ENDOMEMBRANES AND POLLEN WALL PATTERN FORMATION IN VIGNA VEXILLATA L.

During the initiation of pollen exine wall formation in Vigna, localized accumulations of membranes in the microspore cortex coincide with sites which during further development reflect the lumina of me reticulate exine, and with apertural sites. Multi-membrane bodies are prominent in the cytoplasm, especially subtending aperture sites. Multi-membrane structures continue to be present as pollen wall development proceeds, notably during the early patterning stages. Labelling with the endomembrane-specific fluorochrome DiOC6 does not conclusively lead to membrane identification. However, electron micrographs illustrate elaborate membrane systems during stages when the most obvious developmental activity is initiation of the microspore wall. This suggests that there may be a causal relationship between endomembranes and exine pattern formation.