TRANSMISSION ELECTRON MICROSCOPY OF FUNGAL NEMATODE-TRAPPING DEVICES

Abstract

The nematode-trapping devices of Arthrobotrys dactyloides (constricting rings), Monacrosporium cionopagum (adhesive columnar processes and scalariform loops) and a Dactylella sp. (sticky knobs) were investigated by electron microscopy. The cells of the constricting rings prior to inflation contained normal cytoplasmic organelles and some unusual, oblong, electron-dense inclusions in the luminal side of the protoplast, and lomasomes associated with papillate cylindrical bodies in the peripheral side. Their luminal walls differed from their peripheral walls in structure and thickness. After inflation, the ring cells had thinner luminal walls, the electron-dense inclusions were absent, there were fewer lomasomes, the cells had larger vacuoles, some of which contained electron-dense fine granules, and Woronin bodies were plugging the septal pores. It is postulated that the cells of constricting rings are inflated by means of rapidly generated gases rather than by an inflow of fluids. The sticky knob, adhesive columnar process, and scalariform loop trapping devices exhibited numerous globose electron-dense bodies, especially in their peripheral protoplasts.