Effects Of High CO2 Research Articles

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

Thermal sensitivity determines the effect of high CO2 on carbon uptake in Populus tremula and Inga edulis

Thermal sensitivity determines the effect of high CO2 on carbon uptake in Populus tremula and Inga edulis

High CO2 facilitates fatty acid biosynthesis and mitigates cellular oxidative stress caused by CAC2 dysfunction in Arabidopsis.

Increasing concentration of CO2 has significant impacts on many biological processes in plants, and its impact is closely associated with changes in the ratio of photosynthesis to photorespiration. Studies have reported that high CO2 can promote carbon fixing and alleviate plant oxidative damage in response to environmental stresses. However, the effect of high CO2 on fatty acid (FA) metabolism and cellular redox balance in FA-deficient plants is rarely reported. In this study, we identified a high-CO2 -requiring mutant cac2 through forward genetic screening. CAC2 encodes biotin carboxylase, which is one of the subunits of plastid acetyl-CoA carboxylase and participates in de novo FA biosynthesis. Null mutation of CAC2 is embryonic lethal. A point mutation of CAC2 in cac2 mutants produces severe defects in chloroplast development, plant growth and photosynthetic performance. These morphological and physiological defects were largely absent under high CO2 conditions. Metabolite analyses showed that FA contents in cac2-1 leaves were decreased, while photorespiratory metabolites, such as glycine and glycolate, did not significantly change. Meanwhile, cac2 exhibited higher reactive oxygen species (ROS) levels and mRNA expression of stress-responsive genes than the wild-type, indicating that cac2 plants may suffer oxidative stress under ambient CO2 conditions. Elevated CO2 significantly increased FA contents, especially C18:3-FA, and reduced ROS accumulation in cac2-1 leaves. We propose that stress mitigation by high CO2 in cac2 could be due to increased FA levels by promoting carbon assimilation, and the prevention of over-reduction due to decreased photorespiration.

Short-term exposure to near-future CO2has limited influence on the energetics and behaviour of young-of-year salmonids

In many freshwater ecosystems, carbon dioxide (CO2) is increasing. Unknown are the risks that high CO2poses for freshwater organisms, especially fish. The objective of this study was to determine how CO2may influence the growth rate, metabolic rate, feeding rate, and volitional behaviour of young-of-year Arctic charr ( Salvelinus alpinus (Linnaeus, 1758)), brook charr ( Salvelinus fontinalis (Mitchill, 1814)), and rainbow trout ( Oncorhynchus mykiss (Walbaum, 1792)). For this study, fish stayed in control (1100 microatmospheres (µatm)) or elevated (5236 µatm) CO2levels for 15 days. During this time, metabolic rate and behavioural tests were conducted on alternating days for each treatment. Weight and length of each fish were taken on days 0, 7, and 15. There was no evidence that elevated CO2affected the growth rate, feeding rate, or behaviour in any of these species. The standard metabolic rate in Arctic charr differed based on CO2exposure. Therefore, salmonids can withstand short periods of elevated CO2under these conditions. By comparing closely related species, the implications of this work are more ecologically relevant and will also help industry quantify the effects of high CO2on young salmonids.

Low O2 and high CO2 atmospheres have no impact on efficacy of phytosanitary irradiation doses for Drosophila suzukii larvae

Use of irradiation as a phytosanitary treatment has been restricted in atmospheres with low O2 because extreme low O2 exposure can potentially induce radioprotective responses and enhance survival after irradiation. In addition to being low in O2, many controlled atmosphere treatments and modified atmosphere packaging materials maintain high CO2 levels along with low O2. Few studies have combinatorically tested the combined effects of high CO2 and low O2 on radiation sensitivity, and none have done so in a fully factorial design. Here we exposed larvae of the fly Drosophila suzukii to a range of concentrations of low O2 and high CO2 at a series of radiation doses up to 60 Gy. We found that low levels of O2 (≤ 5 kPa) induced a radioprotective response, with the radioprotective response greatest at the lowest O2 concentrations (2.5 & 0 kPa). Adding CO2 significantly decreased this protective response of low O2 on healthy adult emergence when O2 was 2.5 & 5 kPa, but this effect was only apparent at lower radiation doses, well below those used for phytosanitary treatments for this pest. Our study suggests that either controlled atmospheres or modified atmosphere packaging will not challenge the efficiency of phytosanitary irradiation for D. suzukii, and that high CO2 may act as an additional mitigation measure to disinfest insect pests from fresh commodities.

Responses of High Carbon Dioxide Concentration on Postharvest Quality of Fresh Fig Fruit during Storage

The aim of this study was to determine the effects of high CO2 with the constant O2 level on the postharvest quality of fig cv. Bursa Siyahi. For this purpose, the atmospheric compositions of 3% O2 + 10% CO2 (PA-1), 3% O2 + 15% CO2 (PA-2), 3% O2 + 20% CO2 (PA-3), and 21% O2 + 0.03% CO2 (RA) were tested under a palliflex controlled atmosphere (PA) storage system at 0°C for 28 days. At the end of the storage, weight loss increased during the storage period, but this increase slowed down in all tested PAs compared to RA. PA-1 and PA-2 delayed softening while PA-3 accelerated this process. There were no side effects in fruits stored under PAs for taste. The lowest total microorganism and decay rates were found in PA-2 and PA-3. The fig fruits stored under PAs had higher sugar and organic acid contents compared to the figs stored under the RA. Respiration rate decreased in all PAs compared to the RA. Ethylene productions increased with senescence in all atmospheres, but PA-3 inhibited this increase. Consequently, 15% CO2 (PA-2) can be used to maintain postharvest quality of Bursa Siyahi fresh fig for 28 days at 0 °C.

The Effects of High CO2 and Strigolactones on Shoot Branching and Aphid-Plant Compatibility Control in Pea.

Elevated atmospheric CO2 concentrations (eCO2) regulate plant architecture and susceptibility to insects. We explored the mechanisms underpinning these responses in wild type (WT) peas and mutants defective in either strigolactone (SL) synthesis or signaling. All genotypes had increased shoot height and branching, dry weights and carbohydrate levels under eCO2, demonstrating that SLs are not required for shoot acclimation to eCO2. Since shoot levels of jasmonic acid (JA) and salicylic acid (SA) tended to be lower in SL signaling mutants than the WT under ambient conditions, we compared pea aphid performance on these lines under both CO2 conditions. Aphid fecundity was increased in the SL mutants compared to the WT under both ambient and eCO2 conditions. Aphid infestation significantly decreased levels of JA, isopentenyladenine, trans-zeatin and gibberellin A4 and increased ethylene precursor ACC, gibberellin A1, gibberellic acid (GA3) and SA accumulation in all lines. However, GA3 levels were increased less in the SL signaling mutants than the WT. These studies provide new insights into phytohormone responses in this specific aphid/host interaction and suggest that SLs and gibberellins are part of the network of phytohormones that participate in host susceptibility.

Structural Changes Caused by CO2 or Ethanol Deastringency Treatments in Cold-Stored ‘Giombo’ Persimmon

Persimmon cv. Giombo is astringent at harvest and must be subjected to astringency removal treatment. To date, the most widespread treatment for this variety involves applying ethanol instead of high CO2 concentrations, which is the usual treatment with other varieties. This study aims to evaluate the effect of high CO2 or ethanol concentrations as deastringency treatments on the quality and flesh structure of ’Giombo´ persimmon during cold storage. The deastringency process was faster in the fruit treated with CO2 than with ethanol. One day after treatment, the CO2-treated fruit showed lower soluble tannin levels than those detected sensorially for this variety, while with the ethanol-treated fruit, these values were obtained after 25 storage days plus the shelf-life period. The tannin insolubilisation process was observed by light microscopy. Loss of flesh firmness during storage was more pronounced when fruit were previously treated with ethanol than with CO2. This is closely related to greater parenchyma degradation during storage caused by ethanol treatment, which was observed by a microstructural study by cryo-scanning electron microscopy. Therefore, as deastringency treatment for ‘Giombo’, applying CO2 instead of ethanol treatment is recommended for better fruit quality, especially when fruit are to be cold-stored.

Respiratory metabolism and quality in postharvest sweet cherries ( Prunus avium L.) in response to high CO 2 treatment

The effects of high CO2 (5% and 10%), on respiratory metabolism and quality of sweet cherries (‘Rainier’ and ‘8–102’ varieties), were evaluated following storage at 0 °C for 60 d. Quality (respiration rate, weight loss, firmness, etc.) in sweet cherries was significantly improved by high CO2 in storage. And high CO2 enhanced pentose phosphate pathway (PPP), decreased in the glycolytic pathway (EMP) and tricarboxylic acid cycle (TCA) in aerobic respiration proved by elevated the contents of NADP(H), source and fructose, as well as alleviated levels of NAD(H). Cell membrane integrity was also better in these conditions, with higher activities of pyruvate kinase (PK), phosphofructokinaseb (PFK), adenosine triphosphatase (ATPase) and lower activities of polyphenol oxidases (PPO) and cytochrome C oxidases (CCO). Moreover, high CO2 decreased anaerobic respiration by inhibited accumulations of pyruvic acid, ethanol and acetaldehyde, as well as by reduced the activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH).

Elevated CO2 Increases Overwintering Mortality of Varroa destructor (Mesostigmata: Varroidae) in Honey Bee (Hymenoptera: Apidae) Colonies.

Indoor storage of honey bees (Apis mellifera L.) during winter months has been practiced for decades to protect colonies from the adverse effects of long, harsh winter months. Beekeepers have recently employed indoor storage to reduce labor, feeding costs, theft, and woodenware degradation. Despite the growing number of colonies stored indoors, national survey results still reveal high losses. Varroa mites (Varroa destructor Anderson and Trueman) are the most critical threat to colony winter survival and health of colonies because they contribute to the transmission of viruses and colony mortality. To investigate the effect of high CO2 on varroa mites during the indoor storage of honey bees, 8-frame single deep colonies were stored in two separate environmental chambers at 4°C each. One environmental chamber was set at 8.5% CO2 (high CO2), while the other was set at low CO2 (0.12%). Dead and falling mites were collected and counted from the bottom of individual colonies weekly during the experiment. There was a significant difference in mite mortality of colonies with high CO2 compared to colonies held at low CO2. These results indicated that high CO2 could increase mite mortality during the period of indoor storage, potentially improving honey bee health coming out of the winter months. Our research offers a critical addition to beekeepers' tools for managing varroa mite populations.

Enhanced lipid productivity coupled with carbon and nitrogen removal of the diatom Skeletonema costatum cultured in the high CO2 level

Rising CO2 is causing noticeable environmental and social problems and thus to reduce CO2 emission is becoming extremely urgent. Biodiesel from microalgae is considered to have immense potential in replacing fossil fuels and reducing CO2 emission, apart from remediating eutrophic waters. How to increase biodiesel yield with low cost is the key for successful application of biofuel. In this study, we used high CO2 concentration (5%) to culture the marine diatom Skeletonema costatum and aimed to enhance lipid productivity through the combination of low temperature shock. High CO2 first inhibited the specific growth rate but then increased it after a 24 h pause of gas supply. High CO2 increased lipid content by 26.8% and lipid productivity by 29.0%; the combination with low temperature shock resulted in a further stimulation (50.0% for lipid content and 42.5% for lipid productivity). High CO2 also stimulated carbon and nitrogen assimilation, leading to the increase of carbon and nitrogen removal rates by 28.9% and 22.7%, respectively; while low temperature shock did not show a significant effect. High CO2 increased maximum photochemical efficiency but reduced non-photochemical quenching, with insignificant effects of low temperature shock on either. Therefore, the stimulating effects of high CO2 on lipid accumulation could be attributed to increased photosynthetic performance because photosynthesis can supply ATP and carbon skeleton for lipid synthesis. These findings indicate the success of the combination of high CO2 and low temperature shock in enhancing algal lipid yield and bioremediation capacity.

Elevated CO2 and Temperature Resetting the Expression of Resistance, Pest Incidence, Geographical Distribution and Physiology in Insect-pests of Grain Legumes: A Review

The most important factor that affects the crop production in terms of nutritional content of foliar plants is the global climate change. Herbivore’s growth, development, survival and geographical distribution all are determined by elevated CO2 and temperature. The interactions between herbivores and plants have changed due to increasing level of CO2 and temperature. The effect of high CO2 and temperature on grain legume plant which change in to plant physiology (e.g., nutritional content, foliage biomass) and how it change in herbivory metabolism rate and food consumption rate. Plant injury is determined by two factors viz. resistance and tolerance and both are influenced by greater CO2 and temperature. Legumes are an important source of food and feed in the form of proteins and also improve the soil environment. The repercussions of the abiotic factors mentioned above needs discussion among the scientific community. We may able to limit the negative repercussions of stated factors in future breeding projects by harnessing the practical favourable impacts and by including such influences of elevated CO2 and temperature on pulses productivity. The extensive research is necessary to overcome the negative effects of high CO2 and temperature on insect-plant interaction.

Effects of high CO2 on the quality and antioxidant capacity of postharvest blueberries (Vaccinium spp.)

Effects of high CO2 on the quality and antioxidant capacity of postharvest blueberries (Vaccinium spp.)

High-CO2 Treatment Prolongs the Postharvest Shelf Life of Strawberry Fruits by Reducing Decay and Cell Wall Degradation

Improved methods are needed to extend the shelf life of strawberry fruits. The objective of this study was to determine the postharvest physiological mechanism of high-CO2 treatment in strawberries. Harvested strawberries were stored at 10 °C after 3 h of exposure to a treatment with 30% CO2 or air. Pectin and gene expression levels related to cell wall degradation were measured to assess the high-CO2 effects on the cell wall and lipid metabolism. Strawberries subjected to high-CO2 treatment presented higher pectin content and firmness and lower decay than those of control fruits. Genes encoding cell wall-degrading enzymes (pectin methylesterase, polygalacturonase, and pectate lyase) were downregulated after high-CO2 treatment. High-CO2 induced the expression of oligogalacturonides, thereby conferring defense against Botrytis cinerea in strawberry fruits, and lowering the decay incidence at seven days after its inoculation. Our findings suggest that high-CO2 treatment can maintain strawberry quality by reducing decay and cell wall degradation.

Long-term effects of high CO2 on growth and survival of juveniles of the striped venus clam Chamelea gallina: implications of seawater carbonate chemistry

Long-term effects of high CO2 on growth and survival of juveniles of the striped venus clam Chamelea gallina: implications of seawater carbonate chemistry

Effect of high CO2 atmospheric packaging on postharvest quality of fresh pistachio fruits (‘Badami’)

Effect of high CO₂ atmospheric packaging on postharvest quality of fresh pistachio fruits (‘Badami’)

Future CO2 , warming and water deficit impact white and red Tempranillo grapevine: Photosynthetic acclimation to elevated CO2 and biomass allocation.

Due to the CO2 greenhouse effect, elevated atmospheric concentration leads to higher temperatures, accompanied by episodes of less water availability in semiarid and arid areas or drought periods. Studies investigating these three factors (CO2 , temperature and water availability) simultaneously in grapevine are scarce. The present work aims to analyze the combined effects of high CO2 (700 ppm), high temperature (ambient +4°C) and drought on the photosynthetic activity, biomass allocation, leaf non-structural carbon composition, and carbon/nitrogen (C/N) ratio in grapevine. Two grapevine cultivars, red berry Tempranillo and white berry Tempranillo, were used, the latter being a natural, spontaneous mutant of the red cultivar. The experiment was performed on fruit-bearing cuttings during a 3-month period, from June (fruit set) to August (maturity). The plants were grown in research-oriented facilities, temperature-gradient greenhouses, where temperature, CO2 , and water supply can be modified in a combined way. Drought had the strongest effect on biomass accumulation compared to the other environmental variables, and root biomass allocation was increased under water deficit. CO2 and temperature effects were smaller and depended on cultivar, and on interactions with the other factors. Acclimation effects were observed on both cultivars as photosynthetic rates under high atmospheric CO2 were reduced by long-term exposition to elevated CO2 . Exposure to such high CO2 resulted in increased starch concentration and reduced C/N ratio in leaves. A correlation between the intensity of the reduction in photosynthetic rates and the accumulation of starch in the leaves was found after prolonged exposure to elevated CO2 .

Effects of high CO2 and low O2 on biochemical changes in cut Dendrobium orchids

Exportation of cut flowers entails long distance transportation, and the quality of cut flowers deteriorates as the distance and transportation time increase. Low storage temperatures and modified atmosphere are commonly used to extend the life of cut flowers. As a result, this research explored the potential use of high CO2 and low O2 to prolong the shelf life of cut flowers. Specifically, this study examined the effects of high CO2 and low O2 storage on the biochemical changes in cut Dendrobium pink stripe orchid flowers. The experiments were conducted under normal and high CO2 and low O2 conditions, and results were compared. Under the normal condition, carbon dioxide (CO2) and oxygen (O2) concentrations were 0.03 % and 21 %. In the high CO2 and low O2 environment, CO2 was varied between 5 and 10 %; and O2 between 2, 4, 6, and 8 %. The storage temperature and relative humidity were 13 °C and 95 %. The originality of this work is the use of high CO2 and low O2 storage environments to investigate the biochemical changes in cut Dendrobium orchid flowers. The experimental results showed that high CO2 and low O2 significantly enhanced the storage life of Dendrobium orchid flowers (p < 0.05). The longest storage life of 28.33 days was achieved under 5 % CO2 and 2 % O2 atmosphere condition, compared with 11.67 days under the normal atmosphere condition. High CO2 and low O2 storage also helped to retain total anthocyanin content while lowering fresh weight loss, respiration rate, ethylene production, protein degradation, and protease activity.

Short-term responses to ocean acidification: effects on relative abundance of eukaryotic plankton from the tropical Timor Sea

Anthropogenic carbon dioxide (CO2) emissions drive climate change and pose one of the major challenges of our century. The effects of increased CO2in the form of ocean acidification (OA) on the communities of marine planktonic eukaryotes in tropical regions such as the Timor Sea are barely understood. Here, we show the effects of high CO2(mean ± SDpCO2= 1823 ± 161 μatm and pHT= 7.46 ± 0.05) versusin situCO2(504 ± 42 µatm, 7.95 ± 0.04) seawater on the community composition of marine planktonic eukaryotes after 3 and 48 h of treatment exposure in a shipboard microcosm experiment. Illumina sequencing of the V9 hypervariable region of 18S rRNA (gene) was used to study the eukaryotic community composition. Increased CO2significantly suppressed the relative abundances of different eukaryotic operational taxonomic units (OTUs), including important primary producers, although the chlorophyllaconcentration remained constant. OA effects on eukaryotes were consistent between total (DNA-based) and active (cDNA-based) taxa after 48 h, e.g. for the diatomsTrieres chinensisandStephanopyxis turris.Effects of OA on the relative abundances of OTUs were often species- or even ecotype-specific, and the incubation selectively allowed for detection of the OA-sensitive OTUs that benefitted the most from incubation in a closed bottle, as containment effects on the community structure were evident after 48 h. Many OTUs were adversely affected by sudden decreases of seawater pH, suggesting high sensitivity to OA at the base of the tropical marine biodiversity and difficult-to-predict outcomes for food-web functioning in the future ocean.

Hypercapnia Regulates Gene Expression and Tissue Function.

Carbon dioxide (CO2) is produced in eukaryotic cells primarily during aerobic respiration, resulting in higher CO2 levels in mammalian tissues than those in the atmosphere. CO2 like other gaseous molecules such as oxygen and nitric oxide, is sensed by cells and contributes to cellular and organismal physiology. In humans, elevation of CO2 levels in tissues and the bloodstream (hypercapnia) occurs during impaired alveolar gas exchange in patients with severe acute and chronic lung diseases. Advances in understanding of the biology of high CO2 effects reveal that the changes in CO2 levels are sensed in cells resulting in specific tissue responses. There is accumulating evidence on the transcriptional response to elevated CO2 levels that alters gene expression and activates signaling pathways with consequences for cellular and tissue functions. The nature of hypercapnia-responsive transcriptional regulation is an emerging area of research, as the responses to hypercapnia in different cell types, tissues, and species are not fully understood. Here, we review the current understanding of hypercapnia effects on gene transcription and consequent cellular and tissue functions.