Service-learning outreach to attract high school students to degrees and careers in agricultural sciences.

Given projected deficits and a lack of diversity, there is a critical need to recruit and develop the next generation of the agricultural workforce. The objectives of our study were to evaluate if AgCamp, a one day workshop focused on agriculture delivered through a college student-led service-learning platform: (1) increased high school students' knowledge of agriculture, (2) changed their interests in pursuing degrees and careers in agriculture, and (3) increased their comfort and confidence in communicating with others in agriculture. We hosted high school students at AgCamp and provided them with instruction in animal science, horticulture, and agricultural mechanics.

Challenges Faced by U.S. Veterinary Technicians in the Workplace During COVID-19.

During COVID-19, the demand for veterinary technicians increased due to increased animal care appointments booked, decreased worker productivity, pandemic-related staffing shortages, and adapted methods of care delivery. Research has been conducted to assess the effect of the COVID-19 pandemic on educators and human healthcare workers, but there is a lack of literature on veterinary technicians, the animal healthcare equivalent of nurses. The objective of our study was to evaluate how COVID-19 affected veterinary technicians.

TIR domains of plant immune receptors are NAD-cleaving enzymes that promote cell death.

Plant nucleotide-binding leucine-rich repeat (NLR) immune receptors activate cell death and confer disease resistance by unknown mechanisms. We demonstrate that plant Toll/interleukin-1 receptor (TIR) domains of NLRs are enzymes capable of degrading nicotinamide adenine dinucleotide in its oxidized form (NAD). Both cell death induction and NAD cleavage activity of plant TIR domains require known self-association interfaces and a putative catalytic glutamic acid that is conserved in both bacterial TIR NAD-cleaving enzymes (NADases) and the mammalian SARM1 (sterile alpha and TIR motif containing 1) NADase.

Selective formation of heteroaryl thioethers via a phosphonium ion coupling reaction.

Heteroaryl thioethers, comprised of pyridines and diazines, are an important class of compounds with relevance to medicinal chemistry. Metal-catalyzed cross-couplings and SAr are traditionally used to form C-S bonds in these systems but are limited by available halogenated precursors. An alternative approach is presented where pyridines and diazines are transformed into heterocyclic phosphonium salts and then C-S bonds are formed by adding thiolate nucleophiles.

A Unified Approach to Couple Aromatic Heteronucleophiles to Azines and Pharmaceuticals.

Coupling aromatic heteronucleophiles to arenes is a common way to assemble drug-like molecules. Many methods operate via nucleophiles intercepting organometallic intermediates, via Pd-, Cu-, and Ni-catalysis, that facilitate carbon-heteroatom bond formation and a variety of protocols. We present an alternative, unified strategy where phosphonium salts can replicate the behavior of organometallic intermediates.

Conserved RxLR Effectors From Oomycetes Hyaloperonospora arabidopsidis and Phytophthora sojae Suppress PAMP- and Effector-Triggered Immunity in Diverse Plants.

Effector proteins are exported to the interior of host cells by diverse plant pathogens. Many oomycete pathogens maintain large families of candidate effector genes, encoding proteins with a secretory leader followed by an RxLR motif. Although most of these genes are very divergent between oomycete species, several genes are conserved between Phytophthora species and Hyaloperonospora arabidopsidis, suggesting that they play important roles in pathogenicity.

Signaling from the plasma-membrane localized plant immune receptor RPM1 requires self-association of the full-length protein.

Plants evolved intracellular immune receptors that belong to the NOD-like receptor (NLR) family to recognize the presence of pathogen-derived effector proteins. NLRs possess an N-terminal Toll-like/IL-1 receptor (TIR) or a non-TIR domain [some of which contain coiled coils (CCs)], a central nucleotide-binding (NB-ARC) domain, and a C-terminal leucine-rich repeat (LRR). Activation of NLR proteins results in a rapid and high-amplitude immune response, eventually leading to host cell death at the infection site, the so-called hypersensitive response.

TIR-only protein RBA1 recognizes a pathogen effector to regulate cell death in .

Detection of pathogens by plants is mediated by intracellular nucleotide-binding site leucine-rich repeat (NLR) receptor proteins. NLR proteins are defined by their stereotypical multidomain structure: an N-terminal Toll-interleukin receptor (TIR) or coiled-coil (CC) domain, a central nucleotide-binding (NB) domain, and a C-terminal leucine-rich repeat (LRR). The plant innate immune system contains a limited NLR repertoire that functions to recognize all potential pathogens.

Second Generation Modifiers of Colistin Resistance Show Enhanced Activity and Lower Inherent Toxicity.

We recently reported a 2-aminoimidazole-based antibiotic adjuvant that reverses colistin resistance in two species of Gram-negative bacteria. Mechanistic studies in demonstrated that this compound downregulated the PmrAB two-component system and abolished a lipid A modification that is required for colistin resistance. We now report the synthesis and evaluation of two separate libraries of substituted 2-aminoimidazole analogues based on this parent compound.

Recent Progress in RXLR Effector Research.

Some of the most devastating oomycete pathogens deploy effector proteins, with the signature amino acid motif RXLR, that enter plant cells to promote virulence. Research on the function and evolution of RXLR effectors has been very active over the decade that has transpired since their discovery. Comparative genomics indicate that RXLR genes play a major role in virulence for Phytophthora and downy mildew species.

A PCR assay for the quantification of growth of the oomycete pathogen Hyaloperonospora arabidopsidis in Arabidopsis thaliana.

The accurate quantification of disease severity is important for the assessment of host-pathogen interactions in laboratory or field settings. The interaction between Arabidopsis thaliana and its naturally occurring downy mildew pathogen, Hyaloperonospora arabidopsidis (Hpa), is a widely used reference pathosystem for plant-oomycete interactions. Current methods for the assessment of disease severity in the Arabidopsis-Hpa interaction rely on measurements at the terminal stage of pathogen development; namely, visual counts of spore-producing structures or the quantification of spore production with a haemocytometer.

The exocyst subunit Exo70B1 is involved in the immune response of Arabidopsis thaliana to different pathogens and cell death.

Components of the vesicle trafficking machinery are central to the immune response in plants. The role of vesicle trafficking during pre-invasive penetration resistance has been well documented. However, emerging evidence also implicates vesicle trafficking in early immune signaling.

Crosstalk between the circadian clock and innate immunity in Arabidopsis.

The circadian clock integrates temporal information with environmental cues in regulating plant development and physiology. Recently, the circadian clock has been shown to affect plant responses to biotic cues. To further examine this role of the circadian clock, we tested disease resistance in mutants disrupted in CCA1 and LHY, which act synergistically to regulate clock activity.

The ubiquitin ligase PUB22 targets a subunit of the exocyst complex required for PAMP-triggered responses in Arabidopsis.

Plant pathogens are perceived by pattern recognition receptors, which are activated upon binding to pathogen-associated molecular patterns (PAMPs). Ubiquitination and vesicle trafficking have been linked to the regulation of immune signaling. However, little information exists about components of vesicle trafficking involved in immune signaling and the mechanisms that regulate them.

Homologous RXLR effectors from Hyaloperonospora arabidopsidis and Phytophthora sojae suppress immunity in distantly related plants.

Diverse pathogens secrete effector proteins into plant cells to manipulate host cellular processes. Oomycete pathogens contain large complements of predicted effector genes defined by an RXLR host cell entry motif. The genome of Hyaloperonospora arabidopsidis (Hpa, downy mildew of Arabidopsis) contains at least 134 candidate RXLR effector genes.

Propagation, storage, and assays with Hyaloperonospora arabidopsidis: A model oomycete pathogen of Arabidopsis.

The oomycete pathogen Hyaloperonospora arabidopsidis is a natural pathogen of Arabidopsis thaliana and a laboratory model for (1) understanding how Arabidopsis responds to pathogen attack; (2) comparative and functional genomics of oomycetes; and (3) the molecular basis and evolution of obligate biotrophy. Here, we describe procedures for propagation and long-term storage of H. arabidopsidis, which address complications arising from its biotrophic lifestyle that precludes growth on synthetic media.

Conserved C-terminal motifs required for avirulence and suppression of cell death by Phytophthora sojae effector Avr1b.

The sequenced genomes of oomycete plant pathogens contain large superfamilies of effector proteins containing the protein translocation motif RXLR-dEER. However, the contributions of these effectors to pathogenicity remain poorly understood. Here, we show that the Phytophthora sojae effector protein Avr1b can contribute positively to virulence and can suppress programmed cell death (PCD) triggered by the mouse BAX protein in yeast, soybean (Glycine max), and Nicotiana benthamiana cells.