Growth and Biochemical Responses of Green and Red Perilla Supplementally Subjected to UV‐A and Deep‐blue LED Lights

Abstract

This study investigated the effects of UV-A and UV-A-closed visible light (deep-blue [DB]) on the growth and bioactive compound accumulation of green and red perilla. Four-weekold seedlings were cultivated in an environment control room under visible light with red, blue and white LEDs for 4 weeks and then were continuously grown under supplemental UV-A (365 nm and 385 nm) and DB (415 nm and 430 nm) lights for 7 days. UV-A and DB treatments did not enhance the growth characteristics of green perilla compared with the control; while these treatments enhanced the growth parameters of red perilla, and the values were highest in DB 415 nm. The photosynthesis rate of both cultivars showed similar trends as the growth results of each cultivar. The electron transport rate and maximum quantum yield of both cultivars were reduced under UV-A 365 nm, while these values were maintained in DB treatments. In both cultivars, total phenolic, antioxidant capacity, rosmarinic and caffeic acids and perillaldehyde levels were enhanced in DB treatments, whereas UV-A 365 nm and DB 415 nm increased the total anthocyanin content. Overall, supplemental DB 415 nm and 430 nm was suitable for improving the growth and biochemical accumulation of both perilla cultivars.

Effect of UV-A Irradiation on Bioactive Compounds Accumulation and Hypoglycemia-Related Enzymes Activities of Broccoli and Radish Sprouts

“…According to Zhang et al [18], UV-A irradiation significantly enhanced anthocyanin accumulation in radish sprouts by upregulating the expression of genes related to anthocyanin biosynthesis, including CRY, PHOT and COP1. Moreover, Nguyen et al [19] also reported UV-A irradiation increased anthocyanin accumulation in "green and red perilla". Similar results were also obtained in the present study.…”

UV-A for Tailoring the Nutritional Value and Sensory Properties of Leafy Vegetables

“…Under these conditions, it was concluded that green-leaf lettuce was more responsive to preharvest supplemental UV-A treatment than red-leaf lettuce: it accumulated~20% more proteins and higher amounts of Mg, Cu, and Zn compared to red-leaf lettuce. Nguyen et al [34] performed experiments with red and green perilla cultivars and did not find significantly different responses of the cultivars to 365, 385, 415 nm light, 25 W m −2 applied for 7 days. At our UV-A dosages applied, red leaf lettuce 'Belino' contained the highest amounts of α-tocopherol, epicatechin, however more pronounced reducing UV-A light impact was observed on its growth parameters and sugar (fructose and glucose contents, while growth parameters and sugar contents were not remarkably affected in other investigated leafy vegetables.…”

Blue spectral quality contributes to yield and ascorbic acid content in ‘Micro Tom’ tomato under sole-source lighting

“…For another leafy crop, perilla, blue light with peak wavelengths of 385 nm, 415 nm and 430 nm, was supplemented to white LED light and the photosynthetic rate, leaf area and dry weight was increased but only in the red cultivar, not the green. For both cultivars, the biomass correlated with the photosynthetic rate and also biochemical changes (Nguyen and Oh, 2022). Finally, varied responses in biomass and photosynthetic rate were found for three unrelated leafy greens supplemented with peak wavelengths of either 450 nm or 420 nm plus 440 nm blue light (Taulavuori et al, 2018).…”