Physiologia plantarum最新文献

{"title":"Functional Characterisation of Alternative Oxidase Protein Isoproteins in Arabidopsis thaliana.","authors":"Cunman He, Andreas Hartmann, Minxuan Li, Yanqiao Zhu, Reena Narsai, Kemeng Xiao, Kun Qian, Oliver Berkowitz, Jennifer Selinski, James Whelan","doi":"10.1111/ppl.70468","DOIUrl":"https://doi.org/10.1111/ppl.70468","url":null,"abstract":"<p><p>The Alternative Oxidase (AOX) is encoded by a small gene family in plants. While being one of the most intensively studied plant mitochondrial proteins, it is primarily only one isoform, AOX1a, that is well studied. We investigated the sub-and neo-functionalisation of AOX isoforms in Arabidopsis thaliana by constructing over-expressing lines for all five AOX isoforms in an aox1a knock-out mutant line, where no AOX protein can be detected. In Arabidopsis thaliana, knock-out mutants for aox1a are unable to support germination on antimycin A, despite the presence of four functional AOX genes. Sub-functionalisation was observed for AOX1a in that its 3 kb promoter region supports germination on antimycin A when driving the expression of other AOX isoforms, indicating that it is a promoter-based trait, rather than a specific function of the AOX1a isoprotein. Further evidence of sub-functionalisation was evident as AOX1d and AOX1a tagged with GFP enhanced epidermal expression but not when the other isoforms were used. Arabidopsis AOX1c represents an example of neo-functionalisation as aox1c knock-out had a slightly retarded growth phenotype, while mis-expression of AOX1c, using either the CaMV 35S promoter or the 3 kb of the AOX1c promoter, resulted in enhanced growth. This was even more evident under high-light conditions, where greater tolerance to high light was observed compared to wild type (Col-0) plants. These examples indicate that functional analysis of all AOX isoforms is crucial to gain a full understanding of the role of AOX in plant metabolism and growth.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70468"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12391748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965039","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":"Acclimation of Synechocystis sp. PCC 6803 to Alkaline pH Under Ambient Air.","authors":"Henna Mustila, Michal Hubáček, Dorota Muth-Pawlak, Yagut Allahverdiyeva","doi":"10.1111/ppl.70474","DOIUrl":"https://doi.org/10.1111/ppl.70474","url":null,"abstract":"<p><p>Cyanobacteria can thrive at a wide pH range from neutral up to pH 11 depending on the species. Even though cyanobacteria are alkaliphilic, only limited information on the metabolic acclimation to alkaline pH is available. In this study, we conducted a mass-spectrometry-based comparative proteomic analysis of Synechocystis sp. PCC 6803 grown in BG-11 medium buffered at pH 7.5, pH 8.2, and pH 9.2 under ambient air. When comparing cells grown at pH 8.2 to those at pH 7.5, only minor changes in the proteome were observed, with most of the altered proteins originating from the plasma membrane. However, when comparing cells grown under pH 9.2 to those at pH 7.5, a total of 235 proteins were differentially expressed. Synechocystis cells growing at pH 9.2 seem to display a different composition of bicarbonate transporters. Subunits of the ATP-dependent bicarbonate transporter BCT1 increased in abundance under pH 9.2 compared to pH 7.5 or pH 8.2, while the abundance of the sodium-dependent bicarbonate transporter SbtA was diminished. The increased contribution of the BCT1 complex to total bicarbonate transport at high pH was confirmed by evaluating the activity of different bicarbonate transporters. Furthermore, several changes in the abundance of ion transporters were observed, including upregulation of copper, potassium, and zinc efflux proteins. In contrast, the levels of several proteins involved in nitrogen assimilation and amino acid biosynthesis were reduced at pH 9.2. To conclude, the induction of several transporters indicates the cells' ability to regulate the internal ion and pH homeostasis as well as the carbon: nitrogen ratios under alkaline conditions.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70474"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12382314/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965103","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":"SCL15 Regulates the Release of Seed Dormancy in Arabidopsis thaliana by Integrating the Circadian Clock, Hormonal Signals and Cell Wall Remodelling.","authors":"Ming-Jun Gao, Qi Chen, Cathy Coutu, Fuyou Fu, Bianyun Yu, Xiang Li, Z Jeffrey Chen, Dwayne Hegedus","doi":"10.1111/ppl.70467","DOIUrl":"10.1111/ppl.70467","url":null,"abstract":"<p><p>Dormancy release and germination of the seed are two separate, but continuous phases controlled by both external (e.g., light and temperature) and internal (e.g., circadian clock and hormones) cues. In eudicot seeds, the endosperm tissues play a key role in dormancy release and germination through dynamic modulation of wall components and biomechanics. However, the mode of action by which the circadian oscillator influences dormancy release by modulation of endosperm wall biomechanics remains elusive. SCARECROW-LIKE15 (SCL15) represses embryonic gene expression in seedlings through interaction with HISTONE DEACETYLASE19 (HDA19) in Arabidopsis thaliana. Here, we report that SCL15 plays a positive role in primary dormancy release, which is associated with gene expression changes in circadian, abscisic acid, auxin and cell wall (CW) remodelling pathways, based on studies using SCL15 mutant and Napin promoter-driven SCL15 expression lines. SCL15 was found to affect the expression of genes whose products modify endosperm wall biomechanical features, possibly through regulation of local auxin accumulation and evening-phased clock components. RNA-seq analysis supported the notion that dormancy release is associated with changes in the expression of genes associated with circadian and hormone-mediated pathways, which in turn affect CW structure.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70467"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12415678/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145016085","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":"Unveiling the Genetic and Physiological Synergies of Iron and Sulfur Homeostasis in Durum Wheat: From Root to Grain.","authors":"Alessandro Bruschini, Eleonora Coppa, Giulia Quagliata, Miriam Marín-Sanz, Andrea Ferrucci, Matteo Spada, Francesco Sestili, Francisco Barro, Gianpiero Vigani, Stefania Astolfi","doi":"10.1111/ppl.70524","DOIUrl":"10.1111/ppl.70524","url":null,"abstract":"<p><p>Fe deficiency is a major global challenge for agriculture. While high sulfur (S) supply can improve Fe nutrition in some grasses, the underlying mechanisms are poorly understood. This study investigated four genetically distinct durum wheat genotypes (Svevo, Karim, LcyE A^-B^-, and Svems16) to test the hypothesis that they employ different S-mediated strategies to maintain Fe homeostasis under varying Fe availability. Fe deficiency inhibited plant growth and induced chlorosis with genotypic differences in severity. Notably, high S mitigated chlorosis in Karim and promoted root development in most genotypes, especially Svems16. Ionomic analysis showed that Fe deficiency primarily drove nutrient shifts in roots, but adding S restored shoot ionomic profiles. Total S analysis revealed genotype-specific accumulation. Svevo showed consistently low S, possibly due to a sulfate transporter variant. Conversely, Karim exhibited elevated root S under combined stress, suggesting increased S channeling to phytosiderophore (PS) biosynthesis, supported by genotype-dependent PS release. Genotyping-by-sequencing identified variants in methionine metabolism and PS-related genes, offering molecular bases for the observed physiological differences. ATPS and OASTL activity patterns further confirmed the genotype-specific role of root S metabolism in Fe deficiency response. Grain ionomics revealed that LcyE A^-B^- enhanced Fe accumulation under combined high S and Fe deficiency, Svems16 under high S, while Karim, the most sensitive, had reduced grain Fe under deficiency. Our results highlight distinct, genotype-specific strategies for maintaining Fe homeostasis and identify promising targets for breeding programs aimed at improving nutrient use efficiency and biofortification in durum wheat.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70524"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12446894/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145086864","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":"Transcriptomic Analysis Reveals the Key Role of Photosynthetic System Stability and Carotenoid Accumulation in Drought Tolerance in Maize.","authors":"Wenqing Li, Ruilin An, Xiaodong Xie, Zhiqin Zhang, Li Yan, Haiyu Zhou, Hexia Xie, Xiang Yang, Weidong Cheng, Lanqiu Qin, Yuxin Xie, Xunbo Zhou, Yufeng Jiang","doi":"10.1111/ppl.70519","DOIUrl":"https://doi.org/10.1111/ppl.70519","url":null,"abstract":"<p><p>Due to climate change, drought has emerged as a major threat to maize production globally. To explore the molecular mechanisms of drought stress adaptation at the maize seedling stage, previously identified as drought-tolerant inbred line CML323 and drought-sensitive inbred line CB2-49-1 were treated for 5 days (d) of drought treatment, and day 0 was defined as the time point when soil water content reached 60% of the field water content. After drought treatment, a change in carotenoid content was detected; at the same time, the leaves were collected for transcriptome analysis. Analyzing the mechanisms of drought stress response in the third leaf stage at physiological and transcriptional levels. The results showed that: (1) The number of DEGs in CML323 was 32.98% more than that in CB2-49-1 at 1 day of drought, which could rapidly activate the ABA signaling pathway to reduce water loss through stomatal closure and osmoregulation; (2) CML323 maintained the stable expression of photosystem genes and had a significantly higher carotenoid content of 21.43% compared to CB2-49-1 at 5 days of drought stress. And carotenoids synergized with substances such as isoprene to scavenge ROS; (3) Co-expression network analysis identified a hub gene, ZmPBS1, which may positively regulate drought stress. In summary, changes in the expression of crucial genes and signal transmission processes are induced by drought stress, thus initiating adaptive and protective mechanisms. These findings provide new insights into the mechanisms of carotenoid accumulation and photosynthetic stability under drought stress in maize.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70519"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145131697","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":"Functional Analysis of the Pepper RING-Type E3 Ligase CaANKR1 Involved in Drought Stress Tolerance via Modulation of Abscisic Acid Signaling.","authors":"Mirim Kim, Chae Woo Lim, Dae Sung Kim, Sung Chul Lee","doi":"10.1111/ppl.70522","DOIUrl":"10.1111/ppl.70522","url":null,"abstract":"<p><p>Plants have developed a diverse array of mechanisms that facilitate survival under stress conditions, among which the ubiquitin-proteasome system (UPS) is a post-translational system used to modulate abiotic stress responses at the molecular level. Within the UPS, E3 ligase plays a key role in determining substrate specificity and has been implicated in the abscisic acid (ABA) signaling pathway during drought stress. In this study, we isolated CaANKR1, an ankyrin repeat-containing C3HC4-type RING E3 ligase, from pepper and characterized its functions in plants subjected to drought stress. CaANKR1 expression was induced by various abiotic stresses, including dehydration, salinity, and mannitol. CaANKR1 was found to be localized in the nucleus and to possess E3 ligase activity. Additionally, we generated CaANKR1-silenced peppers and CaANKR1-overexpressing (OE) Arabidopsis transgenic plants to analyze the functional roles of CaANKR1 in response to drought stress. CaANKR1-silenced peppers exhibited enhanced drought tolerance, which was associated with reduced transpirational water loss and increased ABA sensitivity. In contrast, CaANKR1-OE Arabidopsis transgenic plants showed reduced drought tolerance and decreased sensitivity to ABA. Collectively, these findings suggest that CaANKR1 functions as a negative regulator in drought stress responses.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70522"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12440645/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075911","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":"Speed Breeding of Soybean by Using 22 h Photoperiod Increases Photochemical Efficiency of Pods and Produces Six Generations Per Year.","authors":"Seher Bahar Aciksoz, Shellie Wall, Stuart James Lucas, Mustafa Atilla Yazıcı, Tracy Lawson","doi":"10.1111/ppl.70511","DOIUrl":"10.1111/ppl.70511","url":null,"abstract":"<p><p>Fast generation cycling of plants has the potential to overcome the bottleneck of traditional breeding programmes, which often require several years to achieve the desired outcomes. Recent speed breeding methodologies have reduced generation times in both short- and long-day species by optimizing environmental conditions. However, protocols for short-day plants impose a constant short-day photoperiod throughout the entire life cycle, even though plants could benefit from extended light exposure. Here, we report a speed breeding scheme for soybean (Glycine max) based on a long-day photoperiod of 22 h (LD-22 h) applied upon flowering initiation (stage R1) using light-emitting diodes (LEDs) with a cool white (6000 K) and red light (660 nm) spectrum at 550 μmol/(m²s) photosynthetic photon flux at canopy level. We also outline an immature seed germination technique for early harvested green seeds collected from speed-breeding plants that markedly increased the germination rate. Combining these methods allowed our soybean speed breeding system to acquire a 92% germination rate from 58-day-old seeds, enabling six generations y^-1 compared to typically only 1-3 using standard approaches. The impact of long photoperiods on soybean leaf and pod photochemical efficiency was examined. Although photosynthetic capacity (Vc_max, J_max, and A_max) was significantly lower in leaves grown under LD-22 h photoperiod, seed production was unaffected, while PSII operating efficiency (F_q'/F_m') in pods was markedly higher under LD-22 h compared to the SD-10 h photoperiod. Implementing our post-flowering long photoperiod conditions followed by an enhanced germination technique could facilitate rapid breeding for soybeans and be adapted for use with other photoperiod-sensitive short-day crops.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70511"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12426813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145041066","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":"Multi-Omics Integration Reveals Heavy Ion-Induced Enhancement of Soybean Isoflavone Biosynthesis.","authors":"Kezhen Zhao, Huilong Hong, Xiulin Liu, Xueyang Wang, Chunlei Zhang, Fengyi Zhang, Rongqiang Yuan, Sobhi F Lamlom, Honglei Ren, Bixian Zhang","doi":"10.1111/ppl.70508","DOIUrl":"10.1111/ppl.70508","url":null,"abstract":"<p><p>Isoflavones are valuable bioactive compounds in soybeans with significant therapeutic potential, yet conventional breeding approaches face limitations in enhancing their accumulation. We hypothesized that heavy ion radiation could effectively stimulate isoflavone biosynthesis through coordinated molecular reprogramming mechanisms. To test this hypothesis, we conducted an integrated transcriptomic-proteomic analysis investigating radiation effects on isoflavone metabolism across four developmental stages in soybean. Heavy ion treatment validation confirmed our hypothesis, substantially increasing isoflavone accumulation with total isoflavones showing significant enhancement (p = 7.34 × 10^-6), alongside specific increases in genistin (p = 3.46 × 10^-4) and genistein (p = 1.61 × 10^-4). Multi-omics profiling revealed the molecular basis underlying these metabolic changes: RNA sequencing identified 3639 differentially expressed genes, while quantitative proteomics revealed 1458 differentially expressed proteins, indicating extensive macromolecular reprogramming in response to radiation treatment. Integration of transcriptomic and proteomic datasets revealed coordinated regulatory networks driving enhanced isoflavone production. Pathway enrichment analysis identified 89 overlapping KEGG pathways, with 33 showing significant co-enrichment (p < 0.05). Six key pathways exhibited coordinated upregulation: pentose phosphate pathway, glutathione metabolism, amino acid biosynthesis, lipid metabolism, flavonoid biosynthesis, and fatty acid synthesis. Notably, glutathione metabolism was most extensively regulated (12 genes, 27 proteins), suggesting that enhanced isoflavone production functions as part of an integrated antioxidant defense mechanism triggered by radiation stress. The tight coordination between molecular and metabolic responses was demonstrated through strong correlations (r > 0.8, p < 0.01) between mRNA expression, protein abundance, and metabolite accumulation. RT-qPCR validation confirmed transcriptomic findings (r > 0.85, p < 0.001), supporting the reliability of our multi-omics approach. These results establish heavy ion radiation as an effective biotechnological tool for enhancing secondary metabolite production and provide mechanistic insights into coordinated macromolecular responses that could inform future crop improvement strategies.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70508"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145065012","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":"Effect of Ultraviolet Radiation on Morphology, Physiology and Antioxidant Defense System of the Rice-Field Cyanobacterium Anabaena sp. Strain VKB01.","authors":"Nasreen Amin, Vinod K Kannaujiya","doi":"10.1111/ppl.70544","DOIUrl":"https://doi.org/10.1111/ppl.70544","url":null,"abstract":"<p><p>Anthropogenic-induced variation in ultraviolet-B radiation (UV-B) of the solar spectrum causes dramatic changes in agricultural crops and associated nitrogen-fixing cyanobacteria. A few or limited studies have been conducted to explore the adaptive strategies of cyanobacteria to elevated UV-B radiation. Despite their ecological importance, the adaptive strategy of rice-field cyanobacteria under elevated UV radiation remains poorly understood. In the present study, we investigated the morphological, physiological, and biochemical responses of the heterocystous cyanobacterium Anabaena sp. strain VKB01 under a combination of ultraviolet and photosynthetically active radiation [PAR (P), PAR + UV-A (PA), PAR + UV-A + UV-B (PAB)]. Cyanobacterial cultures exposed to PAR exhibited enhanced growth, pigment accumulation, and photosynthetic efficiency, whereas the same cultures irradiated with PA and PAB showed a marked reduction in these parameters. Structural analyses (SEM, TEM) revealed thylakoid disorganization and cytoplasmic damage, particularly under PAB treatment. Defense responses included elevated carotenoids, allophycocyanin, and carbohydrate levels, along with significant increases in antioxidant enzyme activity and radical scavenging capacity. Malondialdehyde content and fluorescence intensity also rose markedly under UV stress, indicating oxidative damage. Notably, mycosporine-like amino acids (MAAs) accumulated up to sixfold under prolonged PAB exposure, highlighting their role as photoprotective metabolites. These current findings demonstrate that Anabaena sp. strain VKB01 employs a multifaceted defense system, including pigment modulation, antioxidant regulation, and MAAs biosynthesis, to withstand UV-B-induced stress. This study enhances our understanding of cyanobacterial resilience in rice-field ecosystems and suggests potential applications in sustainable agriculture and the biotechnological production of natural photoprotective compounds.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70544"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145150459","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":"CO₂-Dependent Promotion of Photosynthesis Drives Metabolic Photoacclimation in Chlamydomonas reinhardtii.","authors":"Ana Pfleger, Erwann Arc, Thomas Roach","doi":"10.1111/ppl.70461","DOIUrl":"https://doi.org/10.1111/ppl.70461","url":null,"abstract":"<p><p>Light and inorganic carbon (C_i) drive photosynthesis, which fuels cellular maintenance, energy storage, and growth in photosynthetic organisms. Despite its pivotal role, how primary metabolism adjusts to contrasting light and C_i availability in algae remains elusive. Here, we characterized bioenergetics and profiled primary metabolites of photoautotrophic Chlamydomonas reinhardtii cultures grown under constant low/sub-saturating (LL) or high/saturating (HL) light with 2% (CO₂) or ambient 0.04% (Amb) CO₂. HL-Amb cells suffered photoinhibition and limitation of photosystem I electron flow at the donor side, but not the acceptor side, indicating use of alternative electron pathways to fuel ATP synthesis. Further, more glycolate was excreted under HL-Amb, indicative of photorespiration. In contrast, HL-CO₂ cells upregulated the cytochrome b₆f complex, ascorbate metabolism, and PTOX2 for maintaining plastid redox homeostasis. Enhanced glycerol excretion under HL enabled dissipation of excess reducing equivalents to adjust the cellular energy balance. CO₂-enhanced photosynthesis promoted respiration and primary metabolite accumulation, driving faster growth while promoting nitrogen (N) metabolism. Hence, C_i-dependent photoacclimation influenced the interplay between the TCA cycle and N assimilation, as supported by proteomic data. Overall, abundant C_i supported growth by promoting electron flow for C_i assimilation, which supplied C skeletons for N assimilation while mitigating photorespiration and photoinhibition.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 5","pages":"e70461"},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12381912/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965048","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}