I. The Effects of Ionizing Radiation on Plants: Biochemical and Physiological Aspects

Abstract

The author discusses briefly what ionizing radiation is and what is thought to happen when radiation is absorbed by relatively simple systems. The primary effect appears to be the formation of free radicals and ions. The syntheses of DNA and auxin, both reactions which can be characterized chemically and are apparently sensitive to low doses of radiation, are discussed as examples of how plant metabolism is disturbed under the influence of radiation. The author reports experiments showing that radiation interferes with auxin synthesis, rather than accelerating its enzymatic or physical destruction, and that neither nuclear nor cellular replication is necessary for the manifestation of this effect. He concludes that auxin is required for DNA synthesis and that the primary target is the cytoplasmic molecular complex which is responsible for the synthesis of auxin.