Effect of p-fluorophenylalanine and amino acid derivatives on variation of somatic chromosome number in grape root tip cells.

Abstract

To analyze the pattern of variations in chromosome number of root tip cells of grape seedlings induced by p-fluorophenylalanine (PFP), the effectiveness of treatment with phenylalanine derivatives and amino acid analogs during germination period was investigated. The frequency of cells showing variations in the chromosome number was significantly correlated with the frequency of occurrence of abnormal mitosis, but not with seed germination, seedling growth nor mitotic activity in the root tips. Compounds closely related to phenylalanines, such as those obtained by substitution on the phenyl ring, the replacement of the phenyl ring by a thienyl ring, or the methylation on the side chain, were effective, though less than PFP. A comparison of the stereoisomers of PFP showed that L-PFP induced a reduction of the chromosome number, unlike the D-enantoimer. N-acetyl-PFP, which was a modification of the amino group of PFP, did not induce chromosome variation. Among eight analogs of other amino acids, only m-fluorotyrosine and 5-fluorotryptophan induced variation in the chromosome number to the same extent as PFP.