Short term UV-B radiation mediated modulation of physiological traits and withanolides production in Withania coagulans (L.) Dunal under in-vitro condition

Abstract

Accumulation of secondary metabolites is a key process in the growth and development of plants under different biotic/abiotic constraints. Many studies highlighted the regulatory potential of UV-B treatment towards the secondary metabolism of plants. In the present study, we examined the impact of UV-B on the physiology and secondary metabolism of Withania coagulans , which is an important ayurvedic plant with high anti-diabetic potential. Results showed that in-vitro UV-B exposure negatively influenced chlorophyll content and photosynthetic machinery. However, Fv/Fm ratio was found non-significantly altered up to 3 h UV-B exposure. The maximum lipid peroxidation level was recorded with 46.8% higher malondialdehyde content in the plants supplemented with 5 h UV-B radiation, that was indicated the oxidative stress in W. coagulans . Conversely, UV-B treatment significantly increased the plant's stress protective compounds like carotenoids, anthocyanin, phenol and proline, in W. coagulans . Free radical scavenging activity was also significantly increased ~ 18% than the control with 3 h UV-B treatment. The maximum antioxidative enzymes activities were observed with the short-term (up to 3 h) UV-B treatment. Specifically, UV-B radiation exposure significantly increased the content of withaferin A and withanolide A in W. coagulans with maximum 1.38 and 3.42-folds, respectively. Additionally, withanolides biosynthesis related genes transcript levels were found over-expressed under the response of UV-B elicitation. The acquired results suggested that short-term UV-B supplementation triggers secondary metabolism along with combating oxidative stress via improving the antioxidative defense system in W. coagulans . Also, UV-B can be used as an efficient abiotic elicitor to increase pharmaceutical compounds (withanolides) production. Supplementary Information The online version contains supplementary material available at 10.1007/s12298-021-01046-7.

Flavonoids metabolism and physiological response to ultraviolet treatments in Tetrastigma hemsleyanum Diels et Gilg

“…As the final decomposition product of lipid peroxidation and due to the combined mechanisms above, MDA contents reflect the lipid peroxidation level and cellular lipid peroxidation damage to a certain extent ( Zeng et al, 2019 ). Our results were similar to those of other research ( Tripathi et al, 2021 ), short-term UV radiation significantly enhanced the anti-oxidant enzyme systems. Other studies ( Li et al, 2019 ) showed that with further stress, the peroxidation of the membrane system was enhanced, and the MDA content increased.…”

Melatonin Confers NaCl Tolerance in Withania coagulans L. by Maintaining Na+/K+ Homeostasis, Strengthening the Antioxidant Defense System and Modulating Withanolides Synthesis-Related Genes

“…In fact, NaCl stress increased the expression of enzymes involved in the biosynthesis of withanolides, causing an increase in the accumulation of these medicinal compounds in leaves. Similar results of increased accumulation of withanolides under cold stress [ 52 ] and UV-B radiation [ 17 ] have been previously documented. It has been reported that secondary metabolites are involved in improving the adaptation of plants under stressful conditions, so the increase in the accumulation of withanolides can indicate the induction of defense mechanisms in order to improve the adaptation of plants during NaCl stress [ 9 ].…”

“…Recent studies have shown that the biosynthesis of secondary metabolites is influenced by abiotic and biotic elicitors [ 11 ]. Recently, it has been shown that the use of different elicitors has an effect on the accumulation of withanolides in W. coagulans [ 17 ], W. somnifera [ 18 ], and Physalis peruviana [ 19 ] plants. However, there is no reports on the interaction effects of ML with abiotic stresses as two important elicitors of withanolide accumulation in W. somnifera .…”

Photosynthetic, Biochemical and Secondary Metabolite Changes in a Medicinal Plant Chlorophytum borivillianum (Safed musli) against Low and High Doses of UV‐B Radiation

“…Literature review denoted both increased, decreased or sometimes unchanged Ci concentration in UV‐B‐exposed plants such as in Withania coagulans , Curcuma caesia , C. longa , Paubrasilia echinata and Oryza sativa (12,21,46,47). Therefore, low stomatal conductance and transpiration were reported in the present study.…”

“…Phenolics are the products of phenylpropanoid pathway and extensively studied under UV exposure. Several studies have reported both increase and decrease in alkaloids, terpenes and phenolics (12,(17)(18)(19)(20)(21)(22). Among several groups of compounds studied, only few studies have been so far conducted on plants having saponin content.…”