Auxin and the control of plant growth and development

Plants are remarkable organisms. Unlike animals, they cannot flee and, rooted in one place, they must cope with whatever challenges arise — nutrient scarcity, drought, shade, wind or obstacles in the soil. Their extraordinary ability to survive in such unstable environmental conditions lies in their capacity to adapt. In response to environmental signals, plants can rapidly adjust the rate of organ growth, change the direction of growth, bend toward resources, or remodel their body architecture by promoting or suppressing the formation of new organs such as lateral roots, branches, leaves, or flowers. This unique developmental plasticity depends on chemical signals, plant hormones that serve as regulators and coordinators of endogenous molecular and cellular processes. Chief among these signals is auxin, a plant hormone central to nearly every aspect of plant life.