Infecting invasion

Powdery mildew infects a barley cell

Vibrant colours, bizarre shapes – What could this glowing green bubble be? What is the pink ball all about?

In fact, the photograph shows a barley leaf cell (Hordeum vulgare) infected by a pathogenic fungus, powdery mildew. Barley powdery mildew is characterised by a white, flaky fungal structure on the surface of the plant. A confocal laser microscope allows a glimpse into the inside of the cell. It shows the round nucleus of the infected barley cell in pink. The lighter pink strands visualise the cytosceleton, a type of plasma that surrounds all organelles in the cell. The fungus (unstained) invades the cell and is surrounded by a special plant membrane, highlighted in glowing green.