CHARACTERIZATION OF AN ANTHER-SPECIFIC GLYCOPROTEIN IN LILIUM-LONGIFLORUM

Antiserum was raised in rabbits against a lily (Lilium longiflorum) anther-specific glycoprotein (LLA-75). LLA-75 protein bound to concanavalin A, suggesting that it was a glycoprotein. Monospecific anti-LLA-75 antibodies were prepared to investigate its distribution during anther development. Immunoblot analyses of total protein from floral and vegetative organs show that LLA-75 glycoproteins accumulated to detectable levels primarily in one discrete stage of anther development, during the microspore and early pollen phase when the tapetum is actively secreting. A cross-reactive protein with molecular mass of 43.0 kD was also observed. Immunoblots of two-dimensional polyacrylamide gels of lily anther proteins indicated that the four isoforms of LLA-75 glycoprotein ranged from isoelectric point 5.6 to 6.1. These affinity purified antibodies to LLA-75 cross-reacted with anther proteins in two dicot species of the Bignoniaceae. In situ localization data using antirabbit immunoglobulin G (IgG) conjugated with gold particles was not definitive but demonstrated that LLA-75 glycoprotein in lily anthers occurred prominently in tapetal tissue and all other tissues to a lesser degree.