Corn embryo’s being planted on May 1 are about ¼ inch (0.6 cm) in length. The future shoot portion of the embryo is half the size of the embryo. Two to three months later that shoot length has been multiplied by 800-1000. Within the embryo are cells with organelles such as mitochondria, plastids, ribosomes and other membranous structures needed to carry out this remarkable growth rate. Within the nuclei of these cells are the 10 pairs of chromosomes with the 30-40000 genes, coded by long strings of nucleic acids. Within a few hours of water imbibition, the few genes in the mitochondria are activated. Appropriate codes within their DNA produce RNA strings of nucleic acid, that are moved to ribosomes, producing proteins appropriate to enzymatically remove the energy binding the carbon and oxygen molecules in glucose and moving that energy into adenosine triphosphate (ATP). This energy is utilized in manufacturing the other structures for rapid cell elongation and cell duplication, pushing the seedling shoot to the soil surface.
With exposure to light, some cellular plastids with guidance from their own DNA and supplies from the other cell components, produce chlorophyll. This pigment allows absorption of light frequencies providing energy to drive the capture of carbon, oxygen and hydrogen molecules in the process of photosynthesis. Resulting glucose molecules are moved to the growing cells that utilize the new molecules in manufacture of structural complex molecules such as fatty acids and proteins used for cell metabolism and cell wall structures such as cellulose and lignin.
It is easy to be amazed when we seed the rapid growth of young corn plants and even more impressed to know that we are only seeing the result of remarkable interactions occurring at the cellular level.
About Corn Journal
The purpose of this blog is to share perspectives of the biology of corn, its seed and diseases in a mix of technical and not so technical terms with all who are interested in this major crop. With more technical references to any of the topics easily available on the web with a search of key words, the blog will rarely cite references but will attempt to be accurate. Comments are welcome but will be screened before publishing. Comments and questions directed to the author by emails are encouraged.