Quantitative cytochemistry of β-galactosidase in normal and enzyme deficient (gal) pollen of Brassica campestris: Application of the indigogenic method

Abstract

The available cytochemical methods for localization of β-galactosidase have been evaluated using pollen grains of Brassica campestris. β-Galactosidase-deficient pollen (gal), served as a control. Azo dye methods involving naphthyl substrates showed high and nonspecific background staining to the exine. The indigogenic method, employing 5-bromo-4-chloro-3-indoxyl β-d-galactoside (X-gal) as the enzyme substrate, gave specific opaque-blue final reaction pproduct, while mutant pollen grains remained colourless. Final reaction product formation was blocked by d-galactono-1,4-lactone, thus demonstrating the specificity of the enzyme reaction. Using microspectrophotometry, the absorbance of the fin..