Answer:
Brassinosteroids are synthesized from phytosterols and they promote plant growth and development by modulating cellular processes (e.g, cell division, elongation, photomorphogenesis, responses to environmental stimuli, etc).
Explanation:
Brassinosteroids are phytohormones similar to steroid hormones. Phytosterols include sitosterol, campesterol, and stigmasterol, i.e., lipid (cholesterol) molecules that form the cell membranes. These polyhydroxylated steroidal phytohormones play a wide range of cellular roles during plant growth, development and immunity. Examples of brassinosteroid functions include plant development, xylem differentiation, responses to biotic/abiotic stresses, reproduction, etc. For example, campesterol, which is a precursor of brassinosteroid hormones, is an integral membrane component that functions during plant embryogenesis by regulating the permeability of cell membranes and by altering membrane-associated proteins, as well as signal transduction pathways.
