Page 100 - The Miracle In The Seed

THE MIRACLE IN THE SEED

In a fresh seed, the nutrient re-
serve is a rich, moist gel sur-
rounding the embryo. As the
seed dries, it hardens into a
shape suitable for storage, and
the nutrient reserve hardens
too. Later, when the seed is
moistened, the nutrient turns
back into a liquid gel that nour-
ishes the roots and stem until it
sprouts leaves that can feed the
plant. This process is easily ob-
served in sweet corn, which is
soft when fresh, but the corn
hardens as it dries out. As fresh
corn dries, its sugar turns into
starch. But when moistened,
this starch turns back into
sugar. The seed needs water to
undergo this chemical change.

Seeds Awakening from the Dormant Phase
When the conditions mentioned above prevail simultaneously,
certain chemical processes take place within the seed. As mentioned
above, before germination the seed is in a dormant state. The embryo
remains dormant by the action of certain plant hormones, the most im-
portant of which is abscisic acid. The seed coat is dense and tough
enough to prevent gas penetration and to restrict the activities of the
embryo, which is another reason why it remains dormant. But when
the seed gets water, its coat swells. Enzymes in the cells of the embryo
are activated, producing a new hormone called gibberellin that coun-
teracts the abscisic acid maintaining the dormant state. Once the effect
of this acid is neutralized, the digestive enzyme alpha-amylase comes
into play, breaking down the starch stored in the endosperm, making it
available to the young plant as sugar and thus creating the energy nec-
essary for cell division. 53