Some effects of 2,4-dichlorophenoxyacetic acid on soluble nucleotides & nucleic acid of soybean seedlings

Abstract

It was shown that treatment of 2.5 day-old etiolated soybean seedlings with 5 x 10-4 M 2,4-D resulted in a doubling of the RNA content within 48 hours. This increase in RNA occurred primarily in the mature regions of the hypocotyl where considerable cell division was being initiated. The protein/RNA ratio was markedly decreased by 2,4-D at 48 hours after treatment, but tended to drop back toward normality during the next 2 days, primarily due to a decrease in RNA. The auxin treatment resulted in an increase in the concentration of soluble nucleotides. Marked changes in the concentration of adenine nucleotides and changes in the ratio of ADP/ATP were suggestive of the nature of auxin-induced changes in the respiration rate of treated tissues. Ascorbic acid was found to accumulate in treated seedlings.