Effects of red and blue light on leaf anatomy, CO2 assimilation and the photosynthetic electron transport capacity of sweet pepper (Capsicum annuum L.) seedlings

Abstract

Background: The red (R) and blue (B) light wavelengths are known to influence many plant physiological processes during growth and development, particularly photosynthesis. To understand how R and B light influences plant photomorphogenesis and photosynthesis, we investigated changes in leaf anatomy, chlorophyll fluorescence and photosynthetic parameters, and ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) and Calvin cyclerelated enzymes expression and their activities in sweet pepper (Capsicum annuum L.) seedlings exposed to four light qualities: monochromatic white (W, control), R, B and mixed R and B (RB) light with the same photosynthetic photon flux density (PPFD) of 300 μmol/m 2 •s. Results: The results revealed that seedlings grown under R light had lower biomass accumulation, CO 2 assimilation and photosystem II (PSII) electron transportation compared to plants grown under other treatments. These changes are probably due to inactivation of the photosystem (PS). Biomass accumulation and CO 2 assimilation were significantly enriched in Band RB-grown plants, especially the latter treatment. Their leaves were also thicker, and photosynthetic electron transport capacity, as well as the photosynthetic rate were enhanced. The up-regulation of the expression and activities of Rubisco, fructose-1, 6-bisphosphatase (FBPase) and glyceraldehyde-phosphate dehydrogenase (GAPDH), which involved in the Calvin cycle and are probably the main enzymatic factors contributing to RuBP (ribulose-1, 5-bisphosphate) synthesis, were also increased. Conclusions: Mixed R and B light altered plant photomorphogenesis and photosynthesis, mainly through its effects on leaf anatomy, photosynthetic electron transportation and the expression and activities of key Calvin cycle enzymes.

Blue Light Improves Photosynthetic Performance during Healing and Acclimatization of Grafted Watermelon Seedlings

“…This increased carbohydrate accumulation has been associated with both down-regulation of photosynthesis [ 62 ] and feedback inhibition on sucrose synthesis and sugar phosphates’ cytosol accumulation [ 63 ]. Since B light generally up-regulates the genes encoding key enzymes in the Calvin-Benson cycle, feedback control is ruled out in the inhibition of photosynthesis under monochromatic B light [ 63 , 64 ].…”

Transcriptome sequencing revealed the influence of blue light on the expression levels of light-stress response genes in Centella asiatica

“…The enriched GO terms of the DEGs in Group 3 indicated that the expression of the genes that were involved in the photosynthesis and electron transport under blue light was higher than that under red light ( Table 1 ). It has been shown that CO 2 assimilation, photosystem II (PSII) electron transportation, and photosynthesis in plants treated with red light were impaired to a greater extent than the plants treated with blue light [ 42 , 43 ]. Ribose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activity under red light was also lower than that under blue light [ 43 ].…”

“…It has been shown that CO 2 assimilation, photosystem II (PSII) electron transportation, and photosynthesis in plants treated with red light were impaired to a greater extent than the plants treated with blue light [ 42 , 43 ]. Ribose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activity under red light was also lower than that under blue light [ 43 ]. In this study, the expression of gene encoding Rubisco small subunit under blue light was higher than that red light ( Fig 2B and S4 Table ).…”

Photosynthetic Efficiency and Anatomical Structure of Pepper Leaf (Capsicum annuum L.) Transplants Grown under High-Pressure Sodium (HPS) and Light-Emitting Diode (LED) Supplementary Lighting Systems

“…Artificial irradiation influences the carotenoid content in leaves and fruits [ 23 , 26 ]. As reported by Li et al [ 27 ], mixed R and B light alters plant photomorphogenesis and photosynthesis, mainly by affecting the leaf anatomy, stoichiometry of photosystems I and II, photosynthetic electron transport, and the expression and activity of key Calvin cycle enzymes. It was found that when pepper seedlings were illuminated with mixed RB (red–blue) light, the leaves were thicker and the photosynthetic electron transport efficiency and photosynthetic rate increased compared to plants illuminated with white light; therefore, using LED lamps with a higher proportion of blue light can increase the supplementary light efficiency.…”