PROSTELAR AUTOLYSIS: A FURTHER EXAMPLE OF A PROGRAMMED SENESCENCE.

A pattern of degeneration, which terminates in total autolysis of the cells concerned, is described for certain stelar cells (termed prostelar cells) in young regions of the root in cress. The early senescence of these cells is characterized by extensive cytolysome formation, while final autolysis follows tonoplast dissolution. Degenerated prostelar cells are soon replaced by differentiating cambial derivatives. It is suggested that the sequence of events which occurs during the degeneration of these cells is under genetic control and the possibility of genetic programmes controlling certain senescence processes in plants is considered. These observations are discussed in the light of generally held concepts of plant anatomy. [ABSTRACT FROM AUTHOR]