Effects of Polysaccharide Elicitors on Secondary Metabolite Production and Antioxidant Response inHypericum perforatumL. Shoot Cultures

Abstract

The effects of polysaccharide elicitors such as chitin, pectin, and dextran on the production of phenylpropanoids (phenolics and flavonoids) and naphtodianthrones (hypericin and pseudohypericin) in Hypericum perforatum shoot cultures were studied. Nonenzymatic antioxidant properties (NEAOP) and peroxidase (POD) activity were also observed in shoot extracts. The activities of phenylalanine ammonia lyase (PAL) and chalcone-flavanone isomerase (CHFI) were monitored to estimate channeling in phenylpropanoid/flavonoid pathways of elicited shoot cultures. A significant suppression of the production of total phenolics and flavonoids was observed in elicited shoots from day 14 to day 21 of postelicitation. This inhibition of phenylpropanoid production was probably due to the decrease in CHFI activity in elicited shoots. Pectin and dextran promoted accumulation of naphtodianthrones, particularly pseudohypericin, within 21 days of postelicitation. The enhanced accumulation of naphtodianthrones was positively correlated with an increase of PAL activity in elicited shoots. All tested elicitors induced NEAOP at day 7, while chitin and pectin showed increase in POD activity within the entire period of postelicitation. The POD activity was in significantly positive correlation with flavonoid and hypericin contents, suggesting a strong perturbation of the cell redox system and activation of defense responses in polysaccharide-elicited H. perforatum shoot cultures.

Polysaccharide elicitors enhance phenylpropanoid and naphtodianthrone production in cell suspension cultures of Hypericum perforatum

“…Among the tested polysaccharides, CHI was shown as a much more prominent elicitor of naphtodianthrone production in H. perforatum cells. On the contrary, we have previously reported that CHI did not show any stimulatory effect on naphtodianthrone accumulation in H. perforatum shoots, while PEC and DEX evoked the production of HYP and PHYP (Gadzovska Simic et al 2014). Discrepancy in these data could result, either, in a better exposition of cells into the liquid medium, or in possible difficulties of CHI as an elicitor to penetrate into shoots independently of their differentiation state.…”

“…As far as the authors are aware, naphtodianthrone production has been intensively studied in cell, tissue and organ cultures of H. perforatum (Sirvent and Gibson 2002;Walker et al 2002;Santarem et al 2008;Gadzovska et al 2013;Tusevski et al 2014b). Among the Hypericum elicitation studies, it has been reported that polysaccharides are effective elicitors of naphtodianthrone production in shoots (Kirakosyan et al 2000;Gadzovska Simic et al 2014), seedlings (Yamaner et al 2013) and calli (Vardapetyan et al 2006). Present results revealed that all applied polysaccharides increased naphtodianthrone production in the early phase of cell growth.…”

“…An increase in TP and TF contents has also been observed in H. perforatum root cell cultures upon sucrose-induced osmotic stress (Cui et al 2010). On the other hand, our previous studies with another culture system, in particular, H. perforatum shoots elicited with SA and polysaccharides (CHI, PEC and DEX) demonstrated a suppression of TP and TF production (Gadzovska et al 2013;Gadzovska Simic et al 2014). Similarly, work with other Hypericum spp.…”

“…For instance, H. perforatum cell, tissue and organ cultures have been tested for their ability to produce naphtodianthrones, acyl-phloroglucinols, flavonoids and xanthones upon elicitation with signalling molecules such as jasmonic acid (JA), methyl jasmonate (MeJA) and salicylic acid (SA), (Sirvent and Gibson 2002;Walker et al 2002;Conceição et al 2006;Gadzovska et al 2007Gadzovska et al , 2013, fungal elicitors Phytophthora cinnamoni, Colletotrichum gloeosporioides and Aspergillus flavus (Walker et al 2002;Conceição et al 2006;Gadzovska Simic et al 2012), as well bacterial elicitors Agrobacterium tumefaciens and A. rhizogenes (Santarem et al 2008;Tusevski et al 2014a). In this context, several studies have been carried out to investigate the effects of polysaccharide Plant Cell Tiss Organ Cult elicitors such as mannan, b-1,3-glucan, pectin (PEC), chitin (CHI) and dextran (DEX) on naphtodianthrone production in Hypericum shoots, calli and seedlings (Kirakosyan et al 2000;Vardapetyan et al 2006;Yamaner et al 2013;Gadzovska Simic et al 2014). Our recent study was focused on the effects of polysaccharides such as CHI, PEC and DEX on the production of phenylpropanoids (phenolics and flavonoids) and naphtodianthrones hypericin (HYP) and pseudohypericin (PHYP) in H. perforatum shoot cultures (Gadzovska Simic et al 2014).…”

“…In this context, several studies have been carried out to investigate the effects of polysaccharide Plant Cell Tiss Organ Cult elicitors such as mannan, b-1,3-glucan, pectin (PEC), chitin (CHI) and dextran (DEX) on naphtodianthrone production in Hypericum shoots, calli and seedlings (Kirakosyan et al 2000;Vardapetyan et al 2006;Yamaner et al 2013;Gadzovska Simic et al 2014). Our recent study was focused on the effects of polysaccharides such as CHI, PEC and DEX on the production of phenylpropanoids (phenolics and flavonoids) and naphtodianthrones hypericin (HYP) and pseudohypericin (PHYP) in H. perforatum shoot cultures (Gadzovska Simic et al 2014). In elicited shoots, we have reported that the induction of phenylalanine ammonia lyase (PAL) activity could trigger an alternative synthetic naphtodianthrone pathway, while suppressed chalcone-flavanone isomerase activity (CHFI) resulted in decrease of flavonoid accumulation.…”