Environmental and Experimental Botany最新文献

{"title":"Dynamic LED spectral strategy enhances lettuce (Lactuca sativa) productivity via periodic activation of light-responsive genes and improved light energy use efficiency","authors":"Yanke Liu ,&nbsp;Xinying Gao ,&nbsp;Rong Ye ,&nbsp;Zhanyi Li ,&nbsp;Rongcheng Lin ,&nbsp;Yang Li","doi":"10.1016/j.envexpbot.2026.106337","DOIUrl":"10.1016/j.envexpbot.2026.106337","url":null,"abstract":"<div><div>Artificial lighting in plant factories typically adopts a static, continuous spectral regime dominated by red light, with red-to-blue and red-to–far-red ratios generally maintained at approximately 3–6:1, resulting in limited exploration of dynamic light regulation strategies. In this study, blue and far-red light were alternately applied at 30-min intervals, reducing their daily light integrals while increasing the proportion of red light, thereby improving light energy utilization and signal responsiveness. Our results demonstrated that alternating light treatments significantly enhanced lettuce yield, with the optimized red-to-alternating light ratio increasing yield by 20.22% compared with the static control. Even low-intensity alternating light induced marked morphological responses, including stem elongation and leaf expansion, resulting in a 16.64% increase in total leaf area and an increase of 2.11 leaves per plant. These effects were primarily attributable to enhanced far-red–induced signaling; although this reduced chlorophyll content, an increased red light proportion maintained the net photosynthetic rate. These phenotypic changes were consistent with elevated expression levels of light-responsive genes, indicating that the dynamic lighting effectively leverages the signal enhancement mediated by alternating light to optimize light energy utilization. Dynamic transcriptome analysis revealed that light-responsive genes exhibited consistent periodic expression during 1-hour alternating light cycles, with expression magnitude modulated by light dose. Moreover, weighted gene co-expression network analysis identified gene modules that were strongly correlated with phenotypic traits and displayed regular response patterns, suggesting that these genes may be directly involved in the light response process in lettuce. These findings demonstrate that alternating light regimes entrain periodic gene activation and thereby enhance the coordination between light energy supply and signal regulation. The optimized dynamic spectral strategy increases artificial light use efficiency and crop productivity, providing a mechanistically informed framework for lighting optimization in plant factories.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106337"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaf photosynthetic and morphological traits underlie heat stress resilience in northern highbush blueberry (Vaccinium corymbosum L.)","authors":"Stephanie Rett-Cadman,&nbsp;Joshua Vander Weide","doi":"10.1016/j.envexpbot.2026.106327","DOIUrl":"10.1016/j.envexpbot.2026.106327","url":null,"abstract":"<div><div>Northern highbush blueberry (<em>Vaccinium corymbosum</em> L.) is a temperate fruit crop increasingly exposed to heat stress as heatwaves become more frequent. This suggests the need to characterize thermotolerance traits to facilitate sustainable production. We hypothesized that variation in leaf photosynthetic temperature responses, thermotolerance, and morphology underpin genotypic differences in heat stress resilience in <em>V. corymbosum</em>. Leaf photosynthesis temperature response curves and chlorophyll fluorescence-based thermotolerance curves (LT₅₀) were measured at three phenological stages (bloom, mid-ripening, post-ripening) in ten genetically diverse <em>V. corymbosum</em> genotypes. Leaf morphological traits were also assessed at mid-ripening. Significant genotypic variation was observed in the photosynthesis temperature optimum (<em>T</em>_Opt) and LT₅₀ at all stages, and the leaf thermotolerance threshold of <em>V. corymbosum</em> was established at 43.1–47.2 °C, lower than values reported for many other plant species. To validate the functional relevance of these traits, four genotypes spanning the range of <em>T</em>_Opt and LT₅₀ were evaluated during a natural heatwave. Genotypes with the highest <em>T</em>_Opt and LT₅₀ maintained greater photosystem II efficiency and gas exchange under heat stress, whereas genotypes with the lowest values were more susceptible. Most genotypes exhibited long-term seasonal acclimation of photosynthesis from bloom to mid-ripening, while only the resilient genotype showed evidence of short-term acclimation of <em>A</em>_Opt during the heatwave. Leaf size and color were positively associated with LT₅₀, linking structural traits with thermotolerance. Collectively, these results demonstrate that photosynthetic <em>T</em>_Opt, LT₅₀, and leaf size and color determine heat stress resilience in <em>V. corymbosum</em>, providing mechanistic insight into plant responses to episodic heat stress.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106327"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key regulators of floral induction in faba bean (Vicia faba L.) are revealed from spatio-temporal gene expression analysis of contrasting genotypes","authors":"Umer Mahmood,&nbsp;Per Hofvander,&nbsp;Åsa Grimberg","doi":"10.1016/j.envexpbot.2026.106334","DOIUrl":"10.1016/j.envexpbot.2026.106334","url":null,"abstract":"<div><div>Flowering time is a crucial trait for crop adaptation and yield stability, yet its genetic regulation in <em>Vicia faba</em> remains poorly understood. In this study, we performed RNA-sequencing of shoot apex (SA) and leaf tissues to investigate the genetic mechanisms underlying variation in flowering time between two contrasting cultivars, Gubbestad (early flowering) and Honey (late flowering). Based on differential gene expression analysis, <em>K</em>-means clustering and weighted gene co-expression network analysis (WGCNA), we identified key transcriptional modules enriched in genes associated with gibberellin (GA) signaling, photoperiod response, and floral induction. Notably, <em>FT</em> homologs exhibited distinct expression patterns: two <em>FT</em> genes were expressed in Gubbestad, whereas only one was detected in Honey, in the SA during the reproductive stage. The late-flowering cultivar displayed high expression of the transcriptional cofactor <em>TFL1</em> and transcription factor <em>AP2</em> in the SA at the vegetative stage, which likely contributed to late floral initiation by suppressing downstream activators of flowering such as <em>SOC1</em>, <em>AP1</em>, and <em>SPL</em>/miR156. In contrast, the early-flowering cultivar showed <em>FT</em> gene expression in both leaf and SA, promoting <em>LFY</em>, <em>SOC1</em> which accelerate floral transition. Through co-expression analysis, WGCNA identified <em>SOC1</em> and <em>AG</em> as key hub genes within flowering-related modules, co-expressed with multiple genes encoding regulators of floral development. Our findings highlight the interplay between GA-mediated flowering pathways and photoperiod-responsive genes, revealing a complex regulatory network that controls floral induction. Unraveling these molecular mechanisms provides insights into breeding faba bean cultivars that are better adapted to different geographical regions.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106334"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian clock regulation of low R/FR light signaling and photosynthetic cross-talk in crop development","authors":"Ting Huang ,&nbsp;Yue Wu ,&nbsp;Chen Chen ,&nbsp;Jian-Ping Tao ,&nbsp;Ai-Sheng Xiong ,&nbsp;Xiong You","doi":"10.1016/j.envexpbot.2026.106328","DOIUrl":"10.1016/j.envexpbot.2026.106328","url":null,"abstract":"<div><div>The environmental light condition serves as a pivotal external cue governing plant growth and development. In particular, a low ratio of red to far-red light (low R:FR), resulting from vegetative shading, significantly limits crop yield under high-density planting—as often seen in cereal and horticultural crops. Plants perceive alterations in R:FR ratio via phytochromes, transduce this signal into multifaceted intracellular responses and initiate adaptive processes such as shade avoidance syndrome (SAS). This review comprehensively examines the molecular mechanisms of low R:FR-controlled photosynthesis mediated by the circadian clock. First of all, we elaborate on phytochromes initiation of downstream signaling cascades through nucleocytoplasmic partitioning and interactions with key components such as PIFs. We then systematically outline the cross-talk between low R:FR signaling and the core circadian oscillator. The central clock components, including LHY/CCA1 and TOC1, act as critical regulatory nodes within the phytochrome signaling network. By integrating photoperiodic and circadian information, these components finely modulate photosynthesis-related gene expression, chloroplast development, stomatal movement, and photosynthetic carbon assimilation, thereby optimizing photosynthetic performance in dynamically changing light environments. This review aims to provide integrative insights into how plants synchronize light signaling with the circadian clock to maximize photosynthetic efficiency, and to suggest potential molecular targets for breeding crops with improved shade tolerance and higher productivity in dense cultivation systems.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106328"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon dynamics in European beech and Norway spruce under present and future RCP scenarios","authors":"Qiao-Lin Gu ,&nbsp;Benjamin D. Hesse ,&nbsp;Manuela Baumgarten ,&nbsp;Bálint Jákli ,&nbsp;Manfred Reppke ,&nbsp;J. Philipp Benz ,&nbsp;Anja Rammig ,&nbsp;Thorsten E.E. Grams","doi":"10.1016/j.envexpbot.2026.106330","DOIUrl":"10.1016/j.envexpbot.2026.106330","url":null,"abstract":"<div><div>To elucidate how trees adjust their C dynamics under future climate, we conducted a unique growth chamber experiment with tree saplings grown for three years under the present climate conditions (PC), a mitigation scenario (RCP2.6) and a worst-case scenario (RCP8.5). The RCPs were simulated by increased air temperature, vapor pressure deficit, irradiance, CO₂ and O₃ concentrations at hourly resolution. Both species, European beech and Norway spruce, grew more biomass under RCP8.5 than PC and RCP2.6, accompanied by increased partition to belowground. Towards the end of the three-year experiment, the mean residence time (MRT) and mean transit time (MTT) of C along the tree-soil system were assessed in a ¹³CO₂ tracer experiment. MRT in leaves was unaffected in both species but decreased significantly in beech stem CO₂ efflux under both RCP scenarios. MTT for beech from leaves to stem CO₂ efflux decreased under RCP2.6. For both species, we found a negative correlation between MTT and maximum assimilation, indicating faster C flux through trees at higher assimilation rates. Conversely, no positive correlation was found between biomass growth and maximum assimilation rates. After three years of growth under the simulated RCP scenarios, we conclude that C turnover would accelerate under future climate conditions. The additional C fixed by photosynthesis will be released back to the atmosphere more rapidly, as a smaller fraction could remain in the biomass. These results support the implementation of faster C turnover in process-based dynamic vegetation models, although confirmation for mature trees is still needed.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106330"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the mechanisms by which sodium promotes growth of euhalophytes under potassium deficiency: A case study of Suaeda salsa","authors":"Dong Zhang ,&nbsp;Axiang Cai ,&nbsp;Changyan Tian ,&nbsp;Wenxuan Mai","doi":"10.1016/j.envexpbot.2026.106343","DOIUrl":"10.1016/j.envexpbot.2026.106343","url":null,"abstract":"<div><div><em>Suaeda salsa</em> L<em>.</em> is a leaf succulent euhalophyte. Its leaves are rich in secondary metabolites, such as polyphenols and flavonoids, which enhance its salt tolerance and have industrial value in pharmaceuticals, antioxidants, and food additives<em>.</em> Its growth is promoted under moderate salinity conditions<em>.</em> However, the mechanisms by which euhalophytes maintain a balance between growth and salt stress tolerance have not been elucidated, especially under K⁺ deficiency. Here, we used multi-omics and physiology analyses to investigate the role of Na⁺ in the growth and metabolic processes of <em>S. salsa</em>. Exogenous NaCl application significantly enhanced the photosynthetic efficiency of <em>S. sals</em>a under K⁺ deficiency, including the net photosynthetic rate, PSII photochemistry (Fv/Fm), photochemical quenching (qP), non-photochemical quenching (NPQ), and the activities of enzymes such as ferredoxin-NADP⁺ reductase (FNR) and Rubisco. Meanwhile, transcriptomic analysis revealed that NaCl treatment upregulated genes related to photosynthetic subunits, light-harvesting complexes (LHCs), and key Calvin cycle enzymes, including phosphoglycerate kinase (PGK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and Rubisco. These findings provide strong molecular evidence for the observed recovery of photosynthetic efficiency in NaCl-treated <em>S. salsa</em> under K⁺ deficiency. Furthermore, the relative contents of flavonoids and isoflavonoids, including isorhamnetin, isolupalbigenin, osajin, corylin, and wedelolactone, as well as unsaturated fatty acids (9-Hexadecenoic acid), were significantly upregulated treating with NaCl and KCl. These results suggest that <em>S. salsa</em> can utilize Na⁺ to enhance photosynthesis under high salinity and low K⁺ conditions, thereby enabling it to balance salt tolerance and growth. Our findings elucidate the key mechanisms underlying the critical role of Na⁺ in the physiological and metabolic processes of halophytes, providing a theoretical basis for the development of saline agriculture.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106343"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change-related deacclimation disrupts sugar allocation and transport in winter oilseed rape (Brassica napus L.)","authors":"Magdalena Rys ,&nbsp;Barbara Jurczyk ,&nbsp;Ewa Pociecha ,&nbsp;Pasquale Luca Curci ,&nbsp;Jan Bocianowski ,&nbsp;Maciej Szaleniec ,&nbsp;Piotr Waligórski ,&nbsp;Anna Janeczko","doi":"10.1016/j.envexpbot.2026.106332","DOIUrl":"10.1016/j.envexpbot.2026.106332","url":null,"abstract":"<div><div>Winter oilseed rape achieves frost tolerance through cold acclimation (CA). CA is a process usually naturally occurring in autumn and triggered by low but non-freezing temperatures. Among various metabolic adjustments, changes in sugar management are one of the more important ones. Due to climate changes, increasingly frequent temperature fluctuations and appearance of warm breaks in late autumn/winter may lead to deacclimation (DA). DA may lower the frost tolerance causing problems with winter survival of plants. Physiological/biochemical background of DA still requires explanation. The aim of these studies was to answer the question if and how deeply deacclimation (one week at 16 ℃/9 ℃ [d/n]) modifies sugar metabolism in leaves, root necks and roots of two cultivars of winter oilseed rape. The studies include analysis of the changes in the sugar content supported by analysis of activity of selected enzymes involved in sugar synthesis/degradation and analysis of expression of sugar transporters. Typical changes accompanying CA were observed, such as an increase in the content of glucose, fructose, sucrose and kestose, as well as an increase in the activity of sucrose synthase and sucrose phosphate synthase (SUS and SPS) enzymes in all tested plant tissues compared to the non-acclimated control. DA reversed all these changes. CA decreased, while DA increased again the relative expression of sugar transporters <em>BnSUC1</em> and <em>BnSWEET11</em>. The negative impact of warm breaks during the period of cold acclimation on sugar accumulation and transport is discussed in the light of resumption of plant growth and reduced frost tolerance induced by deacclimation.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106332"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light quality affects diurnal gas exchange but not diurnal deacidification in CAM leaves","authors":"Stijn Daems ,&nbsp;Rune Keysers ,&nbsp;Bram Van de Poel ,&nbsp;Johan Ceusters","doi":"10.1016/j.envexpbot.2026.106326","DOIUrl":"10.1016/j.envexpbot.2026.106326","url":null,"abstract":"<div><div>During the light period, crassulacean acid metabolism (CAM) plants remobilise malic acid from the vacuole and decarboxylate it to supply CO₂ for Rubisco behind closed stomata. Whilst it has been well documented that diurnal deacidification depends strongly on light availability, the impact of light quality on daytime leaf gas exchange and deacidification remains poorly understood. The obligate CAM model species <em>Kalanchoë fedtschenkoi</em> was subjected to either different monochromatic wavelengths (blue, green, red) or modified full-spectrum (white) light spectra with a particular waveband omitted (blue, orange, red, far-red, blue+red). Leaf gas exchange parameters and different biochemical parameters associated with diurnal deacidification [i.e., malate and starch content, <em>in vitro</em> activities of malic enzyme (ME), pyruvate orthophosphate dikinase (PPDK), and Rubisco] were measured at dawn, midday, and late afternoon. Under high light intensities of 300 µmol m⁻² s⁻¹, blue wavelengths were found to be a key determinant in promoting high daytime stomatal conductance (Phases II and IV), resulting in improved C₃ carboxylation. Furthermore, omitting red wavelengths from the light spectrum led to a substantially higher overall diel CO₂ uptake (+300 %) compared to plants subjected to spectra lacking either blue or both blue and red wavelengths. In contrast to the large impact on leaf gas exchange, light spectral composition had only a minor impact on diurnal changes in intrinsic enzyme activities of NAD(P)-ME, PPDK, and Rubisco. Consistent with these observations, the diurnal malate degradation and starch accumulation rates were remarkably similar under different spectral compositions. Our findings reveal that stomatal behavior and gas exchange are primarily influenced by light quality, with a more pronounced role for blue compared to red wavelengths. The core biochemical events associated with diurnal deacidification are mainly influenced by light intensity and rather insensitive to changes in spectral composition.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106326"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lichen symbiotic stress as a precursor to biodiversity loss – Rapid assessment using Evernia prunastri as a bioindicator for nitrogen pollution","authors":"Lumbani Mwafulirwa ,&nbsp;Ajinkya G. Deshpande ,&nbsp;Matthew R. Jones ,&nbsp;Mark A. Sutton ,&nbsp;Christopher J. Ellis","doi":"10.1016/j.envexpbot.2026.106333","DOIUrl":"10.1016/j.envexpbot.2026.106333","url":null,"abstract":"<div><div>Excess reactive nitrogen (N_r) emitted from farming (NH_x) and fossil fuels (NO_x) is a major global threat to biodiversity and ecosystem function. Environmental N_r is often monitored using bioindicators such as lichens, which provide valuable insights in the absence of instrumental monitoring stations. As key bioindicators, lichen responses to N_r have been widely studied using either short-term highly controlled laboratory experiments or field sampling, linking functional aspects of lichen biology with real-world outcomes. However, a missing component in the available evidence base could be provided by field-scale experiments to isolate the response of lichens to contrasting N_r levels over longer time periods. Here, we investigated the response of the bioindicator lichen <em>Evernia prunastri</em> to contrasting ammonia (NH₃) concentrations within a novel field-scale experiment and over a 12-week period. We measured fungal cell membrane damage and algal chlorophyll content as markers related to lichen tissue nitrogen accumulation, revealing impacts on the fungal and algal symbionts and explaining net outcomes on lichen relative growth rates. We compared the results of the field-scale experiment to trends observed in the real world. Our results suggest that <em>E. prunastri</em> tissue nitrogen content becomes saturated at 1.3 % with long-term NH₃ concentrations of c. 2 μg m⁻³, beyond which the species experiences unmitigated physiological damage. This response is however critically dependent on the exposure duration, which interacts with atmospheric NH₃ to constrain acclimation through increased chlorophyll content, while causing accumulative damage to fungal cell membranes that compromises growth and leads to eventual mortality.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106333"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147402634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stomatal, mesophyll, and biochemical limitation to photosynthesis of soybeans under waterlogging and reoxygenation","authors":"Shigehiro Kubota ,&nbsp;Gaku Yokoyama ,&nbsp;Toshimune Shibata ,&nbsp;Daisuke Yasutake ,&nbsp;Tomoyoshi Hirota","doi":"10.1016/j.envexpbot.2026.106325","DOIUrl":"10.1016/j.envexpbot.2026.106325","url":null,"abstract":"<div><div>While waterlogging stress slows photosynthetic rate (<em>A</em>_sat), the underlying processes remain poorly understood. Here, we aimed to characterize the limitations to photosynthesis imposed by stomatal conductance (<em>g</em>_s), mesophyll conductance (<em>g</em>_m), and biochemical processes during waterlogging and after drainage of excess water from the soil, i.e., during reoxygenation. Two soybean cultivars (<em>Glycine max</em> L. cv. Fukuyutaka and Iyodaizu) were subjected to 6 days of waterlogging, after which excess water was drained. The responses of <em>A</em>_sat, <em>g</em>_s, <em>g</em>_m, and the maximum carboxylation rate (<em>V</em>_cmax) were investigated. In both cultivars, <em>A</em> declined significantly within 4 days of waterlogging and did not recover completely by two weeks of reoxygenation. During waterlogging, CO₂ concentration at carboxylation site decreased in parallel with <em>g</em>_s and <em>g</em>_m, indicating that photosynthesis was mainly limited by diffusional factors (combination of <em>g</em>_s and <em>g</em>_m). After drainage, diffusional limitation persisted for 3 days after drainage, whereas biochemical limitation due to reduced <em>V</em>_cmax became dominant after 7 days of reoxygenation. Therefore, maintaining high diffusional conductances and <em>V</em>_cmax during waterlogging and reoxygenation, respectively, is important for enhancing photosynthetic tolerance to waterlogging stress. Overall, our results demonstrate that <em>A</em>_sat under waterlogging and reoxygenation is dynamically constrained by multiple factors, emphasizing the need for comprehensive assessment of gas diffusion and carbon assimilation processes.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"243 ","pages":"Article 106325"},"PeriodicalIF":4.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}