We have just been out planting seeds in our garden – big ones such as peas, beans, and squash, and little ones such as lettuce, basil, and radish. After preparing the soil, we made the thin little trenches and dropped the seeds in. The big ones remain visible till we cover them up. The little ones vanish the moment they leave our dirty fingers. Invisible. Dead and gone even before we pull a little fine soil over the trench. As I Corinthians 3:6,7 tell it, the planting and watering are no big deal really. It is God who makes it grow.
Seed Germination
Inside every viable seed, no matter how small, is a tiny dormant embryo, living but at a very slow pace, nestled snugly in among the starchy endosperm, its food source until the embryo can raise its head out of the ground. The embryo looks like a miniature plant with a root end and a shoot end. If you open a dried peanut carefully you can see the tiny embryo with its leaves all formed ready to go – except in dry, roasted, or salted peanuts the embryo is dead. OK, then, how does the seed germinate?
Seeds soak up water first. Since seeds are store quite dry, they can absorb several times their weight in water and will swell to at least double their size when dry. Once they have enough moisture, metabolism kicks into high gear, and they need to get nutrients and start growing. The starchy endorsperm all around them is in a good energy storage form but not much use for providing energy to the embryo. So the embryo sends out a chemical signal (at least this is what happen in cereal seeds) that triggers the production and release of a starch-digesting enzyme from the aleurone – a layer just under the seed coat. The enzyme goes to work on the starch, breaking it down into sugars that the embryo can use. Though the growth of an embryo does involve cell division, most of the increase in size comes from cell expansion resulting from water uptake. What a marvelous system God has created to provide food for the embryo just when it needs it.