Bouchra El Omari, Silvia Lembo, Matteo Dainese, Paul Illmer, Nadine Praeg, Andreas Meul, Dolores Asensio, Georg Niedrist
Climate change is a major factor shaping the distribution of plant species. A well-documented response consequence is the upward shift of plant species to higher elevations as they track their thermal niches. However, plants migrating upward face complex environmental changes shaped by multiple interacting factors. Among these, reduced air pressure remains relatively understudied, its effects are often confounded with other covarying parameters. This study investigated the direct impact of reduced air pressure on the eco-physiological responses of two plant species (Hieracium pilosella L. and Trifolium pratensis L.). The plants were grown for four weeks in controlled climatic chambers under different air pressures (85, 75, and 62 kPa), while all other environmental parameters were kept constant. At the end of the experiment, photosynthesis, chlorophyll fluorescence, growth, carbohydrate content, carbon stable isotopes, and plant nitrogen concentrations were determined. Reduced air pressure decreased growth, carbon isotopic discrimination and chlorophyll content, but increased CO2 fixation efficiency and carbohydrate accumulation in the leaves. These results suggest that reduced air pressure impacts plant performance during upslope migration and may, in turn, contribute to shaping future distribution patterns in alpine ecosystems.
{"title":"Eco-physiological responses of Hieracium pilosella and Trifolium pratense to reduced air pressure","authors":"Bouchra El Omari, Silvia Lembo, Matteo Dainese, Paul Illmer, Nadine Praeg, Andreas Meul, Dolores Asensio, Georg Niedrist","doi":"10.1093/plphys/kiaf631","DOIUrl":"https://doi.org/10.1093/plphys/kiaf631","url":null,"abstract":"Climate change is a major factor shaping the distribution of plant species. A well-documented response consequence is the upward shift of plant species to higher elevations as they track their thermal niches. However, plants migrating upward face complex environmental changes shaped by multiple interacting factors. Among these, reduced air pressure remains relatively understudied, its effects are often confounded with other covarying parameters. This study investigated the direct impact of reduced air pressure on the eco-physiological responses of two plant species (Hieracium pilosella L. and Trifolium pratensis L.). The plants were grown for four weeks in controlled climatic chambers under different air pressures (85, 75, and 62 kPa), while all other environmental parameters were kept constant. At the end of the experiment, photosynthesis, chlorophyll fluorescence, growth, carbohydrate content, carbon stable isotopes, and plant nitrogen concentrations were determined. Reduced air pressure decreased growth, carbon isotopic discrimination and chlorophyll content, but increased CO2 fixation efficiency and carbohydrate accumulation in the leaves. These results suggest that reduced air pressure impacts plant performance during upslope migration and may, in turn, contribute to shaping future distribution patterns in alpine ecosystems.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"11 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zidi He, Xingshuai Ma, Hang Zhang, Zishang Kong, Fei Wang, Ye Yuan, Minglei Zhao, Jianguo Li
Auxin transport through the abscission zone (AZ) is crucial for preventing organ abscission in plants; however, the regulatory mechanisms involved remain poorly understood. Here, we demonstrate that exogenous auxin application alone fully inhibits abscission triggered by litchi (Litchi chinensis Sonn.) fruitlet removal, which depletes auxin in the AZ. Following fruitlet removal, we observed sequential and significant alterations in seven biological processes within the AZ, including the transient suppression of auxin signaling and activation of ethylene and abscisic acid (ABA) signaling, followed by the increased production of reactive oxygen species (ROS), reduced carbohydrate content, and ultimately, the induction of programmed cell death (PCD) and cell wall remodeling (CWR). Moreover, we identified 34 transcription factors as potential key regulators and constructed transcriptional regulatory networks involved in auxin depletion-induced abscission. Notably, we characterized LcMYB62 as a positive regulator of abscission, likely functioning by transactivating genes associated with cell wall remodeling. We further showed that the transcription factor AUXIN RESPONSE FACTOR 5 (LcARF5) binds to and activates LcMYB62, suggesting a LcARF5-LcMYB62-CWR transcriptional regulatory cascade in litchi fruitlet abscission. Overall, our findings provide a comprehensive overview of the gene regulatory network governing auxin-mediated fruitlet abscission in litchi, providing insights into the mechanisms by which auxin depletion in the AZ triggers this process.
{"title":"Deciphering the regulatory network underlying auxin depletion-induced fruitlet abscission in litchi ( Litchi chinensis Sonn.)","authors":"Zidi He, Xingshuai Ma, Hang Zhang, Zishang Kong, Fei Wang, Ye Yuan, Minglei Zhao, Jianguo Li","doi":"10.1093/plphys/kiaf676","DOIUrl":"https://doi.org/10.1093/plphys/kiaf676","url":null,"abstract":"Auxin transport through the abscission zone (AZ) is crucial for preventing organ abscission in plants; however, the regulatory mechanisms involved remain poorly understood. Here, we demonstrate that exogenous auxin application alone fully inhibits abscission triggered by litchi (Litchi chinensis Sonn.) fruitlet removal, which depletes auxin in the AZ. Following fruitlet removal, we observed sequential and significant alterations in seven biological processes within the AZ, including the transient suppression of auxin signaling and activation of ethylene and abscisic acid (ABA) signaling, followed by the increased production of reactive oxygen species (ROS), reduced carbohydrate content, and ultimately, the induction of programmed cell death (PCD) and cell wall remodeling (CWR). Moreover, we identified 34 transcription factors as potential key regulators and constructed transcriptional regulatory networks involved in auxin depletion-induced abscission. Notably, we characterized LcMYB62 as a positive regulator of abscission, likely functioning by transactivating genes associated with cell wall remodeling. We further showed that the transcription factor AUXIN RESPONSE FACTOR 5 (LcARF5) binds to and activates LcMYB62, suggesting a LcARF5-LcMYB62-CWR transcriptional regulatory cascade in litchi fruitlet abscission. Overall, our findings provide a comprehensive overview of the gene regulatory network governing auxin-mediated fruitlet abscission in litchi, providing insights into the mechanisms by which auxin depletion in the AZ triggers this process.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"45 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
My research journey began with the development of inhibitors targeting the photosynthetic electron transport chain, aiming for their application as herbicides. After a period of herbicide research at an agrochemical company, I joined RIKEN in 1991, where my primary focus shifted to developing plant hormone regulators. The research here initially aimed not only at applications for agricultural use, but also at applications for understanding fundamental plant biology. Forty years ago, compared to the present, the biological knowledge and chemical principles for designing biologically active compounds were insufficient. However, I have consistently pursued a biorational approach as much as possible. Along the way, I have also been fortunate to experience numerous moments of serendipity. In the initial stages of developing photosynthetic electron transport inhibitors, compound design was carried out based on 2D knowledge. Subsequently, we attempted structure-based design utilizing the three-dimensional structure of the target protein. However, such approaches were not yet efficient at the time. Today, with the remarkable progress in structural biology and AI-based target structure prediction, truly rational, structure-guided compound design is becoming increasingly feasible. Motivated by this progress, I have continued my research even after retiring from the University of Tokyo, now at Yokohama City University, where I remain engaged in the development of novel biorational bioactive compounds. My goal is to design and synthesize bioactive compounds that contribute to both plant science and agriculture, and I find great joy in engaging in such research.
{"title":"From molecular probes to novel agrochemicals: a journey through plant hormone research using modern plant science findings","authors":"Tadao Asami","doi":"10.1093/plphys/kiaf403","DOIUrl":"https://doi.org/10.1093/plphys/kiaf403","url":null,"abstract":"My research journey began with the development of inhibitors targeting the photosynthetic electron transport chain, aiming for their application as herbicides. After a period of herbicide research at an agrochemical company, I joined RIKEN in 1991, where my primary focus shifted to developing plant hormone regulators. The research here initially aimed not only at applications for agricultural use, but also at applications for understanding fundamental plant biology. Forty years ago, compared to the present, the biological knowledge and chemical principles for designing biologically active compounds were insufficient. However, I have consistently pursued a biorational approach as much as possible. Along the way, I have also been fortunate to experience numerous moments of serendipity. In the initial stages of developing photosynthetic electron transport inhibitors, compound design was carried out based on 2D knowledge. Subsequently, we attempted structure-based design utilizing the three-dimensional structure of the target protein. However, such approaches were not yet efficient at the time. Today, with the remarkable progress in structural biology and AI-based target structure prediction, truly rational, structure-guided compound design is becoming increasingly feasible. Motivated by this progress, I have continued my research even after retiring from the University of Tokyo, now at Yokohama City University, where I remain engaged in the development of novel biorational bioactive compounds. My goal is to design and synthesize bioactive compounds that contribute to both plant science and agriculture, and I find great joy in engaging in such research.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"33 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tim J Lynch, B Joy Erickson McNally, Teodora Losic, Jonas Lindquist, Ruth Finkelstein
The central components of the ABA core signaling pathway are families of receptors, clade A type 2C protein phosphatases (PP2Cs), SNF1-Related Protein Kinases (SnRK2s), and diverse sets of proteins regulated by phosphorylation via these kinases, including basic leucine zipper (bZIP) transcription factors such as ABA-INSENSITIVE(ABI)5. The larger network of ABA signaling factors includes additional kinases and E3 ligases that modify these components to affect their activity and stability. ABI5-Binding Proteins (AFPs) are negative regulators of the ABA response, and this study shows that Arabidopsis thaliana AFPs interact with specific family members of all components of this pathway and are substrates for SnRK2s and PP2Cs. AFPs also interact with subsets of MAP kinases (MPKs) and 14-3-3 proteins previously found to regulate the activity of the ABI5-related clade of transcription factors. Residues predicted to be phosphorylated are conserved between AFPs, but are located within regions predicted to be unstructured. ABA promotes phosphorylation of AFP2, but conditions that prevent phosphorylation of AFP2 result in decreased stability, a shift in localization toward dispersed foci, and reduced effectiveness for inhibiting ABA response at germination. Thus, AFP2 appears to be an important hub in the ABA core signaling pathway.
ABA核心信号通路的核心成分是受体家族，进化支A型2C蛋白磷酸酶（pp2c）， snf1相关蛋白激酶（SnRK2s），以及通过这些激酶磷酸化调节的各种蛋白质，包括碱性亮氨酸拉链（bZIP）转录因子，如ABA-不敏感（ABI）5。更大的ABA信号因子网络包括额外的激酶和E3连接酶，它们修饰这些成分以影响其活性和稳定性。abi5 binding protein （AFPs）是ABA应答的负调控因子，本研究表明拟南芥AFPs与该通路所有组分的特定家族成员相互作用，并且是SnRK2s和pp2c的底物。AFPs还与MAP激酶（mpk）亚群和14-3-3蛋白相互作用，这些蛋白先前被发现可调节abi5相关转录因子分支的活性。预测被磷酸化的残基在AFPs之间是保守的，但位于预测的非结构化区域内。ABA促进了AFP2的磷酸化，但阻止AFP2磷酸化的条件导致稳定性降低，定位向分散灶转移，并且降低了萌发时抑制ABA反应的有效性。因此，AFP2似乎是ABA核心信号通路中的一个重要枢纽。
{"title":"ABI5-Binding Proteins are substrates of key components in the ABA core signaling pathway affecting seeds","authors":"Tim J Lynch, B Joy Erickson McNally, Teodora Losic, Jonas Lindquist, Ruth Finkelstein","doi":"10.1093/plphys/kiaf674","DOIUrl":"https://doi.org/10.1093/plphys/kiaf674","url":null,"abstract":"The central components of the ABA core signaling pathway are families of receptors, clade A type 2C protein phosphatases (PP2Cs), SNF1-Related Protein Kinases (SnRK2s), and diverse sets of proteins regulated by phosphorylation via these kinases, including basic leucine zipper (bZIP) transcription factors such as ABA-INSENSITIVE(ABI)5. The larger network of ABA signaling factors includes additional kinases and E3 ligases that modify these components to affect their activity and stability. ABI5-Binding Proteins (AFPs) are negative regulators of the ABA response, and this study shows that Arabidopsis thaliana AFPs interact with specific family members of all components of this pathway and are substrates for SnRK2s and PP2Cs. AFPs also interact with subsets of MAP kinases (MPKs) and 14-3-3 proteins previously found to regulate the activity of the ABI5-related clade of transcription factors. Residues predicted to be phosphorylated are conserved between AFPs, but are located within regions predicted to be unstructured. ABA promotes phosphorylation of AFP2, but conditions that prevent phosphorylation of AFP2 result in decreased stability, a shift in localization toward dispersed foci, and reduced effectiveness for inhibiting ABA response at germination. Thus, AFP2 appears to be an important hub in the ABA core signaling pathway.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"11 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Beach grass to Brassicas: A novel salt-tolerant endophyte finds new roots.","authors":"James M Bradley","doi":"10.1093/plphys/kiaf672","DOIUrl":"https://doi.org/10.1093/plphys/kiaf672","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"24 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145807933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Balancing to stay green: Two key proteins determine leaf color and photosynthesis in rice.","authors":"Gunjan Sharma","doi":"10.1093/plphys/kiaf670","DOIUrl":"https://doi.org/10.1093/plphys/kiaf670","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"6 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145807932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiacan Sun, Timothy J Brodribb, Eloise Foo, Ibrahim Bourbia
Arbuscular mycorrhizal (AM) fungi are known to enhance plant drought tolerance, but the physiological mechanism behind this benefit remains unclear. One explanation is that AM colonization improves root hydraulic conductance (Kr), thereby facilitating more efficient water uptake under soil drying, though this mechanism remains highly debated. Here, we measured Kr in tomato (Solanum lycopersicum L.) and pea (Pisum sativum L.) with and without AM using a non-invasive rehydration technique under soil drying and this was complemented with the evaporative flux method under hydrated conditions. AM colonization was manipulated either through soil sterilization or by using non-mycorrhizal mutants, ensuring precise control of AM status. In both species, AM colonization had no positive impact on Kr under both well-hydrated and drought conditions. The finding suggests that the improved drought performance often observed in AM-colonized plants is not due to enhanced root water transport capacity. Instead, AM-induced benefits under drought may be mediated by other physiological adjustments.
{"title":"Arbuscular mycorrhizal colonization does not improve root hydraulic supply in tomato and pea","authors":"Jiacan Sun, Timothy J Brodribb, Eloise Foo, Ibrahim Bourbia","doi":"10.1093/plphys/kiaf669","DOIUrl":"https://doi.org/10.1093/plphys/kiaf669","url":null,"abstract":"Arbuscular mycorrhizal (AM) fungi are known to enhance plant drought tolerance, but the physiological mechanism behind this benefit remains unclear. One explanation is that AM colonization improves root hydraulic conductance (Kr), thereby facilitating more efficient water uptake under soil drying, though this mechanism remains highly debated. Here, we measured Kr in tomato (Solanum lycopersicum L.) and pea (Pisum sativum L.) with and without AM using a non-invasive rehydration technique under soil drying and this was complemented with the evaporative flux method under hydrated conditions. AM colonization was manipulated either through soil sterilization or by using non-mycorrhizal mutants, ensuring precise control of AM status. In both species, AM colonization had no positive impact on Kr under both well-hydrated and drought conditions. The finding suggests that the improved drought performance often observed in AM-colonized plants is not due to enhanced root water transport capacity. Instead, AM-induced benefits under drought may be mediated by other physiological adjustments.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"8 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The distribution of spikelets significantly affects wheat (Triticum aestivum L.) spike architecture. However, traditional methods lack the precision to study spikelet distribution effectively. We developed RachisSeg, a deep learning-based phenotyping pipeline that automatically measures traits from scanned rachis images. In addition to traditional spikelet number per spike (SNS), rachis length (RL), and spikelet density (SD, SNS/RL), we introduced spikelet distribution traits based on rachis internode lengths, providing quantitative insights into spike architecture. RachisSeg showed high consistency with manual measurements for SNS and RL, with the R2 values of 0.975 and 0.998, respectively. Using RachisSeg, we analyzed spikelet distribution patterns across wheat germplasm and found that traits such as spikelet distribution index (SDI) and apical-to-basal spikelet number ratio (AVB_SNS) were moderately correlated with grain yield per spike (GYPS) (r = 0.57 and 0.53, respectively), while internode width (IW) showed a strong positive correlation with GYPS (r = 0.75). Specifically, a denser spikelet arrangement in the upper spike negatively impacted grain number and weight in that section. Furthermore, comparative analysis revealed distinct spikelet distribution patterns among landraces, American cultivars, and Chinese cultivars. In a recombinant inbred line population, we identified 46 quantitative trait loci (QTLs) associated with rachis traits. A major QTL controlling SDI was detected on chromosome 6B, explaining up to 24.8% of the phenotypic variance. Candidate gene analysis suggested TraesCS6B02G417000 as a potential gene, whose mutant exhibited significant changes in RL and SDI. RachisSeg is a powerful tool for quantifying spikelet distribution, facilitating wheat genetic analysis, gene discovery, and breeding.
{"title":"Image-based rachis phenotyping facilitates genetic dissection of spikelet distribution in wheat","authors":"Renxiang Lu, Shusong Zheng, Lingjie Yang, Zongyang Li, Yaoqi Si, Minru Yan, Xigang Liu, Hong-Qing Ling, Ni Jiang","doi":"10.1093/plphys/kiaf666","DOIUrl":"https://doi.org/10.1093/plphys/kiaf666","url":null,"abstract":"The distribution of spikelets significantly affects wheat (Triticum aestivum L.) spike architecture. However, traditional methods lack the precision to study spikelet distribution effectively. We developed RachisSeg, a deep learning-based phenotyping pipeline that automatically measures traits from scanned rachis images. In addition to traditional spikelet number per spike (SNS), rachis length (RL), and spikelet density (SD, SNS/RL), we introduced spikelet distribution traits based on rachis internode lengths, providing quantitative insights into spike architecture. RachisSeg showed high consistency with manual measurements for SNS and RL, with the R2 values of 0.975 and 0.998, respectively. Using RachisSeg, we analyzed spikelet distribution patterns across wheat germplasm and found that traits such as spikelet distribution index (SDI) and apical-to-basal spikelet number ratio (AVB_SNS) were moderately correlated with grain yield per spike (GYPS) (r = 0.57 and 0.53, respectively), while internode width (IW) showed a strong positive correlation with GYPS (r = 0.75). Specifically, a denser spikelet arrangement in the upper spike negatively impacted grain number and weight in that section. Furthermore, comparative analysis revealed distinct spikelet distribution patterns among landraces, American cultivars, and Chinese cultivars. In a recombinant inbred line population, we identified 46 quantitative trait loci (QTLs) associated with rachis traits. A major QTL controlling SDI was detected on chromosome 6B, explaining up to 24.8% of the phenotypic variance. Candidate gene analysis suggested TraesCS6B02G417000 as a potential gene, whose mutant exhibited significant changes in RL and SDI. RachisSeg is a powerful tool for quantifying spikelet distribution, facilitating wheat genetic analysis, gene discovery, and breeding.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"31 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M Fenech, V Zulian, J Moya-Cuevas, D Arnaud, I Morilla, N Smirnoff, M A Botella, A N Stepanova, J M Alonso, C Martin-Pizarro, V Amorim-Silva
Ascorbate is the most abundant water-soluble antioxidant in plants and an essential molecule for normal plant development. Although present in all green plants, ascorbate concentrations vary among plant species and tissues. While ascorbate accumulation is a trait of nutritional, and therefore, agronomical interest, the impact of different concentrations on cellular homeostasis remains elusive. To shed light on this question, we compared Arabidopsis (Arabidopsis thaliana) lines with very low (vtc2 mutant, 20% of wild-type (WT) levels), low (vtc4 mutant, 65% of WT levels), and high (vtc2/OE-VTC2, 165% of WT levels) ascorbate concentration in four-week-old rosette leaves. An 80% reduction of ascorbate increased the expression of genes implicated in defense against pathogens but repressed genes associated with abiotic stress responses. Unexpectedly, lines with increased (165% of WT) and decreased (65% of WT) ascorbate levels shared 85% of induced transcription factors and the gene ontology terms associated with their transcriptional programs. We identified TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1), a gene encoding the enzyme that catalyzes the first step of auxin biosynthesis, among the group of genes whose expression was positively correlated with ascorbate content. Using a combination of genetic and pharmacological approaches in fluorescent and histochemical reporter lines for auxin biosynthesis and signaling activity, we revealed that TAA1- and TAA1 RELATED 2 (TAR2)-mediated auxin biosynthesis is necessary for plants to cope with increased ascorbate concentration in a light-dependent manner, revealing a layer of complexity in the regulatory landscape of redox homeostasis.
抗坏血酸是植物中含量最丰富的水溶性抗氧化剂，是植物正常发育所必需的分子。尽管所有的绿色植物都含有抗坏血酸，但其浓度因植物种类和组织而异。虽然抗坏血酸的积累是一种营养特性，因此具有农学意义，但不同浓度对细胞稳态的影响仍然难以捉摸。为了阐明这个问题，我们比较了4周龄玫瑰叶中抗坏血酸浓度极低（vtc2突变体，野生型（WT）水平的20%）、低（vtc4突变体，WT水平的65%）和高（vtc2/OE-VTC2， WT水平的165%）的拟南芥（拟南芥）系。减少80%的抗坏血酸增加了与病原体防御有关的基因的表达，但抑制了与非生物应激反应相关的基因。出乎意料的是，抗坏血酸水平增加（WT的165%）和减少（WT的65%）的品系共享85%的诱导转录因子和与其转录程序相关的基因本体术语。我们在一组表达与抗坏血酸含量正相关的基因中，鉴定了拟南芥色氨酸氨基转移酶1 （TAA1）基因，该基因编码催化生长素生物合成的第一步酶。利用遗传和药理学方法结合荧光和组织化学报告系研究生长素的生物合成和信号活性，我们发现TAA1-和TAA1 RELATED 2 （TAR2）介导的生长素生物合成是植物以光依赖的方式应对抗坏血酸浓度增加所必需的，揭示了氧化还原稳态调控的复杂性。
{"title":"Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis","authors":"M Fenech, V Zulian, J Moya-Cuevas, D Arnaud, I Morilla, N Smirnoff, M A Botella, A N Stepanova, J M Alonso, C Martin-Pizarro, V Amorim-Silva","doi":"10.1093/plphys/kiaf667","DOIUrl":"https://doi.org/10.1093/plphys/kiaf667","url":null,"abstract":"Ascorbate is the most abundant water-soluble antioxidant in plants and an essential molecule for normal plant development. Although present in all green plants, ascorbate concentrations vary among plant species and tissues. While ascorbate accumulation is a trait of nutritional, and therefore, agronomical interest, the impact of different concentrations on cellular homeostasis remains elusive. To shed light on this question, we compared Arabidopsis (Arabidopsis thaliana) lines with very low (vtc2 mutant, 20% of wild-type (WT) levels), low (vtc4 mutant, 65% of WT levels), and high (vtc2/OE-VTC2, 165% of WT levels) ascorbate concentration in four-week-old rosette leaves. An 80% reduction of ascorbate increased the expression of genes implicated in defense against pathogens but repressed genes associated with abiotic stress responses. Unexpectedly, lines with increased (165% of WT) and decreased (65% of WT) ascorbate levels shared 85% of induced transcription factors and the gene ontology terms associated with their transcriptional programs. We identified TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1), a gene encoding the enzyme that catalyzes the first step of auxin biosynthesis, among the group of genes whose expression was positively correlated with ascorbate content. Using a combination of genetic and pharmacological approaches in fluorescent and histochemical reporter lines for auxin biosynthesis and signaling activity, we revealed that TAA1- and TAA1 RELATED 2 (TAR2)-mediated auxin biosynthesis is necessary for plants to cope with increased ascorbate concentration in a light-dependent manner, revealing a layer of complexity in the regulatory landscape of redox homeostasis.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"36 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145807838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anthocyanins critically determine fruit color, nutrition, and stress resilience in cultivated strawberry (Fragaria × ananassa), directly influencing consumer preference. Despite complex genetic and environmental regulation of their biosynthesis, the basis for tissue-specific pigmentation, notably the widespread occurrence of red skin and pale flesh, remains poorly understood. We integrated genomic, transcriptomic, and functional analyses across 200 cultivars to dissect receptacle pigmentation regulation. Approaches included FaMYB10-2 allele mining, promoter structural variant (SV) identification, expression profiling, regulatory interaction assays, and characterization of upstream light-responsive factors. FaMYB10-2 was identified as the key R2R3-MYB regulator of fruit anthocyanin biosynthesis. Alleles FaMYB10-2.2 and FaMYB10-2.3 encode truncated proteins retaining bHLH-binding capacity but lacking activation domains, functioning as dominant-negative repressors. A promoter SV 986 bp upstream of FaMYB10-2 was associated with reduced pale fruit due to cis-regulatory divergence. The SV (Alt) allele is prevalent in Asian cultivars, while the Ref allele is enriched in Western germplasm. Crucially, a light-responsive FaHYH-FaWRKY71 cascade activates FaMYB10-2 and structural genes haplotype-dependently, compensating for weak MYB activity in the skin. Our findings reveal a multilayered regulatory system integrating allelic variation, cis-regulatory divergence, and environmental signals, advancing anthocyanin understanding and providing engineering targets for polyploid crop color improvement.
{"title":"Allelic variation and light-responsive regulation of FaMYB10-2 underlie tissue-specific anthocyanin accumulation in strawberry","authors":"Huazhao Yuan, Chao Wang, Feiyue Quan, Linlin Xu, Jiahui Liang, Fuhua Pang, Zhiliang Pan, Bingbing Li, Yushan Qiao, Mizhen Zhao","doi":"10.1093/plphys/kiaf665","DOIUrl":"https://doi.org/10.1093/plphys/kiaf665","url":null,"abstract":"Anthocyanins critically determine fruit color, nutrition, and stress resilience in cultivated strawberry (Fragaria × ananassa), directly influencing consumer preference. Despite complex genetic and environmental regulation of their biosynthesis, the basis for tissue-specific pigmentation, notably the widespread occurrence of red skin and pale flesh, remains poorly understood. We integrated genomic, transcriptomic, and functional analyses across 200 cultivars to dissect receptacle pigmentation regulation. Approaches included FaMYB10-2 allele mining, promoter structural variant (SV) identification, expression profiling, regulatory interaction assays, and characterization of upstream light-responsive factors. FaMYB10-2 was identified as the key R2R3-MYB regulator of fruit anthocyanin biosynthesis. Alleles FaMYB10-2.2 and FaMYB10-2.3 encode truncated proteins retaining bHLH-binding capacity but lacking activation domains, functioning as dominant-negative repressors. A promoter SV 986 bp upstream of FaMYB10-2 was associated with reduced pale fruit due to cis-regulatory divergence. The SV (Alt) allele is prevalent in Asian cultivars, while the Ref allele is enriched in Western germplasm. Crucially, a light-responsive FaHYH-FaWRKY71 cascade activates FaMYB10-2 and structural genes haplotype-dependently, compensating for weak MYB activity in the skin. Our findings reveal a multilayered regulatory system integrating allelic variation, cis-regulatory divergence, and environmental signals, advancing anthocyanin understanding and providing engineering targets for polyploid crop color improvement.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"17 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：