Response of photomorphogenesis and photosynthetic properties of sweet pepper seedlings exposed to mixed red and blue light

Abstract

Various light spectra, especially red (RL) and blue light (BL), have great effects on physiological processes and growth of plants. Previously, we revealed that the plant photomorphogenesis and photosynthesis of sweet pepper was significantly altered under BL or mixed RL and BL. The present study aimed to elucidate how mixed RL and BL influences plant photosynthesis during photomorphogenesis. We examined the growth, plant morphology, photosynthetic response of sweet pepper seedlings under monochromatic RL, BL, different ratios of mixed RL and BL (9R1B, 6R1B, 3R1B, 1R1B, 1R3B) with the same photosynthetic photon flux density of 300 μmol·m-2·s-1. White light (WL) were used as a control. The findings showed that the elongation of hypocotyl and first internode as well as leaf expansion were all stimulated by RL, while significantly restrained by BL compared with WL. Conversely, the leaf development, biomass accumulation and photosynthetic properties were inhibited by RL but promoted by BL. Additionally, compared with WL and other treatments, 3R1B could significantly improve the net photosynthetic rate, gas exchange, photosynthetic electron transport capacity, photochemical efficiency, shoot and root biomass accumulation. Furthermore, seedlings grew robustly and exhibited the greatest value of seedling index when exposed to this treatment. Overall, these results suggested that pepper seedlings grown under 3R1B performed better, possibly due to the more balanced light spectrum. It was more conducive to improve the plant photomorphogenesis and photosynthesis of sweet pepper, and a higher biomass accumulation and energy utilization efficiency could be achieved simultaneously under this mixed light spectrum.

Data-Independent Acquisition Proteomics Reveals the Effects of Red and Blue Light on the Growth and Development of Moso Bamboo (Phyllostachys edulis) Seedlings

“…It can be speculated that there is a unique pathway in bamboo that enables it to produce cellulose more efficiently using red light. Red light promotes the height of sweet pepper plants, while blue light promotes the stem diameter of sweet pepper [ 51 ]. In addition, red light increases the diameter of the hypocotyl of soybean compared to darkness, but inhibits hypocotyl elongation [ 52 ].…”

Brassica microgreens cabbage (Brassica oleracea), radish (Raphanus sativus) and rocket (Eruca vesicaria) (L.) Cav: application of red‐light emitting diodes lighting during postharvest storage and in vitro digestion on bioactive compounds and antioxidant activity

“…Lim et al . (2023) state that flavonoid glycosides were controlled by light irradiation, and biosynthesis genes were expressed under red light.…”

“…Chemical structure significantly affected the sensitivity of flavonol glycosides and hydroxycinnamic acids to varying light treatments (Neugart et al, 2019). Lim et al (2023) state that flavonoid glycosides were controlled by light irradiation, and biosynthesis genes were expressed under red light.…”

Magic Blue Light: A Versatile Mediator of Plant Elongation

“…Under sole-source lighting at a PPFD of 100 µmol m −2 s −1 and a photoperiod of 18 h, the optimal blue proportion in RB-LED lighting was 10% for cucumber seedlings and 30–50% for tomatoes [ 59 ]. Under RB-LED lighting at 300 µmol m −2 s −1 for 12 h d −1 , the optimal BL percentage was 25% for sweet pepper and eggplant transplants, which showed the best performance not only in compact morphology but also in robust growth, with the highest seedling index value [ 23 , 60 ]. A similar optimal BL percentage has been identified in rice seedlings grown under RB-LED lighting at 100 µmol m −2 s −1 for 12 h d −1 [ 66 ].…”