VIEW ARTICLE

Cytology and Histology

Ultrastructure of Haustorium Development in Puccinia coronata f. sp. avenae: Cytochemistry and Energy Dispersive X-ray Analysis of the Haustorial Mother Cells. J. Chong, Agriculture Canada, Research Station, 195 Dafoe Road, Winnipeg, Manitoba, Canada R3T 2M9; D. E. Harder, Agriculture Canada, Research Station, 195 Dafoe Road, Winnipeg, Manitoba, Canada R3T 2M9. Phytopathology 72:1518-1526. Accepted for publication 5 May 1982. Copyright 1982 Department of Agriculture, Government of Canada.. DOI: 10.1094/Phyto-72-1518.

In young haustorial mother cells (HMCs) of Puccinia coronata f. sp. avenae all of the mitochondria were arranged around the periphery of the protoplast. With uranyl acetate and lead citrate staining, five HMC wall layers were resolved compared to two in the hyphal walls. With periodic acid-thiocarbohydrazide-silver proteinate staining, three layers were observed in the HMC walls, but only one layer in the hyphal walls. The HMC septa contained more layers than did septa in the mycelial hyphae. All mycelial walls and septa were shown to contain protein, lipid, and polysaccharide components. Energy dispersive X-ray (EDX) analysis revealed silicon deposits in the walls of many HMCs, including their septa, located at or near the centers of the infection colonies. Haustorial mother cells with heavy silicification were often collapsed, and were associated with aberrant haustoria. Phosphorus-rich iron and sulphur-containing deposits were commonly detected by EDX analysis in the protoplasts of HMCs and older haustoria.