Environmental and Experimental Botany最新文献

{"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}

{"title":"Plant resistance to the whitefly Bemisia tabaci is compromised in salt-stressed Capsicum","authors":"Lotte Caarls ,&nbsp;Faith Enigimi ,&nbsp;Wendy P.C. van ’t Westende ,&nbsp;Kas Swinkels ,&nbsp;Wouter Kohlen ,&nbsp;Gerard van der Linden ,&nbsp;Ben Vosman","doi":"10.1016/j.envexpbot.2025.106101","DOIUrl":"10.1016/j.envexpbot.2025.106101","url":null,"abstract":"<div><div>Climate change has profound effects on crop production, for example through increasing temperatures, and more frequent extreme weather events. Climate change can also lead to increased pest pressure. How plants cope under double stress conditions is dependent on pest species, environment, and plant genotype, and for many plant-insect interactions, this knowledge is lacking. The whitefly <em>Bemisia tabaci</em> is an important pest worldwide and can be destructive for pepper (<em>Capsicum)</em> production. Breeding resistant varieties could aid in combatting whiteflies in a sustainable manner. In this study, we aimed to identify <em>Capsicum</em> accessions with resistance to <em>B. tabaci</em>, and study how this resistance was affected by salt stress. We grew 25 <em>Capsicum</em> accessions under salt treatment, and measured <em>B. tabaci</em> survival and oviposition. We identified four accessions with increased whitefly resistance, exhibited as higher adult mortality. Under salt stress, growth of most accessions was inhibited, and Na⁺ accumulated in shoots. Importantly, in all plants that had experienced salt stress, whitefly survival and oviposition increased, essentially nullifying resistance in salt-stressed plants. When plants were treated with salt, the phytohormone jasmonic acid was reduced compared to whitefly-infested plants without salt, possibly resulting in reduced defense to whiteflies. The results of this study will contribute to a better understanding of pest resilient plants in a changing climate.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106101"},"PeriodicalIF":4.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349201","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":"Decoding phytohormone signaling in plant stress physiology: Insights, challenges, and future directions","authors":"Naeem Khan","doi":"10.1016/j.envexpbot.2025.106099","DOIUrl":"10.1016/j.envexpbot.2025.106099","url":null,"abstract":"<div><div>Phytohormones are pivotal regulators of plant stress physiology, orchestrating adaptive responses to environmental challenges and ensuring crop resilience. This comprehensive review explores the intricate signaling networks through which phytohormones operate, emphasizing their critical contributions to stress adaptation. Highlighting the complex crosstalk and feedback mechanisms among multiple hormones (viz. Abscisic acid (ABA), Jasmonic acid (JA), Ethylene, Cytokinin, Gibberellic acid (GA) and Brassinosteroids) and pathways, the review elucidates the role of phytohormones in shaping stress responses at various regulatory levels, from transcriptional to epigenetic regulation. Despite significant progress, deciphering phytohormone signaling networks presents formidable challenges, including inherent complexity and technical constraints. Addressing these hurdles requires interdisciplinary collaboration and innovative methodologies. The review outlines promising research directions aimed at unraveling additional layers of hormonal regulation and enhancing our predictive capabilities for engineering stress-tolerant plants. Overall, this review highlights the pivotal role of phytohormones in plant stress physiology and their implications for sustainable agriculture and food security.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106099"},"PeriodicalIF":4.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379046","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":"Drought memory expression varies across ecologically contrasting forest tree species","authors":"Andrei Toca ,&nbsp;Carlos A. Gonzalez-Benecke ,&nbsp;Andrew S. Nelson ,&nbsp;Douglass F. Jacobs","doi":"10.1016/j.envexpbot.2025.106094","DOIUrl":"10.1016/j.envexpbot.2025.106094","url":null,"abstract":"<div><div>Trees may exhibit long-lasting morpho-physiological acclimation in response to drought (i.e. drought memory) throughout their extensive life cycles. This acclimation might be particularly crucial for seedlings and saplings due to their limited access to water. We studied the development of drought stress memory in seedlings of black walnut (<em>Juglans nigra L.</em>), western larch (<em>Larix occidentalis</em> Nutt.), and Douglas-fir (<em>(Pseudotsuga menziesii</em> var. <em>menziesii</em> (Mirb.) Franco) in response to controlled drought exposure during their germination year (drought priming). We evaluated the effects of drought priming under a second-year drought, focusing on changes in water uptake capacity and transpiration demand, biomass allocation to new roots and foliage, root architecture, and photosynthesis. Drought priming led to significant morpho-physiological responses in the new leaves and roots developed during the subsequent growing season drought. Western larch showed increased biomass allocation to roots, higher specific root length and root tips, and enhanced water uptake, while Douglas-fir exhibited earlier bud break, greater net photosynthesis, and increased foliage growth. In contrast, black walnut seedlings displayed no notable changes in biomass allocation or physiology. Our results also show that biomass allocation to new roots plays a crucial role in enhancing water uptake capacity and gas exchange during seedling establishment. These findings underscore the importance of drought memory for stress resistance in trees, influencing the capacity of forests to regenerate and respond to recurrent droughts and climate change. The formation and expression of drought memory, however, varied across species, highlighting the complexity of adaptive responses across different forest ecosystems.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106094"},"PeriodicalIF":4.5,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349207","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 waterlogging at different duration on growth and physiological characteristics of Cenchrus fungigraminus","authors":"Simeng Song ,&nbsp;Hengyu Zhou ,&nbsp;Yuan Luo ,&nbsp;Shikui Yu ,&nbsp;Dewei Su ,&nbsp;Dan Zheng ,&nbsp;Zhaoxiong Zhang ,&nbsp;Zongzhi Luo ,&nbsp;Bin Liu ,&nbsp;Zhanxi Lin ,&nbsp;Dongmei Lin","doi":"10.1016/j.envexpbot.2025.106096","DOIUrl":"10.1016/j.envexpbot.2025.106096","url":null,"abstract":"<div><div>Waterlogging, or excessive accumulation of water in the soil, poses significant stress to riparian ecosystems and agroforestry, especially with increasing global rainfall. <em>Cenchrus fungigraminus</em> is a vital agricultural resource, biomaterial, and super-energy plant with high resistance and adaptability. This study examined its morphological and physiological responses under root and above-ground waterlogging for up to 30 days. Results showed that waterlogging significantly inhibited growth, reducing membrane permeability, and root activity, and accelerating leaf senescence (<em>P</em> &lt; 0.05). Despite this, <em>C. fungigraminus</em> achieved 100 % survival after 30 days of waterlogging. The plant adapted to the hypoxic environment by enhancing oxygen channels through cortex cell loosening, lysigenous tissue formation, and adventitious root development. It also activated defense mechanisms, increasing the activities of antioxidant enzymes (SOD, POD, and CAT), levels of non-enzymatic antioxidants (AsA and GSH), osmotic regulators (SS, SP, and Pro), and anaerobic respiratory enzymes (PDC, ADH, and LDH), and hormones (ABA, IAA, GA, and ETH). Under two levels of waterlogging depth, the plant initially adopted the Low-O₂ escape strategy (LOES), but over time, it transitioned to the Low-O₂ quiescence strategy (LOQS), while still retaining some features of the LOES. Our results revealed that <em>C. fungigraminus</em> demonstrates strong adaptability to waterlogging, especially in response to root waterlogging. By employing anatomical adjustments and exceptional cellular defense mechanisms, the species effectively mitigates damage, establishing itself as an excellent forage grass for slope protection under waterlogged conditions. These results offer valuable guidance for selecting waterlogging-tolerant species to restore and rehabilitate degraded riparian ecosystems in the Yellow River Basin, optimize land use in waterlogging-prone areas, and advance the genetic improvement of waterlogging tolerance in other forage varieties.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106096"},"PeriodicalIF":4.5,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377170","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":"Knockout of OsBURP12 enhances salt tolerance in rice seedlings","authors":"Zengtong Luo ,&nbsp;Sijia Yu ,&nbsp;Jialing Chen ,&nbsp;Qianyi Liu ,&nbsp;Mangu Hu ,&nbsp;Xiao Yang ,&nbsp;Yongxiang Huang ,&nbsp;Wuming Xiao","doi":"10.1016/j.envexpbot.2025.106097","DOIUrl":"10.1016/j.envexpbot.2025.106097","url":null,"abstract":"<div><div>The BURP gene family encodes the BURP domain protein, a type of plant-specific protein that plays an important role in plant development, metabolism and stress resistance. Salt stress is one of the major stresses faced by rice. However, there is a lack of systematic understanding of the BURP family involved in the regulation of salt stress in rice, especially for the gene <em>OsBURP12</em>. Our study used <em>japonica</em> rice variety Zhonghua 11 (ZH11), as the wild type (WT), and its <em>OsBURP12</em> knockout lines to fill the gap of the understanding. NaCl solution was used for salt stress treatment. Related physiological and biochemical analyses were carried out to investigate the regulatory mechanism of <em>OsBURP12</em> on salt tolerance in rice seedlings. The results showed that the survival rate, seedling height, root length and fresh weight of the knockout lines were significantly higher than those of the WT under salt stress, indicating that the salt tolerance of the knockout lines was significantly better than that of the WT. Under salt stress, the knockout lines had significantly higher antioxidant enzyme activity, lower accumulation of ROS (reactive oxygen species) and higher expression of genes related to ROS-scavenging than the WT. In addition, the knockout lines showed significantly lower PG activity and Na⁺ content, but significantly higher pectin content, K⁺ and Ca²⁺ content than the WT. Furthermore, the knockout lines had significantly higher ABA and ACC levels than the WT. Quantitative PCR analysis showed that the expression levels of genes related to ABA and ethylene synthesis and signaling were significantly higher in the knockout lines than in the WT. The results suggested that the knockout of <em>OsBURP12</em> can improve ROS-scavenging ability, affect PG activity, regulate Na⁺ uptake, and mediate the synthesis and metabolism of ABA and ACC in response to salt stress for a tolerance in rice. Our study laid the foundation for further analysis of the function of BURP family genes in plants, and provided a valuable genetic resource for studying the mechanism of salt tolerance in rice.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"231 ","pages":"Article 106097"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103437","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":"Light-regulated interactions between Phaeobacter sp. and Ulva ohnoi (Chlorophyta): Effects on microbiome dynamics, metabolome composition, and tropodithietic acid production","authors":"Zujaila Nohemy Qui-Minet ,&nbsp;Thomas Wichard ,&nbsp;Gonzalo Del Olmo ,&nbsp;Mariana Pereira ,&nbsp;Hermann Holbl ,&nbsp;Patricia Ruiz ,&nbsp;Javier Cremades ,&nbsp;José Pintado","doi":"10.1016/j.envexpbot.2025.106093","DOIUrl":"10.1016/j.envexpbot.2025.106093","url":null,"abstract":"<div><div><em>Ulva</em> spp. are economically important macroalgae with various industrial applications, including as biofiltration agents for fish effluents in integrated multi-trophic aquaculture recirculating systems (IMTA-RAS). Recent works have proposed inoculating <em>U. ohnoi</em> with the probiotic bacterium <em>Phaeobacter</em> sp. strain 4UAC3 to tackle fish pathogens such as <em>Vibrio</em> spp. in IMTA-RAS. However, the disappearance of <em>Phaeobacter</em> sp. 4UAC3 upon inoculation of <em>U. ohnoi</em> under a regular photoperiod presents significant challenges. This study aimed to investigate how different light regimes impact the relationship between the <em>U. ohnoi</em> holobiont and <em>Phaeobacter</em> sp., focusing on how the colonization of <em>Phaeobacter</em> sp. strain 4UAC3 on <em>U. ohnoi</em> surfaces affects the alga's microbiome and metabolome dynamics. We also sought to validate the presence of tropodithietic acid (TDA), which can act as a probiotic. The study revealed the critical role of light in shaping microbial interactions between <em>Phaeobacter</em> sp. and <em>U. ohnoi</em>: The light regime significantly altered the microbial community structure, metabolite production, and physiological responses of both the bacterium and the alga. <em>Phaeobacter</em> sp. strain 4UAC3 thrived in darkness, modulating the microbiome and the <em>exo</em>- and <em>endo</em>-metabolomes of <em>U. ohnoi</em>. TDA was only identified under dark conditions and released into the algal chemosphere, while <em>Phaeobacter</em> antimicrobial properties were most pronounced in close association with the alga. These findings underline the importance of environmental factors, such as light regime, in driving microbial and molecular dynamics in marine holobionts. In addition, our results have direct implications for the application of <em>U. ohnoi</em> and <em>Phaeobacter</em> sp. in aquaculture, providing valuable insights for future research and practical applications in the field.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"230 ","pages":"Article 106093"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136115","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}