Small but thick enough--the Arabidopsis hypocotyl as a model to study secondary growth

Physiol Plant. 2014 Jun;151(2):164-71. doi: 10.1111/ppl.12118. Epub 2013 Nov 10.


The continuous production of vascular tissues through secondary growth results in radial thickening of plant organs and is pivotal for various aspects of plant growth and physiology, such as water transport capacity or resistance to mechanical stress. It is driven by the vascular cambium, which produces inward secondary xylem and outward secondary phloem. In the herbaceous plant Arabidopsis thaliana (Arabidopsis), secondary growth occurs in stems, in roots and in the hypocotyl. In the latter, radial growth is most prominent and not obscured by parallel ongoing elongation growth. Moreover, its progression is reminiscent of the secondary growth mode of tree trunks. Thus, the Arabidopsis hypocotyl is a very good model to study basic molecular mechanisms of secondary growth. Genetic approaches have succeeded in the identification of various factors, including peptides, receptors, transcription factors and hormones, which appear to participate in a complex network that controls radial growth. Many of these players are conserved between herbaceous and woody plants. In this review, we will focus on what is known about molecular mechanisms and regulators of vascular secondary growth in the Arabidopsis hypocotyl.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Biological Evolution
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant*
  • Hypocotyl / genetics
  • Hypocotyl / growth & development*
  • Hypocotyl / metabolism
  • Models, Biological
  • Plant Growth Regulators / metabolism
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plant Roots / metabolism
  • Plant Stems / genetics
  • Plant Stems / growth & development
  • Plant Stems / metabolism
  • Plant Vascular Bundle / genetics
  • Plant Vascular Bundle / growth & development
  • Plant Vascular Bundle / metabolism


  • Arabidopsis Proteins
  • Plant Growth Regulators