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Accumulation of Phytoferritin and Starch Granules in Developing Nodules of Soybean Roots Infected with Heterodera glycines. M. P. Ko, Graduate assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616; Pi-yu Huang(2), Jeng-sheng Huang(3), and K. R. Barker(4). (2)(3)(4)Research cooperator, associate professor, and professor, respectively, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616. Phytopathology 75:159-164. Accepted for publication 20 August 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/Phyto-75-159.

Structural changes in developing soybean (Glycine max) nodules as affected by race 1 of the soybean cyst nematode, Heterodera glycines, were investigated by light and electron microscopy. Emerging nodules from cyst-nematode-infected roots were poorly organized, with less distinct zones of nodular tissues and early appearance of vascular elements and sclerenchyma layers. However, the most conspicuous features in the infected plants were the massive accumulation of starch granules and crystalline arrays of phytoferritin in the plastids of cells in the nodular central tissues. Although small starch granules occasionally occurred in similar tissues of control plants, phytoferritin was not observed. Starch and phytoferritin are, respectively, energy and iron reserves. Their accumulation in nodules of nematode-infected soybeans suggests that the metabolism of carbohydrates and iron-containing compounds is affected by the presence of the cyst nematode.

Additional keywords: nitrogen fixation, nodulation, Rhizobium japonicum.