Sustainable biocatalytic synthesis of substituted muconic acids.

The development of sustainable routes to organic building blocks is a critical endeavor for reducing the environmental impact of chemical synthesis. Biocatalysts are poised to play an important role in sustainable synthesis, as they perform highly selective reactions under mild conditions. The application of enzymes to organic synthesis requires an approach which is operationally simple, inexpensive to prepare, and reasonably scalable. In this work, we demonstrated the utility of a Type I ring-cleaving dioxygenase CatA (P. putida KT2440) for preparative-scale synthesis of muconic acid derivatives. Muconic acids are important precursors in the synthesis of polymers and commodity chemicals. In this work, we optimized the performance of CatA under millimolar substrate concentrations and characterized the activity of the enzyme with an array of catechol substrates. Furthermore, we developed a scalable platform using cellular lysates to produce diverse muconic acids, generating up to a gram of the desired product. A simple trituration procedure was utilized for the purification of these muconic acids that obviated the need for chromatographic purification and reduced overall solvent waste.

Something to Chew on; Plate-Waste at an Ontario Veteran's Centre.

There is paucity of data assessing levels of food/beverage waste in long-term care (LTC) facilities, especially in Ontario. Observations in the Veteran's Centre (VC) at Sunnybrook Health Sciences Centre (Sunnybrook) indicated food/beverage waste may be high, potentially impacting sustainability efforts within our institution. Before proceeding with waste reduction efforts, we conducted a comprehensive 3-day waste-audit of food/beverage items provided to VC residents with the goal of understanding the extent of food/beverage waste at VC, items wasted, and any other factors that may inform future changes. Our results indicate that 28% of items served to residents were wasted. Lunch was the meal with greatest waste at 31% and waste of solid items was 12% higher than that of liquids. We observed a large variability in waste between residents and within each resident, with 15% of residents wasting >50% of items provided. This study provides a deeper insight into the magnitude of food/beverage waste in a LTC population and highlights the importance of considering individualized strategies to address waste to avoid negative impact on residents.

The use of biomarkers and HPV genotyping to improve diagnostic accuracy in women with a transformation zone type 3.

BACKGROUND: Twenty percent of women referred to colposcopy have a type 3 transformation zone-where colposcopic assessment for high-grade dysplasia (CIN2+) is not possible. This study examines the effectiveness of HPV biomarkers and genotyping in combination with techniques that sample an endocervical TZ. METHODS: A prospective diagnostic accuracy study. Women booked for large-loop excision (LLETZ) with squamous dyskaryosis, high-risk HPV and a TZ3 were recruited. Immediately prior to LLETZ samples were collected for p16/Ki-67 dual-stained cytology, HPV genotyping and H&E, p16- and Ki-67-stained endocervical curettings. RESULTS: In women with low-grade screening (n = 64), 35.9% had CIN2+; dual-stained cytology had the greatest effect on the PPV of routine screening (76.1% vs 35.9%) and perfectly predicted the absence of CIN2+. In women with a high-grade screening result (n = 37); 75.6% had CIN2+ and dual-stained curettings improved the PPV (96.5 vs 75.6%). CONCLUSIONS: With high-grade screening and a TZ3, LLETZ appears safest as three quarters have CIN2+ . Women with low-grade screening and a TZ3 have a twofold increased risk of CIN2+ when compared to women where the TZ is visible. The use of dual-stained cytology may help identify those women who can be safely offered surveillance and those who require treatment.

Secondary Organic Aerosol Mass Yields from NO3 Oxidation of α-Pinene and Δ-Carene: Effect of RO2 Radical Fate.

Dark chamber experiments were conducted to study the SOA formed from the oxidation of α-pinene and Δ-carene under different peroxy radical (RO2) fate regimes: RO2 + NO3, RO2 + RO2, and RO2 + HO2. SOA mass yields from α-pinene oxidation were <1 to ∼25% and strongly dependent on available OA mass up to ∼100 µg m-3. The strong yield dependence of α-pinene oxidation is driven by absorptive partitioning to OA and not by available surface area for condensation. Yields from Δ-carene + NO3 were consistently higher, ranging from ∼10-50% with some dependence on OA for <25 µg m-3. Explicit kinetic modeling including vapor wall losses was conducted to enable comparisons across VOC precursors and RO2 fate regimes and to determine atmospherically relevant yields. Furthermore, SOA yields were similar for each monoterpene across the nominal RO2 + NO3, RO2 + RO2, or RO2 + HO2 regimes; thus, the volatility basis sets (VBS) constructed were independent of the chemical regime. Elemental O/C ratios of ∼0.4-0.6 and nitrate/organic mass ratios of ∼0.15 were observed in the particle phase for both monoterpenes in all regimes, using aerosol mass spectrometer (AMS) measurements. An empirical relationship for estimating particle density using AMS-derived elemental ratios, previously reported in the literature for non-nitrate containing OA, was successfully adapted to organic nitrate-rich SOA. Observations from an NO3- chemical ionization mass spectrometer (NO3-CIMS) suggest that Δ-carene more readily forms low-volatility gas-phase highly oxygenated molecules (HOMs) than α-pinene, which primarily forms volatile and semivolatile species, when reacted with NO3, regardless of RO2 regime. The similar Δ-carene SOA yields across regimes, high O/C ratios, and presence of HOMs, suggest that unimolecular and multistep processes such as alkoxy radical isomerization and decomposition may play a role in the formation of SOA from Δ-carene + NO3. The scarcity of peroxide functional groups (on average, 14% of C10 groups carried a peroxide functional group in one test experiment in the RO2 + RO2 regime) appears to rule out a major role for autoxidation and organic peroxide (ROOH, ROOR) formation. The consistently substantially lower SOA yields observed for α-pinene + NO3 suggest such pathways are less available for this precursor. The marked and robust regime-independent difference in SOA yield from two different precursor monoterpenes suggests that in order to accurately model SOA production in forested regions the chemical mechanism must feature some distinction among different monoterpenes.

Hotels as Noncongregate Emergency Shelters: An Analysis of Investments in Hotels as Emergency Shelter in King County, Washington During the COVID-19 Pandemic.

This study analyzes the COVID-19 homelessness response in King County, Washington, in which people were moved out of high-density emergency shelters into hotel rooms. This intervention was part of a regional effort to de-intensify the shelter system and limit the transmission of the virus to protect vulnerable individuals experiencing homelessness. This study used quantitative and qualitative methods to describe the experiences of and outcomes on individuals who were moved from shelters to noncongregate hotel settings. The study highlights a new approach to shelter delivery that not only responded to the public health imperatives of COVID-19, but also indicated positive health and social outcomes compared to traditional congregate settings. The findings establish an evidence base to help inform future strategic responses to homelessness as well as to contribute to the broader policy conversations on our nation's response to homelessness.

Efficacy, Use, and Acceptability of a Web-Based Self-management Intervention Designed to Maximize Sexual Well-being in Men Living With Prostate Cancer: Single-Arm Experimental Study.

BACKGROUND: Sexual dysfunction is a frequent side effect associated with different prostate cancer treatment approaches. It can have a substantial impact on men and their partners and is associated with increased psychological morbidity. Despite this, sexual concerns are often not adequately addressed in routine practice. Evidence-based web-based interventions have the potential to provide ongoing information and sexual well-being support throughout all stages of care. OBJECTIVE: The aim of this study is to examine the efficacy of a web-based self-management intervention designed to maximize sexual well-being in men living with prostate cancer and explore user perspectives on usability and acceptability. METHODS: We used a single-arm study design, and participants were provided with access to the 5-step intervention for a period of 3 months. The intervention content was tailored based on responses to brief screening questions on treatment type, relationship status, and sexual orientation. Efficacy was assessed by using two-tailed, paired sample t tests for comparing the mean differences between pre- and postintervention measurements for exploring the participants' self-reported knowledge and understanding, sexual satisfaction, and comfort in discussing sexual issues. Usability and acceptability were determined based on the program use data and a postintervention survey for exploring perceived usefulness. RESULTS: A total of 109 participants were recruited for this study. Significant postintervention improvements at follow-up were observed in the total scores (out of 20) from the survey (mean 12.23/20 points, SD 2.46 vs mean 13.62/20, SD 2.31; t88=9.570; P=.001) as well as in individual item scores on the extent to which the participants agreed that they had sufficient information to manage the impact that prostate cancer had on their sex life (mean 2.31/4 points, SD 0.86 vs mean 2.57/4, SD 0.85; t88=3.660; P=.001) and had the potential to have a satisfying sex life following treatment (mean 2.38/4 points, SD 0.79 vs mean 3.17/4, SD 0.78; t88=7.643; P=.001). The median number of intervention sessions was 3 (range 1-11), and intervention sessions had a median duration of 22 minutes (range 8-77). Acceptable usability scores were reported, with the highest result observed for the question on the extent to which the intervention provided relevant information. CONCLUSIONS: This study provides evidence on the efficacy of a tailored web-based intervention for maximizing sexual well-being in men living with prostate cancer. The results indicate that the intervention may improve one's self-perceived knowledge and understanding of how to manage sexual issues and increase self-efficacy or the belief that a satisfactory sex life could be achieved following treatment. The findings will be used to refine the intervention content before testing as part of a larger longitudinal study for examining its effectiveness.

Transitioning to Homeownership: Asset Building for Low- and Moderate-Income Households.

This paper assesses the asset building of households that take part in shared-equity homeownership (SEH) models. The contribution of this paper is a comparison of outcomes for households participating in shared-equity programs to other low- and moderate-income households who rent or own properties without restrictions on appreciation. We matched participants in SEH programs to households with similar characteristics from the Panel Study of Income Dynamic (PSID) over the 1997-2017 period. The findings indicate that in real terms, median SEH homeowners accumulated about $1,700 in housing wealth annually or around $10,000 during their holding period. This amount is lower than the $2,100 median annual gain in home equity experienced by similar PSID owners but statistically and economically significantly larger than the $16 in annual gain experienced by similar PSID renters. The findings provide evidence that households participating in SEH programs experienced positive, but modest, wealth gains that were slightly lower than homeowners in unrestricted units but substantially higher than renters.

A peptide inhibitor of Tau-SH3 interactions ameliorates amyloid-ß toxicity.

The microtubule-associated protein Tau is strongly implicated in Alzheimer's disease (AD) and aggregates into neurofibrillary tangles in AD. Genetic reduction of Tau is protective in several animal models of AD and cell culture models of amyloid-ß (Aß) toxicity, making it an exciting therapeutic target for treating AD. A variety of evidence indicates that Tau's interactions with Fyn kinase and other SH3 domain-containing proteins, which bind to PxxP motifs in Tau's proline-rich domain, may contribute to AD deficits and Aß toxicity. Thus, we sought to determine if inhibiting Tau-SH3 interactions ameliorates Aß toxicity. We developed a peptide inhibitor of Tau-SH3 interactions and a proximity ligation assay (PLA)-based target engagement assay. Then, we used membrane trafficking and neurite degeneration assays to determine if inhibiting Tau-SH3 interactions ameliorated Aß oligomer (Aßo)-induced toxicity in primary hippocampal neurons from rats. We verified that Tau reduction ameliorated Aßo toxicity in neurons. Using PLA, we identified a peptide inhibitor that reduced Tau-SH3 interactions in HEK-293 cells and primary neurons. This peptide reduced Tau phosphorylation by Fyn without affecting Fyn's kinase activity state. In primary neurons, endogenous Tau-Fyn interaction was present primarily in neurites and was reduced by the peptide inhibitor, from which we inferred target engagement. Reducing Tau-SH3 interactions in neurons ameliorated Aßo toxicity by multiple outcome measures, namely Aßo-induced membrane trafficking abnormalities and neurite degeneration. Our results indicate that Tau-SH3 interactions are critical for Aßo toxicity and that inhibiting them is a promising therapeutic target for AD.

Parental Perceptions, Risks, and Incidence of Pediatric Unintentional Injuries.

INTRODUCTION: More than 9,000 children die annually from various causes of unintentional injury. Of all the pediatric unintentional injuries occurring in the United States, 8.7 million are treated in emergency departments, and 225,000 require hospitalization annually. Health education programs are available to address these injuries. The objective of this research was to examine the distribution of self-reported high priority injury risks in an urban Midwestern pediatric level 1 trauma center and investigate the relationship between parental perceptions and injury-prevention behaviors. Prevalence rates for 3 data sources are compared. METHODS: Missouri Information for Community Assessment (MICA) was categorized to mirror variables corresponding with risks of injury presented in the Safe 'n' Sound (SNS) program. Level 1 trauma center data were examined to determine how the variables were distributed compared with MICA data and with the parent-reported levels. RESULTS: A total of 429 SNS surveys were compared with ED data and MICA data. For SNS users, car crashes were identified as the highest risk, specifically due to the use of incorrect car seats. The injuries seen most often in the emergency department were falls, and falls were also the most prevalent injury captured by MICA. Controlling for demographics, parental perceptions predicted several risks for injury. DISCUSSION: Because parental perceptions are significantly related to risks of injury, prevention programs aiming to decrease injuries could focus on the perceptions. Not only can perceptions be used to tailor health communication materials, these perceptions can be the targets of change. Further work might investigate the extent to which changes in perceptions result in increased adoption of safety practices.

Gas-Phase Carboxylic Acids in a University Classroom: Abundance, Variability, and Sources.

Gas-phase carboxylic acids are ubiquitous in ambient air, yet their indoor occurrence and abundance are poorly characterized. To fill this gap, we measured gas-phase carboxylic acids in real-time inside and outside of a university classroom using a high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) equipped with an acetate ion source. A wide variety of carboxylic acids were identified indoors and outdoors, including monoacids, diacids, hydroxy acids, carbonyl acids, and aromatic acids. An empirical parametrization was derived to estimate the sensitivity (ion counts per ppt of the analytes) of the HRToF-CIMS to the acids. The campaign-average concentration of carboxylic acids measured outdoors was 1.0 ppb, with the peak concentration occurring in daytime. The average indoor concentration of carboxylic acids was 6.8 ppb, of which 87% was contributed by formic and lactic acid. While carboxylic acids measured outdoors displayed a single daytime peak, those measured indoors displayed a daytime and a nighttime peak. Besides indoor sources such as off-gassing of building materials, evidence for acid production from indoor chemical reactions with ozone was found. In addition, some carboxylic acids measured indoors correlated to CO2 in daytime, suggesting that human occupants may contribute to their abundance either through direct emissions or surface reactions.

Impact of Thermal Decomposition on Thermal Desorption Instruments: Advantage of Thermogram Analysis for Quantifying Volatility Distributions of Organic Species.

We present results from a high-resolution chemical ionization time-of-flight mass spectrometer (HRToF-CIMS), operated with two different thermal desorption inlets, designed to characterize the gas and aerosol composition. Data from two field campaigns at forested sites are shown. Particle volatility distributions are estimated using three different methods: thermograms, elemental formulas, and measured partitioning. Thermogram-based results are consistent with those from an aerosol mass spectrometer (AMS) with a thermal denuder, implying that thermal desorption is reproducible across very different experimental setups. Estimated volatilities from the detected elemental formulas are much higher than from thermograms since many of the detected species are thermal decomposition products rather than actual SOA molecules. We show that up to 65% of citric acid decomposes substantially in the FIGAERO-CIMS, with ∼20% of its mass detected as gas-phase CO2, CO, and H2O. Once thermal decomposition effects on the detected formulas are taken into account, formula-derived volatilities can be reconciled with the thermogram method. The volatility distribution estimated from partitioning measurements is very narrow, likely due to signal-to-noise limits in the measurements. Our findings indicate that many commonly used thermal desorption methods might lead to inaccurate results when estimating volatilities from observed ion formulas found in SOA. The volatility distributions from the thermogram method are likely the closest to the real distributions.

Characteristics of patients making serious inhaler errors with a dry powder inhaler and association with asthma-related events in a primary care setting.

OBJECTIVE: Correct inhaler technique is central to effective delivery of asthma therapy. The study aim was to identify factors associated with serious inhaler technique errors and their prevalence among primary care patients with asthma using the Diskus dry powder inhaler (DPI). METHODS: This was a historical, multinational, cross-sectional study (2011-2013) using the iHARP database, an international initiative that includes patient- and healthcare provider-reported questionnaires from eight countries. Patients with asthma were observed for serious inhaler errors by trained healthcare providers as predefined by the iHARP steering committee. Multivariable logistic regression, stepwise reduced, was used to identify clinical characteristics and asthma-related outcomes associated with ≥1 serious errors. RESULTS: Of 3681 patients with asthma, 623 (17%) were using a Diskus (mean [SD] age, 51 [14]; 61% women). A total of 341 (55%) patients made ≥1 serious errors. The most common errors were the failure to exhale before inhalation, insufficient breath-hold at the end of inhalation, and inhalation that was not forceful from the start. Factors significantly associated with ≥1 serious errors included asthma-related hospitalization the previous year (odds ratio [OR] 2.07; 95% confidence interval [CI], 1.26-3.40); obesity (OR 1.75; 1.17-2.63); poor asthma control the previous 4 weeks (OR 1.57; 1.04-2.36); female sex (OR 1.51; 1.08-2.10); and no inhaler technique review during the previous year (OR 1.45; 1.04-2.02). CONCLUSIONS: Patients with evidence of poor asthma control should be targeted for a review of their inhaler technique even when using a device thought to have a low error rate.

Reconstruction of a conic-section surface from autocollimator-based deflectometric profilometry.

We present a description of our method to process a set of autocollimator-based deflectometer one-dimensional line scans taken over a large optical surface and reconstruct them to a best-fit conic-section surface. The challenge with our task is that each line scan is in a different (unknown) coordinate reference frame with respect to the other line scans in the set. This problem arises due to the limited angular measurement range of the autocollimator used in the deflectometer and the need to measure over a greater range. This results in the optic under measurement being rotated (in pitch and roll) between each scan to bring the autocollimator back into measurement range and therefore each scan is taken in a different coordinate frame. We describe an approach using a 6N+2 dimension optimization (where N is the number of scan lines taken across the mirror) that uses a gradient-based nonlinear least squares fitting combined with a multistart global-search strategy to find the best-fit surface. Careful formulation of the problem is required to reduce numerical noise and allow the routine to converge on a solution of the required accuracy.

Possible number systems.

Number systems-such as the natural numbers, integers, rationals, reals, or complex numbers-play a foundational role in mathematics, but these systems can present difficulties for students. In the studies reported here, we probed the boundaries of people's concept of a number system by asking them whether "number lines" of varying shapes qualify as possible number systems. In Experiment 1, participants rated each of a set of number lines as a possible number system, where the number lines differed in their structures (a single straight line, a step-shaped line, a double line, or two branching structures) and in their boundedness (unbounded, bounded below, bounded above, bounded above and below, or circular). Participants also rated each of a group of mathematical properties (e.g., associativity) for its importance to number systems. Relational properties, such as associativity, predicted whether participants believed that particular forms were number systems, as did the forms' ability to support arithmetic operations, such as addition. In Experiment 2, we asked participants to produce properties that were important for number systems. Relational, operation, and use-based properties from this set again predicted ratings of whether the number lines were possible number systems. In Experiment 3, we found similar results when the number lines indicated the positions of the individual numbers. The results suggest that people believe that number systems should be well-behaved with respect to basic arithmetic operations, and that they reject systems for which these operations produce ambiguous answers. People care much less about whether the systems have particular numbers (e.g., 0) or sets of numbers (e.g., the positives).

Iron-sulfur chemistry can explain the ultraviolet absorber in the clouds of Venus.

The clouds of Venus are believed to be composed of sulfuric acid (H2SO4) and minor constituents including iron-bearing compounds, and their respective concentrations vary with height in the thick Venusian atmosphere. This study experimentally investigates possible iron-bearing mineral phases that are stable under the unique conditions within Venusian clouds. Our results demonstrate that ferric iron can react with sulfuric acid to form two mineral phases: rhomboclase [(H5O2)Fe(SO4)2·3H2O] and acid ferric sulfate [(H3O)Fe(SO4)2]. A combination of these two mineral phases and dissolved Fe3+ in varying concentrations of sulfuric acid are shown to be good candidates for explaining the 200- to 300-nm and 300- to 500-nm features of the reported unknown UV absorber. We, therefore, hypothesize a rich and largely unexplored heterogeneous chemistry in the cloud droplets of Venus that has a large effect on the optical properties of the clouds and the behavior of trace gas species throughout Venus's atmosphere.

Continuous ultraviolet to blue-green astrocomb.

Cosmological and exoplanetary science using transformative telescopes like the ELT will demand precise calibration of astrophysical spectrographs in the blue-green, where stellar absorption lines are most abundant. Astrocombs-lasers providing a broadband sequence of regularly-spaced optical frequencies on a multi-GHz grid-promise an atomically-traceable calibration scale, but their realization in the blue-green is challenging for current infrared-laser-based technology. Here, we introduce a concept achieving a broad, continuous spectrum by combining second-harmonic generation and sum-frequency-mixing in an MgO:PPLN waveguide to generate 390-520 nm light from a 1 GHz Ti:sapphire frequency comb. Using a Fabry-Pérot filter, we extract a 30 GHz sub-comb spanning 392-472 nm, visualizing its thousands of modes on a high-resolution spectrograph. Experimental data and simulations demonstrate how the approach can bridge the spectral gap present in second-harmonic-only conversion. Requiring only [Formula: see text]100 pJ pulses, our concept establishes a new route to broadband UV-visible generation at GHz repetition rates.

Development of small-molecule Tau-SH3 interaction inhibitors that prevent amyloid-ß toxicity and network hyperexcitability.

Alzheimer's disease (AD) is the leading cause of dementia and lacks highly effective treatments. Tau-based therapies hold promise. Tau reduction prevents amyloid-ß-induced dysfunction in preclinical models of AD and also prevents amyloid-ß-independent dysfunction in diverse disease models, especially those with network hyperexcitability, suggesting that strategies exploiting the mechanisms underlying Tau reduction may extend beyond AD. Tau binds several SH3 domain-containing proteins implicated in AD via its central proline-rich domain. We previously used a peptide inhibitor to demonstrate that blocking Tau interactions with SH3 domain-containing proteins ameliorates amyloid-ß-induced dysfunction. Here, we identify a top hit from high-throughput screening for small molecules that inhibit Tau-FynSH3 interactions and describe its optimization with medicinal chemistry. The resulting lead compound is a potent cell-permeable Tau-SH3 interaction inhibitor that binds Tau and prevents amyloid-ß-induced dysfunction, including network hyperexcitability. These data support the potential of using small molecule Tau-SH3 interaction inhibitors as a novel therapeutic approach to AD.

Impact of Fasting on Patients With Cancer: An Integrative Review.

Background: Patients with cancer often pursue nutrition as an avenue to positively impact their care management and disease outcomes. Nutritional interventions are increasing in popularity, especially intermittent fasting as an adjunct to chemotherapy. However, limited research is available on the impact of intermittent fasting on patients with cancer. Methods: A comprehensive literature search was conducted using Ovid MEDLINE, Ovid EMBASE, and CINAHL databases. Results: 514 articles were identified from the three databases. Seven studies remained after applying inclusion and exclusion criteria. The seven studies included in this review examined fasting compliance, malnutrition, therapy side effects, endocrine parameters, quality of life measures, and cancer outcomes. Data suggest overall good compliance, no malnutrition, minimal side effects, a trend toward improved endocrine parameters, unchanged quality of life (QOL), and mixed results for cancer outcomes. Conclusion: Intermittent fasting as an adjunct to chemotherapy in normal-weight patients with cancer has potential as a safe, tolerable, and feasible nutritional intervention that could positively impact treatment outcomes and QOL. Large-scale randomized controlled trials are needed to validate these findings and determine what future role intermittent fasting may play in cancer management.

Rapid and precise genotyping of transgene zygosity in mice using an allele-specific method.

Precise determination of transgene zygosity is essential for use of transgenic mice in research. Because integration loci of transgenes are usually unknown due to their random insertion, assessment of transgene zygosity remains a challenge. Current zygosity genotyping methods (progeny testing, qPCR, and NGS-computational biology analysis) are time consuming, prone to error or technically challenging. Here, we developed a novel method to determine transgene zygosity requiring no knowledge of transgene insertion loci. This method applies allele-specific restriction enzyme digestion of PCR products (RE/PCR) to rapidly and reliably quantify transgene zygosity. We demonstrate the applicability of this method to three transgenic strains of mice (Atm TgC3001L, Nes-Cre, and Syn1-Cre) harboring a unique restriction enzyme site on either the transgene or its homologous sequence in the mouse genome. This method is as accurate as the gold standard of progeny testing but requires 2 d instead of a month or more. It is also exceedingly more accurate than the most commonly used approach of qPCR quantification. Our novel method represents a significant technical advance in determining transgene zygosities in mice.

Uncovering genetic and metabolite markers associated with resistance against anthracnose fruit rot in northern highbush blueberry.

Anthracnose fruit rot (AFR), caused by the fungal pathogen Colletotrichum fioriniae, is among the most destructive and widespread fruit disease of blueberry, impacting both yield and overall fruit quality. Blueberry cultivars have highly variable resistance against AFR. To date, this pathogen is largely controlled by applying various fungicides; thus, a more cost-effective and environmentally conscious solution for AFR is needed. Here we report three quantitative trait loci associated with AFR resistance in northern highbush blueberry (Vaccinium corymbosum). Candidate genes within these genomic regions are associated with the biosynthesis of flavonoids (e.g. anthocyanins) and resistance against pathogens. Furthermore, we examined gene expression changes in fruits following inoculation with Colletotrichum in a resistant cultivar, which revealed an enrichment of significantly differentially expressed genes associated with certain specialized metabolic pathways (e.g. flavonol biosynthesis) and pathogen resistance. Using non-targeted metabolite profiling, we identified a flavonol glycoside with properties consistent with a quercetin rhamnoside as a compound exhibiting significant abundance differences among the most resistant and susceptible individuals from the genetic mapping population. Further analysis revealed that this compound exhibits significant abundance differences among the most resistant and susceptible individuals when analyzed as two groups. However, individuals within each group displayed considerable overlapping variation in this compound, suggesting that its abundance may only be partially associated with resistance against C. fioriniae. These findings should serve as a powerful resource that will enable breeding programs to more easily develop new cultivars with superior resistance to AFR and as the basis of future research studies.