Wheat leaf dark respiration acclimates more strongly at night than in the day when responding to nocturnal warming

Rising night temperatures pose a significant threat to wheat productivity, yet the physiological basis of wheat adaptation to nocturnal warming remains poorly understood. We evaluated leaf photosynthetic and respiratory traits in ten Australian wheat cultivars released between 1901 and 2012 to warm nights under temperature-controlled environments. When exposed to warmer nights, rates of leaf net CO2 assimilation measured at 25 °C (Anet25) remained stable across cultivar release date despite declines in photosynthetic capacity (Vcmax and J1500) in newer cultivars. In most cultivars leaf respiratory CO2 release in the dark (Rdark) exhibited divergent thermal responses: warm nights suppressed temperature-normalised night Rdark (Rdark_night) but stimulated or maintained Rdark in the daytime (Rdark_day). The results suggest that a century of yield-focused breeding may have inadvertently maintained Anet25 under warmer nights in modern cultivars. This likely reflects the selection of genotypes..., Materials and methods
The experiment was conducted in controlled-environment facilities (glasshouses and growth chambers) at the University of New England (UNE) in Armidale, Australia (30.48°S, longitude 151.63°E, elevation 1021.5 m a.s.l.) in 2022.
Plant materials and growth conditions
A set of 10 wheat genotypes (Supplementary Table 1) were used in this experiment. The genotypes included commercial Australian wheat varieties spanning over a century (1901-2012) of breeding. Seeds of ten Australian wheat cultivars were planted in 4.5 L plastic pots (18 cm diameter and 60 cm height) containing Professional premium potting mix with slow-release fertiliser (J.C. & A.T. Searle Pty. Ltd., Qld. Australia). Potted plants were raised in glasshouse bays set to day/night temperatures of 20/12 °C, 70% relative humidity and a natural photoperiod of 12 hours. The plants were grown for four weeks in the glasshouse until the tillering stage (Zadok 20-29) (Zadoks et al., 1974). During this period, ..., # Wheat leaf dark respiration acclimates more strongly at night than in the day when responding to nocturnal warming

This README file was last updated on: 2026-04-15 (updated to address Dryad curation queries)
Corresponding author: Onoriode Coast ([[e-mail]](mailto:[e-mail]))
Corresponding author institution: University of New England, Armidale, NSW, Australia

## GENERAL INFORMATION

1. Title of Dataset: Wheat leaf dark respiration acclimates more strongly at night than in the day when responding to nocturnal warming
2. Citation for this dataset:
Rana Shahi, P., Scafaro, A. P., Thistlethwaite, R. J., Atkin, O. K., Trethowan, R. M., Rader, R., Burns, A., & Coast, O. (2025). Data from: Wheat leaf dark respiration acclimates more strongly at night than in the day when responding to nocturnal warming. Dryad Digital Repository.
3. Link to related publication:
Rana Shahi, P., Scafaro, A. P., Thistlethwaite, R. J., Atkin, O. K, Trethowan, R. M., Rader, R., Burns, A., ..., ,