Role of Different Transporting Systems in the Secretion of Alkaloids by Hairy Roots of Catharanthus roseus (L) G. Don

<p>Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in <em>Catharanthus roseus</em>. Therefore, in order to determine the role of different transporting systems involved in the MIAs translocation, we employed a pharmacological approach by using transport inhibitors such as, KCN, Na3VO4, quinidine and glibenclamide in hairy root cultures of <em>C. roseus</em>. It was found that the accumulation of ATP drastically decreased in the presence of KCN or 100 μM acetylsalicylic acid (ASA)/100 μM KCN. The treatment with the inhibitors KCN and glibenclamide in the presence of ASA significantly increased the ajmalicine secretion compared to the control. The secretion of serpentine was undetected during the first 24 h in all the samples. Treatment with the inhibitors quinidine and glibenclamide provoked a significant reduction of serpentine secretion in the hairy roots compared to the control. Based on our results, we found evidence that ABC transporters might participate in the secretion of MIAs by <em>C. roseus </em>hairy roots.</p>