Elevated Carbon Dioxide Research Articles

Elevated CO2 and nitrogen addition enhance the symbiosis and functions of rhizosphere microorganisms under cadmium exposure

Soil microbes are fundamental to ecosystem health and productivity. How soil microbial communities are influenced by elevated atmospheric carbon dioxide (eCO2) concentration and nitrogen (N) deposition under heavy metal pollution remains uncertain, despite global exposure of terrestrial ecosystems to eCO2, high N deposition and heavy metal stress. Here, we conducted a four year's open-top chamber experiment to assess the effects of soil cadmium (Cd) treatment (10 kg hm−2 year−1) alone and combined treatments of Cd with eCO2 concentration (700 ppm) and/or N addition (100 kg hm−2 year−1) on tree growth and rhizosphere microbial community. Relative to Cd treatment alone, eCO2 concentration in Cd contaminated soil increased the complexity of microbial networks, including the number links, average degree and positive/negative ratios. The combined effect of eCO2 and N addition in Cd contaminated soil not only increased the complexity of microbial networks, but also enhanced the abundance of microbial urealysis related UreC and nitrifying related amoA1 and amoA2, and the richness of arbuscular mycorrhiza fungi (AMF), thereby improving the symbiotic functions between microorganisms and plants. Results from correlation analysis and structural equation model (SEM) further demonstrated that eCO2 concentration and N addition acted on functions and networks differently. Elevated CO2 positively regulated microbial networks and functions through phosphorus (P) and Cd concentration in roots, while N addition affected microbial functions through soil available N and soil organic carbon (SOC) concentration and microbial network through soil Cd concentration. Overall, our findings highlight that eCO2 concentration and N addition make microbial communities towards ecosystem health that may mitigate Cd stress, and provide new insights into the microbiology supporting phytoremediation for Cd contaminated sites in current and future global change scenarios.

Comprehensive analysis of Trichoderma ressei mediated CO2 stress attenuating responses and de novo transcriptome sequencing of rice flag leaf

AbstractThe objective of this study was to investigate the alterations in physiological, biochemical, and transcriptional reactions in the flag leaf of rice following the application of Trichoderma as a biofertilizer (BF) at both ambient (aCO2; 395 ppm) and enhanced (eCO2; 550 ppm) carbon dioxide levels. A comparatively smaller percentage change was observed in the photosynthetic parameters, including photosynthetic rate, respiration, and stomatal conductance, subsequent to the introduction of BF in the elevated carbon dioxide (eCO2) environment. Furthermore, biochemical analysis revealed a noteworthy elevation in photosynthetic pigments, total sugar, proline, and ascorbate peroxidase concentration levels in plants treated with BF under ambient and increased carbon dioxide conditions. The buildup of indole‐3‐acetic acid (IAA) was shown to be increased in rice treated with BF under both conditions. Moreover, ICP‐MS analysis demonstrated an augmentation in the levels of vital micronutrients in the experimental group while observing no alterations in the carbon‐to‐nitrogen ratio within the flag leaf. The examination of transcriptional responses in the flag leaf demonstrated an increase in the expression of genes associated with the photosynthetic system, amino acid metabolism, several transporters, including aquaporin, and the phosphate pathway, as well as carbon and nitrogen metabolism. Hence, our work elucidates the effective role of Trichoderma in mitigating the adverse consequences associated with elevated levels of atmospheric carbon dioxide (eCO2).

Elevated carbon dioxide to suppress Botrytis growth during reefer container transport of table grapes

Elevated carbon dioxide to suppress <i>Botrytis</i> growth during reefer container transport of table grapes

Effects of elevated and super-elevated carbon dioxide on salad crops for space

ABSTRACT Space habitats typically have elevated CO2 and NASA is considering growing leafy greens in space to supplement astronauts’ diets. Dragoon’ and ‘Outredgeous’ lettuce, ‘Amara’ mustard, ‘Extra Dwarf’ pak choi, shungiku, ‘Red Russian’ kale, ‘Toscano’ kale, and ‘Barese’ Swiss chard were grown for 4 weeks at 400, 1500, 3000, and 6000 ppm CO2. Shoot fresh mass at 28 days was greater for one of more elevated CO2 levels for all species/cultivars except ‘Toscano’ kale. Fresh mass varied by species/cultivar, with pak choi and ‘Dragoon’ lettuce showing the greatest yields. Super-elevated CO2 (6000 ppm) reduced shoot mass for both lettuce cvs. compared to 3000 ppm. Elevated CO2 increased K levels for most species/cultivars but decreased Mg for some species/cultivars. CO2 affected Vitamin B1 and Vitamin C content but had no effect on Vitamin K. ‘Toscano’ and ‘Red Russian’ kale, and Amara mustard had the highest mineral and vitamin content.

Elevated atmospheric CO2 promotes the contribution of autotrophic nitrification to N2O emissions in a typical summer maize field

Elevated atmospheric carbon dioxide (CO2) concentration generally stimulates nitrous oxide (N2O) emissions from upland soils, leading to a promoted feedback on climate change. However, the underlying mechanisms on how elevated CO2 (eCO2) stimulates N2O emissions from nitrogen (N)-fertilized upland soils remain poorly known. Here, we investigated the effects of eCO2 on soil N2O production pathways and associated gross N transformation rates, as well as on nitrifying and denitrifying microbes. Based on a 13 years of free-air CO2 enrichment (FACE) platform, we found that N2O emissions were significantly increased by 46.7% under eCO2 in a typical summer-maize field. The 15N tracing experiment showed that autotrophic nitrification rate was significantly increased by 11.6% under eCO2, coincided with the significantly higher abundance and shift composition of ammonia-oxidizing bacteria (AOB) under eCO2. Also, eCO2 enhanced gross ammonium (NH4+) immobilization rate but reduced gross nitrate (NO3−) immobilization rate. Autotrophic nitrification accounted for approximately 78% of N2O emissions, followed by heterotrophic nitrification (about 19%) and denitrification (about 3%). It was found that eCO2 increased carbon (C) deposition in soil, which could affect the availability of soil labile organic C and N and alter the composition and activity of nitrifiers. These changes promoted the N2O production derived from autotrophic nitrification, resulting in higher N2O emissions under eCO2. We could deduce that nitrifier denitrification contributed to the increased N2O emissions greatly under eCO2, derived by strongly stimulated ammonia oxidation and microbial respiration (i.e. higher soil CO2 emissions) caused suboxic conditions (i.e. lower soil oxygen (O2) concentration), along with higher abundance ratios of (nirK+nirS)/nosZ. Our results suggest that controlling autotrophic nitrification appropriately is crucial for mitigating N2O emissions from upland soils under rising atmospheric CO2 concentration.

Effects of elevated carbon dioxide on plant growth and leaf photosynthesis of annual ryegrass along a phosphorus deficiency gradient

IntroductionSoil phosphorus (P) deficiency limits plant growth and productivity in grassland ecosystems and may moderate the growth-promoting effects of “carbon dioxide (CO2) fertilization effect”.MethodsTo evaluate the interactive effects of these two factors on the growth and physiology for annual ryegrass (Lolium multiflorum Lam.), plants were grown in controlled growth chambers with a range of P supply (0.004, 0.012, 0.02, 0.06, 0.1 and 0.5 mM) under two levels of CO2 (400 and 800 μmol mol-1, respectively).ResultsElevated [CO2] dramatically increased the aboveground biomass and net photosynthetic rates of annual ryegrass by 14.5% and 25.3% under sufficient P supply (0.5 mM), respectively, whereas decreased the belowground biomass and net photosynthetic rates under lower P supply of P0.004, P0.02, and P0.06. Two-way ANOVA results showed that CO2 × P (p &amp;lt; 0.001) significantly affected stomatal traits, leaf photosynthesis and biomass. The stimulation of growth and photosynthesis by elevated CO2 concentration (e[CO2]) was reduced or highly suppressed, indicating that the sensitivity of annual ryegrass to P deficiency was enhanced under e[CO2].DiscussionThese results indicated that P limitation may offset the positive effects of e[CO2] on plant growth by altering stomatal traits, leaf photochemical processes and biochemical composition in annual ryegrass.

Elevated carbon dioxide concentrations increase the risk of Cd exposure in rice.

Since the Industrial Revolution, crops have been exposed to various changes in the environment, including elevated atmospheric carbon dioxide (CO2) concentration and cadmium (Cd) pollution in soil. However, information about how combined changes affect crop is limited. Here, we have investigated the changes of japonica and indica rice subspecies seedlings under elevated CO2 level (1200 ppm) and Cd exposure (5 μM Cd) conditions compared with ambient CO2 level (400 ppm) and without Cd exposure in CO2 growth chambers with hydroponic experiment. The results showed that elevated CO2 levels significantly promoted seedling growth and rescued the growth inhibition under Cd stress. However, the elevated CO2 levels led to a significant increase in the shoot Cd accumulation of the two rice subspecies. Especially, the increase of shoot Cd accumulation in indica rice was more than 50% compared with control. Further investigation revealed that the decreases in the photosynthetic pigments and photosynthetic rates caused by Cd were attenuated by the elevated CO2 levels. In addition, elevated CO2 levels increased the non-enzymatic antioxidants and significantly enhanced the ascorbate peroxidase (APX) and glutathione reductase (GR) activities, alleviating the lipid peroxidation and reactive oxygen species (ROS) accumulation induced by Cd. Overall, the research revealed how rice responded to the elevated CO2 levels and Cd exposure, which can help modify agricultural practices to ensure food security and food safety in a future high-CO2 world.

Flexible Foliar Stoichiometry Reduces the Magnitude of the Global Land Carbon Sink

AbstractIncreased plant growth under elevated carbon dioxide (CO2) slows the pace of climate warming and underlies projections of terrestrial carbon (C) and climate dynamics. However, this important ecosystem service may be diminished by concurrent changes to vegetation carbon‐to‐nitrogen (C:N) ratios. Despite clear observational evidence of increasing foliar C:N under elevated CO2, our understanding of potential ecological consequences of foliar stoichiometric flexibility is incomplete. Here, we illustrate that when we incorporated CO2‐driven increases in foliar stoichiometry into the Community Land Model the projected land C sink decreased two‐fold by the end of the century compared to simulations with fixed foliar chemistry. Further, CO2‐driven increases in foliar C:N profoundly altered Earth's hydrologic cycle, reducing evapotranspiration and increasing runoff, and reduced belowground N cycling rates. These findings underscore the urgency of further research to examine both the direct and indirect effects of changing foliar stoichiometry on soil N cycling and plant productivity.

Spatio-temporal variability of surface chlorophyll and pCO2 over the tropical Indian Ocean and its long-term trend using CMIP6 models

Under the global climate change scenario, ever-increasing ocean temperatures and elevated carbon dioxide (CO2) concentration levels in the ocean and atmosphere significantly affect ocean biogeochemistry. The spatiotemporal distribution of chlorophyll and partial pressure of CO2 (pCO2) over the Indian Ocean (IO) are investigated using satellite, in-situ, and simulations from eleven Coupled Model Inter-comparison Project phase 6 models. All the models show negative bias near the Somali region over the Arabian Sea (AS) during the southwest monsoon season. The CESMs and CanESM5 models show relatively less bias over the tropical IO except for the AS in all seasons compared to other models. The annual cycle of pCO2 shows a bimodal characteristic, with the first peak in May and the other in October over the northern IO, which the CanESM5, IPSL, and MPIs models reasonably well capture. All the models produce the phase of the annual cycle of pCO2 reasonably well for the southern IO. The pCO2 distribution and its trend decomposition are estimated using the multimodel mean from the CanESM5, IPSL-CM6A-LR, and MPIs models, suggesting that the increase in dissolved inorganic carbon is the dominant factor that contributes to about 70 % of the rise in the total pCO2 trend, and the total alkalinity and sea surface temperature have a secondary role. Region-wise analysis manifests that the southern IO and AS exhibit maximum susceptibility to the long-term variations in the pCO2 trend caused by the changes in dissolved inorganic carbon levels in the ocean. The study discusses substantive factors leading to the variability in the biogeochemical properties of the IO as simulated by these models and, thus, the possibilities for future improvements.

Effect of ambient gas and crystal features on Doppler ultrasound twinkling of pathological mineralizations.

Color Doppler twinkling on kidney stones and other pathological mineralizations is theorized to arise from stable microbubbles, which suggests twinkling will be sensitive to ambient gas. Here, lab-grown cholesterol, calcium phosphate, and uric acid crystals were imaged with ultrasound in water while varying oxygen, carbon dioxide, and nitrogen levels. Twinkling was found to increase on cholesterol in elevated oxygen, cholesterol and calcium phosphate in elevated carbon dioxide, and no crystals in elevated nitrogen. These results support the crevice microbubble theory of twinkling and suggest gases may be varied to enhance twinkling on some mineralizations.

Cross-scale assessments of the impacts and resilience of subtropical montane cloud forests to chronic seasonal droughts and episodic typhoons.

Montane cloud forests (MCFs) are ecosystems frequently immersed in fog and are vital for the terrestrial hydrological cycle and biodiversity hotspots. However, the potential impacts of climate change, particularly intensified droughts and typhoons, on the persistence of ecosystems remain unclear. Our study conducted cross-scale assessments using 6-year (2016-2021) ground litterfall and 21-year (2001-2021) satellite greenness data (the Enhanced Vegetation Index [EVI] and the EVI anomaly change [ΔEVI% ]), gross primary productivity anomaly change (ΔGPP% ), and meteorological variables (the standardized precipitation index [SPI] and wind speed). We found a positive correlation between summer EVI and ΔGPP% with the SPI-3 (3-month time scale), while winter litterfall showed a negative correlation. Maximum typhoon daily wind speed was negatively correlated with summer and the monthly ΔEVI% and ΔGPP% . These findings suggest vegetation damage and productivity loss were related to drought and typhoon intensities. Furthermore, our analysis highlighted that chronic seasonal droughts had more pronounced impacts on MCFs than severe typhoons, implying that high precipitation and frequent fog immersion do not necessarily mitigate the ramifications of water deficit on MCFs but might render MCFs more sensitive and vulnerable to drought. A significant negative correlation between the summer and winter ΔEVI% and ΔGPP% of the same year, suggesting disturbance severity during summer may facilitate vegetation regrowth and carbon accumulation in the subsequent winter. This finding may be attributed to the ecological resilience of MCFs, which enables them to recover from the previous summer. In the long-term, our results indicated an increase in vegetation resilience over two decades in MCFs, likely driven by rising temperatures and elevated carbon dioxide levels. However, the enhancement of resilience might be overshadowed by the potential intensified droughts and typhoons in the future, potentially causing severe damage and insufficient recovery times for MCFs, thus raising concerns about uncertainties regarding their sustained resilience.

Manipulating atmospheric CO2 concentration induces shifts in wheat leaf and spike microbiomes and in Fusarium pathogen communities.

Changing atmospheric composition represents a source of uncertainty in our assessment of future disease risks, particularly in the context of mycotoxin producing fungal pathogens which are predicted to be more problematic with climate change. To address this uncertainty, we profiled microbiomes associated with wheat plants grown under ambient vs. elevated atmospheric carbon dioxide concentration [CO2] in a field setting over 2 years. We also compared the dynamics of naturally infecting versus artificially introduced Fusarium spp. We found that the well-known temporal dynamics of plant-associated microbiomes were affected by [CO2]. The abundances of many amplicon sequence variants significantly differed in response to [CO2], often in an interactive manner with date of sample collection or with tissue type. In addition, we found evidence that two strains within Fusarium - an important group of mycotoxin producing fungal pathogens of plants - responded to changes in [CO2]. The two sequence variants mapped to different phylogenetic subgroups within the genus Fusarium, and had differential [CO2] responses. This work informs our understanding of how plant-associated microbiomes and pathogens may respond to changing atmospheric compositions.

Kidney stone twinkling power in elevated oxygen, carbon dioxide, and nitrogen environments

Clinically, ∼66% of kidney stones exhibit the Doppler ultrasound twinkling artifact. Previous studies show breathing pure oxygen at elevated pressures increases twinkling compared to ambient air. Here, we investigate how different gases influence twinkling on ex vivo and in vivo human kidney stones. 38 kidney stones were imaged with a research ultrasound system and ATL L7-4 transducer in elevated oxygen, carbon dioxide, and nitrogen environments. In vivo stones were imaged with the same ultrasound system and ATL C5-2 transducer in 25 human subjects before and after breathing pure oxygen for 15 min. IQ data were processed by calculating the average Doppler power, or twinkling, for a region of interest containing the stone. In the lab, increasing oxygen by 55%, carbon dioxide by 100%, and nitrogen by 17% increased twinkling power an average of 70 ± 28%, 137 ± 53%, and 79 ± 31%, respectively. In human subjects, breathing oxygen increased twinkling power an average of 27 ± 58%, with seven subjects showing a strong increase (&amp;gt;30%); stone composition and patient age influenced twinkling in patients breathing oxygen. These results suggest that varying ambient gases may be leveraged to increase the consistency of twinkling and improve kidney stone detection with ultrasound. [Work supported by the PSU Center for Biodevices.]

Interactive Effect of Elevated Carbon Dioxide, Temperature and Nitrogen on the Growth Parameters of Rice at Active Tillering Stage

Ever since industrialization began, carbon dioxide [CO2] concentration in the atmosphere got increased and it consecutively raised the temperature. This change in climate would affect the agricultural production and crop growth. A pot culture experiment was conducted during the Kuruvai season (June - September) of the year 2023 at Anbil Dharmalingam Agricultural College &amp; Research Institute, Tiruchirappalli to assess the rice growth up to active tillering stage under elevated [CO2] and temperature conditions at different doses of nitrogen (N) fertilization. Rice seedlings were grown inside the four Open Top Chambers (OTC) at ambient (422 ppm) and elevated CO2 (550 ppm) conditions as well as chamber controlled and elevated temperature (+2°C) with four different doses of N (control, 100% recommended dose of N (RDN), 150% RDN and 200% RDN). Plant growth parameters like plant height, number of tillers, leaf area, root length and root volume, root and shoot dry matter were increased significantly under elevated [CO2] (eCO2) conditions. Whereas, all the growth parameters were severely influenced by increased temperature. Increasing N concentration increased the plant growth irrespective of the treatments and the effect was more pronounced in eCO2 treatment due to the fertilization effect of [CO2] as it directly necessitates photosynthesis which improves overall growth of rice plants. Under the future changing climatic conditions suitable N doses should be optimized for the better crop production.

Effect of Elevated Temperature Interaction with Elevated Carbon Dioxide on Physiological Quality of Groundnut (Arachis hypogaea L.) Genotypes under Fate Condition

Four genotypes of groundnut (Arachis hypogaea L.) viz., K-6, Naryani, Darani and K-9 were raised under Free Air Temperature Elevated (FATE) condition. The plants were raised in open rings with elevated temperature (+3°C) and carbon dioxide (550ppm) during rabi 2016 to investigate the effect of increased temperature and its interaction with CO2 on various seed quality parameters. The physiological parameters decreased under elevated CO2 and temperature. The results revealed that germination ranged from 81.5 to 90 per cent between four genotypes i.e., K-6, Naryani, Darani and K-9. Similarly speed of germination 49 to 83.02, shoot length 14.73 to 7.70, root length ranges from 20.80 to 9.50, and seedling vigour index 123.47 to 98.53 and seedling dry weight 0.919 to 0.100 g. Further, biochemical parameters like SOD, MDA and α amylase content increased at eT + eCO2 as compared to control treatment. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required. The predicted environmental changes will lead to losses of seed quality particularly for seed vigour and possibly germination. The present study shows that temperature impacts the groundnut crop’s physiological and quality parameters.

Responses of Two-Row and Six-Row Barley Genotypes to Elevated Carbon Dioxide Concentration and Water Stress

Barley (Hordeum vulgare L.) is a crucial cereal crop globally, and its productivity is influenced by environmental factors, including elevated carbon dioxide (CO2) levels and water stress. The aim of this study is to investigate the effects of water stress and increased CO2 concentration on the growth, physiological responses, and yield of two-row and six-row barley genotypes. Univariate data analysis revealed significant effects of CO2 concentration on most traits except chlorophyll a (Chla), crop antioxidant capacity as evaluated by the activity of plant extracts to scavenge the 2,2-diphenyl-1-picrylhydrazyl (DPPH), and on the maximum quantum yield of photosystem II (Fv/Fm). Mean comparisons showed that elevated CO2 increased certain traits such as shoot dry weight (ShDW) (34.1%), root dry weight (RDW) (50.8%), leaf area (LA) (12.5%), grain weight (GW) (64.1%), and yield-related traits and combination of significant indices (CSI) (72.5%). In comparison, Proline (−19.3%), Malondialdehyde (MDA) (−34.4%) levels, and antioxidant enzyme activities, including ascorbate peroxidase (APX) (−39.1%), peroxidase (POX) (−26.1%), and catalase (CAT), (−34.4%) decreased. Water stress negatively affected ShDW (−40.2%), GW (−43.7%), RDW (−28.5%), and LA (−28.8%), while it positively affected DPPH (36.0%), APX (54.8%), CAT (85.1%), and MDA (101%). Six-row barley genotypes (Goharan and Mehr) had the highest yield under normal humidity and elevated CO2 concentrations, while under water stress conditions, their yield decreased more than two-row genotypes (Behrokh and M9316). Principal component analysis and heatmapping revealed that two-row barley genotypes exhibited the highest stress resistance under elevated CO2 concentrations, with the highest levels of secondary metabolites.

DFT Calculation of Carbon-Doped TiO2 Nanocomposites.

Titanium dioxide (TiO2) has been proven to be an excellent material for mitigating the continuous impact of elevated carbon dioxide concentrations. Carbon doping has emerged as a promising strategy to enhance the CO2 reduction performance of TiO2. In this study, we investigated the effects of carbon doping on TiO2 using density functional theory (DFT) calculations. Two carbon doping concentrations were considered (4% and 6%), denoted as TiO2-2C and TiO2-3C, respectively. The results showed that after carbon doping, the band gaps of TiO2-2C and TiO2-3C were reduced to 1.58 eV and 1.47 eV, respectively, which is lower than the band gap of pure TiO2 (2.13 eV). This indicates an effective improvement in the electronic structure of TiO2. Barrier energy calculations revealed that compared to pure TiO2 (0.65 eV), TiO2-2C (0.54 eV) and TiO2-3C (0.59 eV) exhibited lower energy barriers, facilitating the transition to *COOH intermediates. These findings provide valuable insights into the electronic structure changes induced by carbon doping in TiO2, which can contribute to the development of sustainable energy and environmental conservation measures to address global climate challenges.

Elevated CO2, O3 and their interaction have differential impact on soil microbial diversity and functions in wheat agroecosystems

Elevated carbon dioxide (EC) and elevated ozone (EO) due to changing climate have a significant impact on the plant growth rate, primary productivity, and root turnover. EC and EO could have a differential impact on the structure and functioning of soil microbial communities in terrestrial ecosystems via modifications in the microbial population, soil enzyme activity, decomposition of organic compounds and cycling of nutrients. For the development of sustainable agroecosystems, soil microbial communities are essential due to their major roles in nutrient cycling, crop-microbe interplay and resistance towards biotic/abiotic factors. However, it remains difficult to project how multiple climate change factors would affect below-ground functions. Free-Air CO2 and O3 enrichment facility (FAOCE) was used to explore the effects of EC (550 ± 50 ppm) and EO (65 ± 10 ppb) along with their combined interactive treatment ECO on the structure and abundance of soil microbial community, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbes involved in N cycling in wheat crop (Triticum aestivum) under field conditions. The MBC increased by 20% in EC and declined by 5% in EO to ambient control. Treatments EC and ECO stimulated the growth of ammonia and nitrite-oxidizing bacteria. Heterotrophic microbial populations were favoured under EC and inhibited under EO. Treatments indirectly affected the soil microbial community structure by altering N-cycling microbes and modifying MBC and MBN which eventually changed soil fertility and biogeochemistry.

The Impact of Increased CO2 and Drought Stress on the Secondary Metabolites of Cauliflower (Brassica oleracea var. botrytis) and Cabbage (Brassica oleracea var. capitata).

Elevated carbon dioxide and drought are significant stressors in light of climate change. This study explores the interplay between elevated atmospheric CO2, drought stress, and plant physiological responses. Two Brassica oleracea varieties (cauliflowers and cabbage) were utilized as model plants. Our findings indicate that elevated CO2 accelerates assimilation rate decline during drought. The integrity of photosynthetic components influenced electron transport, potentially due to drought-induced nitrate reductase activation changes. While CO2 positively influenced photosynthesis and water-use efficiency during drought, recovery saw decreased stomatal conductance in high-CO2-grown plants. Drought-induced monoterpene emissions varied, influenced by CO2 concentration and species-specific responses. Drought generally increased polyphenols, with an opposing effect under elevated CO2. Flavonoid concentrations fluctuated with drought and CO2 levels, while chlorophyll responses were complex, with high CO2 amplifying drought's effects on chlorophyll content. These findings contribute to a nuanced understanding of CO2-drought interactions and their intricate effects on plant physiology.

The Impact of Elevated Atmospheric Carbon Dioxide Exposure on Magic Tomatoes' Nutrition-Health Properties.

The release of carbon dioxide (CO2) into the atmosphere has accelerated during the last two decades. Elevated atmospheric CO2 concentration (eCO2) is known as an agent that improves plant photosynthesis. However, eCO2 was also correlated with alterations in the macronutrient and micronutrient compositions of various dietary crops. In order to explore the effect of eCO2 on the nutritional and health properties of tomatoes, three parental lines of the Magic population, which includes a large part of the genetic diversity present in large fruit varieties, were used as models. The plants were grown in growth chambers under ambient (400 ppm) or eCO2 (900 ppm) conditions. The macronutrient and micronutrient contents were measured. The anti-oxidant and anti-inflammatory bioactivities were assessed in vitro on activated macrophages. These analyses highlighted that the carbohydrate content was not affected by the eCO2, whereas the protein, carotenoid, lycopene, and mineral contents decreased. Regarding the anti-oxidant properties, no influence of eCO2 exposure was observed. Similarly, the anti-inflammatory properties were not affected by the eCO2. These data are in contrast with previous studies conducted on different plant species or accessions, indicating that the effect of eCO2 on crops' nutrition and health properties is based on complex mechanisms in which growth conditions and genetic backgrounds play a central role.