Phytohormonal Control of Root Development and Architecture

Root System Architecture (RSA) is a critical determinant of plant water and nutrient acquisition, stress tolerance, and anchorage. Its development is orchestrated by a complex network of phytohormones that integrate genetic programs with environmental cues. Auxin acts as the central regulator for directing meristem differentiation, cell elongation, and lateral root initiation, xylem differentiation while hormones like cytokinins, gibberellins, ethylene, jasmonic acid, abscisic acid, strigolactones, and brassinosteroids modify the activity of Auxin or influence specific RSA traits independently. The crosstalk among the hormones decides the dynamic reprogramming of growth patterns of root under various stresses such as drought, salinity, and nutrient limitations. Understanding these regulatory interactions provides valuable opportunities for crop breeding with optimised root traits for improved resource-use efficiency and tolerance against changing climate.