Changes in levels of peroxidases and phenolics during root formation in Vitis cultured in vitro

Root formation in vine (Vitis vinifera L. cv. Albariño) was accompanied by at first a rise and then a fall in total peroxidase (EC 1.11.1.7) activity in the explant. These variations ran parallel to similar changes in the amount of the three cathodic isope‐roxidases detected, the most abundant of which, C2, also exhibited IAA oxidase activity. The anodic isoperoxidase bands detected were very weak and underwent no variation during rooting. Changes in the opposite direction (a fall followed by a rise) were shown by certain endogenous phenolics, including monoferuloyl, monocaffeoyl and mono‐ρ‐coumaroyl tartaric acids, some of which may act as auxin protectors.