Structure of plant cell nucleus viewed by scanning electron microscopy

The three-dimensional structure of the nucleus ta meristematic and differentiated phloem ray parenchyma cells of shortleaf pine ( Pinus echinata Mili.) is viewed by scanning electron microscopy. The fixed and dehydrated plant tissues were freeze-fractured in absolute ethanol and dried by the critical point method. Some of the features observed in the fractured nuclei are aggregates of chromatin some of which possess a spiral orientation, the attachment of chromatin to the nuclear envelope, and small canals in the fractured envelope probably representing nuclear pores.