Relationship between Auxins and Nucleic Acid Synthesis in Coleoptile Tissues

Abstract

THAT auxins may affect nucleic acid metabolism in plants has been suggested by a number of workers. Silberger and Skoog¹ had observed an increase in both the deoxyribonucleic acid and ribonucleic acid content of tobacco pith cells incubated with 0.01 to 10 mgm./l. of indole acetic acid. Growth continued in a manner somewhat similar to changes in the ribonucleic acid content for a few days even though the synthesis of nucleic acids had apparently stopped after four days of application of indole acetic acid. Holmes et al. ² have shown that in Vicia root, as the distance from the root tip increased the content of deoxyribonucleic acid per cell also increased. Attempts have been made to correlate root growth with nucleic acid metabolism in other plants as well^3–5. In maize roots it has been found that application of indole acetic acid resulted in a slowing down of growth accompanied by a decrease of both deoxyribonucleic acid and ribonucleic acid³. Some workers are inclined to believe that growth and synthesis of deoxyribonucleic acid in plants continues only in the presence of auxins^6–8. The present communication summarizes the results obtained in an investigation on the incorporation of compounds labelled with phosphorus-32 and carbon-14 into the coleoptile tissues as affected by indole acetic acid.