Phycomyces belongs to a basal fungal lineage, considered simpler and ancestral, yet the large (to a microbiologist) spore-bearing structures, called sporangiophores, respond to light, gravity, wind, and even the proximity of an object. Image: Corrochano et al. Current Biology (2016), with permission.
Southern corn leaf blight fungus growing between leaf cells of the host plant. 
The fungus attacks the plant and encounters plant defenses, including an oxidative burst. The fungus responds to the oxidants by expressing genes for enzymes with antioxidant activities.
This response is programmed by transcription factors. By genetic engineering, we tagged one of these, called ChAP1, with the green fluorescent protein Gfp. Gfp-ChAP1 is visible in the nuclei of the fungi. The chloroplasts of the leaf cells are visible by their red fluorescence.
Trichoderma hyphae colonizing a tomato root. Imaged by confocal microscopy following staining with fluorescent-labelled wheat germ agglutinin (WGA) and counterstaining with propidium iodide. Image: Ariella Alperovitch-Lavy
