THE DECAY OF X-RAY INDUCED FREE RADICALS IN PLANT SEEDS AND STARCH

Abstract

The fate of the x-ray induced free radicals in living seeds and amylopectin of different water contents has been studied by means of electron spin resonance absorption. The same amount of free radicals is primarily produced in the seeds independently of their water content. The radicals remain unchanged in the driest ssmples but an increasing proportion of them decays as the water content increases. The initial, relatively rapid decay which is apparently second order falls to a semiconstant level that decreases very slowly. The observed growth inhibitory effects at the different water contents are found to be proportional to these semiconstant levels. The radicals induced in amylopectin are very sensitive to oxygen. The reaction in air is first order with respect to the radical concentration; its velocity increases with the water content. (auth)