Eukaryotic Cell doi:10.1128/EC.00248-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
The L-type calcium ion channel, Cch1, affects ascospore discharge and mycelial growth in the filamentous fungus Gibberella zeae (anamorph Fusarium graminearum)
Heather E. Hallen
and
Frances Trail*
Department of Plant Biology, and Department of Plant Pathology, Michigan State University, East Lansing, MI 48824-1312, USA
* To whom correspondence should be addressed. Email:
trail{at}msu.edu.
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Abstract |
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Cch1, a putative voltage-gated calcium ion channel, was investigated for its role in ascus development in Gibberella zeae. Gene replacement mutants of CCH1 were generated and found to have asci which did not forcibly discharge spores, although morphologically ascus and ascospore development in the majority of asci appeared normal. Additionally, mycelial growth was significantly slower and sexual development was slightly delayed in the mutant; mutant mycelia showed a distinctive fluffy morphology; and no cirrhi were produced. Wheat infected with
cch1 mutants developed symptoms comparable to wheat infected with the wild-type, however, the mutants showed a reduced ability to protect the infected stalk from colonization by saprobic fungi. Transcriptional analysis of gene expression in mutants using the Affymetrix Fusarium microarray showed 2449 genes with significant, two-fold or greater changes in transcript abundance across a developmental series. This work extends the role of CCH1 to forcible spore discharge in G. zeae, and suggests that this channel has subtle effects on growth and development.