Induction and proliferation of adventitious roots from Aloe vera leaf tissues for in vitro production of aloe-emodin

We have inspected aloe-emodin and aloin compounds in different tissues of Aloe vera which were grown in Aloe farm for three years. Surprisingly, aloe emodin contents were much richer in the roots (574.8 ± 92.4 μg/g) than in leaves (5.52 ± 0.32 μg/g) that encouraged us to establish adventitious root culture system of the plant. The optimal condition for induction and proliferation of adventitious roots using young Aloe vera leaves was established by treatments of variety of conditional media and auxin supplements. Adventitious root induction was suitable by enrichment of 0.5 mg/L 1-naphthalene acetic acid (NAA) and 0.2 mg/L 6-benzylaminopurine (BA) in Murashige & Skoog (MS) medium. However root proliferation was hindered by accumulation of phenolic compounds in the media that was overcome by pre-washing of the adventitious roots with more than 4 g/L of polyvinylphyrollidine (PVP) analogs increasing the survival rate (up to 60 %). Inspection of aloe-emodin contents in various adventitious roots grown different basal medium revealed that aloe-emodin accumulation is much higher on B5 medium (133.08 ± 0.12 μg/g) than on MS medium (3.56 ± 0.26 μg/g).