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Fungal communities in ephemeral wetland habitats of the Pacific Northwest (PNW) are poorly understood. Because Camassia (camas) populations are a distinctive component of native plant communities in wetland areas of the PNW, camas plant tissue, seed, and associated soil samples were taken from populations growing in wetland habitats in Oregon, Idaho, and Washington. Enumeration of fungal taxa from above- and below-ground camas tissues was accomplished using high-throughput sequencing of fungal internal transcribed spacer genes. Operational taxonomic units (OTUs) affiliated with at least 200 fungal families were found in root, tunic, leaf, rhizosphere, and proximal soil samples (n = 2,984 OTUs). Significant variation in fungal community composition was explained by sample type, habitat of origin, and their interaction. Taxa related to Cladophialophora, Cadophora, and Exophiala, believed to be dark septate endophytes, together with Penicillium, Ceratobasidium, and Ilyonectria were differentially abundant in roots compared with the rhizospheres. Seed-associated communities comprised just 127 OTUs but were highly diverse with at least 50 families detected. Comparison of communities from camas seeds, leaves, roots, and rhizospheres revealed 68 fungal taxa in common, including Alternaria, Fusarium, Selenophoma, Cladosporium, Cryptococcus, and Sporobolomyces. This study provides a baseline understanding into the composition and diversity of fungal communities associated with camas growing in wetland habitats in the PNW.

Therapeutic approaches to fight Alzheimer's disease include anti-Amyloidβ (Aβ) antibodies and secretase inhibitors. However, the blood-brain barrier (BBB) limits the brain exposure of biologics and the chemical space for small molecules to be BBB permeable. The Brain Shuttle (BS) technology is capable of shuttling large molecules into the brain. This allows for new types of therapeutic modalities engineered for optimal efficacy on the molecular target in the brain independent of brain penetrating properties. To this end, we designed BACE1 peptide inhibitors with varying lipid modifications with single-digit picomolar cellular potency. Secondly, we generated active-exosite peptides with structurally confirmed dual binding mode and improved potency. When fused to the BS via sortase coupling, these BACE1 inhibitors significantly reduced brain Aβ levels in mice after intravenous administration. In plasma, both BS and non-BS BACE1 inhibitor peptides induced a significant time- and dose-dependent decrease of Aβ. Our results demonstrate that the BS is essential for BACE1 peptide inhibitors to be efficacious in the brain and active-exosite design of BACE1 peptide inhibitors together with lipid modification may be of therapeutic relevance.

Cultural practices, such as tillage, often have widespread impacts on phytobiomes. No-till has been increasingly adopted by wheat growers in the dryland cropping areas of the inland Pacific Northwest in the United States to reduce soil erosion and decrease fuel and labor inputs, yet there are limited data on how conversion to no-till impacts plant-associated bacteria in this highly productive system. To address this knowledge gap, we evaluated bacterial communities in bulk and rhizosphere soil of wheat in two locations (Idaho and Washington) for 2 years, comparing long-term no-till plots and adjacent plots under conventional tillage. In this study, members of phylum Proteobacteria were relatively more abundant in rhizosphere soil, while Acidobacteria and Gemmatimonadetes were more abundant in bulk soil than in the rhizosphere. Bacteroidetes were more frequent under conventional than conservation tillage. In general, bacterial families were more affected by the position of the sample (rhizosphere versus bulk soil) than by tillage practices. Families generally regarded as copiotrophic (Oxalobacteriaceae, Pseudomonadaceae, and Cytophagaceae) were more abundant in rhizosphere soil than bulk in both years. On the contrary, oligotrophic families such as Gaiellaceae and those within Gemmatimonadetes were more abundant in bulk soil than in the rhizosphere. Families affected by tillage varied between the 2 years. These results suggest that bacterial communities in soil were more influenced by plant proximity (rhizosphere versus bulk soil) than by tillage practices, but that specific differences were not consistent and may vary among locations and years.

In the dryland Pacific Northwest wheat cropping systems, no-till is becoming more prevalent as a way to reduce soil erosion and fuel inputs. Tillage can have a profound effect on microbial communities and soilborne fungal pathogens, such as Rhizoctonia. We compared the fungal communities in long-term no-till (NT) plots adjacent to conventionally tilled (CT) plots, over three years at two locations in Washington state and one location in Idaho, US. We used pyrosequencing of the fungal ITS gene and identified 422 OTUs after rarefication. Fungal richness was higher in NT compared to CT, in two of the locations. Humicola nigrescens, Cryptococcus terreus, Cadophora spp. Hydnodontaceae spp., and Exophiala spp. were more abundant in NT, while species of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum were more abundant in CT in most locations. Other abundant groups that did not show any trends were Fusarium, Mortierella, Penicillium, Aspergillus, and Macroventuria. Plant pathogens such as Rhizoctonia (Ceratobasidiaceae) were not abundant enough to see tillage differences, but Microdochium bolleyi, a weak root pathogen, was more abundant in NT. Our results suggest that NT fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. CT fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia. But a larger proportion of the fungal community is not affected by tillage and may be niche generalists.