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

Sugar storage in corn stalks

8/24/2017

 
​Inner parts of a corn stalk are composed of vascular bundles and large living cells called parenchyma cells.  Movement of sugars produced by photosynthesis in leaf cells move to the phloem cells. Concentration of sugars causes water to move via osmosis into those phloem cells, putting pressure for movement of the soluble sugars through the small connections (plasmadesmata) between phloem cells.  Digestion and respiration in the growing points of the roots and eventually the newly pollinated ear ovules, with the assistance of cytokinins, directs the pressure towards the root through the stalk. 
 
Large pith cells adjacent to the phloem cells become storage locations for sugars as the plasmadesmata connect between the parenchyma cells.  These glucose and sucrose sugars accumulate in the stalk pith tissue. This storage reaches its peak shortly after pollination when the direction of flow switches to the newly formed kernel embryos. Sugars in stalk pith cells become a reserve that allows a constant movement to developing kernels, despite short-term reduction in photosynthesis because of cloudy weather or even the more long-term damage from leaf disease or insects.  Although some of the sugars are utilized in cellular metabolism of the pith cells, the excessive accumulation becomes essential to maintaining life in root tissues as well as warding off potential stalk pathogen invaders.
 
The 50 days of grain fill causes a drain on the sugars stored in the stalk parenchyma cells.  Genetics and environment affect the corn plants ability to produce sufficient photosynthates to meet the demand for sugars to flow to the ear. The genetic complexity of this is huge.  It must involve factors affecting photosynthetic rates, efficiency of movement of sugars, storage capacity of pith cells, size and structure of roots and size and number of kernel embryos.
 
Given the variable environments and multiple genetics for corn grain production we should not be surprised that no single corn hybrid is perfect every year in every field

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