Novel Use of Laser Scanning Confocal Microscopy to Image Dark Septate Endophytic Fungi in Cucurbita maxima

Abstract

This manuscript provides a novel technical report on the first use of laser scanning confocal microscopy to image dark septate endophytic fungi. This research was conducted using the model organism, Cucurbita maxima, which is known for its diversely shaped and enormously sized fruits. Dark septate endophytic fungi are a paraphyletic group of fungi that convergently evolved to express phenotypes with highly melanized hyphae, septae, and are obligate endophytes of thousands of plant species. These fungi are known to be in association with various mycorrhizas ranging from arbuscular, orchidaceous, and ectomycorrhiza, although the ecological role of dark septate endophytic fungi within their host is still unclear. Dark septate endophytic fungal research has been documented with bright field light microscopy due to their melanized hyphae, but until now, no researchers have imaged dark septate endophytic fungi with laser scanning confocal microscopy. This manuscript provides the first laser scanning confocal micrographs of dark septate endophytic fungi and the first laser scanning confocal micrographs of dark septate endophyte fungi in Cucurbita maxima to date.