Jasmonate-status and transcriptional regulation in Catharanthus roseus (L.) G. Don (Apocynaceae)

Catharanthus roseus (L.) G. Don (Apocynaceae) is one of the most important medicinal plants worldwide given that the alkaloids naturally present in this species had been used for more than 40 years due to their potent anti-tumor activities. Consequently, it became one of the best-studied medicinal plants and it has served as a model system for biotechnological studies on plant secondary metabolism. To these days, the leaves of this species remain as the only natural source of 130 terpenoid-indole alkaloids (TIA's), such as the anticancer drugs vinblastine and vincristine, administered as single agents or in combination therapy for several neoplasms, and the antihypertensive compounds like serpentine and ajmalicine. Here we describe a targeted metabolomic approach for the elucidation of alkaloid, fatty acid and jasmonate derivatives status, as well as the gene expression, involved in the biosynthetical response after the elicitation of cell suspension cultures with jasmonic acid, a lipid-derived phytohormone. Fatty acids were separated and identified as methyl esters by GC-MS. This allowed the quantification of saturated and unsaturated species ranging from C10:0 to C24:0. The major fatty acids found were palmitic acid, linoleic acid and linolenic acid, being the saturated acids predominant over the unsaturated ones. The analysis of TIA's was performed by HPLC-DAD, which allowed the identification of 13 different TIA's like serpentine, tabersonine, strictosidine and catharanthine and were further confirmed by LC-MS.