Part of the glucose use in the corn leaf cell is respiration, providing energy for the many physiology processes in the cell. However, much of the glucose becomes integrated into building cell walls. Polysaccharides, such as cellulose, hemicellulose and pectin are major components, several other molecules that include proteins, phenols and acids join in forming the cell walls.
As a newly formed cell develops a thin, flexible layer forms outside of the plasma membrane of the cell. This first layer formed is nearly gelatinous, composed of carbohydrates, magnesium and calcium pectates. Next the cell forms a layer called the primary cell wall. This is composed of carbohydrates with pectin holding it together. The primary cell wall is flexible, allowing cell expansion. As the cell matures, expanding to its maximum, a thicker layer, called the secondary cell wall forms outside the primary wall. This has the effect of limiting the swelling of the cell as water is imbibed into the cell.
The middle lamella allows for gluing cells together, the primary wall allows some expansion of the cell and the secondary cell wall provides a stronger boundary, limiting cell expansion and offering resistance of invasion by potential pathogens and insects.
Cell walls in each part of the corn plant has its own specific arrangement of these cell walls. The Primary cell walls of the leaf epidermis cells produces a waxy outer layer limiting water absorption and further protection against invasion by pathogens. Cells of the xylem, that essentially form tubes for the transport of water from the roots to the upper plant parts have exceptionally thick secondary layers forming ridged tubes with little obstruction for the movement of water and solutes.
Cell walls have small holes that allow movement of molecules between cells. Regulation of movement into the individual cell is dependent on the living functions of the cellular membrane and often this requires a complex interaction with specific proteins within the cell.
There is a lot going on in these smallest structural components of a corn plant that ultimately contribute to the final product of our interest.
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.