Ejection mechanics and trajectory of the ascospores of Gibberella zeae (anamorph Fuarium graminearum).


Journal Article

Since wind speed drops to zero at a surface, forced ejection should facilitate spore dispersal. But for tiny spores, with low mass relative to surface area, high ejection speed yields only a short range trajectory, so pernicious is their drag. Thus, achieving high speeds requires prodigious accelerations. In the ascomycete Gibberella zeae, we determined the launch speed and kinetic energy of ascospores shot from perithecia, and the source and magnitude of the pressure driving the launch. We asked whether the pressure inside the ascus suffices to account for launch speed and energy. Launch speed was 34.5 ms-1, requiring a pressure of 1.54 MPa and an acceleration of 870,000 g--the highest acceleration reported in a biological system. This analysis allows us to discount the major sugar component of the epiplasmic fluid, mannitol, as having a key role in driving discharge, and supports the role of potassium ion flux in the mechanism.

Full Text

Cited Authors

  • Trail, F; Gaffoor, I; Vogel, S

Published Date

  • June 2005

Published In

Volume / Issue

  • 42 / 6

Start / End Page

  • 528 - 533

PubMed ID

  • 15878295

Pubmed Central ID

  • 15878295

Electronic International Standard Serial Number (EISSN)

  • 1096-0937

International Standard Serial Number (ISSN)

  • 1087-1845

Digital Object Identifier (DOI)

  • 10.1016/j.fgb.2005.03.008


  • eng