Differential DNA Replication in Plants: A Critical Review

Abstract

Summary Differential DNA replication is a controversal item of plant physiology and cell biology. While some authors envisage such events as basic mechanisms of cell differentiation and morphogenesis, others consider them as pathological slips or even methodical errors. This critical review may help to realize the facts and questions, and to find out the advantage and disadvantage of the methods used at present. New evidence of differential DNA replication is reported, and some suggestions concernig methodical improvements are made. Although the occurrence of somatic DNA amplification and DNA underreplication is very likely, it cannot be proven unequivocally with the present-day techniques, and thus its physiological significance remains speculative. It is emphasized that more data should be gathered using improved methods, and that experimental systems should be elaborated which allow to analyze the possible causal relationship between differential DNA replication and cell differentiation and morphogenesis.