Abstract
Calcium (45Ca2+) absorption by 1‐cm root tips of sorghum [Sorghum bicolor (L.) Moench. cv GP‐10] was measured in the presence of: (a) nifedipine (0, 0.001, 0.01, 0.1, or 1.0 μM), (b) verapamil (0, 0.01, 0.1, 1.0, and 10 mM), and (c) nifedipine (0.1 μM) plus verapamil (0,0.01,0.1,1.0, or 10 mM). Nifedipine (>0.1 μM) inhibition of 45Ca2+ absorption was 42–45%. Verapamil (>1 mM) inhibition of 45Ca2+ absorption was 35–50%. In the presence of 0.1 μM nifedipine, verapamil (>1 mM) inhibited 45Ca2+ absorption indicating some ion channels were nifedipine insensitive and verapamil sensitive.