Corn Journal
  • Corn Journal
  • Author
  • Stalk Rot Booklet
  • Seed Testing
  • Corn Genetics
  • Pathology
  • Sponsors
  • Contact
"You can see a lot by just looking"-Yogi Berra

Corn root expansion

6/6/2017

 
​At about the V3 stage of development, the primary root function begins to be replaced by the nodal, secondary roots.  Energy provided by photosynthesis in young leaves, and heat, drive the production of the metabolites for cell division and cell elongation in these young root tissues.  Whereas auxin hormone causes increased cell elongation in stem and leaf cells, auxin reduce this activity in the root cells.  Consequently, although the nodal roots initially emerge horizontally from the stem nodes beneath the soil surface, gravity causes more auxin to accumulate on the lower root epidermal cells.  This results in longer epidermal cells on the upper side than on the lower side, effectively turning the root growth downwards.
 
Root tip meristem cells rapidly divide, producing the root cap cells below to protect the dividing cells as it pushes through the soil and functioning root cells above the dividing cells.  Outer layer root cells composing the epidermis are thin-walled and porous to water via osmosis.  A short distance from the meristem of the root tip, epidermal cells form protrusions (root hairs), effectively expanding the surface area exposed to water and minerals of the soil.
 
Cells in the core of the new root differentiate to form vascular tissue that connects to the stem vascular tissue through the nodes.  This vascular tissue allows transport of water and minerals upwards through the xylem and carbs downwards through the phloem. A few cells in this vascular portion of the young root maintain cell division capability, becoming stimulated by another group of hormones (cytokinins) to increase cells laterally, pushing through the epidermal cell layer becoming lateral roots with their own root meristems.
 
As with all aspects of corn growth a combination of genetics and environment influences the growth of the root system.  Total volume of roots and depth of root growth tendencies will vary among genotypes. The fibrous nature of corn roots not only increase absorption from the soil but also provide support for the stalk as it elongates. 

Comments are closed.

    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.

    Archives

    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015

    Categories

    All

    RSS Feed

© COPYRIGHT 2023. ALL RIGHTS RESERVED
  • Corn Journal
  • Author
  • Stalk Rot Booklet
  • Seed Testing
  • Corn Genetics
  • Pathology
  • Sponsors
  • Contact