Table I.

Comparison of α- and β-expansins

Characteristicα-Expansinsβ-Expansins
No. of genes in Arabidopsis≥16≥1
No. of genes in rice≥4≥7
Activity in dicot wallsHigh-a Low-b
Activity in grass wallsLow-b High-b
  • F0-a Measured for α-expansins from cucumber, oat, maize, and rice.

  • F0-b Measured only with Zea m1.