Fourier transform infrared (FTIR) spectroscopy is used for non-invasive characterization of organic compounds including complex mixtures such as cytoplasm. Studies on rapidly frozen and dried fungal hyphae, using brilliant synchrotron IR sources, showed that fungal tips have lower content than subapical regions in the same cells, and that hyphal composition changes in response to environmental perturbation. Recently (in conjunction with other methods) we used an FTIR microscope with improved sensitivity, a globar IR source, and a 64 x 64 focal plane array (FPA) detector to document hyphal mannitol distribution. These studies were limited to ~ 6:m pixel size. Now, a unique synchrotron IR source called IRENI with 12 IR beamlines illuminating a single FPA detector permits diffraction-limited resolution. With IRENI, we can 1) collect data at 0.5:m x 0.5:m pixel definition, 2) characterize hyphal cytoplasm and exudate, 3) analyze hyphae as they grow in a moist chamber. Here, we compare wild type and single gene deletion strains of Aspergillus nidulans: A4 (used for the genome sequencing project), AAE1 (an nkuA strain with wild type hyphal morphology), and nkuA strains further deleted for ugmA or ugeA, key members of the galactofuranose biosynthesis pathway that have abnormal hyphal morphology and wall architecture. With this technology and these strains we are beginning to unpack the biochemical complexity of fungal tip growth.
Full conference title:
26th Fungal Genetics Conference
- Fungal Genetics Conference 26th (2005)