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Aims: Studies dealing with plants' mineral nutrient status under elevated atmospheric CO2 concentration (eCO2) are usually conducted in closed hydroponic systems, in which nutrient solutions are entirely renewed every several days. Here, we investigated the contribution of the fluctuation of concentrations of N ([N]), P ([P]), and K ([K]) in nutrient solutions in this short period on their concentrations in cucumber plants exposed to different [CO2] and N levels. Methods: Cucumber (Cucumis sativus L.) plants were hydroponically grown under two [CO2] and three N levels. [N], [P], and [K] in nutrient solutions and cucumber plants were analyzed. Results: The transpiration rate (Tr) was significantly inhibited by eCO2, whereas Tr per plant was increased due to the larger leaf area. Elevated [CO2] significantly decreased [N] in low N nutrient solutions, which imposed an additional decrease in [N] in plants. [P] in nutrient solutions fluctuated slightly, so the change of [P] in plants might be attributed to the dilution effect and the demand change under eCO2. [K] in moderate and high N nutrient solutions were significantly decreased, which exacerbated the [K] decrease in plants under eCO2. Conclusions: The short-term fluctuation of [N] and [K] in nutrient solutions is caused by the asynchronous uptakes of N, K, and water under eCO2, which has an appreciable influence on [N] and [K] in plants besides the dilution effect. This defect of the closed hydroponic system may let us exaggerate the negative impact of eCO2 itself on [N] and [K] in plants. [ABSTRACT FROM AUTHOR]

The morphology analysis of arc plasma inside a low‐voltage circuit breaker is a practical approach to investigate its current interruption performance. It is a typical ill‐posed problem to determine the arc current distribution from the induced magnetic field of arc plasma. The regularization method has been proven effective in solving inverse magnetic problems. However, the arrangement of current‐carrying conductors in arc chamber and the time‐varying characteristics of arc plasma make it difficult to yield a reasonable inverse solution. In this paper, a heuristic search algorithm is proposed. The solving procedure is as follows. First, a series of inverse models with supposed arc root positions are created dynamically. Second, the Tikhonov regularization method with quasi‐optimality criterion is applied to solve the inverse problems iteratively. Then each solution is evaluated and the best solution can be found out. After all the models according to the different arcing stages have been solved, an image list of current density distribution of arc plasma is formed. An experimental system measuring the 2D magnetic field of arc plasma has been built, in which a 64‐unit hall‐effect sensor array and the corresponding data acquisition system are adopted to detect the arc magnetic field; meanwhile, the waveforms of arc voltage and current are recorded by a digital oscilloscope and the optical images of arc plasma are captured by a high speed charge‐coupled device camera. The experimental results show that the inverse results of arc current density distribution are in accordance with the optical images. The proposed inverse method provides a noninvasive technique for the diagnosis of arc plasma. [ABSTRACT FROM AUTHOR]

Background and Aims Soil acidity currently limits root growth and crop production in many regions, and climate change is leading to uncertainties regarding future food supply. However, it is unknown how elevated CO2 (eCO2) affects the performance of wheat crops in acid soils under field conditions. We investigated the effects of eCO2 on plant growth and yield of three pairs of near-isogenic hexaploid wheat lines differing in alleles of aluminium-resistant genes TaALMT1 (conferring root malate efflux) and TaMATE1B (conferring citrate efflux). Methods Plants were grown until maturity in an acid soil under ambient CO2 (aCO2; 400 µmol mol−1) and eCO2 (550 µmol mol−1) in a soil free-air CO2 enrichment facility (SoilFACE). Growth parameters and grain yields were measured. Key Results Elevated CO2 increased grain yield of lines carrying TaMATE1B by 22 % and lines carrying only TaALMT1 by 31 %, but did not increase the grain yield of Al3+-sensitive lines. Although eCO2 promoted tiller formation, coarse root length and root biomass of lines carrying TaMATE1B, it did not affect ear number, and it therefore limited yield potential. By contrast, eCO2 decreased or did not change these parameters for lines carrying only TaALMT1, and enhanced biomass allocation to grains thereby resulting in increased grain yield. Despite TaMATE1B being less effective than TaALMT1 at conferring Al3+ resistance based on root growth, the gene promoted grain yield to a similar level to TaALMT1 when the plants were grown in acid soil. Furthermore, TaALMT1 and TaMATE1B were not additive in their effects. Conclusions As atmospheric CO2 increases, it is critical that both Al3+-resistance genes (particularly TaALMT1) should be maintained in hexaploid wheat germplasm in order for yield increases from CO2 fertilization to be realized in acid soils. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Elevated carbon dioxide (CO2) and nitrogen (N) availability can interactively promote cucumber yield, but how the yield increase is realized remains unclear, whilst the interactive effects on fruit quality are unknown. In this study, cucumber plants (Cucumis sativus L. cv. Jinmei No. 3) were grown in a paddy soil under three CO2 concentrations – 400 (ambient CO2), 800 (elevated CO2, eCO2) and 1200 µmol mol−1 (super‐elevated CO2) – and two N applications – 0.06 (low N) and 0.24 g N kg−1 soil (high N). RESULTS: Compared with ambient CO2, eCO2 increased yield by 106% in high N but the increase in total biomass was only 33%. This can result from greater carbon translocation to fruits from other organs, indicated by the increased biomass allocation from stems and leaves, particularly source leaves, to fruits and the decreased concentrations of fructose and glucose in source leaves. Super‐elevated CO2 reduced the carbon allocation to fruits thus yield increase (71%). Additionally, eCO2 also increased the concentrations of fructose and glucose in fruits, maintained the concentrations of dietary fiber, phosphorus, potassium, calcium, magnesium, sulfur, manganese, copper, molybdenum and sodium, whilst it decreased the concentrations of nitrate, protein, iron, and zinc in high N. Compared with eCO2, super‐elevated CO2 can still improve the fruit quality to some extent in low N availability. CONCLUSIONS: Elevated CO2 promotes cucumber yield largely by carbon allocation from source leaves to fruits in high N availability. Besides a dilution effect, carbon allocation to fruits, carbohydrate transformation, and nutrient uptake and assimilation can affect the fruit quality. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 (eCO2) enhances the yield of vegetables and could also affect their nutritional quality. We conducted a meta-analysis using 57 articles consisting of 1,015 observations and found that eCO2 increased the concentrations of fructose, glucose, total soluble sugar, total antioxidant capacity, total phenols, total flavonoids, ascorbic acid, and calcium in the edible part of vegetables by 14.2%, 13.2%, 17.5%, 59.0%, 8.9%, 45.5%, 9.5%, and 8.2%, respectively, but decreased the concentrations of protein, nitrate, magnesium, iron, and zinc by 9.5%, 18.0%, 9.2%, 16.0%, and 9.4%. The concentrations of titratable acidity, total chlorophyll, carotenoids, lycopene, anthocyanins, phosphorus, potassium, sulfur, copper, and manganese were not affected by eCO2. Furthermore, we propose several approaches to improving vegetable quality based on the interaction of eCO2 with various factors, including species, cultivars, CO2 levels, growth stages, light, O3 stress, nutrient, and salinity. Finally, we present a summary of the eCO2 impact on the quality of three widely cultivated crops, namely, lettuce, tomato, and potato. [ABSTRACT FROM AUTHOR]

Background & aim: It is unclear how elevated CO2 (eCO2) affects the response of crops to soil acidity. This study examined the effect of eCO2 on acid-soil tolerance of hexaploid wheat genotypes that vary in Al3+ resistance due to differences in root efflux of citrate and malate.Methods: Three pairs of near-isogenic lines were grown for 24-25 days under ambient CO2 (400 µmol mol-1) and eCO2 (800 µmol mol-1) in acid soils and hydroponics with various Al3+ concentrations. The lines consisted of pairs that differed in alleles of the TaALMT1 and TaMATE1B genes. Plant growth parameters and rhizosphere soil properties were measured.Results: Elevated CO2 increased the slope of negative correlations between root and shoot biomass and Al3+ concentration in the rhizosphere of a line that has an Al3+-sensitive allele of the TaALMT1 gene conditioning malate efflux (ES8), but did not change that of a near-isogenic sister line with an Al3+-resistant TaALMT1 allele (ET8). Elevated CO2 decreased the relative root length and biomass (% of limed soil) of a line that lacked both malate and citrate efflux (Egret), but did not affect lines that possessed either malate or citrate efflux. Elevated CO2 had no effect on either malate or citrate efflux from root tips of Al3+-resistant lines. Elevated CO2 also increased Al3+ concentration and decreased NH4+ concentration in rhizosphere soil, but decreased concentrations of Al and Zn in shoots.Conclusions: Elevated CO2 decreased acid-soil tolerance of Al3+sensitive genotypes but not of Al3+ resistant genotypes. Malate efflux played a dominant role in conferring acid-soil tolerance to hexaploid wheat. [ABSTRACT FROM AUTHOR]

Aims: Nitrogen supply and atmospheric CO2 concentration ([CO2]) could influence root exudates directly by altering compound concentrations in roots and indirectly by regulating root morphology. This study assessed these direct and indirect effects on cucumber root exudation.Methods: Cucumber roots with various morphological traits were obtained in different combinations of nitrogen supplies and [CO2] treatments. Then, the correlations between ten compounds in root exudates and their concentrations in root extracts as well as root morphological traits were evaluated.Results: In case of root exudates, the amounts of sugars were more closely correlated to the root surface area, whereas organic acids and amino acids were more closely associated with the number of root tips. Moreover, fructose, glucose, sucrose and oxalic acid in root exudates were correlated to their concentrations in root extracts, whereas there was little correlation between root exudates and extracts for malic acid, citric acid or four amino acids.Conclusions: Sugars were probably released from the whole roots by passive or facilitated diffusion, so both the direct and indirect effects were important. Organic acids and amino acids were mainly secreted from the root apices by active transport, thus the indirect effect was more important. [ABSTRACT FROM AUTHOR]

This article studied the effects of nitrogen (N) and CO2enrichment on biomass and N accumulation and partitioning of cucumber grown in open top chambers. At the seedling stage, elevated CO2increased the biomass and N content of the entire plant. The root had the largest increase in biomass and N content among the organs and more biomass allocation. The largest drops of N concentration showed in root at moderate and high N, in leaf at low N, respectively. Elevated CO2increased stem biomass allocation at moderate and high N, but decreased leaf biomass allocation at all N levels. At the initial fruit stage, the response to elevated CO2of biomass and N content decreased. Elevated CO2increased biomass allocation to leaf and resulted in the largest drop of leaf N concentration at low and moderate N supply. High N supply promoted biomass production and N reallocation from the leaf to fruit, but decreased leaf biomass allocation. Thus, biomass allocation is initially affected by root–shoot growth balance to adapt to enriched CO2, leading to the largest root growth, then biomass allocates to another sink (stem). Long exposure of elevated CO2results in photosynthetic acclimation in deficient N supply, which probably attributes to excessive stem and leaf biomass allocation and shortage of fruit storage. But high N shifts biomass allocation from leaf to fruit. Practically, sufficient N supply is needed for an efficient transport of carbohydrates to fruits and increases the yields under elevated CO2. [ABSTRACT FROM PUBLISHER]

Global human health and sustainable production are threatened by an imbalance and deficiency of plant-based diet vegetable consumption across countries worldwide. Here, we analyzed the data on vegetable consumption, production, trade and eating habits. In addition, we conducted the predictions of vegetable supply in 2030, 2050, and when reached a plateau. The vegetable supply is predicted to increase from 386 g capita−1 day−1 in 2018 by 23–26 g capita−1 day−1 in 2030 and by 97–112 g capita−1 day−1 when it reached a plateau, lower than the recommended level of vegetable intake (300 g capita−1 day−1) when frequently concerning 50% vegetable lose and waste. The regions or countries with top vegetable supply are centred at global vegetable belt, e.g. Eastern Asia, Central Asia, and the Mediterranean basin, including Southern Europe and North Africa. The top vegetable supply is due to climate-dependent greater yield than the area harvested per capita. The regions not far from the global vegetable belt, e.g. South-eastern (Viet Nam), Western Africa (Niger and Mali), and Southern Asia (India), had moderate vegetable supply. These regions are predicted to increase the area harvested more than the yield to keep up with the relatively high vegetable supply in 2030. The developed regions, e.g. Northern America and Western Europe, cannot ensure the required vegetable supply by increased import and yield. Whilst the meat-preferred Caribbean, Central and South America, South-eastern Asia, and Southern Africa currently and will maintain low levels of vegetable supply. Sufficient vegetable supply cannot be guaranteed due to increased meat prefer of customers and decreased vegetable requirements potentially due to urban lifestyle and modern vegetable supply systems. Herein, it is required to reshape the dietary pattern to encourage vegetable intake and increase vegetable availability by fully utilizing the local climate primarily, and then increasing harvested area and advanced horticultural technology, thus achieving sustainable food production and a healthy diet. [ABSTRACT FROM AUTHOR]

Greenhouse cultivation forms a relatively closed environment for heat preservation in winter, which inevitably leads to a lack of atmospheric CO 2 concentration ([CO 2 ]), and thus low [CO 2 ] level has become a limiting factor for the photosynthesis and growth of greenhouse vegetables. Most cucurbits and solanaceous vegetables are sensitive to low temperature, but it is difficult to keep the optimum root-zone temperature (RZT) for them in greenhouse soil cultivation in winter. Therefore, low RZT is another limiting factor for greenhouse vegetables growth in winter. This study investigated the effects of [CO 2 ], RZT, and their interactions on cucumber yield, growth, photosynthesis, and photosynthate allocation in four open-top chambers for a growth period of 73 days after transplanting. We found elevated RZT increased yield and total dry weight of cucumber plants to a greater extent than elevated [CO 2 ]. We also observed long-term elevated [CO 2 ] limited the increase of net photosynthetic rate (Pn) and decreased the stomatal conductance (Gs) and transpiration rate (Tr) of cucumber plants at ambient RZT, resulted in the photosynthetic acclimation, as illustrated by the significant reduction of nitrogen concentration and the increased concentrations of soluble sugar and starch in leaves. In comparison, the combination of elevated [CO 2 ] and RZT decreased the concentrations of soluble sugar and starch and maintained the nitrogen concentration in leaves, which caused a higher Pn, Gs and Tr. Meanwhile, more soluble sugar and starch were allocated from leaves to roots due to the higher root respiratory under elevated [CO 2 ] and RZT treatment. Moreover, elevated RZT could facilitate the mineral nutrients absorption by roots and the upward transportation because of the larger root system and higher Tr. Therefore, elevated RZT could offset the decrease in Pn and improve Gs and Tr under elevated [CO 2 ], which indicated an alleviation of the photosynthetic acclimation of cucumber plants exposed to long-term elevated [CO 2 ]. [Display omitted] • Root-zone temperature (RZT) had a greater impact on cucumber dry weight than CO 2 concentration ([CO 2 ]). • Long-term elevated [CO 2 ] caused photosynthetic acclimation at ambient RZT. • Elevated RZT was favorable for transporting photosynthate from leaves to roots. • Elevated RZT promoted the nitrogen absorption by roots and upward transportation. • Elevated RZT alleviated the photosynthetic acclimation of cucumber plants. [ABSTRACT FROM AUTHOR]

Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s11104-021-05050-4. B Correction to: Plant Soil b https://doi.org/10.1007/s11104-021-04993-y The original version of the article unfortunately contains a mistake introduced during the production phase. [Extracted from the article]

Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s11104-021-05050-4. B Correction to: Plant Soil b https://doi.org/10.1007/s11104-021-04993-y The original version of the article unfortunately contains a mistake introduced during the production phase. [Extracted from the article]

Boundary properties, collage and collision time of Erguna and Xing'an block, and old crystal substrate of the blocks are basic geological scientific issues for studying the evolution of north Great Xing'an Range. This study reviewed researches on Erguna and Xing'an block in the past years, and summarized two major problems: one is collage and collision time of both blocks; the other is ancient crystal substrate of the blocks. The two problems are significant for understanding tectonic-magma evolution of the north Great Xing'an Range. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO 2 (eCO 2) concentration can increase root exudation into soils, which improves plant tolerance to abiotic stresses. This review used a meta-analysis to assess effect sizes of eCO 2 on both efflux rates and total amounts of some specific root exudates, and dissected whether eCO 2 enhances plant's resistance to nutrient deficiency and ion toxicity via root exudates. Elevated CO 2 did not affect efflux rates of total dissolved organic carbon, a measure of combined root exudates per unit of root biomass or length, but increased the efflux amount of root systems per plant by 31% which is likely attributed to increased root biomass (29%). Elevated CO 2 increased efflux rates of soluble-sugars, carboxylates, and citrate by 47%, 111%, and 16%, respectively, but did not affect those of amino acids and malate. The increased carbon allocation to roots, increased plant requirements of mineral nutrients, and heightened detoxification responses to toxic ions under eCO 2 collectively contribute to the increased efflux rates despite lacking molecular evidence. The increased efflux rates of root exudates under eCO 2 were closely associated with improved nutrient uptake whilst less studies have validated the associations between root exudates and resistance to toxic ions of plants when grown under eCO 2. Future studies are required to reveal how climate change (eCO 2) affect the efflux of specific root exudates, particularly organic anions, the corresponding nutrient uptake and toxic ion resistance from plant molecular biology and soil microbial ecology perspectives. Unlabelled Image • Elevated CO 2 (eCO 2) increases total efflux of root exudates from root systems. • Elevated CO 2 increases efflux rates of soluble sugars, carboxylates and citrate. • Increased root exudation enhances nutrient uptake under eCO 2. • Contributions of root exudates to toxic-ion resistance under eCO 2 need further validation. [ABSTRACT FROM AUTHOR]