Expansins and cell growth

Curr Opin Plant Biol. 2003 Dec;6(6):603-10. doi: 10.1016/j.pbi.2003.09.003.


Expansins are now generally accepted to be key regulators of wall extension during growth. Several alternative roles for expansins have emerged in which the emphasis of their action is on wall breakdown or softening in processes such as fruit ripening, pollination, germination and abscission. Expansins are commonly encoded by substantial gene families and have classically been divided into two subfamilies, referred to as alpha- and beta-expansins. Two further subfamilies have now been identified: gamma-expansins, which were first described in Arabidopsis, and delta-expansins, which were identified in rice and are absent from Arabidopsis. Both are truncated versions of alpha- and beta-expansins, with gamma-expansins representing the amino-terminal half of a mature expansin and delta-expansins the carboxy-terminal half of a beta-expansin. Functional roles for gamma- and delta-expansins have yet to be defined, although recent data indicate a signalling role for gamma-expansins.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism
  • Cell Wall / genetics
  • Cell Wall / physiology
  • Molecular Sequence Data
  • Mutation
  • Oryza / genetics*
  • Oryza / growth & development
  • Oryza / metabolism
  • Phylogeny
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Signal Transduction / genetics
  • Signal Transduction / physiology


  • Plant Proteins
  • expansin protein, plant