Each kernel of corn holds the potential to develop into a new plant, producing its own seeds in turn. The growth of a corn plant from seed not only provides fascinating insight into the plant kingdom, it also helps farmers and gardeners better understand how to manage their crops, as pointed out on the North Dakota State University Extension's website.
Botanists discuss several important anatomical structures when talking about seed germination. Seeds possess three major structures that help their growth. The seed coat protects the embryo inside of the seed. The embryo consists of a single cotyledon, or primitive leaf, in corn plants. Endosperm occupies the rest of the seed, providing energy to the developing embryo.
Germination begins when the corn seed absorbs a lot of water--30 percent of its weight, according to the North Dakota State University Extension. With water, respiration begins, converting food (stored in the endosperm) into energy that powers rapid growth of the plant inside the seed. Soon, the embryo is too large for the seed coat and bursts free.
When planting corn seeds in your garden, dig a shallow furrow and drop them in, one by one. Even if you don't pay attention to how they're oriented, the plants always grow with the leaves emerging upward and the roots extending downward. This phenomenon is called gravitropism. As demonstrated by Indiana University as part of the Plants in Motion project, even seeds planted upside-down will orient their leaves and roots in the correct direction.
The corn plant's tiny root, called the radicle, emerges first from the seed. The radicle anchors the seed into place. While the endosperm continues to provide energy for the developing seedling, the plant still lacks a source of water and minerals at this point, so the radicle begins absorbing water and minerals from the soil.
The shoot emerges next, pressing toward the surface of the soil. The tiny shoot contains the corn plant's first leaves, as well as fast-growing tissue that will allow the plant to grow quickly in the weeks to come. The growing point may remain below the soil surface for three to four weeks to protect itself from harsh weather conditions and insect damage.