Simulated climate change deferentially impacts phenotypic plasticity and stoichiometric homeostasis in major food crops
Grain yield and product quality responses of major food crops to variation in resource availability continue to be important considerations in agronomic research, particularly under abiotic stresses. Indices of grain quality and phenotypic plasticity of crop cultivars with C3 or C4 metabolic pathways and producing seed with either carbohydrate, protein, oil; or a combination of carbohydrate-protein or oil-protein as their major product, were quantified for six years under two phases of single and multiple abiotic stresses. Decreasing resource availability caused by short growing season and high population density, singly or in combination, resulted in significant changes in allometric relationships among most traits under study. Temporal quantitative and qualitative differences between “heatmaps” of stress phases, partitioning and analysis of total variance due to fixed and random factors, and functional relationship at hierarchical levels of organization, indicated a shift over time of phenotypic plasticity and quality indices. Moreover, relationships of phenotypic plasticity and quality index with biomass, grain yield, macro- and micronutrients, and nutrient ratios were largely modulated by differences between crop products within metabolic pathways. However, further research is needed for in-depth understanding and insights into the interdependencies of the large number of traits that crop plants should optimize to produce economic yield combined with adequate nutritional quality under abiotic stress.