Materials and Methods
Iiiciubationis. The endosperm along with any remaining
nucellus was removed with a spatula from
E. niiacrocarpa seed which had been stored at -20°.
One average seed yielded about one-half ml of the
semi-fluid endosperm nucellus. This preparation is
referred to subsequently as the endosperm, although
it should be noted that smaller and variable amounts
of nucellus were always present. This undiluted tissue
was gently homogenized in a glass homogenizer
and the resulting suspension was passed through glass
wool to remove cell debris. This extract was used
directly as the source of enzymes in some experiments.
In others the supernatant fraction from the
centrifugation of the extract at 105,000 X g for 1
hour was employed.