Environmental and Experimental Botany最新文献

{"title":"Rhizosphere characteristics combined with physiology and transcriptomics reveal key metabolic pathway responses in Dendrobium officinale upon exposure to calcium-rich karst environments","authors":"Guangying Du ,&nbsp;Ying Zhou ,&nbsp;Chang Liu ,&nbsp;Mansour Ghorbanpour ,&nbsp;Yingyue Hou ,&nbsp;Jing Li","doi":"10.1016/j.envexpbot.2025.106115","DOIUrl":"10.1016/j.envexpbot.2025.106115","url":null,"abstract":"<div><div><em>Dendrobium officinale</em> is a calcicolous herb that adapts to calcium-rich karst environments. However, the mechanism through which <em>D. officinale</em> copes with high calcium stress in karst environments is unclear. In this study, limestone was used as the primary bedrock for cultivating <em>D. officinale</em> in karst areas. The relative calcium content in calcite, which makes up limestone, was 97.46 %, and the total calcium content in black limestone soil was 81.66 mg g⁻¹. Total calcium accumulation in black limestone soil showed a positive correlation with organic matter content, pH, and the dominant microbial groups <em>Firmicutes</em> and <em>Fungi_phy_Incertae_sedis</em> in black limestone soil. Long-term calcium-rich environments induced calcium accumulation and mannose synthesis in the stems of <em>D. officinale</em> grown in karst areas. High calcium stress upregulated the genes implicated in calcium signalling, abiotic stress signalling, mannan degradation, ascorbate biosynthesis, and oxalate transport, including calmodulin-like protein, ascorbate peroxidase 4, and mannan endo-1,4-beta-mannosidase 2 genes, in <em>D. officinale</em> stems. Additionally, high-concentration water-soluble calcium ion stress increased the mannose, ascorbic acid, and calcium oxalate content in the stems of <em>D. officinale</em>. These findings highlight the influence of microbial communities and the physicochemical properties of black limestone soil on high calcium content, as well as the value of calcium oxalate accumulation and the d-mannose pathway of ascorbate biosynthesis in revealing strategies for <em>D. officinale</em> to alleviate calcium-rich soil in karst environments.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106115"},"PeriodicalIF":4.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant plasticity in the face of climate change – CO2 offsetting effects to warming and water deficit in wheat. A review","authors":"Meije Gawinowski ,&nbsp;Karine Chenu ,&nbsp;Jean-Charles Deswarte ,&nbsp;Marie Launay ,&nbsp;Marie-Odile Bancal","doi":"10.1016/j.envexpbot.2025.106113","DOIUrl":"10.1016/j.envexpbot.2025.106113","url":null,"abstract":"<div><div>Future crop production will depend on plant plasticity in response to increases in atmospheric CO₂, mean temperature, heatwave and drought events. The present review intends to highlight the impact of interactions between high CO₂ levels, warming and water deficit in existing published experimental data in the case of wheat. To do so, we identified experiments quantifying the effects of such interactions on traits related to crop productivity and water use. We used the collected data to estimate plasticity indices assessing compensation and interaction between elevated CO₂ and adverse climatic conditions, bringing a new perspective on the matter. In the studied data, even though there is an important variability, we found that crop productivity tends to decrease despite the positive effects of the rise in CO₂ concentration. Conversely, with elevated CO₂, water consumption tends to decrease despite the warmer conditions. We hypothesized that the positive effect of CO₂ on crop productivity is greater under drought conditions, which is confirmed in 54 % of the experiments. This review highlights the need to acquire further experimental data under possible future conditions to calibrate and validate crop models: their range of validity requires more thorough testing under the wide range of projected environmental conditions.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106113"},"PeriodicalIF":4.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of the nitrate transporter NRT1.1 in plant iron homeostasis and toxicity on ammonium","authors":"Guangjie Li ,&nbsp;Zhaoyue Wang ,&nbsp;Lin Zhang ,&nbsp;Herbert J. Kronzucker ,&nbsp;Gui Chen ,&nbsp;Yanqin Wang ,&nbsp;Weiming Shi ,&nbsp;Yan Li","doi":"10.1016/j.envexpbot.2025.106112","DOIUrl":"10.1016/j.envexpbot.2025.106112","url":null,"abstract":"<div><div>Ammonium (NH₄⁺) is toxic to root growth in most plants, and NH₄⁺ toxicity has been linked to disruptions in plant Fe homeostasis. However, only a few genes have been linked to the disruption of Fe homeostasis under NH₄⁺ nutrition, and pathway details have as yet to be resolved. Here, using RNA-seq analysis and RT-qPCR, we explore the response of different genes expressed in the roots of Fe-replete and Fe-starved Arabidopsis plants under NH₄⁺ conditions. The Nitrate Transporter 1.1 (NRT1.1) gene, known to code for a dual-affinity nitrate transporter, but not other NRTs genes, was specifically induced in Fe-replete plants in response to NH₄⁺ provision. NRT1.1 antagonizes NH₄⁺-dependent Fe accumulation, and this antagonism requires NO₃^- supply. Constitutively expressing NRT1.1 confers higher NO₃^- uptake and reduces NH₄⁺-dependent Fe accumulation by increasing pH in the rhizosphere. Building on previous evidence establishing the involvement of root Fe accumulation in the root growth response to elevated NH₄⁺, our study shows that NRT1.1-mediated nitrate uptake curtails symptoms of NH₄⁺ toxicity under elevated NH₄⁺ and in the presence of NO₃^-, by increasing rhizospheric pH, offering new insights into possible pathways for improving the tolerance to NH₄⁺ toxicity in plants.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106112"},"PeriodicalIF":4.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MhbHLH122-MhCLC-c1 regulates Malus hupehensis chloride salt tolerance by promoting Cl- efflux","authors":"Xiaoyue Zhu,&nbsp;Jianfei Song,&nbsp;Wenran Liu,&nbsp;Bing Chen,&nbsp;Jiaxin Lv,&nbsp;Xiaojian Zhang,&nbsp;Weiwei Zhang,&nbsp;Hongqiang Yang","doi":"10.1016/j.envexpbot.2025.106109","DOIUrl":"10.1016/j.envexpbot.2025.106109","url":null,"abstract":"<div><div>Chloride channels (CLCs) are crucial for adapting plants to salt stress. However, the mechanism by which CLCs regulate plants’ responses to chloride salt stress remains unclear. This study identified a basic helix-loop-helix (bHLH) transcription factor, MhbHLH122, which positively regulated <em>MhCLC-c1</em> transcription. The transcription of <em>MhbHLH122</em> was induced by chloride salt stress. Under conditions of chloride salt stress, <em>M. hupehensis</em> [<em>Malus hupehensis</em> (Pamp.) Rehd. var. <em>pingyiensis</em> Jiang] hairy root-composite plants with <em>MhbHLH122</em> overexpressed alone, <em>MhCLC-c1</em> overexpressed alone, and both of them overexpressed together, as well as <em>Arabidopsis thaliana</em>, all showed a decrease in the relative cell death rate, the content of malondialdehyde (MDA), the content of hydrogen peroxide (H₂O₂), and the production rate of superoxide anion (O₂^-.). Furthermore, in the ‘Orin’ apple calli with suppression of <em>MhbHLH122</em>, the expression level of <em>MhCLC-c1</em> was down-regulated and it was more sensitive to chloride salt stress. Under conditions of chloride salt stress, overexpression of <em>MhCLC-c1</em> promoted the efflux of Cl^- from <em>M. hupehensis</em> hairy root-composite plants. Moreover, the Cl^- efflux rate was further increased after <em>MhbHLH122</em> was over-expressed in the <em>MhCLC-c1-</em>overexpression plants. Therefore, MhbHLH122 can regulate Cl^- efflux in the root system by upregulating <em>MhCLC-c1</em> expression, thereby enhancing the tolerance of plants to chloride salt stress.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106109"},"PeriodicalIF":4.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A meta-analysis of crop leaf gas exchange responses to elevated CO2 and water deficits using optimal stomatal theory","authors":"Bin Du ,&nbsp;M.K. Shukla ,&nbsp;Taisheng Du","doi":"10.1016/j.envexpbot.2025.106107","DOIUrl":"10.1016/j.envexpbot.2025.106107","url":null,"abstract":"<div><div>Elevated atmospheric CO₂ concentrations (eCO₂) and soil water deficits significantly influence gas exchange in plant leaves. However, it remains unclear whether crops optimize carbon assimilation and water dissipation processes in response to eCO₂ and water deficit. Through a comprehensive dataset, we quantified the responses of leaf gas exchange induced by eCO₂ under water deficit, and tested whether the optimal stomatal theory could predict gas exchange responses to elevated atmospheric CO₂ between two typical C3 (wheat) and C4 crops (maize). Our results showed that leaf-scale WUE increased in proportion to increasing eCO₂ for all crops under various water conditions, and there exhibited stronger effects of eCO₂ on reductions in g_s than increases in P_n. A significantly lower stimulatory effect of eCO₂ on maize photosynthesis was observed compared to wheat. This difference is attributed to the distinct physiological characteristics of C4 and C3 plants, with P_n of C4 plants generally showing a less pronounced response to elevated CO₂ due to their different carbon fixation pathways. The eCO₂-induced stimulation of P_n was reduced by the water deficit, and there was a synergistic effect of eCO₂ and water deficit on the g_s and T_r reduction, resulting in further reduction in g_s and T_r under water deficit and eCO₂ condition. The optimal g_s model correctly captured stomatal behavior with eCO₂ across most of datasets in different CO₂ application growth conditions. The stomatal slope parameter (g₁) in optimal stomatal model was lower for maize than wheat, and g₁ exhibited strong species specificity in magnitude and sensitivity to water and CO₂. Under eCO₂ conditions, g₁ increased slightly in wheat but decreased in maize. Incorporating the sensitivity parameters derived from different water levels can avoid significant overestimation of evapotranspiration for possible high-CO₂ scenarios in the future.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106107"},"PeriodicalIF":4.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vulnerability of Brassica oleracea L. (cabbage) grown in microplastic-contaminated soil to extreme climatic events associated with freeze-thaw","authors":"Kyungwon Min ,&nbsp;Gyuwon Kim ,&nbsp;Hyoungseok Lee ,&nbsp;Young-Kwan Kim ,&nbsp;Sung-Eun Lee ,&nbsp;Sang-Ryong Lee","doi":"10.1016/j.envexpbot.2025.106110","DOIUrl":"10.1016/j.envexpbot.2025.106110","url":null,"abstract":"<div><div>Climate change and environmental pollution have increased the frequency and severity of extreme weather events, exposing plants to multifactorial stress conditions that are poorly understood. While extensive research has explored plant responses to individual stress factors, the impact of combined stresses—such as microplastic (MP) contamination and freeze-thaw cycles—remains largely unexamined. This research investigated how soil microplastic pollution affects the freezing tolerance of cabbage (<em>Brassica oleracea</em> L.), a crop vulnerable to unexpected frosts. Seedlings were grown in soils containing varying MP concentrations (0 %, 2 %, 5 %, and 10 % w/w), and their physiological responses to freezing events (-2.5°C and −3.5°C) were assessed. Our findings revealed that although MP particles were not detected in leaf tissues, MP contamination significantly reduced freezing tolerance in a dose-dependent manner. Plants grown in 10 % MP-treated soil exhibited higher membrane damage, as indicated by increased ion leakage and malondialdehyde levels, and showed more severe oxidative stress, with elevated superoxide (O₂^•-) and hydrogen peroxide (H₂O₂) accumulation. These stress responses corresponded with suppressed antioxidant enzyme activities, including catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). Principal component analysis (PCA) demonstrated distinct physiological patterns between control and MP-treated plants, emphasizing the disruptive impact of MP pollution on stress resilience. This study provides the first empirical evidence that soil microplastic contamination compromises plant tolerance to freeze-thaw cycles, highlighting an overlooked risk to crop performance in changing environmental conditions and calling for further research into the long-term ecological consequences of terrestrial MP pollution.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106110"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific trait variation and resource allocation trade-offs under water stress unveil divergent survival strategies in emergent macrophytes amid climate change","authors":"Ana Luisa Biondi Fares,&nbsp;Grazielle Sales Teodoro,&nbsp;Thaisa Sala Michelan","doi":"10.1016/j.envexpbot.2025.106105","DOIUrl":"10.1016/j.envexpbot.2025.106105","url":null,"abstract":"<div><div>Human-induced climate change threatens ecosystems, with altered precipitation regimes causing extreme events like flooding and droughts that impact plant traits such as biomass allocation (to aboveground or belowground) and reproductive strategies. These shifts reflect plants’ responses to environmental stress, and such changes in macrophyte traits can affect freshwater ecosystem processes such as productivity and nutrient cycles. Examining intraspecific trait variation (ITV) in macrophytes under climate change is critical to predicting freshwater ecosystem dynamics. However, how macrophytes adjust their ecological strategies to varying water availability remains unclear. In this study, we investigated ITV and biomass allocation trade-offs in <em>Limnocharis flava</em> and <em>Pontederia rotundifolia</em> in a greenhouse experiment where individuals were subjected to flooding and drought conditions. We analyzed traits spanning physiology, morphology and phenology. We hypothesized that drought would induce conservative strategies, while flooding would elicit acquisitive strategies with coordinated organ-level trait responses. Our results revealed species-specific strategies. Individuals of <em>L. flava</em> combined drought escape and avoidance with flood escape, allocating biomass belowground during drought and aboveground during flooding. In contrast, individuals of <em>P. rotundifolia</em> showed osmotic adjustment under drought, maintaining metabolism despite water limitation, and a shift toward vegetative reproduction. Under flooding, individuals directed biomass to roots, reflecting drought tolerance and flood escape strategies. These findings highlight the critical role of ITV in plant survival under contrasting environments, emphasizing species-specific adaptations to water stress. Understanding ITV within populations and communities is essential for conserving biodiversity, particularly in vulnerable freshwater ecosystems, as climate change intensifies.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106105"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Different water and photosynthetic resource use strategies explain the widespread distribution of Dasiphora fruticosa in Qinghai-Tibet Plateau alpine meadows","authors":"Baoli Fan ,&nbsp;Nana Ding ,&nbsp;Tingting Tian ,&nbsp;Pengfei Gao ,&nbsp;Yongkuan Wan ,&nbsp;Miaojun Ma ,&nbsp;Kun Sun","doi":"10.1016/j.envexpbot.2025.106106","DOIUrl":"10.1016/j.envexpbot.2025.106106","url":null,"abstract":"<div><div>Alpine meadow ecosystems, sensitive to global climate change, are experiencing widespread shrub encroachment, with <em>Dasiphora fruticosa</em> emerging as one of the most prominent encroaching species in this region. Hydraulic and photosynthetic use strategies play crucial role in plant adaptation to climate change. However, it remains unclear how <em>D</em>. <em>fruticosa</em> achieves encroachment by adjusting hydraulic and photosynthetic traits. We examined the hydraulic, leaf, and fine root economic traits of <em>D. fruticosa</em> on shady and sunny slopes with varying soil nutrient levels and degrees of encroachment. Results showed that the hydraulic and photosynthetic traits of <em>D. fruticosa</em> were closely related to its encroachment success. Soil nutrients affects the hydraulic adaptation strategies: soil total phosphorus (STP) significantly increased stem hydraulic conductivity (K_S), while soil total nitrogen (STN) and soil pH decreased the water potential at 50 % loss of K_S (P₅₀). Consequently, <em>D. fruticosa</em> on shady slopes exhibited greater K_S, while those on sunny slopes demonstrated lower P₅₀, indicating trade-off between hydraulic efficiency and safety. Furthermore, <em>D. fruticosa</em> on shady slopes could adjust stomatal conductance (g_s) to avoid embolism, facilitating more severe shrub encroachment.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106106"},"PeriodicalIF":4.5,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of photosynthetic response to environmental variation in shaping an elevational cline in leaf variegation","authors":"Cierra N. Sullivan,&nbsp;Matthew H. Koski","doi":"10.1016/j.envexpbot.2025.106100","DOIUrl":"10.1016/j.envexpbot.2025.106100","url":null,"abstract":"<div><div>Mixed findings on the physiological consequences of leaf variegation make its persistence in nature an intriguing evolutionary question, especially since few studies have tested putative agents of selection maintaining variegation in natural populations. We previously discovered an elevational cline in leaf variegation for two <em>Hexastylis</em> species (Aristolochiaceae) that was explained by abiotic heterogeneity: lower elevation populations experiencing higher temperatures and drier soils had a higher proportion of variegated individuals, and these individuals were more intensely variegated. Here, we measured chlorophyll fluorescence and gas exchange under simulated high and low-elevation temperature and soil conditions in growth chambers to investigate whether the elevational cline in leaf variegation may be due to adaptive physiology. There were no differences between uniformly green and variegated performance for most photosynthetic metrics or leaf temperature. Warmer conditions generally resulted in more rapid declines in photosynthetic efficiency which were further exacerbated by drought. Unexpectedly, variegated morphs and more intensely variegated individuals experienced slower declines in photosynthetic performance than uniformly green morphs. Strongly variegated individuals had higher carbon assimilation rates under low-elevation conditions (warm, dry). Together, our results suggest that physiological adaptation may contribute to the elevational cline in variegation intensity but not the frequency of variegated individuals in populations. Our results further highlight the complexities of leaf variegation ecophysiology, suggesting that differential functioning afforded by multicolored leaf tissue can yield similar, if not improved, photosynthetic resilience than uniformly colored tissue under certain environmental contexts.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106100"},"PeriodicalIF":4.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of ozone on leaf nitrogen assimilation and nitrogen utilization in photosynthetic apparatus of Fagus crenata seedlings grown under different atmospheric CO2 and soil nitrogen conditions","authors":"Yoshiyuki Kinose ,&nbsp;Takuro Aoki ,&nbsp;Misako Matsumoto ,&nbsp;Jing Li ,&nbsp;Ryo Ariura ,&nbsp;Tsuyoshi Fuse ,&nbsp;Yazhuo Zhang ,&nbsp;Masahiro Yamaguchi ,&nbsp;Makoto Watanabe ,&nbsp;Takeshi Izuta","doi":"10.1016/j.envexpbot.2025.106098","DOIUrl":"10.1016/j.envexpbot.2025.106098","url":null,"abstract":"<div><div>Ozone (O₃) impairs photosynthesis and growth of plants, depending on atmospheric CO₂ and soil N levels. Previously, we found that CO₂ exposure mitigated O₃-induced reduction in maximum carboxylation rate (<em>V</em>_cmax) of <em>Fagus crenata</em> seedlings in September. This effect was more pronounced with soil N supply in July. To better understand these physiological mechanisms, we investigated leaf N assimilation and its utilization in the photosynthetic apparatus of <em>F. crenata</em> seedlings. Seedlings were grown with two O₃ levels (low and twice ambient), two CO₂ levels (ambient and 700 µmol mol⁻¹), and three soil N levels (0, 50, and 100 kg N ha⁻¹ year⁻¹). CO₂ exposure mitigated the negative effects of O₃ on ribulose bisphosphate carboxylase/oxygenase (Rubisco) concentration rather than on the ratio of <em>V</em>_cmax to Rubisco concentration in September. Furthermore, such mitigative effects tended to be more pronounced with soil N supply in July, although a three-factor interaction among O₃, CO₂, and soil N was not statistically significant. Additionally, in July and September, the degrees of O₃-induced changes in Rubisco concentration under each CO₂ and N treatment composition were similar to those of the ratio of Rubisco concentration to total soluble protein (TSP) concentration and leaf N allocation to Rubisco, in contrast to the TSP concentration and N assimilation process. Therefore, changes in the N utilization characteristics as proteins involved in the photosynthetic apparatus and the Rubisco quantity in response to O₃, CO₂, and soil N could cause the interactive effect on the <em>V</em>_cmax of <em>F. crenata</em> seedlings.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106098"},"PeriodicalIF":4.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}