The Genetic Basis and Domestication of Root System Architecture in Cereals.

Cereal root systems are critical for nutrient and water uptake as well as for anchorage and thus for plant productivity. This review synthesizes the current understanding of the morphological and cellular organization and the genetic regulation of the different cereal root types. We highlight conserved and lineage-specific developmental mechanisms across maize, rice, and barley. Genetic dissection of cereal root system formation has uncovered key regulators of root initiation and elongation as well as genes controlling root architecture via the root setpoint angle. Moreover, we discuss genes that determine cell and tissue identity and genes that link root traits to domestication. By integrating molecular genetics with developmental and evolutionary perspectives, we highlight how insights into the molecular mechanisms of root system architecture can contribute to the production of high-yielding and at the same time sustainable crops, ensuring global food security.