Programmed cell death in the nucellus of Tillandsia (Bromeliaceae)

We report the ultrastructural aspects and histochemical assay regarding the degenerating nucellar cells of Tillandsia during early female gametophyte development. Nucellar cells degeneration was observed to start during the somatogenesis of the gametophyte. Ultrastructural features of degenerating process and TUNEL assay indicated that the nucellar cells death mechanism is genetically controlled. Mitochondria and cytoplasmic vesicles persisted until cell degeneration was completed. This feature represens a peculiar aspect of the PCD mechanism in this specific case.