Physiological, biochemical, and postharvest characteristics of two cut rose cultivars are regulated by various supplemental light sources

Abstract

Light is not only a photosynthetic energy source for biochemically plant cellular accumulation but also the most important signaling messenger for plant growth, development, and environmental adaptations, influencing the postharvest quality and longevity. In this study, to optimize the biochemical and physiological responses of cut rose flowers cv. ‘Jumilia’ and ‘Samurai’ to the different light quality provided by metal halide (MH), high pressure sodium (HPS), and light-emitting diode (LED) lamps and two light intensities of LED (75 and 150 μmol m−2 s−1 PPFD) on the postharvest life. The results showed that flower water content, as well as total carbohydrate, anthocyanin, and carotenoid content, were significantly induced by LED irradiation, but didn't influence the starch content of cut roses. Furthermore, MH and HPS lighting changed the osmotic potential, decreased the membrane stability index, and consequently increased the color change after harvest, resulting in shorter postharvest life of cut roses comparing to the LED environment. More specifically, plants produced by LED lighting reached higher activity of phenylalanine ammonia-lyase (PAL) enzymes and the following higher lignin concentration. LED-exposed rose flowers showed an increase in antioxidant activity and limitation of lipid peroxidation and hydrogen peroxide but were not effective in ascorbate peroxidases (APX) enzyme activity of cut rose flowers. Overall, LED irradiation delayed the senescence of postharvest cut roses mainly by inducting protein biosynthesis, activating the enzymatic system, and inhibiting microbial proliferation. These results suggest that the spectral quality of lighting altered biochemical function, cell wall lignification, and antioxidative defense mechanisms that affect postharvest attributes in roses.