Effects of phenolic compounds on root respiration and root activity of Cerasus sachalinensis Kom.

The application of p-hydroxybenzoic acid and coumarin to seedlings of Cerasus sachalinensis changed the root respiration rate and root activity. These processes were enhanced at low concentration but decreased at high concentrations. The mixture of p-hydroxybenzoic acid and coumarin had additive effects on the root activity. The p-hydroxybenzoic acid and the mixture changed not only the biochemical respiratory pathways, but also the electron transport pathways of C. sachalinensis seedlings. They changed the glycolysis-tricarboxylic acid cycle (EMP-TCA) into pentose phosphate pathway (PPP) and cytochrome pathway (CP) into alternative pathway (AP). However, coumarin alone did not change the direction of respiratory pathways.