Biochemical Changes in Terminal Root Galls Caused by an Ectoparasitic Nematode, Longidorus africanus: Phenols, Carbohydrates and Cytokinins.

Biochemical changes occurred in roots of bur marigold and grapevine infected with Longidorus africanus. Phenols of infected root tips differed quantitatively from those of healthy root tips (optical density of 0.68 and 0.32, respectively). Column chromatography of the phenol extracts resulted in more fractions in the infected than in the healthy root extract. Of the enzymes involved in phenol metabolism, three were tested. No polyphenol oxidase activity was detected and no difference in catalase activity was found between healthy and infected roots. Peroxidase activity, however, was much higher in infected roots. The extra peroxidase was associated mainly with the cortical cells of the infected root tips.Galled roots contained twice the amount of simple sugars and inulin as did the healthy roots. A cytokinin-active fraction was found only in the noninfected roots.