Ultrastructual Study on the Pollen-Microbial Interactions

Abstract

The interactions between the pollen grains of Thalictrum flavum, and the microscopical fungi of Gliocladium roseum were investigated with a TEM instrument of high resolution (2-3 A). The results are the following: 1. The pollen coat and the outermost part of the fungal cell wall have the same electron density. 2. The endoplasmatic reticulum can be demonstrated in the highly magnified pictures of the fungal protoplasm. 3. On the basis of the new TEM data, it is possible that the bacterial action plays an important role in the investigated microbial-pollen interaction. 4. The pollen coat is easily digested by the enzymes of the microbial organisms. 5. The outermost surface of the tectum is also degradable enzymatically. 6. On high magnification the outermost part of the fungal cell wall, and the tectum is very similar. At this biopolymer level, in some cases it is not easy to distinguish them. 7. In consequence of the microbial-pollen interactions enzymatically exposed microchannels of 2-4 A in diameter were also discovered. Similar, but more characteristic system was observed on the fungal cell wall. This may play a role in the diffusion of the enzyme.