Proteins of the pollen coat of Brassica oleracea

Summary In higher plants, proteins in the coat of the pollen grain are assumed to play an important role in the interaction between pollen and stigma upon pollination. A polyclonal antiserum was raised against a mixture of these proteins. The antiserum strongly reacted with proteins extracted from the pollen coat and from whole stamens, whereas there was only a faint cross-reactivity to proteins from other tissues. Western blot analysis and immunolocalisation of pollen before and after rinsing with cyclohexane, a treatment that selectively removes the coat layer, showed that the proteins were exclusively located in the pollen coat. The same proved to hold for pollen coat proteins from other Brassica species. The availability of an antiserum creates the opportunity to identify coat protein encoding sequences in a cDNA library of anthers.