Ribonucleic Acid Synthesis in the Bud Essential Component of Floral Induction in Xanthium

It has been shown in earlier papers (8, 9) that photoperiodic induction of the cocklebur is inhibited by application to the plant of the pyrimidine, 5-fluorouracil (5-FU). It was further found that the inhibitor is most effective in this function if applied directly to the bud at the beginning of the otherwise inductive dark period. It has been further concluded that the inhibitor functions by adversely affecting processes which take place in the bud during the inductive dark period and which are essential to photoperiodic induction. In this paper we shall show that the process in the bud which is inhibited by 5-FU and which is related to inhibition of induction is the synthesis of ribonucleic acid (RNA).