Abstract
It is shown that callose synthesis in the Oenothera biennis pollen tube is regulated by the endogenous Ca2+ level. Calcium antagonists reduced the amount of callose in the wall above the tip of the pollen tube (Verapamil - calcium channels blocker) and at the tube tip after stopping tube growth (La3+ - a Ca2+ substitute). Ruthenium red and ionophore A 23187, which raise the Ca 21 level in the cytoplasm, induced callose synthesis at the tip of pollen tube.
Keywords
pollen tube; callose synthesis; calcium channel blocker; ionophore A 23187; ruthenium red; Oenothera biennis