Functional analyses of two syntaxin-like SNARE genes, GzSYN1 and GzSYN2, in the ascomycete Gibberella zeae

We identified two syntaxin-like SNARE genes, named GZSYN1 and GzSYN2, from the plant pathogenic ascomycete Gibberella zeae, and characterized the functions and cellular localization of these genes. The GzSYN1 deletion mutant (Delta gzsyn1) had 71% reduced hyphal growth compared to the wild-type strain, but produced perithecia with normal ascospores. Delta gzsyn2 had the same hyphal growth rate as the wildtype, but completely lost both self and female fertility. When Delta gzsyn2 was spermatized for Delta mat1-1 or Delta mat1-2 strains, it retained its male fertility, but the ascus shape was abnormal and ascospore delimitation was delayed. The Delta gzsyn1 and Delta gzsyn2 virulence on barley was reduced by 67% and 75%, respectively, compared to the wild-type. The GFP::GzSYN1 fusion protein was localized in vesicles, vacuoles, plasma membranes, and septa, whereas GFP::GzSYN2 was found only in plasma membranes and septa. These results suggest that syntaxins have key roles in fungal development and virulence in G. zeae. (C) 2010 Elsevier Inc. All rights reserved.