Transcription factors involved in terpenoid indole alkaloid biosynthesis in Catharanthus roseus

Abstract

Plants produce alkaloids, among others, to protect themselves against microbial infection, herbivore attack or ultraviolet irradiation. For man, alkaloid metabolism is the source of many natural products with useful applications, including pharmaceuticals. A major mechanism regulating alkaloid production in plant cells is the control of the transcription of the biosynthetic genes. Several transcription factors involved in the regulation of alkaloid biosynthesis genes have been isolated and studied. There are indications that the abundance and activities of transcription factors themselves are regulated by external signals. The aim of this review is to give an update on the transcriptional regulation of terpenoid indole metabolism in Catharanthus roseus.

The Transcription Factor CrWRKY1 Positively Regulates the Terpenoid Indole Alkaloid Biosynthesis in Catharanthus roseus

“…However, JA also induces the repressors ZCT and GBF, proteins that are known to inhibit the expression of TDC and STR (Memelink and Gantet, 2007). The emerging picture of the transcriptional control of TIA biosynthesis suggests the simultaneous induction of activators and repressors by elicitors and developmental signals.…”

“…The activator, ORCA3, apparently pushes the flux toward the vindoline and catharanthine pathways. Previous work has demonstrated that ORCA3 activates the vindoline pathway enzyme, tabersonine 16-hydroxylase (Memelink and Gantet, 2007), and when sufficient precursors from the terpenoid pathway become available, as the result of G10H overexpression, ORCA3 preferentially activates the catharanthine pathway (Wang et al, 2010a). Conversely, CrWRKY1 induces the serpentine pathway by repressing ORCA3 and activating the serpentine branch genes, including the putative peroxidase gene converting ajmalicine to serpentine.…”

“…For instance, despite the observation that overexpression of the Tryptophan Decarboxylase (TDC) gene has led to a moderate increase of alkaloid accumulation (Hong et al, 2006), it is generally believed that TDC activity does not correlate positively with TIA production (Goddijn et al, 1995;El-Sayed and Verpoorte, 2007). A more promising approach is the ectopic expression of transcription factors (TFs) that regulate the TIA pathway in order to enhance alkaloid production (Memelink and Gantet, 2007). Specific TFs are often capable of coordinating the transcription of multiple biosynthetic pathway genes, making them particularly effective in metabolic pathway engineering.…”

Mapping methyl jasmonate-mediated transcriptional reprogramming of metabolism and cell cycle progression in cultured Arabidopsis cells

“…Various TFs were shown to bind the STR promoter, including CrMYC1, the putative ortholog of MYC2; CrZCT1 to CrZCT3, homologs of STZ/ZAT10 and AZF2; and CrORCA1 to CrORCA3, encoding AP2/ERF proteins homologous to ORA47 (35). It is tempting to speculate that proteins such as MYC2, ORA47, STZ/ZAT10, AZF2, and perhaps other earlyresponsive Arabidopsis TFs regulate not only early MeJA responses such as JA biosynthesis, but also later responses, such as activation of phenylpropanoid metabolism.…”

Molecular Cloning and Characterization of a Vacuolar Class III Peroxidase Involved in the Metabolism of Anticancer Alkaloids in Catharanthus roseus

“…The biosynthesis of vinblastine involves more than 20 enzymatic steps, nine of which are now well characterized at the enzyme and gene level, and several regulatory genes of the pathway (ORCAs) have also been cloned. However, considerable parts of the pathway remain relatively hypothetical, and even enzymatic characterization is still lacking for many steps (for review, see Hilliou et al, 2001;El-Sayed and Verpoorte, 2007;Loyola-Vargas et al, 2007;Memelink and Gantet, 2007).…”