Maintaining grain quality of wheat under climate change is critical for human nutrition, end-use functional properties, as well as commodity value. This paper reviews the current knowledge of high temperature and elevated atmospheric CO2 on whole-grain and functional properties of wheat. It also considers the utility of contemporary crop models for investigating the impacts of climate change on wheat quality; and discusses opportunities for advancing model capability. Under elevated CO2 wheat yield can increase by up to 36%, but universally grain protein concentration decreases and a shift in composition translates to reduced functional properties. High temperature during the post-anthesis period of crops can cause a step change reduction in grain-set, grain size and milling yield. Numerous crop models including APSIM-Nwheat, CropSyst, Sirius, GLAM-HTS account for high CO2 effects through modification of RUE, TE or critical leaf-N concentration and high temperature by accelerated leaf senescence, grain number, potential grain weight or HI modifications. For grain quality, however, crop models are typically restricted to predicting average grain size and grain-N content (concentration), although the SiriusQuality model accounts for the major storage proteins, gliadin and glutenin. For protein composition, high temperature stress reduces the glutenin/gliadin ratio and limits the synthesis of the larger SDS-insoluble glutenin polymers which causes wheat dough to have weaker viscoelasticity properties. This link provides an opportunity to model high temperature effects on grain functional properties. Further development and testing, utilizing grain quality data from global FACE programmes will be particularly valuable for validating and enhancing the performance of such models. For whole-grain characteristics, a single-spike model approach, which accounts for intra-spike variation in assimilate deposition may provide an opportunity to predict grain size distribution and associated screenings percentage and milling yield. Taken together expanding the predictive capability of our crop models to grain quality is an important step in providing a powerful tool for developing adaptation strategies for combating the impacts of climate change to global crop production and grain quality

The effect of different nitrogen (N) management strategies (i.e. N rate; 0, 25, 50, 100 kg ha–1, split N application, foliar N application, legume precropping) were assessed for how they may reverse the reduction of grain protein concentration (GPC) under elevated CO2 (eCO2; 550 µmol mol–1) of wheat (cv. Yitpi) using the Australian Grains Free Air CO2 Enrichment facility. GPC did not increase significantly under eCO2 for most of the N management strategies assessed when compared with ambient CO2 (aCO2; 390 µmol mol–1). Grain yield of cv. Yitpi under aCO2 increased by 43% (P < 0.001) with application of 100 kg N ha–1 when compared with 0 kg N ha–1 at sowing; this response was approximately double (82%) when 100 kg N ha–1 was applied under eCO2 conditions. Under aCO2 conditions, by adding 100 kg N ha–1 at sowing, the GPC increased by 37% compared with the GPC at N0; whereas under eCO2 conditions, by adding the same quantity of N fertiliser, the GPC increased by only 28%. The highest level of N applied (100 kg ha–1), chosen for economic and practical reasons in a low-rainfall, yield-limiting environment, was lower than that reported in other global studies (250–350 kg ha–1). In a low-rainfall, yield-limiting environment, it is not practical to increase GPC by applying N alone; new cultivars may be required if grain growers are to maintain grain protein (and functionality) in the future as CO2 levels continue to increase.