Khan, HammadNakamura, YukikoFurbank, RobertEvans, John2023-04-060022-0957http://hdl.handle.net/1885/288184A growing number of leaf traits can be estimated from hyperspectral reflectance data. These include structural and compositional traits, such as leaf mass per area (LMA) and nitrogen and chlorophyll content, but also physiological traits such a Rubisco carboxylation activity, electron transport rate, and respiration rate. Since physiological traits vary with leaf temperature, how does this impact on predictions made from reflectance measurements? We investigated this with two wheat varieties, by repeatedly measuring each leaf through a sequence of temperatures imposed by varying the air temperature in a growth room. Leaf temperatures ranging from 20 °C to 35 °C did not alter the estimated Rubisco capacity normalized to 25 °C (Vcmax25), or chlorophyll or nitrogen contents per unit leaf area. Models estimating LMA and Vcmax25/N were both slightly influenced by leaf temperature: Estimated LMA increased by 0.27% °C-1 and Vcmax25/N increased by 0.46% °C-1. A model estimating Rubisco activity closely followed variation associated with leaf temperature. Reflectance spectra change with leaf temperature and therefore contain a temperature signal.This work was made possible by funding from the Grains Research and Development Corporation through grant ANU00025, which is part of IWYP60 Using next generation approaches to exploit phenotypic variation in photosynthetic efficiency to increase wheat yield; financial support from the Australian Government through the Australian Research Council Centre of Excellence for Translational Photosynthesis (CE140100015); and a Cooperative Laboratory Study Program grant to YN. We thank Saul Newman for discussions and analysis of spectra with respect to temperatureapplication/pdfen-AU© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology.Chlorophyll contentelectron transport ratehyperspectral reflectanceleaf dry mass per arealeaf nitrogenleaf temperatureRubisco carboxylation activityTriticum aestivum202110.1093/jxb/eraa5142022-01-23