Anisohydric sugar beet rapidly responds to light to optimize leaf water use efficiency utilizing numerous small stomata

Barratt, Georgina E.; Sparkes, Debbie L.; McAusland, Lorna; Murchie, Erik H.

Abstract

© 2020 The Author(s) 2020. Published by Oxford University Press on behalf of the Annals of Botany Company. Under conditions of high transpiration and low soil water availability, the demand for water can exceed supply causing a reduction in water potential and a loss of cell turgor (wilting). Regulation of stomatal aperture mediates the loss of water vapour (gs), which in turn is dependent in part on the anatomical characteristics of stomatal density (SD) and stomatal size (SS). Anisohydric sugar beet (Beta vulgaris) is atypical, exhibiting wilting under high soil water availability. Spinach (Spinacia oleracea) belongs to the same family Chenopodiaceae s.s., but demonstrates a more typical wilting response. To investigate the role of stomatal dynamics in such behaviours, sugar beet and spinach leaves were exposed to step-changes in photosynthetic photon flux density (PPFD) from 250 to 2500 μmol m-2 s-1. Using a four log-logistic function, the maximum rate of stomatal opening was estimated. Concurrent measurements of SD and SS were taken for both species. While sugar beet coupled faster opening with smaller, more numerous stomata, spinach showed the converse. After exposure to drought, maximum gs was reduced in sugar beet but still achieved a similar speed of opening. It is concluded that sugar beet stomata respond rapidly to changes in PPFD with a high rate and magnitude of opening under both non-droughted and droughted conditions. Such a response may contribute to wilting, even under high soil water availability, but enables photosynthesis to be better coupled with increasing PPFD.

Citation

Barratt, G. E., Sparkes, D. L., McAusland, L., & Murchie, E. H. (2021). Anisohydric sugar beet rapidly responds to light to optimize leaf water use efficiency utilizing numerous small stomata. AoB PLANTS, 13(1), Article plaa067. https://doi.org/10.1093/aobpla/plaa067

• Journal Article Type: Article
• Acceptance Date: Nov 18, 2020
• Online Publication Date: Dec 2, 2020
• Publication Date: Feb 1, 2021
• Deposit Date: Dec 7, 2020
• Publicly Available Date: Dec 7, 2020
• Journal: AoB PLANTS
• Electronic ISSN: 2041-2851
• Publisher: Oxford University Press (OUP)
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Article Number: plaa067
• DOI: https://doi.org/10.1093/aobpla/plaa067
• Keywords: Anisohydric, speed of stomatal response, stomatal density, stomatal size, sugar beet, water use efficiency, wilting
• Public URL: https://nottingham-repository.worktribe.com/output/5125443
• Publisher URL: https://academic.oup.com/aobpla/advance-article/doi/10.1093/aobpla/plaa067/6015919