Abstract
Features of chemicals which break seed dormancy and the
mechanisms of their action are discussed with reference to
results obtained with red rice (Oryza sativa) and other
relevant research. The significance of chemical structure,
including the nature and location of functional groups, is
considered, and the fact that similar structures can elicit
different biochemical responses is illustrated with examples.
As yet it is unclear whether changes in cell pH, highly
correlated with the uptake of, and metabolism to, weak acids,
and which some consider a possible trigger or marker in
dormancy breaking, are causative, consequential or merely
correlative. Uptake and metabolism of dormancy-breaking
compounds is, or can be, very rapid and the importance of
establishing the time course of dormancy-breaking, as
opposed to germination events, is emphasized.