%0 Journal Article
%T Friend or foe? Evolutionary history of glycoside hydrolase family 32 genes encoding for sucrolytic activity in fungi and its implications for plant-fungal symbioses
%A Jeri Parrent
%A Timothy Y James
%A Rimvydas Vasaitis
%A Andrew FS Taylor
%J BMC Evolutionary Biology
%D 2009
%I BioMed Central
%R 10.1186/1471-2148-9-148
%X We detected 9 lineages of GH32 genes in fungi, 4 of which we describe for the first time. GH32 gene number in fungal genomes ranged from 0¨C12. Ancestral state reconstruction of GH32 gene abundance showed a strong correlation with nutritional mode, and gene family expansion was observed in several clades of pathogenic filamentous Ascomycota species. GH32 gene number was negatively correlated with animal pathogenicity and positively correlated with plant biotrophy, with the notable exception of mycorrhizal taxa. Few mycorrhizal species were found to have GH32 genes as compared to other guilds of plant-associated fungi, such as pathogens, endophytes and lichen-forming fungi. GH32 genes were also more prevalent in the Ascomycota than in the Basidiomycota.We found a strong signature of both ecological strategy and phylogeny on GH32 gene number in fungi. These data suggest that plant biotrophic fungi exhibit a wide range of ability to access plant-synthesized sucrose. Endophytic fungi are more similar to plant pathogens in their possession of GH32 genes, whereas most genomes of mycorrhizal taxa lack GH32 genes. Reliance on plant GH32 enzyme activity for C acquisition in these symbionts supports earlier predictions of possible plant control over C allocation in the mycorrhizal symbiosis.All Fungi are heterotrophic organisms, and the majority of fungal species rely solely upon plant tissues to meet their carbon (C) demands. In addition to saprotrophic fungi that decompose dead plant organic matter to acquire C, many fungi are biotrophs, forming intimate associations with living plant tissues. Associations between plants and biotrophic fungi are ubiquitous in nature; most plants are colonized from leaf to root with multiple fungal species. The interactions between biotrophic fungi and their plant hosts range from mutually beneficial (e.g. mycorrhizal associations) to context-dependent beneficial interactions (such as some endophytic fungi), to unilaterally antagonistic, pote
%U http://www.biomedcentral.com/1471-2148/9/148