The Histochemical Localization of Several Enzymes of Soybeans Infected with the Root-knot Nematode Meloidogyne...

The sites of activity of alkaline phosphatase, acid phosphatase, esterase, peroxidase, adenosine triphosphatase, and cytochrome oxidase were demonstrated histochemically in fresh sections of 'Lee' soybeans infected by the root-knot nematode Meloidogyne incognita acrita. Each of the six enzymes was more active at the sites of infection than in adjacent non-infected tissue. During the early stages of infection, an increase in enzyme activity was observed in several cells in the proximity of the lip region of the nematode. However, when definite syncytia were observed, increased enzyme activity was confined primarily within the limits of the syncytium. Increased activity paralleled syncytial development and nematode maturation.