Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov 20;24(22):16524.
doi: 10.3390/ijms242216524.

High-Proportion Blue Light Irradiation at the End-of-Production Stage Promotes the Biosynthesis and Recycling of Ascorbate in Lettuce

Chengbo Zhou  1 , Zonggeng Li  1 , Wenke Liu  2   3 , Zhonghua Bian  1 , Wei Lu  4 , Bo Zhou  1 , Sen Wang  1 , Qingming Li  1 , Qichang Yang  1
Affiliations

High-Proportion Blue Light Irradiation at the End-of-Production Stage Promotes the Biosynthesis and Recycling of Ascorbate in Lettuce

Chengbo Zhou et al. Int J Mol Sci. .

Abstract

Ascorbate (AsA), an essential antioxidant for both plants and the human body, plays a vital role in maintaining proper functionality. Light plays an important role in metabolism of AsA in horticultural plants. Our previous research has revealed that subjecting lettuce to high light irradiation (HLI) (500 μmol·m-2·s-1) at the end-of-production (EOP) stage effectively enhances AsA levels, while the optimal light quality for AsA accumulation is still unknown. In this study, four combinations of red (R) and blue (B) light spectra with the ratio of 1:1 (1R1B), 2:1 (2R1B), 3:1 (3R1B), and 4:1 (4R1B) were applied to investigate the biosynthesis and recycling of AsA in lettuce. The results demonstrated that the AsA/total-AsA content in lettuce leaves was notably augmented upon exposure to 1R1B and 2R1B. Interestingly, AsA levels across all treatments increased rapidly at the early stage (2-8 h) of irradiation, while they increased slowly at the late stage (8-16 h). The activity of L-galactono-1,4-lactone dehydrogenase was augmented under 1R1B treatment, which is pivotal to AsA production. Additionally, the activities of enzymes key to AsA cycling were enhanced by 1R1B and 2R1B treatments, including ascorbate peroxidase, dehydroascorbate reductase, and monodehydroascorbate reductase. Notably, hydrogen peroxide and malondialdehyde accumulation increased dramatically following 16 h of 1R1B and 2R1B treatments. In addition, although soluble sugar and starch contents were enhanced by EOP-HLI, this effect was comparatively subdued under the 1R1B treatment. Overall, these results indicated that AsA accumulation was improved by irradiation with a blue light proportion of over 50% in lettuce, aligning with the heightened activities of key enzymes responsible for AsA synthesis, as well as the accrual of hydrogen peroxide. The effective strategy holds the potential to enhance the nutritional quality of lettuce while bolstering its antioxidant defenses.

Keywords: antioxidant; enzyme activity; light quality; plant factory; reactive oxygen species.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Temporal trends of AsA (A) and total−AsA (B) levels in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way ANOVA of light quality, duration, and their interactions. ns and ** indicate insignificant and p < 0.01, respectively.
Figure 2
Figure 2
Temporal changes in GLDH activity in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way ANOVA of light quality, duration, and their interactions. ns and ** indicate insignificant and p < 0.01, respectively.
Figure 3
Figure 3
Temporal changes in APX (A), DHAR (B), MDHAR (C), and GR (D) activities in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way ANOVA of light quality, duration, and their interactions. ns and ** indicate insignificant and p < 0.01, respectively.
Figure 4
Figure 4
Temporal trends of soluble sugar (A) and starch (B) levels in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way ANOVA of light quality, duration, and their interactions. ns and ** indicate insignificant and p < 0.01, respectively.
Figure 5
Figure 5
Temporal changes in O2− (A) and H2O2 (B) levels in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way analysis of variance of light quality, duration, and their interactions. ns and ** indicate insignificant and p < 0.01, respectively.
Figure 6
Figure 6
Temporal changes in MDA level in lettuce leaves under EOP−HLI with varying R−to−B ratios. All data are the means ± SD of four repeats. Different letters at given time points denote p < 0.05. Inset provides the F values and significance derived from two−way ANOVA of light quality, duration, and their interactions. ** indicate p < 0.01.
Figure 7
Figure 7
Simplified illustration of AsA regulation processes under EOP-HLI with different red and blue combinations in lettuce.
Figure 8
Figure 8
Spectra of the employed red and blue LED panels.
Figure 9
Figure 9
Schematic diagram delineating various growth stages, arrangements, and designated sampling instances for the end-of-production high light experiment featuring various R-to-B ratios.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Ntagkas N., Woltering E.J., Marcelis L.F.M. Light regulates ascorbate in plants: An integrated view on physiology and biochemistry. Environ. Exp. Bot. 2018;147:271–280. doi: 10.1016/j.envexpbot.2017.10.009. - DOI
    1. Min Q., Marcelis L.F.M., Nicole C.S., Woltering E.J. High light intensity applied shortly before harvest improves lettuce nutritional quality and extends the shelf life. Front. Plant Sci. 2021;12:615355. doi: 10.3389/fpls.2021.615355. - DOI - PMC - PubMed
    1. Massot C., Genard M., Stevens R., Gautier H. Fluctuations in sugar content are not determinant in explaining variations in vitamin C in tomato fruit. Plant Physiol. Biochem. 2010;48:751–757. doi: 10.1016/j.plaphy.2010.06.001. - DOI - PubMed
    1. Zha L., Zhang Y., Liu W. Dynamic responses of ascorbate pool and metabolism in lettuce to long-term continuous light provided by red and blue LEDs. Environ. Exp. Bot. 2019;163:15–23. doi: 10.1016/j.envexpbot.2019.04.003. - DOI - PMC - PubMed
    1. Laing W., Norling C., Di B., Wright M., Bulley S. Ascorbate concentration in Arabidopsis thaliana and expression of ascorbate related genes using RNAseq in response to light and the diurnal cycle. Cold Spring Harbor Labs J. 2017 doi: 10.1101/138008. - DOI
  NODES
Note 6
twitter 2