Colletotrichum lindemuthianum exhibits different patterns of nuclear division at different stages in its vegetative life cycle

Abstract

Live-cell imaging with fluorescent protein labeling is providing major new insights into nuclear dynamics in filamentous fungi. With this approach we provide a detailed report of nuclear organization and behavior during mitosis in the bean pathogen Colletotrichum lindemuthianum. Nuclear division and nuclear migration were analyzed in ungerminated conidia, conidial germlings and the mature colony. Ungerminated conidia were uninucleate and completion of mitosis was found not to be essential for germ tube formation, conidial anastomosis tube (CAT) formation or fusion. Nuclei in fused conidial germlings exhibited asynchronous mitoses, and nuclear migration through fused CATs occurred after the nuclei had divided. Different patterns of nuclear division were found in vegetative hyphae of the mature colony. Synchronous, parasynchronous and asynchronous patterns of mitosis were observed in apical hyphal compartments at the colony border, while only synchronous and asynchronous mitoses occurred in subapical hyphal compartments. These findings have revealed unexpected diversity in the patterns of mitosis in different cells of C. lindemuthianum.

• cell fusion
• conidial anastomosis tube
• green fluorescent protein
• mitosis
• nuclear division
• nuclear migration

Acknowledgments

We thank Prof Lisete Chamma Davide for critical reading and suggestions, Michael Freitag for providing plasmid pMF357 and Eduardo Alves for providing the microscopy facilities for the widefield fluorescence imaging. This work was supported by a scholarship from CNPQ (Brazil) to FHI, CNPq and FAPEMIG grants (Brazil) and a BBSRC grant ( BB/E010741/1) to NDR.