An introduction to the fundamentals of root systems research in cultivated plants

BACKGROUND: Although oft overlooked due to being hidden below-ground, plant roots are diverse in function and structure, and are fundamental to plant growth and future crop improvement due to their role in resource acquisition, anchorage, interaction with soil organisms, and, in some cases, providing the crop harvestable product itself. Root systems are dynamic, expressing physiological variation between species, cultivars, environments, and even within the continuum of a single root; at each level contributing uniquely to plant and ecosystem processes. SCOPE: Designed as an educational review, this article provides a structured and accessible overview of the complex biology of roots in cultivated plants. We establish a foundational framework by defining different types of root systems, root classes, and specialized root types. Serving as a primer for students, educators, and researchers expanding their expertise, we review how variation in root traits affects plant growth and performance under stress conditions, and briefly introduce how some of these traits are genetically regulated. Finally, we summarize specific root research areas that have shown recent promise, offering a roadmap for further study. CONCLUSIONS: Gaining a comprehensive grasp of root system fundamentals, integrating insights from root physiology, phenotyping, and genetics, is a vital first step for engaging with advanced plant science. This foundational knowledge is paramount for developing sustainable agricultural practices, enhancing crop resilience, and contributing to global food security in an era of environmental change.