Transient Changes During Soybean Imbibition

Abstract

Air dry cotyledons of soybean (Glycine max Merr. variety Wayne) imbibe water rapidly for about 10 min followed by a slower, linear rate of uptake. Leakage of solutes out of the coytledon likewise shows an initial rapid period, followed by a slower, nearly linear rate after 5-10 min; both the rapid and the steady rate leakage are greater for initially drier seeds. Respiratory activity of cotyledons as measured by manometric techniques becomes apparent after about 10 min of imbibition while polarographic studies of ground particles suggest that O2 consumption begins almost immediately upon wetting. Initial wetting of the seed causes the release of adsorbed gases, and a series of changes in volume of the seed-water mixture are charted. Apparently extensive physical changes occur in the first few minutes of water entry, including a rearrangement of membranes changing them from a relatively porous to a less permeable condition, and a release of adsorbed gases which cause inflation or swelling of the seed.