Plant Stress最新文献

{"title":"Integrating ionomics and targeted metabolomics to identify key markers of drought responses in durum wheat (Triticum durum Desf.) genotypes","authors":"Moez Maghrebi ,&nbsp;Giuseppe Mannino ,&nbsp;Noemi Gatti ,&nbsp;Francesco Caldo ,&nbsp;Michele Pesenti ,&nbsp;Fabio Francesco Nocito ,&nbsp;Stefania Astolfi ,&nbsp;Gianpiero Vigani","doi":"10.1016/j.stress.2025.101044","DOIUrl":"10.1016/j.stress.2025.101044","url":null,"abstract":"<div><div>Drought is an environmental constrains limiting plant growth and reduce crop yield, particularly impacting durum wheat cultivation in the Mediterranean region. This research examined the adaptive mechanisms employed by various durum wheat genotypes in response to drought stress conditions. A comprehensive analysis identified significant markers that differentiate the genotypes' responses to drought, revealing a complex interaction of traits that enhance drought tolerance. Notably, 14 markers reflecting drought effects and 16 markers associated with genotype variations were identified. The analysis categorized the genotypes into distinct groups based on their tolerance to drought and metabolic dynamics. The tolerant genotypes, including BULEL, SVEVO, and SVEMS16, demonstrate lower plasticity and stable performance under drought, employing unique strategies such as enhanced ion homeostasis, stress-responsive gene regulation (e.g., <em>TdDHN15.3</em>), and lipid adjustments. SVEMS1 displayed tolerance through compensatory mechanisms, while older varieties (S.CAP, ETRUSCO) showed shared vulnerabilities, including disrupted nutrient uptake and reduced stress signaling. Overall, this research elucidates the interplay of multiple traits in drought adaptation, offering key markers for breeding resilient wheat genotypes to enhance food security in water-limited regions.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101044"},"PeriodicalIF":6.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellulose synthase superfamily key in DAMPs-triggered immunity against Sclerotinia stem rot in Brassica napus","authors":"Wennian Xia ,&nbsp;Yunli Su ,&nbsp;Jiayi Song ,&nbsp;Li Wang ,&nbsp;Meiyun Yang ,&nbsp;Jie Yang ,&nbsp;Ran Zhang ,&nbsp;Xiaomao Cheng ,&nbsp;Feng Zu ,&nbsp;Huizhen Hu","doi":"10.1016/j.stress.2025.101040","DOIUrl":"10.1016/j.stress.2025.101040","url":null,"abstract":"<div><div>The cellulose synthase (CESA) superfamily, critical for cell wall biosynthesis and immunity, is poorly characterized in <em>Brassica napus</em> resistance to Sclerotinia stem rot (SSR). We genome-wide identified 92 <em>BnCESA</em> superfamily genes, phylogenetically clustered into seven subfamilies (BnCESA, BnCSLA-BnCSLG). Structural analysis revealed conserved catalytic (DxD, TED) and regulatory (QxxRW) domains polysaccharide synthesis and immune responses. Intraspecific synteny analysis revealed non-uniform gene distribution across chromosomes, while interspecific comparison with <em>Arabidopsis thaliana, Brassica rapa, Brassica oleracea</em>, and <em>Oryza sativa</em> showed high collinearity with Brassica species (75–159 syntenic pairs) but limited conservation with rice (2 pairs), underscoring evolutionary conservation within Brassicaceae. Promoter <em>cis</em>-elements showed enrichment of jasmonic acid (JA)- and salicylic acid (SA)-responsive motifs, aligning with infection-stage expression dynamics. Transcriptomic profiling identified 36 infection-responsive genes, with 15 core candidates (e.g., <em>BnCSLG2c, BnCESA3b, BnCSLD3d, BnCSLC8a</em>) driving biphasic defense: SA-mediated early responses (6–24 hpi) transitioning to JA-dominated late resistance (36–60 hpi), reducing lesion expansion by up to 50 %. Oligosaccharide-derived damage-associated molecular patterns (DAMPs)—cellobiose (CB), xylooligosaccharides (XOS), and oligogalacturonides (OG), activated distinct programs: CB induced sustained responses (0–60 hpi), OG prioritized wall remodeling (48–60 hpi), and XOS synchronized with circadian-regulated defenses. Molecular docking and comparative expression profiling in resistant/susceptible rapeseed varieties predicted seven core genes (<em>BnCSLG2c, BnCSLC8a, BnCESA6b, BnCESA6a, BnCESA5b, BnCESA3b</em>, and <em>BnCSLD3d</em>) as potential integrators of cell wall integrity and immune signaling. Our finding provides potential genetic resources for precision breeding of SSR-resistant rapeseed.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101040"},"PeriodicalIF":6.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"B-BOX PROTEINS (BBXs) transcription factors in plant: A comprehensive review of their growth, development, abiotic stress responses and phytohormone signals","authors":"Yaxuan Jiang ,&nbsp;Pei Lei ,&nbsp;Ximei Ji ,&nbsp;Jianxin Li ,&nbsp;Yong Zhao ,&nbsp;Mingquan Jiang ,&nbsp;Le Ma ,&nbsp;Xiyang Zhao ,&nbsp;Fanjuan Meng","doi":"10.1016/j.stress.2025.101042","DOIUrl":"10.1016/j.stress.2025.101042","url":null,"abstract":"<div><div>Global climate change exacerbates the effects of environmental stressors, such as drought, temperatures, salinity. Over the past two decades, there have been many studies on B-BOX PROTEINS (BBXs) in plants, with much of the research concentrated on their roles in plant growth and development. Nevertheless, recent findings have revealed that BBXs are also required for environmental stressors. In this review, we survey recent advances in the characterization BBXs of molecular mechanisms in abiotic stress tolerance and plant growth. The interaction between BBXs transcription factor and related proteins and the binding to promoter elements of stress response related genes were emphatic discussed. In addition, we discuss the future challenges and opportunities for extend the BBXs knowledge model plant to other species, and provide a better understanding of plant growth and development in natural conditions.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101042"},"PeriodicalIF":6.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suitable light intensity stimulated polysaccharide biosynthesis in bletilla striata pseudobulbs through regulating starch and sucrose metabolism","authors":"Jiao Zhu ,&nbsp;Liuyan Yang ,&nbsp;Youming Cai ,&nbsp;Xinhua Zeng ,&nbsp;Yongchun Zhang ,&nbsp;Weichang Huang","doi":"10.1016/j.stress.2025.101041","DOIUrl":"10.1016/j.stress.2025.101041","url":null,"abstract":"<div><div><em>Bletilla striata</em> is a famous medicinal plant, which medicinal function on polysaccharide. However, the effect of light intensity on polysaccharide accumulation in <em>B. striata</em> pseudobulbs is largely unknown. <em>B. striata</em> plants were exposed to three different light intensities: low light (5–20 μmol·<em>m</em>⁻²·s⁻¹; LP), middle light (200 μmol·<em>m</em>⁻²·s⁻¹; MP), and high light (400 μmol·<em>m</em>⁻²·s⁻¹; HP). The results indicated that polysaccharide content of new pseudobulbs significantly increased under MP, and enrichment in starch and sucrose metabolism with metabolomics and transcriptomics. More sucrose was produced in the leaves through photosynthesis and was efficiently distributed to the pseudobulbs, where it was hydrolyzed into key metabolites for polysaccharide biosynthesis function by <em>SUS</em> and <em>CSLA</em> genes. The key metabolites in the polysaccharide biosynthetic pathway, such as sucrose-6-phosphate, fructose, fructose-6-phosphate, glucose-6-phosphate, GDP-mannose, and uridine 5′-diphospho-<span>d</span>-glucose, were upregulated under MP. Furthermore, the expression of the <em>UGP2</em> gene involved in polysaccharide biosynthesis was significantly higher under MP than under LP and HP. Conversely, sucrose in leaves was minimally transported into pseudobulbs due to insufficient photosynthesis under LP and energy metabolism related to carbohydrate degradation and oxidation was hindered under HP. Thus, suitable light intensity effectively stimulated polysaccharide formation in <em>B. striata</em> pseudobulbs through starch and sucrose metabolism–mediated regulation.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101041"},"PeriodicalIF":6.8,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon ion beam-induced radiation hormesis in Bupleurum chinense DC.: Insights from growth, physiological, and metabolomic analyses for increased bioactive substances","authors":"Xiao Liu ,&nbsp;Man Wang ,&nbsp;Yuanmeng Wang ,&nbsp;Xuehu Li ,&nbsp;Fusheng Wang ,&nbsp;Zhijun Xin ,&nbsp;Xihong Lu ,&nbsp;Xiaochun Pan ,&nbsp;Li Li ,&nbsp;Yan Du ,&nbsp;Libin Zhou","doi":"10.1016/j.stress.2025.101037","DOIUrl":"10.1016/j.stress.2025.101037","url":null,"abstract":"<div><div><em>Bupleurum chinense</em> DC (<em>B. chinense</em>) is an important medicinal plant widely used in Asian countries. However, the efficacy of its medicinal components has medicinal components during the domestication process from wild to cultivated lines. Studies have shown that appropriate stress, such as ionizing radiation, can promote the accumulation of metabolites in medicinal plants. Nevertheless, the effects of ionizing radiation on <em>B. chinense</em> remains unclear. In this study, we systematically investigated the stimulatory effect of carbon ion beams (CIB) pretreatment on the growth, physiology, and accumulation of secondary metabolites in <em>B. chinense</em>. Although CIB irradiation inhibited the seed germination and survival rates, by the age of 4 months, the plant height and leaf area of the irradiated group had recovered to the levels comparable to the control. The enhanced growth performance during later developmental stages may be attributed to radiation hormesis and ROS-mediated regulation in antioxidant system and the photosynthetic system. One and two years after irradiation at doses of 50 and 100 Gy, no significant differences in root biomass were observed compared to the control group. Metabolically, the content of total flavonoid, saikosaponin a and saikosaponin c were significantly increased following 50 Gy irradiation. Further metabolomic analysis revealed that intermediate metabolites in the flavonoid and terpenoid biosynthetic pathways were significantly up-regulated in the 50 Gy irradiation group. Compounds with pharmacological activity also accumulated in large quantities after irradiation. These results suggest that pretreatment with 50 Gy CIB irradiation could serve as a potential method to promote the accumulation of secondary metabolites in <em>B. chinense</em>. This finding provides strong support for the application of physical radiation technology to enhance the production of secondary metabolites in medicinal plants, offering new avenues for the cultivation of high-quality Chinese herbal medicines.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101037"},"PeriodicalIF":6.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic reconfiguration and proline-mediated responses enhance citrus tolerance to combined water, light and heat stress","authors":"Damián Balfagón,&nbsp;Clara Segarra-Medina,&nbsp;José L. Rambla,&nbsp;Aurelio Gómez-Cadenas","doi":"10.1016/j.stress.2025.101039","DOIUrl":"10.1016/j.stress.2025.101039","url":null,"abstract":"<div><div>The co-occurrence of multiple abiotic stress factors has become increasingly common in agricultural systems, largely driven by the intensification of climate change. These overlapping stressors not only occur more frequently but also with greater intensity, posing complex challenges to crop resilience and overall productivity. In this context, the ability of plants to adjust their metabolism plays a pivotal role in facilitating acclimation to such multifaceted environmental pressures. The present study explores how two citrus rootstocks with differing stress tolerance profiles—Carrizo citrange and Cleopatra mandarin—reconfigure their primary metabolism when simultaneously exposed to water limitation, high light exposure, and elevated temperatures. Our results demonstrate that Carrizo exhibits distinct metabolic alterations under high temperature stress, whereas Cleopatra remains largely unaffected, suggesting an inherently lower heat tolerance in Cleopatra. Furthermore, Carrizo plants accumulate proline in response to the triple stress combination, while Cleopatra instead accumulates γ-aminobutyric acid (GABA). Remarkably, treatment with exogenous proline enhances stress tolerance in both genotypes by increasing antioxidant enzyme activities and activating autophagy-related stress response pathways. While previous studies have explored plant responses to individual stress factors, our research reveals that metabolic reconfiguration and proline accumulation are key to coping with the combined effects of water deficit, high irradiance, and extreme temperatures in citrus. These findings underscore the pivotal role of proline metabolism in mitigating the detrimental effects of complex abiotic stresses and point to potential strategies for improving citrus adaptation through metabolic modulation. Overall, our study provides valuable insights into the mechanisms driving plant responses to environmental challenges, which are essential for developing sustainable agricultural practices in the face of climate change.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101039"},"PeriodicalIF":6.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptional Insights into Soybean Genotypes Under Prolonged Heat Stress: Identification of Key Genes and Soil Influences for Enhanced Tolerance","authors":"Liza Van der Laan ,&nbsp;Dinakaran Elango ,&nbsp;Antonella Ferela ,&nbsp;Jamie A. O’Rourke ,&nbsp;Asheesh K. Singh","doi":"10.1016/j.stress.2025.101038","DOIUrl":"10.1016/j.stress.2025.101038","url":null,"abstract":"<div><div>Heat stress is increasingly a problem in global agriculture production, both in occurrences and durations. Understanding the molecular mechanisms of soybean heat stress response is essential for breeding heat tolerant soybeans. Soybean heat stress studies have primarily focused on response to short periods of stress, however soybean growing regions are consistently exposed to longer and more frequent heat stress events. Additionally, the role of soil-based microbial communities on heat stress tolerance is poorly understood. We used RNA-seq to measure the transcriptional responses in four soybean genotypes exposed to two temperature regimes (control and high heat) and grown in two soil conditions (native soils and autoclaved soils). We hypothesize that the different genotypes will have different heat stress responses and that altered microbial composition or nutrient availability from autoclaved soils impacts soybean response to long-term heat stress exposure. Improving abiotic stress tolerance has been identified as a major topic of importance by the soybean research community as it is paramount for growers to ensure they have successful seasons. This study has identified multiple genes of interest that could be important in developing improving soybean heat stress tolerant varieties. Potential markers were also identified for use in selection of heat tolerant soybeans in breeding programs</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101038"},"PeriodicalIF":6.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding the shading effect in cigar tobacco leaf development through transcriptomic and physiological insights","authors":"Huajun Gao ,&nbsp;Zhaoliang Geng ,&nbsp;Shixin Zhao ,&nbsp;Abdullah Khan ,&nbsp;Keling Chen ,&nbsp;Yuan He ,&nbsp;Chuanxi Peng ,&nbsp;Xinghua Ma","doi":"10.1016/j.stress.2025.101036","DOIUrl":"10.1016/j.stress.2025.101036","url":null,"abstract":"<div><div>Shading or low light is a key agronomic practice affecting the growth, physiology, and quality of cigar tobacco wrapper leaves, yet the physiological and molecular mechanisms underlying shading responses remain poorly characterized. This study investigated the physiological, transcriptomic, and agronomic responses of the cultivar QX103 under three light regimes: full light (CT), moderate shading (MT, 70–80 % transmittance), and heavy shading (LT, 50–60 % transmittance). Shading significantly enhanced wrapper yield (LT&gt;MT&gt;CT), with moderate shading promoting optimal plant height, leaf expansion, SPAD values, and photosynthetic efficiency. Transcriptome analysis revealed distinct gene expression changes, with MT upregulating <em>AMY, UGP2, TREH, WAXY</em>, and <em>SPS</em> genes to enhance starch degradation and sucrose synthesis, whereas LT upregulated <em>TPS, GN1_2_3</em>, and <em>ISA</em>, indicating starch catabolism under low light. Circadian genes (<em>PRR5, CO, CDF1</em>) were activated under MT, while LT disrupted clock entrainment (<em>TOC1, LHY, CRY1/2, COP1</em>). Hormone profiling validated that MT enhanced ICAId and TZR, supporting growth, whereas, LT increased IAA, GA1, GA7, and IPA while reducing SAG, DHJA, and SA, indicating stress. qRT-PCR confirmed that MT promoted primary metabolism, while LT altered hormonal profiles driving a shade-avoidance-like response mediated by altered IAA/GA and JA/SA dynamics. Collectively, these results demonstrate that moderate shading balances growth, metabolism, and stress responses, improving wrapper leaf quality and yield, providing a mechanistic basis for precision shading in cigar tobacco cultivation.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101036"},"PeriodicalIF":6.8,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Auxin metabolism and signaling: Integrating independent mechanisms and crosstalk in plant abiotic stress responses","authors":"Elshan Musazade ,&nbsp;Isack Ibrahim Mrisho ,&nbsp;Xianzhong Feng","doi":"10.1016/j.stress.2025.101034","DOIUrl":"10.1016/j.stress.2025.101034","url":null,"abstract":"<div><div>Plants encounter various abiotic stresses that substantially impact their growth, development, and productivity. As immobile organisms, plants rely on sophisticated stress sensing, signaling, and regulation mechanisms to adapt and survive under challenging conditions. Auxin, a major plant growth regulator, plays a central role in modulating these responses by influencing various molecular, biochemical, and physiological processes. It is synthesized through multiple biosynthetic pathways and tightly regulated via metabolism, transport, and signal transduction. Auxin directly governs stress responses through distinct, stress-specific mechanisms that operate independently of other hormones, as supported by recent studies on auxin-regulated gene expression and signaling modules under individual stress conditions. In parallel, auxin acts as a central integrator in hormonal crosstalk networks, interacting with abscisic acid (ABA), brassinosteroids (BRs), cytokinin (CK), ethylene (ET), jasmonic acid (JA), melatonin (Mel), and salicylic acid (SA) to fine-tune adaptive responses. This review delves into the dual aspects of auxin's role by first analyzing its stress-specific, independent mechanisms and then exploring its integrative functions through hormonal crosstalk during abiotic stress conditions. By shedding light on these distinct regulatory frameworks, this review emphasizes auxin's multifaceted role in enhancing plant resilience and explores potential agricultural strategies for improving stress tolerance.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101034"},"PeriodicalIF":6.8,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Appropriate calcium supply improves photosynthetic nitrogen use efficiency by improving nitrogen distribution and leaf ultrastructure in apple rootstock leaves","authors":"Xinxiang Xu ,&nbsp;Yan Tang ,&nbsp;Daliang Liu ,&nbsp;Xueyong Zhang ,&nbsp;Shuo Zhang ,&nbsp;Yuxia Wang ,&nbsp;Yanju Li ,&nbsp;Xiubo Xia ,&nbsp;Laiqing Song ,&nbsp;Yanxia Sun ,&nbsp;Fen Wang ,&nbsp;Lingling Zhao","doi":"10.1016/j.stress.2025.101035","DOIUrl":"10.1016/j.stress.2025.101035","url":null,"abstract":"<div><div>The photosynthetic nitrogen (N) use efficiency (PNUE) of apple leaves varies under different calcium (Ca) levels, but the underlying physiological mechanism remains unclear. This study systematically elucidated the synergistic regulatory mechanisms of Ca levels on N uptake, allocation, and photosynthetic performance in apple rootstock by integrating a leaf photosynthetic N allocation model, photosynthetic limiting factor analysis, and microstructural observations. Ca stress (low Ca: 0.1 mM Ca²⁺; high Ca: 15 mM Ca²⁺) significantly suppressed nitrate transporter gene (<em>NRT</em>) expression and reduced the net NO₃⁻ influx rate of root surfaces, thereby hindering N uptake and translocation to shoots. Low Ca treatment increased stomatal and biochemical limitations by inducing stomatal closure and reducing the maximum carboxylation rate (<em>V</em>ₘₐₓ). By contrast, high Ca treatment increased mesophyll conductance limitation by increasing cell wall thickness, leaf thickness, and leaf Ca oxalate content, and by decreasing Ca and N availability. Both low and high Ca treatments disrupted leaf N allocation, characterized by increased proportions of non-protein and storage N and decreased allocation to photosynthetic N components, such as carboxylate system N and electron transport N. Together, these changes reduced the leaf PNUE. By contrast, optimal Ca treatment (5 mM Ca²⁺) significantly improved the leaf net photosynthetic rate and PNUE by optimising photosynthetic N allocation, improving leaf structural integrity and reducing starch grain accumulation. This study provides a theoretical basis for precise Ca management in apple orchards.</div></div>","PeriodicalId":34736,"journal":{"name":"Plant Stress","volume":"18 ","pages":"Article 101035"},"PeriodicalIF":6.8,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}