Direct whole-mount imaging of fungal spores by energy-filtering transmission electron microscopy.
Whole-mount fungal spores were examined by energy-filtering transmission electron microscopy. Conidia of Penicillium species and Ustilaginoidea virens were suspended in distilled water and directly placed on a glow-discharged formvar-coated copper grid. Energy-filtered images were taken from 0 to 100eV loss regions. Due to their considerable inherent thickness, their globose morphology was evident. In zero-loss images, the fungal spores appeared to have higher contrast in general, showing darker periphery than unfiltered images. Most spores in zero-loss images exhibited almost homogeneous electron density across the spores. The contrast was partially inversed in low-loss images where more details of the outer cell wall ornamentations of spores could be discerned than zero-loss images. As obvious advantages of whole-mount spore imaging, it allows for ensuring two-dimensional images with higher spatial resolution than light microscopy and conventional scanning electron microscopy. If a higher resolution is needed to observe fungal surface structures such as fimbriae and rodlet layers, or discriminate an outer sheath enveloping spores, whole-mount spore imaging can be employed to unravel structural details.
Kim
Ki Woo
KW
National Instrumentation Center for Environmental Management, Seoul National University, Seoul 151-921, Republic of Korea. kiwoo@snu.ac.kr
D006999:Hypocreales / Q000302:isolation & purification / Q000502:physiology / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D046032:Microscopy, Energy-Filtering Transmission Electron / Q000379:methods*; D012275:Oryza / Q000382:microbiology; D010407:Penicillium / Q000302:isolation & purification / Q000502:physiology / Q000648:ultrastructure*; D010935:Plant Diseases / Q000382:microbiology; D029963:Quercus / Q000382:microbiology; D013172:Spores, Fungal / Q000648:ultrastructure*