UV-B radiation as an elicitor of secondary metabolite production in plants of the genus Alternanthera

Abstract

Ultraviolet B radiation has been described as a potential elicitor agent of the synthesis of secondary metabolites in plants. Thus, the present study aimed to investigate the production of betalains and total flavonoids, as well as the antioxidant activity, of Alternanthera sessilis, A. brasiliana, A. tenella and A. philoxeroides exposed to different periods of UV-B radiation (280-315 nm). Plants of these four species were exposed to UV-B radiation for 0, 2, 4, 6, and 8 hours, which amounts to 0, 10, 20, 30, and 40 J cm −2 of radiation, respectively. Significant increases in betacyanin and betaxanthin levels were observed in A. sessilis and A. brasiliana during the period of UV-B exposure, while no differences were observed for the others species. The highest estimated flavonoid levels were for A. sessilis exposed to UV-B radiation for 8 h, followed by a 24 h recovery period. In conclusion, the action of UV-B radiation as an inducer of defence responses in plants is influenced by increasing exposure periods followed by a recovery period. Both increase the levels of these composts, yet this increase is different among the four Alternanthera species, having a greater influence on the species A. sessilis and A. brasiliana.

Impact of betacyanins on responses to ultraviolet radiation inAmaranthus tricolorL.

“…Flavonoids, total phenolics, betalains, and melatonin have all been previously identified as potential plant responses to UV-B, in one or more species (Jordan et al 1991;Ibdah et al 2002;Afreen et al 2006;Kaur et al 2015;Klein et al 2018). In this experiment flavonoid and melatonin accumulated in response to UV-B (Table 2).…”

“…Presumably, betalain pigments have similar roles in the protection from abiotic stress but supporting evidence for this hypothesis is lacking. The quality and the intensity of visible light and UV-B radiation affect betalain pigment content in certain plant tissues (Girod and Zryd 1987;Kishima et al 1991;Ibdah et al 2002;Klein et al 2018). Water and salt stress can also induce the pigments (Nakashima et al 2011;, but the question remains: do plants with betalains have an advantage in the presence of UV-B?…”

Productivity of medicinal raw materials by different genotypes of Matricia chammomila L. is affected with pre-sowing radiation exposure of seeds

“…One of the effective approaches is the application of both ionizing and non-ionizing radiation exposure (Klein et al, 2018;Jan et al, 2012;Alothman et al, 2009;Vardhan, & Shukla, 2017;Nocchi et al, 2020). It was shown metabolic shift toward the formation of secondary metabolites, mostly radioprotectors, having antioxidant, anticancer, immunomodulatory, and anti-inflammatory effects under acute and chronic radiation exposure (Dai, & Mumper, 2010;Kaur, & Mondal, 2014;Unuofin, & Lebelo, 2020;Pisoschi et al, 2016).…”

Influence of Seasonality and Sunlight Effects on Rollinia mucosa Leaves Fingerprint

“…Generally, these complex molecules present terminal γ-lactone ring units, tetrahydrofuran (THF) units along the aliphatic chain and other functional groups. 14 The environmental factors such as temperature, humidity, seasonality, 15 circadian rhythm, 16 ultraviolet radiation, 17 air pollution and other external conditions affect both the quantitative and qualitative composition of metabolites. 18 Sunlit and shaded leaves of plants differ structurally and therefore adapt to sunlight at different levels.…”