Mechamism Of Jasmonic Acid Regulation Of Terpenoid Indole Alkaloids In The Leaves Of Catharanthus Roseus

Abstract

Catharanthus roseus produces terpenoid indole alkaloids (TIAs) including the pharmaceutically significant vincristine and vinblastine. Vincristine and vinblastine are two complex dimeric compounds, derived by the coupling of vindoline and catharanthine. The yields of vincristine and vinblastine from C. roseus are remarkably low due to their cytotoxicity and the localized production of their monomeric compounds. Jasmonate hormones have been shown to activate transcription factors known to regulate several biosynthetic genes in the TIA pathway. Leaves of mature C. roseus plants were sprayed with Jasmonic Acid and harvested from zero to 96 hours after administration, homogenized, and incubated in a buffer solution. Leaves were also sprayed with clotrimazole and harvested from zero to four hours and alkaloids extracted in Methanol. Results showed no formation of vincristine and vinblastine and high variability in measured alkaloid levels. A complex mechanism of JA acting between neighboring leaves of C. roseus is supported by these results.