MICRO-VESICLES, PYRIFORM VESICLES AND MACRO-VESICLES ASSOCIATED WITH THE PLASMA-MEMBRANE IN THE ROOT HAIRS OF VICIA-HIRSUTA AFTER FREEZE-SUBSTITUTION

After freeze-substitution, micro-vesicles were found only in close proximity to the plasma membrane. Macro and pyriform vesicles were found throughout the cytosol, but also 'packaged' close to the plasma membrane, the package delineated by electron transparent outlines similar to the endoplasmic reticulum. These outlines appeared to be continuous with nearby endoplasmic reticulum and were always associated with Golgi bodies and microtubules. Micro-vesicles were found only in grazing sections of the plasma membrane made between the apical dome and the region of the nucleus, where the cell is the most cytoplasmic, and only in close proximity to the plasma membrane. Micro-vesicles were also found in close proximity to microtubules as well as other vesicle types. From the results it is suggested that pyriform and micro-vesicles may have specialised roles in root hair tip growth.