Warming nights are correlated with declining wheat growth and yield. As a key determinant of plant biomass, respiration consumes O2 as it produces ATP and releases CO2and is typically reduced under warming to maintain metabolic efficiency. We compared the response of respiratory O2 and CO2flux to multiple night and day warming treatments in wheat leaves and roots, using one commercial (Mace) and one breeding cultivar grown in controlled environments. We also examined the effect of night warming and a day heatwave on the capacity of the ATP-uncoupled alternative oxidase (AOX) pathway. Under warm nights, plant biomass fell, respiratory CO2release measured at a common temperature was unchanged (indicating higher rates of CO2release at prevailing growth temperature), respiratory O2 consumption at a common temperature declined, and AOX pathway capacity increased. The uncoupling of CO2and O2 exchange and enhanced AOX pathway capacity suggest a reduction in plant energy demand under warm nights (lower O2 consumption), alongside higher rates of CO2release under prevailing growth temperature (due to a lack of down-regulation of respiratory CO2release). Less efficient ATP synthesis, teamed with sustained CO2flux, could thus be driving observed biomass declines under warm nights.
Bibliographical noteFunding Information:
DZ was supported by the China Scholarship Council. We are grateful to staff of the ANU Research School of Biology Plant Services Team for maintaining the plants in the controlled environments.We also thank the Australian Plant Phenomics Facility, which is supported under the National Collaborative Research Infrastructure Strategy of the Australian Government.
This project was supported by grants from the Grains Research Development Corporation (GRDC) (US00080 and UOS1904-003RTX) and the Australian Research Council Centre of Excellence in Plant Energy Biology (CE140100008). BCP was supported by the Australian Government Research Training Program. OC received support from a GRDC Fellowship (UOS1904-003RTX) and Research England’s ‘Expanding Excellence in England’ (E3)-funded Food and Nutrition Security Initiative of the Natural Resources Institute. DAW was also supported in part by the US Department of Energy contract number DESC0012704 to Brookhaven National Laboratory. PBR was supported in part by the by US National Science Foundation, Biological Integration Institutes grant NSF-DBI-2021898.
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- Alternative oxidase
- high temperature
- night warming
- thermal acclimation
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.