Environmental and Experimental Botany最新文献

{"title":"Responses of photosynthesis and respiration of wheat leaves to elevated CO2 are not constrained by soil nitrogen","authors":"Qi Liu ,&nbsp;Ding Ming Zheng ,&nbsp;Qiao Yu Yan ,&nbsp;Xuming Wang ,&nbsp;Huixing Kang ,&nbsp;Lei Li ,&nbsp;Xiao Ying Gong","doi":"10.1016/j.envexpbot.2025.106132","DOIUrl":"10.1016/j.envexpbot.2025.106132","url":null,"abstract":"<div><div>Low nitrogen (N) availability could attenuate the enhancement of leaf photosynthesis under elevated CO₂ concentration (eCO₂), but there is still conflicting evidence. Moreover, the response of leaf respiration to eCO₂ and N supplementation is not well understood. To explore the effects of eCO₂ and N availability on leaf photosynthesis and respiration, wheat plants (<em>Triticum aestivum</em> L.) were grown under ambient (420 μmol mol⁻¹) and elevated (840 μmol mol⁻¹) CO₂ concentrations in combination with low (2 mmol L⁻¹) and high N (8 mmol L⁻¹ nitrate) treatments. We found that eCO₂ decreased leaf N content but significantly increased the net photosynthesis rate (<em>A</em>_n) of young leaves by c. 10 % under both N levels, and there was no significant interaction between eCO₂ and N treatments on <em>A</em>_n. eCO₂ decreased the <em>A</em>_n of old leaves, which may be due to the accelerated leaf senescence at eCO₂. Leaf respiration in the light (<em>R</em>_L) and darkness (<em>R</em>_Dk) decreased under eCO₂ in both N treatments for both leaf age classes, and eCO₂ amplified the increase in leaf respiration with leaf N. Our results showed that the response of photosynthesis to eCO₂ was not limited by soil N availability, and eCO₂ modulated the relationship between leaf respiration and leaf [N], providing implications for understanding and modeling CO₂ fertilization.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"233 ","pages":"Article 106132"},"PeriodicalIF":4.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734562","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 wheat NAC transcription factor, TaNAC018-7D, regulates seed dormancy and germination by binding to the GA biosynthesis gene TaGA7ox-A1","authors":"Wenlu Chen,&nbsp;Chenchen Wang,&nbsp;Qishi Zhuang,&nbsp;Wei Liu,&nbsp;Renjie Wang,&nbsp;Jinhao Chen,&nbsp;Xinyi Xu,&nbsp;Yanan Yan,&nbsp;Huihui Xu,&nbsp;Chuanxi Ma,&nbsp;Cheng Chang,&nbsp;Haiping Zhang","doi":"10.1016/j.envexpbot.2025.106130","DOIUrl":"10.1016/j.envexpbot.2025.106130","url":null,"abstract":"<div><div>Pre-harvest sprouting (PHS) reduces grain yield and quality and poses a serious threat to global wheat production. Seed dormancy and germination are closely related to PHS resistance. However, the intricate regulatory processes governing seed dormancy and germination remain largely unknown. Here, we reported that a NAC transcription factor gene (<em>TaNAC018–7D</em>) is highly expressed in weak-dormancy wheat cultivar Jing 411 compared with a strong-dormancy landrace Hongmangchun 21 during seed germination. Germination tests revealed that <em>TaNAC018–7D</em> negatively regulates seed dormancy and positively mediates germination in transgenic lines of <em>Arabidopsis</em> and rice, and wheat mutants induced by ethyl methane sulfonate in the Jing 411 background. Subcellular localization analysis indicated that TaNAC018–7D is located in the nucleus and cytoplasm. Physiological, biochemical, and molecular experiments indicated that TaNAC018–7D interacts with the promoter of the GA biosynthesis gene <em>TaGA7ox-A1</em> and activates its expression, thereby shortening seed dormancy and promoting germination. In summary, this study provides a new target gene for improving wheat PHS resistance, and improves the understanding of the complex regulatory network of PHS resistance.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"233 ","pages":"Article 106130"},"PeriodicalIF":4.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726000","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":"Red, blue and far-red light affect strawberry plant development and fruit quality without changing the susceptibility to Botrytis cinerea infection","authors":"Hua Li ,&nbsp;Dorthe H. Larsen ,&nbsp;Rob E. Schouten ,&nbsp;Diede de Jager ,&nbsp;Xinhe Huang ,&nbsp;Salem Agboyinu ,&nbsp;Mengxiao Wang ,&nbsp;Ric C.H. de Vos ,&nbsp;Jan A.L. Van Kan ,&nbsp;Leo F.M. Marcelis ,&nbsp;Ernst J. Woltering","doi":"10.1016/j.envexpbot.2025.106133","DOIUrl":"10.1016/j.envexpbot.2025.106133","url":null,"abstract":"<div><div>Light regulates plant development, fruit quality characteristics and pathogen defense through primary and secondary metabolism. We investigated the effects of light spectrum on plant development, the levels of primary and secondary metabolites and fungal susceptibility in strawberry fruit harvested in turning and red ripe stages. Strawberry plants were grown in a climate chamber under different red (R) to blue (B) light ratios with and without ∼50 μmol m^–2 s^–1 additional far-red (FR) light. A total photosynthetic photon flux density (PPFD) of ∼180 μmol m^–2 s^–1 was applied with a 16 h day length. Low R to B light ratios resulted in lower levels of sucrose but higher levels of ascorbic acid, proanthocyanidin, (<em>E</em>)-2-hexenal and (<em>Z</em>)-3-hexenol in fruit. No effects of R to B ratios on plant morphology, flowering time and fruit set were observed. Additional FR light increased plant height, accelerated flower and fruit formation; decreased levels of ascorbic acid and anthocyanins but increased levels of soluble sugar and strawberry flavor-related volatiles. Fruit susceptibility to <em>B. cinerea</em> was not affected by the light treatments.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"233 ","pages":"Article 106133"},"PeriodicalIF":4.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726002","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":"Physiological response of the endemic Mediterranean seagrass, Posidonia oceanica to multiple stresses","authors":"Judit Garcia ,&nbsp;Tania Mesa ,&nbsp;Sabina Villadangos ,&nbsp;Gaspar Fuster ,&nbsp;Sergi Munné-Bosch","doi":"10.1016/j.envexpbot.2025.106131","DOIUrl":"10.1016/j.envexpbot.2025.106131","url":null,"abstract":"<div><div>The endemic Mediterranean marine angiosperm, <em>Posidonia oceanica</em>, stands out for being a biostructuring seagrass species with a great importance in trophic relations and coastal erosion protection. This study aimed to understand the physiological response of this emblematic seagrass to multiple stresses, with an emphasis on evaluating the acclimatory capacity of juvenile leaves to low temperatures during winter in three sites with a contrasting exposure to heavy metals of anthropogenic origin in the Mediterranean coast near Cadaqués (NE Spain). Heavy metal concentrations together with multiple physiological stress markers, including the capacity of photo- and antioxidant protection and the extent of lipid peroxidation, were evaluated. Shoots from the three studied sites accumulated foliar concentrations of heavy metals that were higher than reference threshold values, especially for Cu, which showed a decreasing concentration gradient from the coast to the open sea. The maximum photochemical efficiency of Photosystem II (PSII) (<em>F</em>_v/<em>F</em>_m ratio) of juvenile leaves was sensitive to low temperatures, despite values attained did not indicate damage to PSII, which was confirmed with studies of recovery of the <em>F</em>_v/<em>F</em>_m ratio and the absence of symptoms of photo-oxidative stress. However, the presence of heavy metals seemed to negatively influence PSII photochemistry, as sites with the highest Cu concentrations also showed the lowest <em>F</em>_v/<em>F</em>_m ratios during spring, even though water temperature had already warmed. <em>F</em>_v/<em>F</em>_m values attained were not recoverable after an extended dark acclimation period, thus indicating damage to PSII. Heavy metals did not seem to exert a negative synergistic effect with low temperatures but rather affected the physiological performance of newly produced juvenile leaves during spring. Despite the great capacity of this species to adapt to multiple stresses, results underscore the need to urgently reduce the current human footprint on seagrass meadows in the Mediterranean basin.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"233 ","pages":"Article 106131"},"PeriodicalIF":4.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726001","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":"Pod lignin biosynthesis contributes to pre-harvest sprouting tolerance of rapeseed","authors":"Tianhua Chen,&nbsp;Qing’ao Cai,&nbsp;Caili Liu,&nbsp;Rui Li,&nbsp;Liyan Wang,&nbsp;Jian’an Chen,&nbsp;Nian Liu,&nbsp;Boshi Yang,&nbsp;Shuo Zhou,&nbsp;Zonghe Zhu,&nbsp;Kejin Zhou,&nbsp;Fugui Zhang","doi":"10.1016/j.envexpbot.2025.106129","DOIUrl":"10.1016/j.envexpbot.2025.106129","url":null,"abstract":"<div><div>Pre-harvest sprouting (PHS) poses a major hazard to rapeseed (<em>Brassica napus</em> L.) production, particularly under rainy, moist conditions during harvest season. PHS tolerance mainly depends on seed dormancy and pericarp structure in other crops. However, little was known about the mechanisms underlying PHS tolerance in rapeseed. In this study, an elite PHS-tolerant genotype was screened from 750 global rapeseed germplasm resources by pod imbibition and seed germination assays. Results of imbibition dynamics have shown that the water absorption was slower in pod shell and seeds within pod of the PHS-tolerant genotype. The tolerant genotype also had higher pod shell thickness, cellulose content, and lignin content. The pod shell of the tolerant genotype was significantly enriched in a large number of differential metabolites involved in the phenylpropanoid metabolism pathway, which contribute to lignin biosynthesis. Moreover, lignin synthesis related genes <em>BnaPAL4</em>, <em>Bna4CL1</em>, <em>BnaCCR1</em>, <em>BnaHST</em> and <em>BnaPER42</em> significantly more expressed in the PHS-tolerant genotype than in the PHS-sensitive genotype. More lignin accumulation in the pod could protect rapeseed from PHS by decreasing the pericarp permeability. All these findings could provide valuable genetic resources for the breeding of PHS-tolerant rapeseed cultivars and understanding of PHS mechanism in <em>Brassica</em> species.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106129"},"PeriodicalIF":4.5,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697139","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":"Soil depth, rather than hydrological gradient, dominates uptake of water and nitrogen by Carex thunbergii in a wetland ecosystem","authors":"Tian Tian ,&nbsp;Chaohe Huangfu","doi":"10.1016/j.envexpbot.2025.106128","DOIUrl":"10.1016/j.envexpbot.2025.106128","url":null,"abstract":"<div><div>Plant acquisition of nitrogen (N) and water is a dominant aspect shaping plant productivity. Plants can achieve adequate uptake levels by modifying root architecture. Resource acquisition, however, is often merely inferred from the distribution of root biomass rather than being actually measured. We used ²H and ¹⁵N (in the form of NO₃^-) stable isotope labeling approach to measure the contribution of different soil depths to the water and N uptake of a sedge species <em>Carex thunbergii</em> across three groundwater table levels in a subtropical riparian wetland system, China. Twenty hours after labelling, the isotopes ²H and ¹⁵N were traced in the transpiration water and leaves, respectively. Concurrently, we measured the vertical patterns of available N and water, as well as absorptive root traits at different soil depths. With increasing water table level, <em>C. thunbergii</em> exhibited a dimorphic root pattern, one being spongy, acquisitive, shallow roots and the other dense, conservative deep roots. Most soil N and absorptive roots (either measured as root length density [RLD], or absorptive root biomass [ARB]) were both concentrated in the topsoil, with more than 85 % of absorptive roots occurring at upper 10 cm depth. We found that water uptake was more sensitive to increased water table depth, lower ARB, and RLD than was N uptake. Also soil depth (<em>F</em> = 61.85, <em>p</em> &lt; 0.001), rather than the hydrological gradient (<em>F</em> = 16.85, <em>p</em> &lt; 0.001), determined the plant water and N acquisition patterns. Water and N uptake patterns were well correlated with each other when data from all soil depths were combined, and more than 50 % of the variation in uptake of N was explained by water uptake. These patterns were themselves correlated with ARB, RLD, and N availability with increasing water table, respectively, suggesting that edaphic factors might override functional traits in controlling resource use under conditions of saturated soils in this wetland ecosystem. These results indicate that <em>C. thunbergii</em> has distinct depth-specific adaptations in terms of water and N acquisition that were independent from the effects of water table.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106128"},"PeriodicalIF":4.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686276","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":"Metabolic network plasticity underpins Eucalyptus water use efficiency under drought","authors":"Caroline Müller ,&nbsp;Letícia dos Anjos ,&nbsp;Francisco Bruno S. Freire ,&nbsp;Alisdair R. Fernie ,&nbsp;Danilo M. Daloso ,&nbsp;Cleiton B. Eller ,&nbsp;Andrew Merchant","doi":"10.1016/j.envexpbot.2025.106127","DOIUrl":"10.1016/j.envexpbot.2025.106127","url":null,"abstract":"<div><div>Several <em>Eucalyptus</em> species are grown worldwide primarily for fiber production, while also playing a crucial role in forest ecosystem health within their natural environment. Although various chemical and physiological traits have been identified as contributors to water-deficit (WD) acclimation, the role of metabolism-mediated mechanisms in <em>Eucalyptus</em> WD responses remains unclear. Here, we performed a comprehensive characterization integrating metabolomic and physiological analyses of 14 <em>Eucalyptus</em> species subjected to well-watered (WW) and WD conditions. Our results showed that different <em>Eucalyptus</em> species employ different strategies to enhance water use efficiency (WUE) in response to WD. A total of 53 metabolites were significantly altered by WD in at least one species. Principal component analyses indicate that <em>E. cloeziana</em> and <em>E. stenostona</em> were the most metabolically responsive species to WD. Notably, these species exhibited highest increases in WUE following WD imposition, which was also closely associated to constating network properties - higher network density in <em>E. cloeziana</em> and network heterogeneity in <em>E. stenostona -</em> but specially with the highest number of hub-like nodes. Overall, WUE was positively correlated with both network density and the number of hub-like nodes in in metabolic networks under WD. Moreover, WD triggered the emergence of new hubs associated with the tricarboxylic acid (TCA) cycle and the related pathways. Our findings highlight that the <em>Eucalyptus</em> metabolic responses to WD are species-specific, but metabolic network plasticity - defined as the ability to modify network topology and density - plays a key role in regulating WUE under WD.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106127"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697783","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":"Stable isotope inferred intrinsic water use efficiency and its relation to N sources in temperate tree regeneration with increasing levels of N deposition, precipitation, and temperature","authors":"Viktoria Dietrich ,&nbsp;Jörg Niederberger ,&nbsp;Markus Hauck","doi":"10.1016/j.envexpbot.2025.106125","DOIUrl":"10.1016/j.envexpbot.2025.106125","url":null,"abstract":"<div><div>Under ongoing climate change, the mechanisms controlling the vigor and growth performance of tree regeneration are still less understood than for mature trees. Using stable isotope signatures (δ¹³C, δ¹⁵N), we studied intrinsic water use efficiency (WUE_i, with δ¹³C as a proxy) and N relations and their interaction in differently drought-tolerant temperate tree species. We conducted a Germany-wide field study representing independent precipitation, temperature, and N deposition levels, comparing European beech (<em>Fagus sylvatica</em>), sessile oak (<em>Quercus petraea</em>), silver fir (<em>Abies alba</em>), and Douglas fir (<em>Pseudotsuga menziesii</em>) in the regeneration stage. At high N deposition WUE_i was decreased in all tree species and in beech in particular, as δ¹³C signatures became more negative. This suggests that high N loads give rise to a differentiated discussion of the drought tolerance of tree species depending on the level of N deposition. In the conifers direct uptake of N from atmospheric deposition was important, as indicated by increasing foliar δ¹⁵N with increasing N concentration. In the broadleaved trees with better decomposable leaf litter, the main effect of N deposition was indicated through low δ¹⁵N signatures suggesting an intensification of uptake from N mineralization. Foliar δ¹⁵N signatures, and hence presumed changes in mineralization, were affected by soil chemistry, mean annual precipitation and temperature, but may also be influenced by deposition or other soil properties, which must be acknowledged when considering our results. To complement our results, comparable studies should be conducted for mature forest stands, including ecophysiological measurements of leaf gas exchange or tree water relations.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106125"},"PeriodicalIF":4.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636284","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 WD-40 repeat-containing protein CmRACK1 negatively regulates chrysanthemum flowering in response to photoperiod and gibberellin signaling","authors":"Wanwan Zhang ,&nbsp;Yvhan Ye ,&nbsp;Yongjian Bao,&nbsp;Xinyi Deng,&nbsp;Binyao Yin,&nbsp;Yang Hong,&nbsp;Siqi Tian,&nbsp;Rujun Wang,&nbsp;Lili Dong,&nbsp;Wanwan Zhang,&nbsp;Ke Wu","doi":"10.1016/j.envexpbot.2025.106126","DOIUrl":"10.1016/j.envexpbot.2025.106126","url":null,"abstract":"<div><div>Chrysanthemums are typical short-day plants, and photoperiod and gibberellic acid (GA) signal perception and transduction are the key factors regulating flowering in the chrysanthemum. The function and molecular mechanism undertaken by the receptors for activated C kinase 1 (RACK1) protein to regulate chrysanthemum flowering are currently unclear. Here, we isolated <em>CmRACK1</em> from chrysanthemum. We found that <em>CmRACK1</em> was induced by the photoperiod and exhibited rhythmic expression characteristics. Compared with the wild-type, the <em>CmRACK1</em> overexpression lines showed delayed flowering, while the artificial micro RNA (amiRNA)-mediated knockdown lines showed early flowering. Transcriptome analysis of <em>CmRACK1</em> transgenic and wild-type lines revealed differential expression of <em>GIBBERELLIC ACID INSENSITIVE DWARF 1B</em> (<em>GID1B</em>), gibberellin 20-oxidase 1, and gibberellin 3-oxidase 1. Quantification of gibberellin levels in transgenic and wild-type plants indicated a significant decrease in GA1 content in the <em>CmRACK1</em> overexpression lines and a notable increase in the knockdown lines. We conducted dual-luciferase reporter assays in <em>Nicotiana benthamiana</em> leaves and found that <em>CmRACK1</em> stimulates the expression of <em>CmGID1B</em>, thereby negatively regulating chrysanthemum flowering via the gibberellin signaling pathway. Our research findings provided a foundation for understanding the molecular mechanisms underlying flowering time regulation in chrysanthemum.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106126"},"PeriodicalIF":4.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686275","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":"Ozone exposure consistently increases δ13C in wheat grain","authors":"Malin C. Broberg ,&nbsp;Melissa Chang Espino ,&nbsp;Felicity Hayes ,&nbsp;Ignacio Gonzalez Fernandez ,&nbsp;Håkan Pleijel","doi":"10.1016/j.envexpbot.2025.106124","DOIUrl":"10.1016/j.envexpbot.2025.106124","url":null,"abstract":"<div><div>Tropospheric ozone (O₃) is a regional air pollutant, formed by solar radiation from nitrogen oxides and volatile organic compounds. It is known to impair crop yields. The mechanisms of O₃ damage to plants are linked to gas exchange and carbon metabolism. The carbon isotopic signature in plant tissues represented by δ¹³C offers a time-integrating approach to assess the performance of plant gas exchange. We combined wheat grain δ¹³C data from seven O₃ experiments performed in four countries (Switzerland, Spain, Sweden, United Kingdom). For one experiment δ¹³C data for stems were available. There was a significant positive relationship between grain δ¹³C and O₃ exposure (R²=0.37). Using a relative scale to account for variation in the δ¹³C level among experiments, a stronger linear relationship was obtained (R²=0.77). Furthermore, the relative yield loss from O₃ was negatively linked to the relative effect on δ¹³C (R²=0.72). Stems were more depleted in ¹³C than grain but also showed a significant, less steep, positive δ¹³C relationship with O₃ exposure. The most important conclusion from the positive relationship between δ¹³C and O₃ exposure is that the O₃ effect on stomatal conductance dominates over the impairment of CO₂ fixation by Rubisco. However, also discrimination associated with redistribution of carbohydrates from non-reproductive plant parts to grains can contribute to the O₃ effect on δ¹³C. Based on the unified pattern of δ¹³C response over a range of experiments performed in different sites, we conclude that the mechanisms of O₃ damage in wheat with respect to gas exchange are highly consistent.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106124"},"PeriodicalIF":4.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609837","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}