Possible lessons of a model experiment: To what extent can UV activate the production of leaf phenolics in indoor plant cultivation?
Year: 2024
Type: article
Abstract: Tobacco ( Nicotiana tabacum L.) plants were grown outdoors (N°46.07, E°18.18) under either natural or UV-deprived sunlight for 25 days in the summer. High PAR resulted in high polyphenol content, which was selectively affected by solar UV-A and UV-B irradiation. Solar UV-A irradiation increased anthocyanins, but not flavonoids, in the epidermis, and this additional protection resulted in higher photochemical yields and lower NPQ. The simultaneous presence of UV-B overrode the effects of UV-A, increased epidermal flavonoids, and decreased anthocyanins. Leaves grown in full sunlight had the same photochemical yields of NPQ as those grown under a UV-excluding filter. A combination of these effects can falsely dismiss the effects of UV-B on outdoor photosynthesis. Phenolic acid content, corresponding to approximately 80% of phenolic compounds, did not depend on solar UV, and total flavonoids increased under full solar UV irradiation, but not under UV-A only. The polyphenol content in outdoor leaves also served as a reference point for an indoor experiment, which showed that even a short, 4-day exposure of low PAR grown plants to UV from an artificial source increased the amount of some, although not all, components close to or even above outdoor levels. In indoor leaves, a selective increase in quercetin glycosides (to 62–85% of outdoor levels) supports both enzymatic and non-enzymatic antioxidant functions, and the increase in crypto- and neochlorogenic acids (to 76% and 117% of outdoor levels, respectively) suggests a redistribution among biosynthesis pathways. These results demonstrate the potential and efficiency of cultivation systems without sunlight. • We studied the effects of solar and indoor UV treatments on Nicotiana tabacum plants. • Solar UV-A and UV-B oppositely affect epidermal anthocyanin and flavonoid contents. • Solar UV-A and UV-B oppositely affect the photochemical use and dissipation of PAR. • Indoor UV-B can bring levels of some phenolic compounds to levels induced by sunlight.
Institution: University of Pecs
Language: English
Topic: Light effects on plants
Subfield: Plant Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,870
Award: G263550192
OpenAlex ID: W4404724159