Comparison of polyphenols and related enzymes in the capsule and nodal tumor of Nicotiana plants

Abstract

Extracts of capsules of Nicotiana tabacum cv. Burley 21 and nodal tumors and capsules of a genetically tumor-prone amphiploid N. suaveolens × N. langsdorffii had a similar composition of phenolic compounds. Dihydroxyphenols, predominantly chlorogenic acid, accumulated to 4% and 13% of the dry weight in the young and old tumors, respectively. In situ synthesis of chlorogenic acid in tumor tissues was demonstrated by incorporation of L-phenylalanine-U-14C. Quantities of polyphenols also increased as floral tissue developed from fertilized flower to capsule. The immature capsule and tumor tissues contained more polyphenoloxidase but less peroxidase than the leaf. Peroxidase zymograms, soluble proteins, and alkaloids in tumor extracts resembled those in capsule extracts. It is suggested that these biochemical similarities may reflect a common mode for the regulation of cell proliferation in tobacco capsules and nodal tumors.