Enhancing cereal productivity by genetic modification of root architecture.

Food security is one of the main topics of today's agriculture, primarily due to increasingly challenging environmental conditions. As most of humankind has a daily intake of cereal grains, current breeding programs focus on these crop plants. Customized endonucleases have been included in the breeders' toolbox after successfully demonstrating their use. Due to technological restrictions, the main focus of the new technology was on above-ground plant organs. In contrast, the essential below ground components were given only limited attention. In the present review, the knowledge of the root system architecture in cereals and the role of phytohormones during their establishment is summarized, and the underlying molecular mechanisms are outlined. The review summarizes how the use of CRISPR-based genome editing methodology can improve the root system architecture to enhance crop production genetically. Finally, future research directions involving this knowledge and technical advances are suggested.