Created by Centers for Disease Control and Prevention’s (CDC) biomedical photographer, James Gathany, under a magnification of 100X, this photomicrograph depicted the histopathologic morphology associated with the agriculturally-related condition known as wheat rust, caused by the fungal organism, Puccinia rust fungus, or Puccinia graminis, as it invaded the cuticle of a wheat stalk.
Symptoms of wheat rust include the formation of “uredinia, or the fruiting bodies of a rust fungus, which generally appear as oval lesions on leaf sheaths, true stem, and spike. Uredinia can appear on the leaves if other diseases have not killed them. Uredinia are brick red in color and can be seen to rupture the host epidermis, on the leaves uredinia generally penetrate to sporulate on both surfaces. Infected areas are rough to the touch.”
For more on the subject of wheat rust, please see the United States Department of Agriculture (USDA) site, which is linked below.