This is a preview. Log in through your library . Abstract The microscopic structure of sieve tube elements was studied in fresh hand sections from Cucurbita pepo, Glycine max and Solanum tuberosum.

The ultrastructural ontogeny of Commelina benghalensis minor-vein elements was followed. The mature minor vein has a restricted number of elements: a sheath of six to eight mestome cells encloses one ...

Figure 1: Model of protein/ribonucleoprotein transport through the microchannels of higher plant plasmodesmata. Figure 2: The plant vascular network and the development of the phloem sieve-tube system ...