Dense accumulations of lipid and protein bodies were visible in
the plumule apical meristem, first true leaves and cotyledons of
fresh seeds (Fig. 3, Fig. S3). However, the number of lipid and
protein bodies in fresh seeds was reduced during cold stratification.
Presumably, lipids were hydrolyzed to fatty acids and sugars by
lipolytic enzymes and storage proteins cleaved to oligopeptides and
amino acids by active proteolytic enzymes (Bewley et al., 2013). In
seeds of M. domestica, proteolytic activity increased markedly
during cold stratification, indicating proteolytic solubilization of
insoluble reserve proteins, and an increase in quantity of free amino
acids paralleled the increase in seed germinability (Lewak et al.,
1975; Dawidowicz-Grzegorzewska, 1989). Likewise, acid lipases
were most active at low temperature, and enzymes also were
activated by GA treatment (_
Zarska-Maciejewska, 1992). Recently, it
was found that protein bodies in olive seeds not only serve as