Study of insertion of adenine into apurinic DNA catalyzed by extracts from radio- and thermoresistant plants

Abstract

Extracts from seedlings of a radioresistant plant, Raphanus sativus, possess DNA-adenine-transferase activity which stimulates the incorporation of 14C-adenine into apurinic DNA. This activity was not present in a radiosensitive plant, Vicia faba. Raphanus sativus seeds were shown to be much more thermoresistant than Vicia faba seeds at 80°C and particularly at 70°C, when a stimulatory effect of heat on the growth and development of radish roots and stems was manifested. It is assumed that DNA-adenine-transferase activity may be one of the factors responsible for radio- and thermoresistance of plants.