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Fan Y, Tcherkez G, Scafaro AP, Taylor NL, Furbank RT, von Caemmerer S, Atkin OK. Variation in leaf dark respiration among C3 and C4 grasses is associated with use of different substrates. Plant Physiol 2024:kiae064. [PMID: 38324704 DOI: 10.1093/plphys/kiae064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/04/2023] [Accepted: 01/11/2024] [Indexed: 02/09/2024]
Abstract
Measurements of respiratory properties have often been made at a single time point either during daytime using dark-adapted leaves or during night-time. The influence of the day-night cycle on respiratory metabolism has received less attention but is crucial to understand photosynthesis and photorespiration. Here, we examined how CO2- and O2-based rates of leaf dark respiration (Rdark) differed between midday (after 30-minute dark adaptation) and midnight in eight C3 and C4 grasses. We used these data to calculate the respiratory quotient (RQ; ratio of CO2 release to O2 uptake), and assessed relationships between Rdark and leaf metabolome. Rdark was higher at midday than midnight, especially in C4 species. The day-night difference in Rdark was more evident when expressed on a CO2 than O2 basis, with the RQ being higher at midday than midnight in all species, except in rice (Oryza sativa). Metabolomic analyses showed little correlation of Rdark or RQ with leaf carbohydrates (sucrose, glucose, fructose or starch) but strong multivariate relationships with other metabolites. The results suggest that rates of Rdark and differences in RQ were determined by several concurrent CO2-producing and O2-consuming metabolic pathways, not only the tricarboxylic acid cycle (organic acids utilisation), but also the pentose phosphate pathway, galactose metabolism, and secondary metabolism. As such, Rdark was time-, type- (C3/C4) and species-dependent, due to the use of different substrates.
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Affiliation(s)
- Yuzhen Fan
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Guillaume Tcherkez
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Nicolas L Taylor
- School of Molecular Sciences and Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, Australia
| | - Robert T Furbank
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- ARC Centre of Excellence in for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Susanne von Caemmerer
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- ARC Centre of Excellence in for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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