DNA ligase activity in deteriorated maize embryo axes during germination: a model relating defects in DNA metabolism in seeds to loss of germinability

Abstract

Abstract Chromosome integrity and DNA polymerase activity are negatively affected by improper storage of maize seeds. We have extended our studies on the effect of improper storage on DNA metabolism by analysing the effect of hot–dry and hot–humid conditions on DNA ligase activity. An assay to measure ligase activity was established by using linearized plasmid DNA as substrate and protein extracts from maize axes. Optimal conditions were established for the in vitro assay. Enzyme activity was importantly reduced under both storage conditions. Activity recovered 6–9 h after imbibition. A model for loss of viability and vigour due to damage of DNA metabolism is proposed.