During germination of embryos, there appear to be two
distinct patterns of mitochondrial development. These patterns,
which are particularly obvious in cotyledons, depend
on the nature of the stored reserves. In starch-storing seeds,
repair and activation of preexisting organelles predominate,
whereas oil-storing seeds typically produce new mitochondria
(Morohashi and Bewley, 1980; Morohashi, 1986). For
example, the biogenesis of mitochondria in germinating maize
embryos (which store oil in the scutellum, although starch is
the major endosperm reserve) involves the synthesis of cytochrome
c oxidase subunits encoded by the organellar
genome, which is followed within hours by the synthesis of
nuclear-encoded subunits (Ehrenshaft and Brambl, 1990).
This observation also implies that the coordinated regulation
of mitochondrial and nuclear genomes in plants begins during
the early stages of germination.