Table 1

Specific induction of leaflike structures on the apical meristem by expansin. Beads loaded with various agents in 50 mM sodium acetate buffer (pH 4.8) were manipulated onto the I2 position of meristems (5). After 5 or 14 days, the apices were analyzed with either a binocular microscope or confocal laser-scanning microscopy (6).

Agent5 days14 days
No. of apices analyzedAltered meristem surfaceIntact leaflike organsNo. of apices analyzedAltered meristem surfaceIntact leaflike organs
Expansin12237770119
Boiled expansin37103100
Buffer alone31002500
BSA* [2% (w/v)]47003100
Cellulase (50 μg/ml)400 02200
OGA§(0.1 mg/ml)32003800
  • * BSA, bovine serum albumin.

  • Cellulase was endocellulase I purified from Trichoderma viridi.

  • Several (18/40) cellulase-treated apices showed necrosis, but no bulges or organized structures, at the I2 position.

  • § OGA, oligogalacturonic acid (DP 12-30) purified from tomato (16).