|
The late stages of embryogenesis in higher plants are dominated by seed formation during which vegetative growth of the embryo is halted and storage reserves are accumulated. In addition, the embryo develops desiccation tolerance to prevent damage by the loss of water at the end of ripening (Goldberg et al. 1994 ;Hughes & Galau 1989;Jürgens & Mayer 1994;West & Harada 1993). By means of seed formation, the plant embryo acquires a quiescent and protected state which allows it to outlast unfavourable environmental conditions such as drought. Under more suitable circumstances, germination can be initiated and further postembryonic vegetative development commences.
In Arabidopsis thaliana, recessive mutations in the FUSCA3 gene (FUS3) lead to a complex phenotype specifically affecting seed formation (Bäumlein et al. 1994 ;Keith et al. 1994). Particularly, fus3 embryos are defective in producing 12S and 2S seed proteins as well as storage lipids but accumulate large amounts of anthocyanin.
|
