Changes in Quercetin Derivatives and Antioxidant Activity in Marigold Petals (Tagetes patula L.) Induced by Ultraviolet-B Irradiation and Methyl Jasmonate

Abstract

Marigold petals contain numerous antioxidative flavonoids and carotenoids that can be affected by environmental stressors. There is yet no detailed study on the relationship between phytochemical accumulation and stressors in marigold petals. This study evaluated quercetin derivatives and antioxidant activity in marigold petals in response to ultraviolet-B (UV-B) irradiation and methyl jasmonate (MeJA) treatment. The limiting UV-B radiation intensity and MeJA dose that caused no wilting damage under 1-h daily treatment for 10 days were <2 W∙m−2∙s−1 and <10 mM, respectively. Marigold petals contained three major flavonoids, quercetin-7-O-glucoside (Q7G, 6.6 mg∙g−1dw), quercetin-3-O-glucoside (Q3G, 62.7 mg), and quercetin (26.6 mg), possessing different antioxidant potential and exhibiting the highest power in quercetin and next value in Q7G. Single UV-B irradiation exerted a limited effect on the changes in the content of the three quercetin derivatives, whereas combined treatment with 1 W UV-B radiation and 5 mM MeJA resulted in the highest total quercetin content, showing >20% increase compared to that without treatment. This increase primarily resulted in an increase in quercetin content. MeJA treatment positively affected the increase in Q3G and Q7G contents in a dose-dependent manner during the 10-d experimental period but exerted no considerable effect on quercetin accumulation. The antioxidant activity was increased when flowers were exposed to mild MeJA treatment of 5–10 mM. UV-B irradiation decreased the antioxidant activity of marigold petals, but this decrease could be compensated by MeJA treatment.

Nutritional Evaluation of Quinoa Genetic Resources Growing in the Climatic Conditions of Central Europe

“…In various plant species, the quercetin level increased due to drought [ 78 ], salt [ 81 ], and lead stress [ 82 ]. Several studies carried out on various plant species concluded that higher quercetin accumulation is a response to increased light exposure and UV-B radiation [ 83 , 84 ], which may partially explain the seasonal variations in the quercetin content observed in our study.…”

Impact of Dry Processing on Secondary Metabolites in the Petals of Marigold (Tagetes spp.) Cultivar

“…Individual flavonoids in marigold petal extracts were determined using a previously published method [13]. In summary, 20 mg of the ground sample underwent extraction using a mixture of water, methanol, and formic acid (28:70:2 v/v).…”

“…Specifically, lutein content has been reported to exhibit significant differences based on flower color [11,12]. Moreover, a recent study emphasized the role of quercetin derivatives in the antioxidant activity of marigold petals [13]. The primary flavonoids in marigolds show notable variations among cultivars, largely attributed to genetic factors rather than external physical characteristics [14].…”