Root cap

• 

  Longitudinal section of the roots :
  2 statocytes with statoliths ,
  4 dead cells

• 

  Root tip :
  2 root hoods

The root cap , also called calyptra or kalyptra (Greek: cover ), is a cap made of short-lived cells in seed plants , which protects the basal root apical meristem in the root apex. The penetration of the root tip into the soil is also facilitated by the strong formation of slime in the outer cells of the root cap.

education

The root cap, which sits above the meristem tissue, is formed in the roots of the grass plants by a separate section of the meristem, the calyptrogen . In most eudicotyledons, on the other hand, the root cap is formed by anticlinic division from the same cell area that also forms the protoderm (dermatocalyptrogen).

The cells of the root cap, which can be defined as permanent tissue, are relatively short-lived and dissolve after a few days. Therefore, the respective meristem layers permanently form new canopy cells, which quickly pass through the differentiation phase and are then fully functional.

function

The cells of the root cap have two tasks: On the one hand, the structure protects the basal root apical meristem in the root tip located under the root cap from injuries or external influences. On the other hand, the outermost and therefore oldest root cap cells show massive pectin excretions (Mucigel). These lead to a heavy build-up of mucus on the cell walls. The outer layer of the root canopy, which contains so much mucus, makes it easier for the root tip to penetrate the soil.

In addition, there are statocytes in the tip of the root , in which heavy particles ( statoliths ) fall due to gravity and thus the direction of growth to the center of the earth can be determined.

literature

• Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Strasburger - textbook of botany. Founded by E. Strasburger. Spektrum Akademischer Verlag, Heidelberg 2008 (36th edition) ISBN 978-3827414557
• Wolfram Braune, Alfred Leman, Hans Taubert: Plant anatomical practical course I. For an introduction to the anatomy of seed plants. Spectrum Akademischer Verlag, Heidelberg 2007 (9th edition) ISBN 3-8274-1742-2

Individual evidence

1. ^ Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Strasburger - textbook of botany. P. 129
2. ↑ Rudolf Schuber, Günther Wagner : Botanical Dictionary. 11th edition Ulmer Verlag, Stuttgart 1993, ISBN 3-8252-1476-1 , p. 270
3. ^ Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Strasburger - textbook of botany. P. 502