A quantitative investigation of symplasmic transport in Chara corallina. I. Ultrastructure of the nodal complex cell walls

Abstract

We present a quantitative ultrastructural study of the size and frequency (density distribution) of plasmodesmata in the cell wall in common between the internodal cell and peripheral cell (and central cell) of Chara corallina. In the wall in common between the central cell and internodal cell the relative area occupied by plasmodesmata is 15.3%; the pore diameter (less the plasmalemma) is 118 nm; the length is 1.54 μm, and the frequency is 1.4 × 10⁹ pores/cm². In the wall in common between the peripheral cell and internodal cell the relative area occupied by the plasmodesmata is 9.6%; the pore diameter is 100 nm; the length is 1.07 μm; and the frequency is 1.2 × 10⁹ pores/cm². The plasmodesmata have an anastomosing structure like Nitella translucens but the pore diameter and frequency are much greater.