Additions to Lindgomyces (Lindgomycetaceae, Pleosporales, Dothideomycetes), including two new species occurring on submerged wood from North Carolina, USA, with notes on secondary metabolite profiles

Abstract

Two new species of freshwater ascomycetes belonging to the genus Lindgomyces (Pleosporales, Dothideomycetes) are described and illustrated from submerged wood in North Carolina, USA. Lindgomyces carolinensis is characterized by immersed to erumpent ascomata, fissitunicate broadly cylindrical to clavate asci, and fusiform ascospores with acute ends surrounded by a large, fusiform gelatinous sheath. Lindgomyces cigarospora morphologically differs from L. carolinensis in that its ascospores are fusiform to cylindrical with rounded ends, without a large fusiform gelatinous sheath. These two new species nest in the family Lindgomycetaceae based on analyses of combined SSU and LSU rDNA sequence data. Phylogenetic analyses using ITS sequence data support the establishment of the new taxa as separate species within Lindgomyces. In addition to the new species, we report new ITS sequence data for L. cinctosporus and L. griseosporus from France, and L. ingoldianus from North Carolina, USA. We report a video exhibiting fissitunicate ascus dehiscence in L. carolinensis showing ascospore discharge and unraveling of the gelatinous sheath in real time. Chemical analysis of the organic extracts of L. carolinensis and L. cigarospora resulted in two known cyclodepsipeptides, Sch 378161 and Sch 217048. The in situ spatial mapping of these secondary metabolites on fungal cultures indicates the presence of both compounds on the surface of mycelia, as well as being exuded into the surrounding agar.

Freshwater Dothideomycetes

“…Other collections were reported from freshwater habitats in China (Cai et al 2006b; this study) and Thailand (Zhang et al 2012a; this study). The phylogenetic position of Clohesyomyces was confirmed in Lindgomycetaceae (Zhang et al 2012a;Raja et al 2017) and this study (Fig. 2).…”

New Dothideomycetes from Freshwater Habitats in Spain

“…The sexual stages of the freshwater ascomycetes have undergone a series of morphological adaptations to survive in aquatic environments. Many of them produce ascospores with appendages and/or mucilaginous sheaths, which facilitate their attachment to substrates into the water [47][48][49]. In this study, the sexual stage of H. polypusiformis, found on plant debris submerged in freshwater, produces ascospores with a mucilaginous sheath, a feature also found in other genera living in similar environments, such as Murispora and Lolia [48,50].…”

Droplet probe: coupling chromatography to the in situ evaluation of the chemistry of nature

“…This general approach has been used several times, where it has been interesting to see where fungal secondary metabolites are concentrated. 81,82 Based on additional literature, 83–86 we suspect that guttates may be a common place for such compounds to be localized.…”