Volatile organic compounds (VOCs) in wildfire smoke pose health concerns, yet limited information exists on their exposure levels and sources in postfire residential environments. We measured 24 VOCs indoors and outdoors at 50 homes across Los Angeles (LA) County from February 10 to April 1, 2025, within roughly two months following the 2025 LA wildfires. For most VOCs, indoor concentrations were up to 10 times higher than those at outdoor levels. Indoor benzene, perchloroethylene, and trichloroethylene exceeded U.S. EPA or California cancer risk screening levels in 52, 20, and 14% of homes, respectively, while outdoor benzene surpassed its screening level at 28% of sampling locations. Indoor-outdoor correlation and principal component analyses indicate that the observed indoor benzene could be primarily attributed to typical outdoor sources (e.g., vehicle emissions). Household products (particularly cleaning agents) and building material off-gassing were major sources of most other indoor VOCs. The analysis also suggests a possible association between indoor naphthalene and wildfire smoke infiltration, although this finding is limited by the low detection frequency of naphthalene and should be validated in future studies with larger sample sizes. These findings can inform the VOC exposure risk assessment and targeted interventions for communities affected by wildfires.

BACKGROUND: Emerging observational studies suggest that air pollution can influence the gut microbiome. However, this association is often highly confounded by factors, such as diet and poverty. The gut virome may influence respiratory health independent of the gut microbiome. We recently demonstrated in a randomized waitlist-controlled trial (ClinicalTrials.gov NCT03351504) that a clean lighting intervention reduced the level of personal exposure to air pollution among adult women in rural Uganda. OBJECTIVES: To determine the effect of a solar lighting intervention on changes to the gut microbiome and virome and secondarily to determine the association between these changes on lung health. METHODS: Between 2018 and 2019, we collected stool samples and assessed respiratory symptoms and spirometry from 80 adult women living in rural Uganda at baseline and 12 and 18 months postrandomization. The intervention group received a solar lighting system after randomization, while the waitlist-controlled group received one at 12 months. Deep metagenomics sequencing of stool was performed and profiled for nonviral and viral taxonomic composition. The primary analysis focused on pre- vs postintervention changes due to power considerations, adjusting for potential confounding by age, diet, antibiotic use, and season. A sensitivity analysis was conducted using intention-to-treat principles. When comparing pre- vs postintervention periods, we used sparse partial least-squares models to identify nonviral and viral signatures of reduced air pollution exposure. Mixed effects models were used to evaluate changes in health outcomes as well as associations between microbial signatures of reduced air pollution exposure and health. RESULTS: The average age was 39.2 years. The solar lighting intervention led to larger changes in viral compared to nonviral microbial community structure and differential abundance of bacteria, eukaryotes, and viruses. Provision of solar lighting systems was associated with a reduction in the presence of respiratory symptoms from 57.1% to 36.1% (p = 0.002), while there was no impact on lung function. Microbiome and virome signatures had AUCs of 0.74 and 0.76, respectively, in predicting pre- vs postintervention stool samples. Microbiome signatures were associated with a lower risk of respiratory symptoms (OR = 0.68 (0.49 - 0.94), p = 0.020). CONCLUSION: Among adult women living in rural Uganda, both nonviral and viral components of the gut microbial community changed after a clean lighting intervention. Microbiome signatures reflective of lower air pollution exposures were associated with improved respiratory symptoms. These observations suggest that air pollution may influence lung health through the gut-lung axis, warranting further exploration in future intervention studies.

Gibberellins (GAs) play a crucial role in modulating developmental processes throughout the plant life cycle. They are particularly significant during the transition and maintenance of the reproductive meristem, as well as in facilitating the development of floral organs. Additionally, GAs regulate the early stages of fruit development, in coordination with auxin and cytokinin, likely due to their involvement in both division and cell expansion. However, it remains unclear whether fluctuations in endogenous GA levels influence fruit development and metabolism during ripening. To address this, we investigated tomato mutant plants deficient in GAs biosynthesis (gib3, moderately deficient; gib2, intermediate deficiency and gib1, extremely deficient in GAs). Notably, gib2 and gib1 mutants were characterized by a complete interruption of their reproductive development at the floral bud level. Although gib3 plants displayed a slight delay in fruit development, at the end of fruit ripening both wild type (WT) and gib3 fruits were highly similar. Only minor differences were found between WT and gib3 mutant plants in terms of floral development and total fruit yield. Our findings revealed that reduced GA levels in gib3 mutant did not result in morphological modifications in fruits, and relatively few metabolic changes were observed between genotypes during fruit ripening. Typical metabolic changes during ripening, including increments in amino acids and soluble sugars along with decreases in starch, were observed. Collectively, our study demonstrate that GAs play a crucial role in transitioning plants from the vegetative to reproductive stage and in initiating fruit set. Tomato plants with reduced endogenous content of gibberellins show interruption or delay of the reproductive stage.

Rationale: Exposure to volatile organic compounds (VOC), a class of emerging indoor air pollutants gaseous at room temperature, is associated with respiratory morbidity in children with asthma. Specific sources of VOC may be challenging to identify, particularly due to their transient nature. We aimed to characterize the relationship between indoor environmental exposures and peak total VOC (TVOC) levels in homes of children with bronchopulmonary dysplasia (BPD), who are at risk of asthma development. Methods: Home environmental monitoring was conducted among a prospective cohort of children aged 6-12 with BPD in greater Boston, including an exposure questionnaire, home environmental assessment, daily activity diaries, and placement of a real-time multipollutant sensor assembly in the child's bedroom to measure hourly indoor temperature, humidity, fine particulate matter (PM2.5), nitrogen dioxide (NO2), and TVOC for one week. Home environmental exposures were grouped into 6 categories, by presence or absence: mold, combustion byproducts, secondhand smoke, household chemicals, pests, and inadequate ventilation. We defined TVOC peaks as 2-hour periods in which maximum TVOC levels in a participant's home were at least 2 standard deviations above that participant's mean TVOC level. We investigated associations between home exposure categories, maximum PM2.5 and NO2 concentrations, temperature, and humidity in the concurrent 2-hour period and the likelihood of a TVOC peak using generalized estimating equations, adjusting for season (warm vs. cold) and demographic characteristics. Results: Among 122 homes, median TVOC was 2917 µg/m3(IQR 1824-6854). The median number of peaks per weeklong home monitoring period was 4 (IQR 1-6). In unadjusted analyses, PM2.5 was associated with an increased likelihood of a concurrent TVOC peak (OR per 1 µg/m3 increase 1.001, 95% CI 1.000, 1.001), as was NO2 (OR per 1 ppb increase 1.004, 95% CI 1.000, 1.008), though these associations did not persist after covariate adjustment. No home exposure categories were linked to TVOC peaks. In adjusted analyses, TVOC peaks were associated with cold season (OR 1.84, 95% CI 1.30-2.61) and temperature (OR per °C increase 1.11, 1.04-1.18). Conclusions: In homes of children with BPD, we did not find any link between categories of home environmental exposures, indoor PM2.5, or indoor NO2 and peak TVOC levels. However, associations with higher indoor temperatures and cold season may suggest home heating as an important driver of TVOC. Mitigation efforts should be individually tailored to successfully reduce home TVOC levels. Figure: Representative plot of Two-Hour Maximum TVOC Peaks for one Participant's Home Monitoring Period

RATIONALE: Emerging observational studies suggest that air pollution can influence the gut microbiome however air pollution exposure is often highly confounded. Recent studies suggest that the gut virome affects respiratory health independently of the gut microbiome. We have demonstrated in a randomized controlled trial (ClinicalTrials.govNCT03351504) that a clean lighting intervention reduced personal exposure to fine particulate matter and black carbon among adult women in rural Uganda. METHODS: Stool samples were collected from 80 adult women living in rural Uganda at baseline, 12- and 18-months post-randomization. Participants randomized to the intervention group received a solar lighting system at baseline, while those randomized to the control group received a solar lighting system at 12 months. Deep metagenomics sequencing was performed and profiled for non-viral and viral taxonomic composition. The most prevalent non-viral microbial constituents belonged to bacteria, archaea, and eukaryotic kingdoms, while the identified viral microbial constituents all belonged to the class Caudoviricetes, double-stranded DNA tailed phages whose hosts are bacteria and archaea. Post-intervention, non-viral and viral signatures of reduced air pollution exposure comparing pre- vs. post- intervention samples were identified. In exploratory analyses, mediation models were used to assess whether microbiome or virome signatures are mediators of the relationship between the solar lighting intervention and improved respiratory symptoms. RESULTS: Provision of solar lighting systems reduced personal exposureto PM2.5 from an average of 82.5 μg/m3 to 49.2 μg/m3 (p = 0.010) andreduced black carbon exposure from 11.5 μg/m3 to 6.3 μg/m3 (p = 0.013) with a reduction in reported respiratory symptoms from 57.1% to 36.1% (p = 0.002). The solar lighting intervention led to greater changes in viral compared to non-viral microbial community structure as well as differential abundance of bacteria, eukaryote, and viral members. Microbial (Figure 1B) and viral (Figure 1A) signatures of reduced air pollution exposure were identified. Bacteriome but not virome signatures mediated 21.3% of the protective effect of the clean lighting intervention on improved respiratory symptoms. CONCLUSIONS: A clean lighting intervention altered both non-viral and viral gut microbial community members, reduced air pollution exposure, and improved respiratory symptoms. One mechanism by which air pollution reduction interventions may improve respiratory symptoms is through changes in gut microbiota. Future large randomized controlled trials of air pollution interventions should investigate the potential of the gut microbiome as a target for interventions to reduce the harmful effects of household air pollution on lung health.

Gibberellins (GAs) serve a multitude of functions in the regulation of processes associated with plant growth and development. The GA demand of an organ can be met through long-range transport from the site of synthesis. To examine the impact of altered GA biosynthesis on metabolism and growth, we performed reciprocal grafts of wild-type (WT; Solanum lycopersicum L.) and mutants exhibiting varying degrees of GA-deficiency (gib lines). The relative growth rate, based on plant height and specific leaf area, of the gib scions demonstrated partial recovery upon grafting to a WT rootstock. In contrast, the WT scion demonstrated recovery of root biomass and the root/shoot ratio in plants with gib rootstocks. Although the majority of free amino acids accumulated and negatively affected root growth of the WT rootstock, while the levels of organic acids and sugars were reduced. Increased levels of sugars and decreased levels of branched-chain amino acids in the roots of gib rootstock suggested that were the main carbon source to sustain the root growth. The multivariate analysis demonstrated growth and metabolism adjustments of the WT rootstock to supply the higher GA demand of the gib scions. In contrast, the WT scion displayed relatively minor metabolic alterations to support high rates of root growth and a reduced GA demand by the gib rootstocks. In this context, the strategic use of grafting between WT plants and GA-deficient mutants offers a viable approach to boosting agricultural productivity and strengthening plant resilience against abiotic stresses, providing an innovative alternative for sustainable crop management under challenging environmental conditions.

Exposure to volatile organic compounds (VOC), ubiquitous indoor air pollutants gaseous at room temperature, is associated with respiratory morbidity in children with chronic lung disease, but specific sources in homes may be challenging to identify. To evaluate how home characteristics or activities related to total VOC levels (TVOC) in homes of children with bronchopulmonary dysplasia (BPD), including short−term, episodic “peak” exposures to TVOC, we conducted home environmental monitoring among 122 children aged 6–12 with BPD in greater Boston. This included weeklong hourly indoor air pollutant measurements. We investigated associations between home environmental exposures and mean TVOC levels or the likelihood of a TVOC peak, adjusting for season and demographic characteristics. The median number of peaks per weeklong home monitoring period was 4 (IQR 1–6). Mean TVOC levels were associated with indoor PM2.5, temperature, humidity, cold season, and indoor combustion sources; and inversely related with indoor NO2 and pets. Cold season, temperature, humidity, and concurrent cleaning activity increased the likelihood of a TVOC peak. Associations with cold season, indoor temperature, and indoor humidity support the importance of air exchange for the clearance of home indoor TVOC. Cleaning may represent an individually modifiable source of VOC exposure.

Blackcurrant (Ribes nigrum L., family Grossulariaceae) is a perennial shrub that is widely cultivated for its edible berries. These are rich in antioxidants, vitamin C, and anthocyanins, making them a valuable ingredient in the food and beverage industry. However, prolonged periods of drought during the fruiting season lead to drought stress, which has serious ecological and agricultural implications, inhibiting blackcurrant growth and reducing yields. To facilitate the analysis of underlying molecular processes, we present the first high-quality chromosome-scale and partially haplotype-resolved assembly of the blackcurrant genome (cv. Rosenthals Langtraubige), also the first in the family Grossulariaceae. We used this genomic reference to analyze the transcriptomic response of blackcurrant leaves and roots to drought stress, revealing differentially expressed genes with diverse functions, including those encoding the transcription factors bZIP, bHLH, MYB, and WRKY, and tyrosine kinase-like kinases such as PERK and DUF26. Gene expression was correlated with the abundance of primary metabolites, revealing 14 with significant differences between stressed leaves and controls indicating a metabolic response to drought stress. Amino acids such as proline were more abundant under stress conditions, whereas organic acids were depleted. The genomic and transcriptomic data from this study can be used to develop more robust blackcurrant cultivars that thrive under drought stress conditions.

Needle blights are serious fungal diseases affecting European natural and planted pine forests. Brown-spot needle blight (BSNB) disease, caused by the fungus Lecanosticta acicola, causes canopy defoliation and severe productivity losses, with consequences depending on host susceptibility. To gain new insights into BSNB plant-pathogen interactions, constitutive and pathogen-induced traits were assessed in two host species with differential disease susceptibility. Six-month-old Pinus radiata D. Don (susceptible) and Pinus pinea L. (more resistant) seedlings were needle inoculated with L. acicola under controlled conditions. Eighty days after inoculation, healthy-looking needles from symptomatic plants were assessed for physiological parameters and sampled for biochemical analysis. Disease progression, plant growth, leaf gas-exchanges and biochemical parameters were complemented with hormonal and untargeted primary metabolism analysis and integrated for a holistic analysis. Constitutive differences between pine species were observed. Pinus pinea presented higher stomatal conductance and transpiration rate and higher amino and organic acids, abscisic acid as well as putrescine content than P. radiata. Symptoms from BSNB disease were observed in 54.54% of P. radiata and 45.45% of P. pinea seedlings, being more pronounced and generalized in P. radiata. For both species, plant height, sub-stomatal CO2 concentration and water-use efficiency were impacted by infection. In P. radiata, total soluble sugars, starch and total flavonoids content increased after infection. No differences in hormone content after infection were observed. However, secondary metabolism was induced in P. pinea visible through total phenolics, flavonoids and putrescine accumulation. Overall, the observed results suggest that P. pinea constitutive and induced traits may function as two layers of a defence strategy which contributed to an increased BSNB resistance in comparison with P. radiata. This is the first integrative study linking plant physiological and molecular traits in Pinus-Lecanosticta acicola pathosystem, contributing to a better understanding of the underlying resistance mechanisms to BSNB disease in pines.

Widespread North American wildfires in 2023 led to exposure to ambient wildfire smoke outside of traditionally wildfire-prone regions. The objective was to evaluate levels of indoor air pollutants in relation to ambient wildfire smoke exposure in eastern Massachusetts. Using a real-time multipollutant sensor system in five Boston area households, this study assessed indoor fine particulate matter (PM2.5), nitrogen dioxide (NO2), and total volatile organic compound concentrations (TVOC) two days before and during days of hazardous wildfire smoke exposure (smoke days). The relationship between ambient PM2.5 from regulatory monitors and indoor PM2.5 before and during smoke days was investigated by mixed effects linear regression. During smoke days and the preceding non-smoke days, median indoor PM2.5 was 9.9 µg/m3 and 3.5 µg/m3 (p < 0.001), respectively; median NO2 was 20.5 ppb and 18.4 ppb (p = 0.11); median TVOC was 6,715 µg/m3 and 5,361 µg/m3 (p = 0.35). A 1% increase in ambient PM2.5 was associated with a 0.93% increase in indoor PM2.5 on smoke days (95% CI, 0.54%-1.32%) and a 0.34% increase on non-smoke days (95% CI, 0.17%-0.66%), though interaction testing of smoke day status was not statistically significant (p = 0.14). In Northeastern US homes, indoor PM2.5 increased significantly during ambient wildfire smoke exposure, which may reflect increased infiltration and increased indoor particle-generating activities during smoke days.Implications: This study reports on household exposure to wildfire smoke in eastern Massachusetts, finding that indoor PM2.5 more than doubled compared to preceding non-smoke days, while indoor NO2 and TVOC did not significantly rise. Though the generalizability of this study is limited by the small number of homes studied, the findings suggest that more investigation is needed to understand indoor air pollution during future wildfire smoke exposure in regions not traditionally wildfire-prone and to inform mitigation efforts.

Plant resistance to agricultural pests is a fundamental element of sustainable crop protection. However, concerns have been raised that strategies to increase resistance may involve phytochemicals that impact fruit ripening and the sensorial perception of the fruit. Here, we experimentally tested for these putative resistance effects by contrasting susceptible varieties of strawberry (Fragaria vesca) with varieties that were either constitutively resistant to pest insects or with resistance induced with jasmonic acid (JA). GC-MS analysis identified 11 volatile compounds, including alcohols, aldehydes, lactone, terpenoids, and esters, which showed higher concentrations in fruits from resistant/induced plants. Fruits from induced plants ripened faster in the field. In sensory analyses, using a trained analytical panel, some variation between the sensory profiles of the strawberry varieties was detected, but we found no systematic correlations between sensory attributes and the level of plant resistance/induction in the varieties. These results suggest that increased plant resistance comes with positive effects of early ripening, while not strongly affecting the overall sensory experience.

Background:Expanding electrification and access to other clean and affordable energy, such as solar energy, is a critical component of the Sustainable Development Goals, particularly in sub-Saharan Africa where 70% of people are energy insecure. Intervention trials related to access or less polluting household energy alternatives have typically focused on air quality and biological outcomes rather than on how an intervention affects the end user's lived experiences, a key determinant of uptake and adoption outside of a research setting. We explored perceptions of and experiences with a household solar lighting intervention in rural Uganda. Methods:In 2019, we completed a one-year parallel group, randomized wait-list controlled trial of indoor solar lighting systems (ClinicalTrials.gov NCT03351504) in rural Uganda where participants are largely relying on kerosene and other fuel-based lighting received household indoor solar lighting systems. In this qualitative sub-study, we conducted one-on-one, in-depth qualitative interviews with all 80 female participants enrolled in the trial. Interviews explored how solar lighting and illumination impacted participants' lives. We applied a theoretical model linking social integration and health to analyse dynamic interactions across aspects of study participants' lived experiences. Sensors were used to measure daily lighting use before and after receipt of the intervention solar lighting system. Results:Introduction of the solar lighting system increased daily household lighting use by 6.02 (95% confidence intervals (CI) = 4.05-8.00) hours a day. The solar lighting intervention had far-reaching social implications with improved social integration and, consequently, social health. Participants felt that lighting improved their social status, mitigated the stigma of poverty, and increased the duration and frequency of social interactions. Household relationships improved with access to lighting because of reduced conflicts over light rationing. Participants also described a communal benefit of lighting due to improved feelings of safety. At the individual-level, many reported improved self-esteem, sense of well-being, and reduced stress. Conclusion:Improved access to lighting and illumination had far reaching implications for participants, including improved social integration. More empirical research, particularly in the light and household energy field, is needed that emphasizes the impacts of interventions on social health. Registration:ClinicalTrials.gov No. NCT03351504.

In the last decades, linkage mapping has help in the location of metabolite quantitative trait loci (QTL) in many species; however, this approach shows some limitations. Recently, thanks to the most recent advanced in high-throughput genotyping technologies like next-generation sequencing, metabolite genome-wide association study (mGWAS) has been proposed a powerful tool to identify the genetic variants in polygenic agrinomic traits. Fruit flavor is a complex interaction of aroma volatiles and taste being sugar and acid ratio key parameter for flavor acceptance. Here, we review recent progress of mGWAS in pinpoint gene polymorphisms related to flavor-related metabolites in fruits. Despite clear successes in discovering novel genes or regions associated with metabolite accumulation affecting sensory attributes in fruits, GWAS incurs in several limitations summarized in this review. In addition, in our own work, we performed mGWAS on 194 Citrus grandis accessions to investigate the genetic control of individual primary and lipid metabolites in ripe fruit. We have identified a total of 667 associations for 14 primary metabolites including amino acids, sugars, and organic acids, and 768 associations corresponding to 47 lipids. Furthermore, candidate genes related to important metabolites related to fruit quality such as sugars, organic acids and lipids were discovered.

This work aims to determine the effect of genotype x environment (GxE) interaction that influence blackcurrant (Ribes nigrum) fruit quality. We applied metabolomics-driven analysis on fruits from four cultivars grown in contrasting European-locations over two seasons. By integrating metabolomics and sensory analysis, we also defined specific metabolic signatures associated with consumer acceptance. Our results showed that rainfall is a crucial factor associated with accumulation of delphinidin- and cyanidin-3-O-glucoside, the two mayor blackcurrant pigments meanwhile temperature affects the main organic acid levels which can be decisive for fruit taste. Sensorial analysis showed that increases in terpenoid and acetate ester volatiles were strongly associated with higher appreciation score, while proacacipetalin, a cyanogenic-glycoside, was positively associated to bitter taste. Our results pave the way for the selection of high-quality cultivars and suitable production sites for blackcurrant cultivation.

The dentate gyrus is one of the few brain regions that show proliferation of neuronal precursors postnatally and in adult life. Proliferation in the dentate gyrus has been shown to be influenced by exercise, stress and drugs such as antidepressants. Traditionally, proliferation studies rely on the time consuming and subjective manual count of labeled cells. Here we adapted the Metamorph software to automatically count cells labeled in the S phase in the developing dentate gyrus of mice. The validity of the computer-assisted method was established by showing an outcome similar to that obtained with the established manual counting procedure. In addition, by using a genetically modified mouse line with increased proliferation, the ability of the computer-assisted method to detect changes in proliferation was demonstrated.

Plant tannins belong to the antioxidant compound family, which includes chemicals responsible for protecting biological structures from the harmful effects of oxidative stress. A wide range of plants and crops are rich in antioxidant compounds, offering resistance to biotic, mainly against pathogens and herbivores, and abiotic stresses, such as light and wound stresses. These compounds are also related to human health benefits, offering protective effects against cardiovascular and neurodegenerative diseases in addition to providing anti-tumor, anti-inflammatory, and anti-bacterial characteristics. Most of these compounds are structurally and biosynthetically related, being synthesized through the shikimate-phenylpropanoid pathways, offering several classes of plant antioxidants: flavonoids, anthocyanins, and tannins. Tannins are divided into two major classes: condensed tannins or proanthocyanidins and hydrolysable tannins. Hydrolysable tannin synthesis branches directly from the shikimate pathway, while condensed tannins are derived from the flavonoid pathway, one of the branches of the phenylpropanoid pathway. Both types of tannins have been proposed as important molecules for taste perception of many fruits and beverages, especially wine, besides their well-known roles in plant defense and human health. Regulation at the gene level, biosynthesis and degradation have been extensively studied in condensed tannins in crops like grapevine (Vitis vinifera), persimmon (Diospyros kaki) and several berry species due to their high tannin content and their importance in the food and beverage industry. On the other hand, much less information is available regarding hydrolysable tannins, although some key aspects of their biosynthesis and regulation have been recently discovered. Here, we review recent findings about tannin metabolism, information that could be of high importance for crop breeding programs to obtain varieties with enhanced nutritional characteristics.

Economic and urban development in sub-Saharan Africa (SSA) may be shifting the dominant air pollution sources in cities from biomass to road traffic. Considered as a marker for traffic-related air pollution in cities, we conducted a city-wide measurement of NOx levels in the Accra Metropolis and examined their spatiotemporal patterns in relation to land use and meteorological factors. Between April 2019 to June 2020, we collected weekly integrated NOx (n = 428) and NO2 (n = 472) samples at 10 fixed (year-long) and 124 rotating (week-long) sites. Data from the same time of year were compared to a previous study (2006) to assess changes in NO2 concentrations. NO and NO2 concentrations were highest in commercial/business/industrial (66 and 76 mu g/m(3), respectively) and high-density residential areas (47 and 59 mu g/m(3), respectively), compared with peri-urban locations. We observed annual means of 68 and 70 mu g/m(3) for NO and NO2, and a clear seasonal variation, with the mean NO2 of 63 mu g/m(3) (non-Harmattan) increased by 25-56% to 87 mu g/m(3) (Harmattan) across different site types. The NO2/NOx ratio was also elevated by 19-28%. Both NO and NO2 levels were associated with indicators of road traffic emissions (e.g. distance to major roads), but not with community biomass use (e.g. wood and charcoal). We found strong correlations between both NO2 and NO2/NOx and mixing layer depth, incident solar radiation and water vapor mixing ratio. These findings represent an increase of 25-180% when compared to a small study conducted in two high-density residential neighborhoods in Accra in 2006. Road traffic may be replacing community biomass use (major source of fine particulate matter) as the prominent source of air pollution in Accra, with policy implication for growing cities in SSA. (C) 2021 Elsevier B.V. All rights reserved.

Although autophagy is a conserved mechanism operating across eukaryotes,its effects on crops and especially their metabolism has received relatively little attention.Indeed,whilst a few recent studies have used systems biology tools to look at the consequences of lack of autophagy in maize these focused on leaf tissues rather than the kernels.Here we utilized RNA interference(RNAi)to generate tomato plants that were deficient in the autophagy-regulating protease ATG4.Plants displayed an early senescence phenotype yet relatively mild changes in the foliar metabolome and were characterized by a reduced fruit yield phenotype.Metabolite profiling indicated that metabolites of ATG4-RNAi tomato leaves just exhibited minor alterations while that of fruit displayed bigger difference compared to the WT.In detail,many primary metabolites exhibited decreases in the ATG4-RNAi lines,such as proline,tryptophan and phenylalanine,while the representative secondary metabolites(quinic acid and 3-trans-caffeoylquinic acid)were present at substantially higher levels in ATG4-RNAi green fruits than in WT.Moreover,transcriptome analysis indicated that the most prominent differences were in the significant upregulation of organelle degradation genes involved in the proteasome or chloroplast vesiculation pathways,which was further confirmed by the reduced levels of chloroplastic proteins in the proteomics data.Furthermore,integration analysis of the metabolome,transcriptome and proteome data indicated that ATG4 significantly affected the lipid metabolism,chlorophyll binding proteins and chloroplast biosynthesis.These data collectively lead us to propose a more sophisticated model to explain the cellular co-ordination of the process of autophagy.

Improving yield, nutritional value and tolerance to abiotic stress are major targets of current breeding and biotechnological approaches that aim at increasing crop production and ensuring food security. Metabolic engineering of carotenoids, the precursor of vitamin-A and plant hormones that regulate plant growth and response to adverse growth conditions, has been mainly focusing on provitamin A biofortification or the production of high-value carotenoids. Here, we show that the introduction of a single gene of the carotenoid biosynthetic pathway in different tomato cultivars induced profound metabolic alterations in carotenoid, apocarotenoid and phytohormones pathways. Alterations in isoprenoid- (abscisic acid, gibberellins, cytokinins) and non-isoprenoid (auxin and jasmonic acid) derived hormones together with enhanced xanthophyll content influenced biomass partitioning and abiotic stress tolerance (high light, salt, and drought), and it caused an up to 77% fruit yield increase and enhanced fruit's provitamin A content. In addition, metabolic and hormonal changes led to accumulation of key primary metabolites (e.g. osmoprotectants and antiaging agents) contributing with enhanced abiotic stress tolerance and fruit shelf life. Our findings pave the way for developing a new generation of crops that combine high productivity and increased nutritional value with the capability to cope with climate change-related environmental challenges.

To identify potential strategies for increasing the efficiency of tomato leaf metabolism, with a focus on the links between nitrogen/carbon metabolism, we explored a diel Flux Balance Analysis (FBA) model of a source leaf in which the metabolic output was varied up to the theoretically-achievable maximum. We noticed a potentially interesting switch in the use of glutamine synthetase (GS) isoforms –from the chloroplast isoform to the mitochondrial one- for nitrogen assimilation. To further explore this prediction, we characterized transgenic tomato plants over-expressing two tomato GS genes, GS1 and GS2 , targeted to mitochondria. Both sets of transgenic plants were characterized as displaying faster growth rate, early flowering and increased fruit yield. In leaves, metabolomic profiling and enzyme activity analysis pointed that GS activity in mitochondrial plays a role in increasing the intracellular synthesis and subsequent export of sugar. Consistent with these changes, higher sucrose concentration in leaf exudates and reduced activities of enzymes involved in leaf starch synthesis were observed. Moreover, mitochondrial GS activity affected chloroplast redox status in a manner that modulated photorespiration and nitrogen metabolism. The combined data reveal the influence of mitochondrial GS activity on both foliar carbon/nitrogen balance and regulation of source-sink metabolism in tomato plants.