IMMUNOLOCALIZATION OF NUCLEAR ANTIGENS AND ULTRASTRUCTURAL CYTOCHEMISTRY ON TAPETAL CELLS OF SCILLA-PERUVIANA AND CAPSICUM-ANNUUM

The nuclei of the secretory tapetum of Scilla peruviana L. and Capsicu m annuum L. are studied by light and transmission electron microscopy using cryoprocessed material. The NAMA-Ur method, specific for DNA, an ti-DNA and anti-histones immunogold labelling show the condensed chrom atin pattern and reveal the presence of chromatin fibres in the interc hromatin region. Different antigens of the nucleoplasmic snRNPs, invol ved in the splicing of the pre-mRNAs, are immunolocalized over the int erchromatin fibres. Nucleolar proteins related to different steps of r RNA processing are immunodetected on the nucleolar components. These a pproaches give new insights in the nuclear function of the tapetum dur ing pollen development.