Salt induced modulations in morphological, physiological, and metabolic attributes in in-vitro grown shoots of Withania somnifera (L.) Dunal

Abstract

Abstract Due to increasing dependency of global population on herbal-based medicines, enhanced production of secondary metabolites has become utmost necessary. Several scientists have revealed the role of NaCl as abiotic elicitor for in-planta enhancement of phytochemical compounds. Thus, we have micropropagated Withania somnifera from callus tissues in varying concentrations of BAP hormone and found that MS medial supplemented with 2 mg L− 1 to be best suited for maximum yield. Further, the microshoots were treated with varying concentration (50–250 mM) of NaCl to assess morphological, physico-biochemical, and molecular characteristic. Higher concentrations of NaCl significantly hampered the morphological and photosynthetic attributes of microshoots. A significant enhancement in the proline, phenol, and sugar contents were recorded and highest accumulation was observed by 136.7%, 60%, and 135.9% respectively with 250 mM treated shoots. Free radical scavenging activity and malondialdehyde level was also up-regulated by 1.24 and 1.92-fold respectively. Similarly, anti-oxidants enzymatic activities were increased linearly. Contrary to this, highest production of flavonoid (49.5%) and withaferin-A (192.9%) was limited only upto 150 mM NaCl. Higher accumulation of withanolide was further attested by the Real-time PCR analysis off related genes which revealed their maximum expression by 150 mM salt treatment. Conversely, expression of photosynthetic-related genes was significantly declined after increasing doses of NaCl. These outcomes depicted that moderate dose of NaCl can act as elicitor for enhanced secondary metabolites of W. somnifera without compromising its growth significantly.