Connections between polar growth and cell cycle arrest during the induction of the virulence program in the phytopathogenic fungus Ustilago maydis.

Elegant work by others has highlighted the importance of connections between polar growth and cell cycle regulation in budding and fission yeast. However, it is striking that little attention has been paid to the study of these connections in phytopathogenic fungi. In these crop pests, germination of spores, the main infective agent, requires a strict control of cell cycle regulation as well as polarity growth. Our finding that a cyclin-cdk pair controls both processes in the corn smut fungus Ustilago maydis supports the importance of such a regulation during the pathogenic development of fungi.