Sequential development of polyphenol oxidase (E.C. in resistant and susceptible tomatoes inoculated with the rooot-knot nematode, Meloidogyne incognita


  • S. Ganguly
  • D. R. Dasgupta


Although phenolics and their oxidation products are reported to be toxic to invading pathogens (Schall and Johnson, 1955), the role of polyphenol oxidase on the expression of disease symptoms caused by plant parasitic nematodes is ill-defined. A number of workers have demonstrated accumulation of phenolics after host-infection with plant parasitic nematodes (Epstein, 1972; Acedo and Rohde, 1971; Huang et al., 1971; Brueske and Dropkin, 1973). These observations suggested a need to examine the role of polyphenol oxidase in the plant response to nematode activity. It has been shown that the sequence of events initiated with nematode infestation are of importance in understanding the mechanism of plant response to the nematode (Ganguly and Dasgupta, 1979, 1979a; Mote and Dasgupta, 1979). The objective of this investigation was to examine some of the qualitative and quantitative changes in polyphenol oxidase activity with reference to the root-knot nematode, Meloidogyne incognita (Kofoid et White) Chitw. infesting resistant and susceptible tomato varieties.