UV-B-induced signaling events leading to enhanced-production of catharanthine in Catharanthus roseus cell suspension cultures

Abstract

BackgroundElicitations are considered to be an important strategy towards improved in vitro production of secondary metabolites. In cell cultures, biotic and abiotic elicitors have effectively stimulated the production of plant secondary metabolites. However, molecular basis of elicitor-signaling cascades leading to increased production of secondary metabolites of plant cell is largely unknown. Exposure of Catharanthus roseus cell suspension culture to low dose of UV-B irradiation was found to increase the amount of catharanthine and transcription of genes encoding tryptophan decarboxylase (Tdc) and strictosidine synthase (Str). In the present study, the signaling pathway mediating UV-B-induced catharanthine accumulation in C. roseus suspension cultures were investigated.ResultsHere, we investigate whether cell surface receptors, medium alkalinization, Ca2+ influx, H2O2, CDPK and MAPK play required roles in UV-B signaling leading to enhanced production of catharanthine in C. roseus cell suspension cultures. C. roseus cells were pretreated with various agonists and inhibitors of known signaling components and their effects on the accumulation of Tdc and Str transcripts as well as amount of catharanthine production were investigated by various molecular biology techniques. It has been found that the catharanthine accumulation and transcription of Tdc and Str were inhibited by 3–4 fold upon pretreatment of various inhibitors like suramin, N-acetyl cysteine, inhibitors of calcium fluxes, staurosporine etc.ConclusionOur results demonstrate that cell surface receptor(s), Ca2+ influx, medium alkalinization, CDPK, H2O2 and MAPK play significant roles in UV-B signaling leading to stimulation of Tdc and Str genes and the accumulation of catharanthine in C. roseus cell suspension cultures. Based on these findings, a model for signal transduction cascade has been proposed.

Effects of PEG-induced drought stress on regulation of indole alkaloid biosynthesis in Catharanthus roseus

“…STR is identified as VIN-biosynthetic gene and one of the bottlenecks involved in the biosynthesis of TIAs (Pandey et al 2016). The expression of TDC and STR affected the accumulation of CAT content (Ramani & Chelliah 2007). In addition, DAT is the key enzyme catalyzing the last step of the reaction of the biosynthesis of VIN from tabersonine (Magnotta et al 2007).…”

Mitogen-activated protein kinase mediates nitric oxide-induced isoflavone accumulation in soybean sprouts under UV-B radiation

“…A previous study has reported that MAPK played important roles in UV-B signaling-induced accumulation of catharanthine (Ramani and Chelliah 2006). However, little is known about whether MAPK is involved in phenylpropanoid pathway isoflavone production in the soybean sprouts under UV-B radiation (Fig.…”

“…Accordingly, MAPK play significant roles in UV-B signaling leading to stimulation of tryptophan decarboxylase (Tdc) and strictosidine synthase (Str) genes and the accumulation of catharanthine in C. roseus cell suspension cultures (Ramani and Chelliah 2006), implying that the MAPK signal pathway(s) was related to secondary metabolism. Both of MAPK and isoflavones accumulation are the results of stress stimuli.…”

Catharanthus roseusmitogen-activated protein kinase 3 confers UV and heat tolerance toSaccharomyces cerevisiae

“…1 Many of the MIAs and transcripts of genes involved in MIAs biosynthesis show enhanced accumulation in response to stresses such as UV and plant stress hormone methyl jasmonate (MeJA). [2][3][4][5][6][7] Mitogen-activated protein kinase (MAPK) signaling is an evolutionarily conserved mechanism in eukaryotes and involved in transducing extracellular signals to produce responses to the stress in question. 8 In C. roseus involvement of protein phosphorylation as well as MAP kinase in stress-induced transcripts accumulation of key genes of MIA biosynthesis have been speculated.…”

“…8 In C. roseus involvement of protein phosphorylation as well as MAP kinase in stress-induced transcripts accumulation of key genes of MIA biosynthesis have been speculated. 7,9 Recently, we have shown cloning and characterization of CrMPK3, a MAPK from C. roseus. CrMPK3 showed enhanced transcripts accumulation and MAPK activity in response to wounding, UV treatment and MeJA application in C. roseus.…”