Ascorbate-mediated regulation of growth, photoprotection, and photoinhibition in Arabidopsis thaliana

Plumb, William; Townsend, Alexandra J; Rasool, Brwa; Alomrani, Sarah; Razak, Nurhayati; Karpinska, Barbara; Ruban, Alexander V; Foyer, Christine H

Abstract

The requirements for ascorbate for growth and photosynthesis were assessed under low (LL; 250 µmol m–2 s–1) or high (HL; 1600 µmol m–2 s–1) irradiance in wild-type Arabidopsis thaliana and two ascorbate synthesis mutants (vtc2-1 and vtc2-4) that have 30% wild-type ascorbate levels. The low ascorbate mutants had the same numbers of leaves but lower rosette area and biomass than the wild type under LL. Wild-type plants experiencing HL had higher leaf ascorbate, anthocyanin, and xanthophyll pigments than under LL. In contrast, leaf ascorbate levels were not increased under HL in the mutant lines. While the degree of oxidation measured using an in vivo redox reporter in the nuclei and cytosol of the leaf epidermal and stomatal cells was similar under both irradiances in all lines, anthocyanin levels were significantly lower in the low ascorbate mutants than in the wild type under HL. Differences in the photosynthetic responses of vtc2-1 and vtc2-4 mutants were observed. Unlike vtc2-1, the vtc2-4 mutants had wild-type zeaxanthin contents. While both low ascorbate mutants had lower levels of non-photochemical quenching of chlorophyll a fluorescence (NPQ) than the wild type under HL, qPd values were greater only in vtc2-1 leaves. Ascorbate is therefore essential for growth but not for photoprotection.

Citation

Plumb, W., Townsend, A. J., Rasool, B., Alomrani, S., Razak, N., Karpinska, B., Ruban, A. V., & Foyer, C. H. (2018). Ascorbate-mediated regulation of growth, photoprotection, and photoinhibition in Arabidopsis thaliana. Journal of Experimental Botany, 69(11), 2823-2835. https://doi.org/10.1093/jxb/ery170

• Journal Article Type: Article
• Acceptance Date: Apr 27, 2018
• Online Publication Date: May 3, 2018
• Publication Date: May 11, 2018
• Deposit Date: Apr 12, 2023
• Publicly Available Date: Apr 19, 2023
• Journal: Journal of Experimental Botany
• Print ISSN: 0022-0957
• Electronic ISSN: 1460-2431
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 69
• Issue: 11
• Pages: 2823-2835
• DOI: https://doi.org/10.1093/jxb/ery170
• Keywords: Plant Science; Physiology
• Public URL: https://nottingham-repository.worktribe.com/output/19294258
• Publisher URL: https://academic.oup.com/jxb/article/69/11/2823/4991886