Continuity of Plastids and Formation of Patterns

Abstract

Plastids form by the division of preexisting plastids (section A. II.). In this chapter our knowledge of the multiplication of plastids is briefly summarized (section F. II.). The requirements for the continuity of plastids throughout the cell line are discussed with regard to the allocation of plastids to daughter cells and the minimum numbers required to prevent the formation of apoplastidic cells (section F. III. 1. and 2.). The puzzling implications of the occurrence of regular monoplastidy in some plants that are otherwise polyplastidic are discussed (section F. III. 3.). In monoplastidic cells continuity is ensured by a regular allotment of one daughter chloroplast to each daughter cell, whereas in polyplastidic cells of the same plant continuity may be achieved in a more random way.