Browsing by Author "Avantika Pandey"

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Alterations in growth, antioxidative defense and medicinally important compounds of Curcuma caesia Roxb. under elevated ultraviolet-B radiation
(Elsevier B.V., 2020) Deepanshi Jaiswal; Avantika Pandey; Arideep Mukherjee; Madhoolika Agrawal; Shashi Bhushan Agrawal
Ultraviolet-B (UV-B) radiation is a well-known stress factor, as involved in the generation of free radicals, and induction factor which permutates growth, metabolic processes, and secondary metabolites synthesis of plants. However, its impact on medicinal plants is less explored particularly in relation to secondary metabolites associated with the medicinally important rhizomes. An endangered medicinal plant (Curcuma caesia Roxb.) grown under natural field conditions was exposed to elevated UV-B (ambient ± 9.6 kJ m−2 d-1) to assess changes in growth, antioxidant profile, defense strategy and the secondary metabolites of the rhizome. Results showed that eUV-B induced the generation of different reactive oxygen species (·O2- radical and H2O2) which were counteracted by induction of UV absorbing pigments (flavonoids and anthocyanin), non-enzymatic (ascorbic acid) and enzymatic antioxidants (peroxidase, ascorbate peroxidase and catalase) at different growth stages. However, phenol, thiol and superoxide dismutase activity showed reduction at all the growth stages. Protection from UV-B was also manifested by an increase in total free radical scavenging activity, metal chelation and reducing activity. Alterations in biomass allocation might be a possible mechanism of defense which persuaded to higher increment in above ground biomass and tuber biomass with 47 % diminution of rhizome biomass. Among the four classes of compounds identified, sterols were increased whereas reductions were more prominent in fatty acids followed by monoterpenes and sesquiterpenes. Increased production of epicurzereonone, elemene, pinandiol, and 1,8-cineole whereas curcumenol, D-camphor, eucalyptol, curcumenone, isocurcumenol, and zederone were reduced. Elevated UV-B also induced the production of some anti-cancerous compounds such as furanodiene and caryophyllene. © 2020 Elsevier B.V.
Individual and combined effects of chromium and ultraviolet-B radiation on defense system, ultrastructural changes, and production of secondary metabolite psoralen in a medicinal plant Psoralea corylifolia L
(Springer Science and Business Media Deutschland GmbH, 2023) Avantika Pandey; Madhoolika Agrawal; Shashi Bhushan Agrawal
The present study focuses on the effects of individual and combined stress of chromium (Cr) and ultraviolet-B (UV-B) radiation on Psoralea corylifolia L. The experiment comprised four sets: (i) control, (ii) eUV-B (elevated UV-B i.e., ambient + 7.2 kJ m−2 day−1 UV-B), (iii) Cr (chromium; 30 mg kg−1 soil), and (iv) Cr + eUV-B (chromium and elevated UV-B; Cr 30 mg kg−1 and ambient + 7.2 kJ m−2 day−1 UV-B). The eUV-B and Cr individually and in combination showed the variable responses on ultrastructure, physiology and biomass however, the impact was more prominent under individual Cr treatment followed by Cr + eUV-B and eUV-B. Higher bioconcentration factor and the lowered translocation factor consequently led to a higher reduction in the below ground biomass and the lesser reduction in above ground biomass under Cr + eUV-B treatment as compared to individual Cr treatment. In addition, higher induction in the enzymatic (glutathione reductase, ascorbate peroxidase, superoxide dismutase, and glutathione-S-transferase) and non-enzymatic antioxidants (glutathione reduced) were found to be responsible for efficient scavenging of hydrogen peroxide and superoxide radical leading to lowered MDA content under combined treatment as compared to Cr treatment. Deposition of Cr as electron dense granules in the cytoplasm, vacuoles, and cell wall under Cr and Cr + eUV-B is contemplated as one of the cellular mechanisms of P. corylifolia against the toxicity of Cr. Psoralen increased under all treatments with a maximum increase under Cr + eUV-B treatment. Taken together our results accentuated that P. corylifolia can be grown in an area contaminated with Cr and has a higher influx of UV-B for the attainment of psoralen considering its pharmaceutical perspectives. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Photosynthetic, Biochemical and Secondary Metabolite Changes in a Medicinal Plant Chlorophytum borivillianum (Safed musli) against Low and High Doses of UV-B Radiation
(John Wiley and Sons Inc, 2023) Deepanshi Jaiswal; Avantika Pandey; Madhoolika Agrawal; Shashi Bhushan Agrawal
Plants are inevitably grown in presence of sunlight, therefore bound to be exposed to natural UV-B radiation. Several studies have already been conducted with UV-B and medicinal plants and only few studies showed dose dependent variation. The present study aims to find out the variations and adaptation in Chlorophytum borivillianum under two different doses of UV-B radiation; ambient + low (3.2 kJm−2 d−1) and high (7.2 kJm−2 d−1) UV-B dose, denoted as LD and HD, respectively. Reduction in photosynthetic rate was higher at HD, while plants receiving LD displayed nonsignificant variation. During vegetative and reproductive stage, significant reduction (P ≤ 0.001) in stomatal conductance was obtained when exposed to HD-eUV-B. Fv/Fm showed more reductions in HD-eUV-B (12.6%) followed by LD-eUV-B (7.9%). Low and high doses of UV-B enhanced the anthocyanin content but the increase was significant in HD, indicates epidermal protection strategy by the plants. Under LD-eUV-B, the content of saponin, a major phytochemical constituent was enhanced by 26%. Phytochemical analysis of roots revealed reduction mostly in fatty acid components whereas the steroidal components (stigmasterol and sarsasapogenin) showed enhancement in response to LD. The study suggests the importance of LD-eUV-B in the stimulation of medicinal compounds in C. borivillianum. © 2022 American Society for Photobiology.
Physiological, biochemical, and molecular responses of the plants against enhanced ultraviolet B and heavy metal stress
(Springer Singapore, 2020) Deepanshi Jaiswal; Avantika Pandey; S.B. Agrawal
Ultraviolet-B (UV-B) radiation and heavy metals (HMs) are well-known stress factors for plants. UV-B is a part of incoming solar radiation reaching to the earth surface and its intensity is regulated by the stratospheric ozone layer, which in recent time had shown a significant depletion due to several natural and anthropogenic factors. HMs have also increased in the environment due to the industrial discharge, emissions from vehicle exhaust and improper disposal of wastes in soil and water, which directly or indirectly influence all types of vegetation. It is impor-tant to identify physiological, biochemical, and molecular changes in plants against stress factors and plant’s strategy to survive successfully under such harsh environment. This review primarily focuses on how UV-B and HMs individually or in combination elicit plant responses, their survival and various adaptation mechanisms in combating stress. Both stresses affect various physiological and biochemical processes at cellular and molecular levels in plants. Induction of several important metabolites such as N-containing compounds, phenolic compounds, terpenes, and essential oils is the major secondary response in plants for long-term stress adaptation under UV-B stress whereas sequestration of HMs by the formation of metal-ligand complex and the antioxidant defense systems are the most important detoxification mechanism used by plants against HMs-induced stress. Based on the outcomes, it will be possible to identify important traits, plants, and various defensive or adaptive mechanisms in plants to cope up with UV-B and metal tolerance. © Springer Nature Singapore Pte Ltd. 2020.
Responses of differential nitrogen doses on biomass, biochemical, and medicinally important metabolites of Andrographis paniculata exposed to elevated level of carbon dioxide
(Springer, 2024) Aradhana Singh; Avantika Pandey; Shashi Bhushan Agrawal; Madhoolika Agrawal
In this study, the effects of different levels of nitrogen (N) and elevated CO2 (ECO2) were evaluated using open-top chambers (OTCs) on the carbon and nitrogen pool, medicinally important metabolites, biomass accumulation, and the biochemical parameters of an important medicinal plant, Andrographis paniculata. In the present study, ECO2 increased the protein and chlorophyll contents at higher N level compared with low N availability. The level of reactive oxygen species decreased with increased N supply under ECO2 however, responses of enzymatic antioxidants to ECO2 at various N treatments showed variable responses. All N treatments resulted in higher organic carbon content due to ECO2. However, a reduction in N content at low and moderate doses of N treatment was observed leading to an increased carbon-to-nitrogen (C/N) ratio under ECO2. At higher N treatments, biomass allocation to the root, stem, and leaf was considerably higher under ECO2. Furthermore, ECO2 increased the total alkaloid content at all N levels; however, the increase was highest at recommended level of N. Further, there were differences in responses of two active medicinally important metabolites of the plant. Though ECO2 increased andrographolide and neo-andrographolide content at N supplementation, but the increment in andrographolide was highest at recommended dose of N. The results of the study indicated that under ECO2, biomass gain is benefitted at high N supply, while medicinally important metabolites were found more at moderate level of N. Graphical Abstract: (Figure presented.). © Indian Society for Plant Physiology 2024.
Role of glutathione in enhancing plant tolerance to organic pollutants
(Elsevier, 2020) Deepanshi Jaiswal; Avantika Pandey
The way to technology-based era accelerates the rate of industrialization, intensive agriculture, use of herbicides/pesticides, and fossil fuel burning that not only disturb the natural vegetation but also increase the contamination of natural resources and accumulation of organic and inorganic pollutants in the soil and in water. Organic pollutants (OPs) are persistent in biota since metabolism is slow and therefore accumulates in the food chain, thereby causing damage to plants and animals. There are reports for the existence of several detoxification mechanisms in plants, among which conjugation with glutathione is one of the important detoxification pathway for OPs. In this process, glutathione S-transferases (GSTs) play a vital role and mediate the conjugation of OPs to reduced glutathione (GSH) followed by compartmentalization of conjugates within vacuole/apoplast through the action of ATP-dependent pumps and their subsequent metabolism in plants. Present paper deals in details on the role of glutathione in enhancing tolerance of plants against organic pollutants. © 2021 Elsevier Inc. All rights reserved.
Secondary Metabolites Biosynthesis and Related Gene Expression Under Ultraviolet-B Radiation
(Springer Nature, 2023) Avantika Pandey; Deepanshi Jaiswal; Madhoolika Agrawal; Shashi Bhushan Agrawal
Plants have a diverse array of secondary metabolites as part of their defense mechanism against various stress conditions. These secondary metabolites are broadly classified into phenolics, alkaloids, and terpenes. Ultraviolet-B (UV-B) radiation is one such environmental factor that acts both as a stressor and regulator for plants. UV-B mediated responses of plants including regulation of secondary metabolites biosynthesis involve two pathways, i.e., UVR8 (UV resistance locus 8) mediated UV-B specific and non-specific pathways. By involving these two pathways UV-B regulate the biosynthesis of secondary metabolites at the transcriptional level. UV-B radiation affects the expression of numerous genes of the enzymes involved in the production of secondary metabolites that may ultimately affect the accretion of secondary metabolites in plants. However, these responses to UV-B vary depending on species, cultivars, UV-B dose, developmental stage of plants, experimental conditions, and existing environmental factors. Therefore, a thorough investigation of the effects of UV-B on gene expression and biosynthesis of secondary metabolites in plants is covered in the present review. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Ultraviolet-B and Heavy Metal-Induced Regulation of Secondary Metabolites in Medicinal Plants: A Review
(MDPI, 2023) Avantika Pandey; Madhoolika Agrawal; Shashi Bhushan Agrawal
Despite a rich history and economic importance, the potential of medicinal plants has not been fully explored under different abiotic stress conditions. Penetration of UV-B radiation and contamination of heavy metals are two important environmental stress for plants with remarkable influence on the defense-related and pharmaceutically important secondary metabolites of medicinal plants. UV-B and heavy metal contamination may become a critical issue that either positively or negatively affects the quality and quantity of secondary metabolites. Such effects may result from changes in the expression level of genes that encode the corresponding enzymes or the inactivation and/or stimulation of specific enzymes involved in the different biosynthetic pathways of the secondary metabolites. Therefore, a comprehensive study of the impact of UV-B and heavy metals individually and in combination on the biosynthesis and accumulation of secondary metabolites in medicinal plants is discussed in the present review. © 2023 by the authors.
Ultraviolet-B mediated biochemical and metabolic responses of a medicinal plant Adhatoda vasica Nees. at different growth stages
(Elsevier B.V., 2021) Avantika Pandey; Deepanshi Jaiswal; Shashi Bhushan Agrawal
In the present study, the effects of elevated UV-B (eUV[sbnd]B; ambient ± 7.2 kJ m−2 day−1) were evaluated on the biochemical and metabolic profile of Adhatoda vasica Nees. (an indigenous medicinal plant) at different growth stages. The results showed reduction in superoxide radical production rate, whereas increase in the content of hydrogen peroxide which was also substantiated by the histochemical localization. Malondialdehyde content, which is a measure of oxidative stress, did not show significant changes at any of the growth stages however photosynthetic rate and chlorophyll content showed reduction at all growth stages under eUV-B exposure. Increased activities of the enzymatic and non-enzymatic antioxidants were noticed except ascorbic acid, which was reduced under eUV-B exposure. The metabolic profile of A. vasica revealed 43 major compounds (assigned under different classes) at different growth stages. Triterpenes, phytosterols, unsaturated fatty acids, diterpenes, tocopherols, and alkaloids showed increment, whereas reduction in saturated fatty acids and sesquiterpenes were observed under eUV-B treatment. Vasicinone and vasicoline, the two important alkaloids of A. vasica, showed significant induction under eUV-B exposure as compared to control. Treatment of eUV-B leads to the synthesis of some new compounds, such as oridonin oxide (diterpene) and α-Bisabolol oxide-B (sesquiterpene), which possess potent anti-inflammatory and anticancerous activities. The study displayed that differential crosstalk between antioxidants and secondary metabolites at different growth stages, were responsible for providing protection to A. vasica against eUV-B induced oxidative stress and enhancing its medicinal properties. © 2021 Elsevier B.V.
Ultraviolet-B radiation: a potent regulator of flavonoids biosynthesis, accumulation and functions in plants
(Indian Academy of Sciences, 2020) Avantika Pandey; Shashi Bhushan Agrawal
Flavonoids represent a diverse group of polyphenolic secondary metabolites which are distributed amongst most of the plant species. Ultraviolet-B (UV-B) radiation is one of the important environmental regulators which governs the flavonoids biosynthesis at the transcriptional level. It is important to find out the role played by UV-B radiation in regulation of flavonoids biosynthesis and function under UV-B stress conditions in plants. This article summarizes the existing knowledge on the regulatory role of UV-B radiation on flavonoids biosynthesis and its accumulation trends in plants; further it discusses the diverse functions of flavonoids under the influence of UV-B radiation in plants. © 2020. All rights reserved.
Ultraviolet-Binduced modifications in growth, physiology, essential oil content and composition of a medicinal herbal plant Psoralea corylifolia
(Springer, 2022) Avantika Pandey; Madhoolika Agrawal; Shashi Bhushan Agrawal
Psoralea corylifolia (bakuchi) is a traditional, medicinally important herbal plant of the family Fabaceae. In particular, seeds are vital in treating skin diseases, such as leprosy, psoriasis, and leukoderma. Global climate change and the threat of stratospheric ozone depletion are already marked, so unveiling the implications of UV-B radiation on medicinal plants is imperative. In this backdrop, the present study aimed to assess the effect of elevated UV-B (eUV-B; ambient + 7.2 kJ m−2 d−1) on the content and composition of essential oils and how other factors such as growth, anatomy and photosynthetic adaptations were involved in this. Plant growth and physiological parameters were lower under eUV-B treatment than in the control (except carotenoid and water use efficiency). Due to eUV-B exposure, the number of racemes, flowers and seeds reduced significantly compared to their numbers in the control. The essential oil content of seeds increased by 46.4% under the eUV-B treatment compared with that in the control. The GC–MS analysis of essential oil revealed that monoterpenes decreased, whereas meroterpene and sesquiterpenes increased under eUV-B treatment as compared to control. Caryophyllene, caryophyllene oxide and bakuchiol (which possesses anti-cancerous and anti-inflammatory activities) were identified as major metabolites and increased under eUV-B as compared to control. The study emphasizes that under eUV-B exposure, a reduction in growth and physiology of P. corylifolia was accompanied by an increase in essential oil content, antioxidant capacity and content of medicinally important compounds. © 2022, The Author(s), under exclusive licence to Korean Society for Horticultural Science.