Interspecific interactions between saprotrophic basidiomycetes : effect on volatile production and gene expression of mycelia

• Main Author: Eyre, Catherine
• Published: Cardiff University 2007
• Subjects: 572.8
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.584076

Saprotrophic basidiomycetes play key roles in decomposition and nutrient cycling within woodland ecosystems. Species compete for space and resources, resulting in interactions with a range of outcomes, ranging from deadlock to replacement. <italic>Trametes versicolor</italic> was chosen to study these interactions in more detail and at a molecular level. During interactions <italic> T. versicolor</italic> produced barrages of aerial mycelium at the interaction front, and hyphal growth was inhibited in the presence of an opponent prior to contact. Volatile sesquiterpenes and aromatic hydrocarbons were produced when <italic>T. versicolor</italic> interacted with <italic>Stereum gauspatum, </italic> which may have inhibitory effects and cause DNA and protein damage. Suppression subtractive hybridisation libraries were constructed for the interaction of <italic>T. versicolor</italic> vs <italic>S. gausapatum.</italic> This is one of the first studies to examine interspecific interactions of saprotrophic basidiomycetes from a molecular perspective. Expressed sequence tag analysis coupled with cDNA microarray technology was used to study the molecular basis of interactions of <italic>T. versicolor</italic> with <italic>S. gausapatum, Bjerkandera adusta</italic> and <italic>Hypholoma fasciculare,</italic> which are replaced, deadlock and replace <italic>T. versicolor,</italic> respectively. Analysis revealed up-regulation of peroxidases, catalase, chaperone proteins and fungal cell wall enzymes, common to interactions. These genes may be employed to deal with an oxidative environment and intracellular damage generated during interactions and responsible for changes in morphology. More genes were common to interactions in which <italic>T. versicolor</italic> deadlocked with, or replaced its competitor, than when it was replaced itself. Different mechanisms may be employed against different species resulting in the range of outcomes observed.