An Arabidopsis thaliana mutant that produces green seeds that are highly insensitive to exogenous ABA, non-dormant and severely desiccation intolerant was isolated from a population of fast neutron-irradiated seeds. Molecular and genetic analysis of this mutant shows that these phenotypes are caused by an internal deletion of approximately one third of the AB13 gene. Therefore abi3 mutants with the above phenotypes are representative of null alleles at this locus.