NaCl amendment improves vinblastine and vincristine synthesis in Catharanthus roseus: a case of stress signalling as evidenced by antioxidant enzymes activities

Abstract

An improved synthesis of vinblastine and vincristine was observed in Catharanthus roseus L. (G). Don by using NaCl as an elicitor. Various in vitro grown embryogenic tissues were cultivated under salinity stress for enhanced synthesis of alkaloids. Different levels of salt [control (0 mM), NT1 (25 mM), NT2 (50 mM), NT3 (75 mM), NT4 (100 mM), and NT5 (125 mM)] were amended in MS and callus biomass growth (fresh-and dryweight) and biochemical attributes at various embryogenic stages were studied. Maximum callus biomass reduction was observed in 125 mM NaCl amended medium. Antioxidant enzymes i.e. superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase and glutathione reductase activities were assayed as in vitro grown tissues were elicitated with NaCl, causing cellular stress. The antioxidant enzymes activity increased linearly with increasing NaCl level in medium, 4.97 EU min -1 mg -1 SOD and 3.14 EU min -1 mg -1 CAT, both being maximum in proliferating embryos at NT5. Quantitative estimation and comparative yield of alkaloids were made in response to NaCl stress in different cultivated tissues by using HPTLC method. Vinblastine content was observed to be maximum in regenerated leaves (14.17 mg/g dry wt) on 25 mM NaCl amended medium, followed by in vitro raised shoots. Similarly, better accumulation of vincristine (5.12 mg/g dry wt) was also noted in NaCl amended medium especially at low level (NT1). The data presented indicate that the synthesis of Catharanthus alkaloids was growth specific and was influenced by NaCl levels.

Abiotic and Biotic Elicitors–Role in Secondary Metabolites Production through In Vitro Culture of Medicinal Plants

“…Salinity also increased the diamine and polyamine content in Oryza sativa [53]. An improved synthesis of vinblastine and vincristine was observed in C. roseus embryogenic tissue culture by using NaCl as an elicitor [55].…”

Nitric Oxide as a Signal in Inducing Secondary Metabolites During Plant Stress

“…Salt stress is known to either induce or reduce the production of secondary metabolites to maximize the tolerance in plants [21,23,29]. Increased production of anthocyanins in Vitis vinifera cultures, polyphenols in Aegiceras corniculatum, tropane alkaloid in Datura innoxia, glycine betaine in Triticum aestivum, vincristine in Catharanthus roseus, and polyamines in Helianthus annuus are some examples of salinity-induced regulation of secondary metabolites [24,57,58]. Similarly a positive correlation between proline accumulation and salinity tolerance has been reported in tomato [29].…”

Induced genetic and morphological changes in Catharanthus roseus L. by cold atmospheric plasma

“…Genetic changes are among the possible ways to increase C. roseus medicinal components. Gamma radiation, UV irritation, somaclonal variation are common ways of increasing growth and medicinal components such as antioxidants and alkaloids (Swanberg & Dai, 2008;Zargar et al, 2010;Verma et al, 2012;Fatima et al, 2015).…”