A Cytochemical Study of Differentiation and Breakdown of Vessel End Walls

Abstract

A cytochemical approach was used to study the architecture of the end wall and its modifications during vessel differentiation in Populus italica and Dianthus caryophyllus. The combination of cytochemical techniques with selective extractions to remove end wall subunits provides information on the different components of the end wall and on the method of perforation. The end wall appears to be formed mainly from pectins and hemicelluloses. No cellulosic components nor lignin were found though the 3, 3'-diaminobenzidine assay revealed the presence of peroxidases. That the method of perforation may depend on the species is discussed.