Activation of the oxidative burst by yeast elicitor in Catharanthus roseus cells occurs independently of the activation of genes involved in alkaloid biosynthesis

Abstract

In Catharanthus roseus cell suspensions, expression of several terpenoid indole alkaloid (TIA) biosynthetic genes, including those encoding strictosidine synthase and tryptophan decarboxylase, is coordinately induced by fungal elicitors such as yeast extract (YE). This induction is mediated by several signaling steps including the biosynthesis of jasmonic acid, and the activation of the jasmonic acid-responsive ORCA transcription factors. We investigated a possible role of reactive oxygen species (ROS) as a second messenger in this system. YE was shown to activate the production of ROS, which was dependent on protein phosphorylation and calcium influx. However, ROS generation was neither necessary for the induction of genes involved in TIA biosynthesis by YE nor by itself sufficient to induce these genes. Therefore, we conclude that activation of the oxidative burst by YE occurs independently of the activation of genes involved in TIA biosynthesis.

The A and B Loci in Tobacco Regulate a Network of Stress Response Genes, Few of which are Associated with Nicotine Biosynthesis

“…For example, oxadecanoid compounds like jasmonic acid (or methyljasmonic acid derivatives) produced during wounding are potent inducers of a variety of alkaloids (Baldwin et al, 1994;Zhang et al, 1997;Pauli and Kutchan, 1998;Huang and Kutchan, 2000). Similarly, fungal extracts are known to induce both regulatory and biosynthetic genes involved in terpenoid indole alkaloid (TIA) biosynthesis in Catharanthus roseus (Menke et al, 1999;van der Fits et al, 2000;Pauw et al, 2004b). The general inducibility of alkaloid biosynthesis indicates there must be signal transduction cascades and specific regulators of alkaloid biosynthetic genes.…”

Some common signal transduction events are not necessary for the elicitor-induced accumulation of silymarin in cell cultures of Silybum marianum

“…In connection with our results, experiments on defense reactions in some species indicate that production of ROS is not an essential requirement for the induction of phytoalexin synthesis. For example, elicited carrot protoplasts that were able to accumulate 4-hydroxybenzoic acid failed to produce any detectable amount of H 2 O 2 (Bach et al, 1993), even in C. roseus cultures, activation of oxidative burst by YE occurred independently of the activation of genes involved in alkaloid biosynthesis (Pauw et al, 2004).…”

Manipulating indole alkaloid production by Catharanthus roseus cell cultures in bioreactors: from biochemical processing to metabolic engineering

“…Different protein kinases may be activated upstream and downstream of jasmonate biosynthesis (Menke et al 1999). Calcium ions influx is identified as a prerequisite for fungal elicitor-induced oxidative stress, jasmonate biosynthesis, and indole alkaloid production (Zhao et al 2001b;Pauw et al 2004;Lee-Parsons and Erturk 2005). Even though H 2 O 2 was shown to stimulate biosynthesis of secondary metabolites, it is still a question whether H 2 O 2 is a signaling compound for indole alkaloid biosynthesis (Zhao et al 2001b;Pauw et al 2004).…”

“…Calcium ions influx is identified as a prerequisite for fungal elicitor-induced oxidative stress, jasmonate biosynthesis, and indole alkaloid production (Zhao et al 2001b;Pauw et al 2004;Lee-Parsons and Erturk 2005). Even though H 2 O 2 was shown to stimulate biosynthesis of secondary metabolites, it is still a question whether H 2 O 2 is a signaling compound for indole alkaloid biosynthesis (Zhao et al 2001b;Pauw et al 2004). In addition, nitric oxide burst was also observed in elicitor-induced C. roseus cell cultures and mediates catharanthine production (Xu et al 2005).…”

“…Almost all responses to elicitation and physiological conditions inducing indole alkaloid biosynthesis may be mediated by the jasmonate pathway. Cytosolic Ca 2+ spiking is required for fungal elicitor-induced jasmonate biosynthesis (Menke et al 1999;Pauw et al 2004). Auxin suppression of STR and TDC expression and indole alkaloid production is also due to suppression of endogenous jasmonate biosynthesis.…”