Rangarajan et al. employ the functional–structural model SimRoot to explore how interactions among architectural phenes in common bean, Phaseolus vulgaris (Fabaceae) determine the acquisition of phosphate and nitrate, two key soil resources contrasting in mobility. The utility of a root architectural phenotype is determined by whether the constituent phenes are synergistic or antagonistic.
Competition for internal resources and trade-offs for external resources result in multiple phenotypes being optimal under a given nutrient regime. No single phenotype is optimal across contrasting environments. These results have implications for understanding plant evolution and also for the breeding of more stress-tolerant crop phenotypes.