Plectosphaerella cucumerina DS2psM2a2 v1.0
Transmission electron microscope (TEM) image showing hypha of Plectosphaerella cucuminera DS2psM2a2.  Dark (electron dense) clusters along the exterior of the cell wall are aggregates of Mn-oxide minerals produced by the fungus.
Transmission electron microscope (TEM) image showing hypha of Plectosphaerella cucuminera DS2psM2a2. Dark (electron dense) clusters along the exterior of the cell wall are aggregates of Mn-oxide minerals produced by the fungus.
Photo by Alice Dohnalkova (Environmental Molecular Sciences Laboratory).

Plectosphaerella (teleomorph) and Plectosporium (anamorph) species are a group of filamentous Ascomycete fungi that are cosmopolitan in distribution and are well-known known as plant pathogens.  Plectospherella cucumerina (synonyms include Monographella cucumerina and Venturia cucumerina) is the teleomorph of Plectosporium tabacinum, and this species has been implicated as the causal pathogen of Plectosporium Blight leading to large losses of cucurbits.   Addditionally, P. cucumerina is a nematophagous fungus that is being evaluated as a biological control agent against potato cyst nematodes (PCN) and other nematode species.  Currently, Plectosphaerella cucumerina isolate DS2psM2a2 is being investigated for its role in the remediation of metal polluted environments due to the oxidation of manganese (Mn) compounds.  Additionally, Mn(III) compounds,  Mn(III/IV) oxide minerals (highly reactive oxidants), and other reactive metabolites produced by P. cucumerina DS2psM2a2 promote carbon degradation as well as the biogeochemical cycling of other metals in the environment. Production of reactive metabolites and oxidants by P. cucumerina DS2psM2a2 is linked, in part, to secreted proteins, cell differentiation, nutrient composition, and species interactions, although the molecular mechanisms are not fully resolved. Genome sequencing in concert with transcriptome and secretome analysis of this and related Ascomycete fungi that promote lignocellulose degradation and Mn(II) oxidation will improve our understanding of the growth-specific production and total production potential of reactive metabolites and oxidants by P. cucumerina DS2psM2a2.  Ultimately, these results will improve model predictions of carbon degradation and CO2 emissions in a changing biogeochemical landscape as well as provide plausible approaches to increase carbon sequestration, metal bioremediation, and pathogen resistance.