Small but powerful

Tomato yellow leaf curl China virus infects the plant Nicotiana benthamiana

Geminiviruses are serious pathogens for crops such as tomatoes and sugar beet. These include the tomato yellow leaf curl China virus, which can infect the wild tobacco plant Nicotiana benthamiana. Gemini viruses encode genetic information for six to eight proteins. To find out more about these proteins, they are analysed using genetic methods. The fluorescently labelled protein C4, which can be seen in the microphotograph, is the smallest of these proteins and, with its high adaptability, is essential for successful infection. We find it in the cell nucleus, in the cell membrane and in the chloroplasts. This diverse spread of the protein within the cell enables C4 to interact with other proteins in order to promote viral infection.