Tuberization response of single-node leaf cuttings from induced potato plants (Solanum tuberosum L.) was reversed when pretreated with 5 millimolar ethyleneglycol-bis-(β-aminoethyl ether)N,N′-tetraacetic acid (EGTA) + 50 micromolar calcium ionophore (A23187) and resumed when transferred to a CaCl(2)-containing medium. Tuberization was inhibited by LaCl(3), chlorpromazine, and trifluoperazine at 5 to 10 micromolar. These results suggest a role for calcium in the tuberization process
