The Effects of Kinetin, Gibberellic Acid, and Light on Expansion and Cell Division in Leaf Disks of Dwarf Bean (Phaseolus vulgaris)

The effects of kinetin (Kn), gibberellic acid (G), and light(L) on cell expansion and division in disks from 6-day-old etiolatedprimary leaves of dwarf bean are described. Cell number wasdetermined by direct counting after disks were digested in apectinase/EDTA mixture to separate the cells. Kn increased leafexpansion wholly by increasing cell size. G also increased cellsize; it increased cell division in the dark but not in thelight. Light also increased cell size and cell division; iteliminated the effect of G on cell division but enhanced theeffect of G on cell expansion.