugs since ancient times. Secondary metabolites derived from plants have revealed therapeutic properties. Artemisinin and its derivatives are the most famous terpenoids in the Asteraceae family. Nowadays, numerous attempts have been done to improve the production rate of these kinds of terpenoids in biotechnological procedures which most of them are allocated to hairy root cultures using Agrobacterium rhizogenes (A4, A7, Ar15834, Ar9534, Ar9402, Ar318 and Ar50). In this study, we tried to investigate the effect different strains of A. rhizogenes on frequency of hairy root induction in A. annua. Explants were prepared from leaves of A. annua. Then they were soaked in A. rhizogenes solution to be infected. They were cultured in MS medium for 14 days. For decreasing plant necrosis, two different concentrations of 0.1 and 0.5 % were added to the medium as anti– oxidant. For hairy root induction approve, PCR method was applied. Hairy roots were obvious in plantlets on 1⁄2 MS medium culture. The presence of T–DNA in different transformed lines of hairy roots was investigated by PCR. The results indicated that making 0.5 % ascorbic acid MS Medium will lead to a dramatic decrease (about 80 %) in plantlet’s browning. In addition, the highest and lowest transformation rate of 79 % and 24 % were yielded, infecting the leaf explants of A. annua by A7 and Ar318 strains respectively. To sum it up, it was shown that all mentioned strains are capable to induce hairy root in A. annua by the help of ascorbic acid as an inhibitor for plantlet’s browning. Because of hormone–autotrophic feature and great lateral branches of hairy roots, the induced hairy roots of A. annua can be applied to increase artemisinin production in pharmaceutical industry. Keyword: Artemisia annua; Agrobacterium rhizogenes; artemisinin; hairy root.