Characteristics of the major DNA polymerases found during early and late maize germination

Abstract

Two types of DNA synthesis have been detected during maize germination (0–24 h). To determine if the difference in these two types of synthesis was due to the presence of distinct DNA polymerases, we partially isolated and characterized the enzymes present at 3 (early) and 24 (late) h of germination. The material used was embryo axes. The result indicates that at both 3 and 24 h, enzymes are similar with regard to optimum pH and temperature, absolute requirement of Mg2+ (12 mM), and stimulation by KCl (50 mM). They are also equally inhibited by N-ethylmaleimide and cytosine-β-D-arabinofuranoside. These facts would classify the enzymes as alpha type; however, the enzymes differ in their sensitivity to aphidicolin and the degree of purification. The nature of the enzymes is discussed.