The Physiology of Host–parasite Relations: Xvi. Fine Structure of the Nucleus in the Rust-Infected Mesophyll Cells of Wheat

The nuclei in rust-infected mesophyll cells of Little Club wheat were examined by electron microscopy. There was a marked increase in the electron density of the diffuse, interchromatin regions of the nuclei at a stage in rust development (8 days after inoculation) at which two- to three-fold increases in RNA are known to occur. In the late stages of rust development (20 to 23 days after inoculation) the interchromatin material disappeared and the dense chromatin disintegrated.