In silico evidence for the utility of parsimonious root phenotypes for improved vegetative growth and carbon sequestration under drought

• DOI: 10.3389/fpls.2022.1010165
• Publication Date: 2022-11-17T06:58:03Z
• Authors: Ernst D. Schäfer; Ishan Ajmera; Etienne Farcot; Markus R. Owen; Leah R. Band; Jonathan P. Lynch
• Keywords: 0301 basic medicine; 0106 biological sciences; 2. Zero hunger; Plant culture; drought; Plant Science; 15. Life on land; maize; root phenotypes; 01 natural sciences; 6. Clean water; functional-structural plant/soil model; carbon assimilation; SB1-1110; 03 medical and health sciences; 13. Climate action; OpenSimRoot_v2

Drought is a primary constraint to crop yields and climate change is expected to increase the frequency and severity of drought stress in the future. It has been hypothesized that crops can be made more resistant to drought and better able to sequester atmospheric carbon in the soil by selecting appropriate root phenotypes. We introduce OpenSimRoot_v2, an upgraded version of the functional-structural plant/soil model OpenSimRoot, and use it to test the utility of a maize root phenotype with fewer and steeper axial roots, reduced lateral root branching density, and more aerenchyma formation (i.e. the ‘Steep, Cheap, and Deep’ (SCD) ideotype) and different combinations of underlying SCD root phene states under rainfed and drought conditions in three distinct maize growing pedoclimatic environments in the USA, Nigeria, and Mexico. In all environments where plants are subjected to drought stress the SCD ideotype as well as several intermediate phenotypes lead to greater shoot biomass after 42 days. As an additional advantage, the amount of carbon deposited below 50 cm in the soil is twice as great for the SCD phenotype as for the reference phenotype in 5 out of 6 simulated environments. We conclude that crop growth and deep soil carbon deposition can be improved by breeding maize plants with fewer axial roots, reduced lateral root branching density, and more aerenchyma formation.