ULTRASTRUCTURE AND ANALYTICAL MICROSCOPY OF SILICON DEPOSITION IN THE INTER-CELLULAR SPACES OF THE ROOTS OF MOLINIA-CAERULEA (L) MOENCH

Silicon accumulation in mature roots of Molinia caerulea (L.) Moench. was investigated by transmission electron and Cora analytical microscopy. Deposits are located in the intercellular spaces (ICS) of the persistent cortical cells immediately external to the endodermis. The earliest deposits are in the form of spheres lining the cavities and are followed by further deposits which eventually fill the ICS. Evidence is presented that prior to and during the earliest silicon formations, many ICS revealed the presence of cell organelles. No silicon was detected in the inner tangential walls of the endodermis.The results are discussed in relation to previous studies of silicon deposits in the roots of Molinia and to possible pathways resulting in deposits associated with the ICS. © 1979, Annals of Botany Company.