Transcriptional regulation of genes involved in terpenoid índole alkaloid production in Catharanthus roseus seedlings

Catharanthus roseus (L.) G Don is a medicinal plant that produces a variety of terpenoid indole alkaloids (TIAs), some of which display pharmacological activity. C. roseus plants and cell cultures have been used to elucidate the TIAs biosynthetic pathway. A considerable number or enzymes have also been characterised, and their respective genes cloned. TIAs production in C. roseus plant and cell cultures is highly regulated at transcriptional-, develop-mental-, and environmental-level. Studies into TIAs biosynthetic gene regulation have been carried out using cell cultures. However, regulation in plants is almost unknown. Here, biosynthetic genes idc, strl, d4h and dat expres-sion levels are qualitatively examined in a developmental series of C. roseus seedlings. The effect of water- and light-stress and methyl jasmonate (MeJa) and acetyl salicylic acid (ASA) elicitation is also examined. Comparison between seedlings and cell cultures strongly suggests that TIAs biosynthetic gene transcriptional regulation is different in C.roseus plants and cell cultures