Connection between Abscisic acid- and Nitrate-induced Inhibition of Blue light-mediated Antheridiogenesis in the Fern Anemia phyllitidis L.Sw.

Abstract

Summary Under growth-retarding conditions as in blue light, ABA effects on antheridiogenesis in Anemia phyllitidis L.Sw. are different from those reported for white light (Schraudolf, 1987). Instead of continuous increases of critical cell numbers (ccn.s) at increasing ABA levels of 1 to 50µM, in blue light ABA at 5 or 10µM has either no effect on ccn.s or blocks antheridium differentiation, depending on the culture medium. Thus the sensitivity of gametophytes towards ABA is higher in blue than in white light. Addition of ABA at concentrations not inhibitory in water alone results in a severe blockage of antheridiogenesis in the presence of µM amounts of KNO 3 , suggesting a connection between ABA and NO 3 - . The bleaching herbicide Norflurazon completely abolishes the blockage of antheridiogenesis by both ABA and nitrate, indicating that both compounds require intact plastids for their inhibitory effects.