Summary (With Christy Fleet) Gibberellins (GAs) were initially identified as fungal compounds that caused strange effects in infected plants, and were subsequently discovered to be endogenously-produced plant growth hormones. “Green revolution” genes that can produce semi-dwarf, high yielding plants have been identified as GA synthesis or response genes. Ongoing research into GA accumulation and response promises further increases in yields. Recently, the DELLA proteins, whose stability is GA-dependent, were shown to be critical integrators of environmental factors that control plant growth responses.