Gibberellin is an endogenous plant growth regulator. Here, we describe our
present understanding of how gibberellin regulates plant growth, using rece
nt results gained from studies of gibberellin-signalling mutants of Arabido
psis. These results show that a signalling pathway represses plant growth a
nd that gibberellin releases this repression. In consequence, the well-know
n growth-promoting properties of gibberellin are due to its activity as an
"inhibitor of an inhibitor" [Brian Pw, Sym Sec. Exp Bio 1957; 11:166-182 (R
ef. 1)] of plant growth. BioEssays 20:1001-1008, 1998, (C) 1998 John Wiley
& Sons, Inc.