Brassinosteroids (BRs) are growth hormones from the steroid family that are found in all plant species. They have a high-growth promoting activity, particularly in pollen and anthers, and take their name from the pollen of canola (Brassica napus), where they were initially discovered. BRs are involved in the control of cell division, elongation and differentiation throughout the growing season and are crucial for plant growth and development. And, acting as growth regulators, they are essential to many responses to stress.