Bioenergy: Plant Cell Wall Degradation
In order to significantly improve plant cell wall degradation and the processing of plant biomass by fungi, we must first understand the principles of these pathways. We are using genetics, genomics and biochemical tools to address these questions, focusing on two related areas: the fungal enzyme secretion pathway and the plant biomass degradation pathway. We are using the filamentous fungus Neurospora crassa as a model cellulolytic fungus to address these questions, and subsequently we will extend these results to other cellulolytic fungi, such as Trichoderma reesei (soft-rot), Phanerochaete chrysogenum (white-rot), and Postia placenta (Brown-rot).
Programmed Cell Death
Self/nonself discrimination is a ubiquitous and essential function of both multicellular and microbial species. In filamentous fungi, nonself recognition is important during vegetative growth. Hyphal fusion between genetically dissimilar individuals results in rejection of heterokaryon formation and programmed cell death of the fusion compartment, an event analogous to nonself recognition following fusion in colonial marine invertebrates such as Hydractinia and Botryllus. Nonself recognition during heterokaryon formation in filamentous fungi is regulated by genetic loci, termed het (for heterokaryon incompatibility) loci. Heterokaryon incompatibility in filamentous fungi has been shown to reduce the risk of transmission of pathogenic elements, such as infectious virus-like dsRNAs. Among filamentous fungal species, Neurospora crassa is the best model to study nonself recognition via heterokaryon incompatibility.
For further details of our research interests in this area, click here.
Cell Fusion
The ability to form a hyphal network is a hallmark of filamentous fungi. In filamentous ascomycete species such as Neurospora crassa, an individual hypha (a multinucleate, multicellular filament with incomplete crosswalls) grows by hyphal tip extension and branching. Behind the growing colony margin, fusions between hyphae are continuously formed, yielding a network of interconnected hyphae, which make up the fungal individual. Although the capacity to form a network is ubiquitous in filamentous fungi, little is known about how they form and function. Our studies have revealed a complex and carefully regulated biological process. For further details of our research interests in this area, click here.
Quantitative Trait Loci Mapping
Compared to the model yeast Saccharomyces cerevisiae, filamentous fungi like Neurospora crassa are characterized by complex life cycles and intricate cellular structures. Underlying this complexity in N. crassa is a relatively large genome (40 Mb) encoding approximately 10,000 genes. Determining the function of genes is still a laborious and time-consuming process, especially for genes with no clearly identifiable, and characterized, homolog in another species. Also, as organism complexity increases so does the likelihood that many genes will control a phenotype of interest. These quantitative (or complex) traits are controlled by multiple loci and do not typically show inheritance patterns consistent with the simple rules of Mendelian genetics. Our goal is to develop tools to uncover the genes responsible for quantitative traits in N. crassa.
For further details of our research interests in this area, click here.