Effects of Nitrogen Fertilization on Polyphenol Content and Oxidase Activities in Tobacco Seedlings¹

Abstract

The effects of three levels of N fertilization on polyphenol content and polyphenoloxidase and peroxidase activities in the juvenile plants of hurley and dark tobaccos, Nicotiana tabacum L. were studied in solution culture. Large amounts of polyphenols were accumulated in the leaf; smaller amounts accumulated in the root. Chlorogenic acid and two isomers were the predominant fractions of polyphenols in the leaf, but the isomer neochlorogenic acid was absent in the root. Roots contained high concentrations of scopolin and scopoletin. The latter was not detected in seedling leaves. The amount and kind of N fertilizer greatly influenced the accumulation of polyphenols. Polyphenols were lowest on medium N, whereas they accumulated in large concentrations on both high and low N solutions. As a result, quantitative difference between the high and low polyphenol strains became less significant. Plants grown in high nitrate N solution contained more polyphenols than those fed with high ammonium nutrition. Polyphenoloxidase and peroxidase activities were higher in root than in leaf extracts and in plants cultured under medium N rate than in either extreme N environment. However, in high ammonium N fertilization the activity of both oxidases increased in the leaf but polyphenoloxidase decreased in the root. The results suggest that a medium rate of N fertilization increases oxidase in roots, polyphenoloxidase in particular, accompanied by a decrease of soluble polyphenol content in leaves, and produces a maximal phenotypic contrast for leaf polyphenol concentration among tobacco strains.

Effects of Nitrogen Fertilization and Stalk Position on Polyphenols and Carbohydrates in the Air-Cured Leaf of Three Tobacco Genotypes

“…The development of low alkaloid (LA) Burley 21 (Legg et al 1970) (Andersen et al 1.970b) but decreased soluble polyphenols (Sheen and Calvert 1969 Brown pigment quantitation employed Chortyk's method (Chortyk et al 1966) (Reid and Lynch 1937 For personal use only. A stalk position X N rate interaction existed for cellulose content.…”

Correlation between Chlorophyll and Chlorogenic Acid Content in Tobacco Leaves

“…Polyphenol quantity was determined by paper chromatography and spectrophotometry according to the procedures previously described (23). PAL (25,27). The (31), with or without cycloheximide (0.5 mg/ml) or phenylpyruvate (0.5 mg/ml).…”

“…stages and curing processes (23). Chlorogenic acid (5-O-caffeoylquinic acid)2 is the predominant phenolic compound in tobacco leaf (25,26). Biosynthesis of chlorogenic acid takes place in the leaf (30) and begins with the deamination by PAL' of L-phenylalanine to cinnamic acid which subsequently undergoes hydroxylation and the formation of caffeoyl ester with quinic acid (2,9,16).…”

Polyphenol Accumulation in Chlorophyll Mutants of Tobacco under Two Cultural Practices

“…A comparison of dark and Burley tobaccos showed a positive correlation between polyphenol and chlorophyll quantities in leaf lamina (10). Burley, as a chlorophyll-deficient mutant, differs from dark tobaccos by two recessive factors, ybt and yht (5), and is low in polyphenol content (12). Polyphenol content in tobacco leaf is also influenced by nitrogen fertilization (13,14).…”