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}
Iron (Fe) deficiency is a major limitation to apple (Malus domestica) growth in calcareous soils. Understanding the molecular mechanisms underlying Fe deficiency responses is crucial for improving Fe use efficiency in fruit trees. In this study, we identified the ETHYLENE RESPONSE FACTOR 4 (MxERF4) as a negative regulator of the Fe deficiency response in apple. Transgenic analysis revealed that overexpression of MxERF4 exacerbated leaf chlorosis and reduced root Fe content under Fe-deficient conditions, whereas RNA interference (RNAi) lines exhibited enhanced tolerance. We further identified the MITOGEN-ACTIVATED PROTEIN KINASE (MxMPK6-2) as an interactor of MxERF4. MxMPK6-2 phosphorylates MxERF4, reducing its protein stability and promoting its degradation. MxERF4 interacted with the key Fe uptake regulator FER-LIKE FE DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (MxFIT) and co-localized with it in root tissues. Phosphorylation weakened the MxERF4-MxFIT interaction, thereby relieving the inhibition of MxFIT-basic Helix-Loop-Helix 38/39 (MxbHLH38/39) complex formation. This in turn restored the activation of Fe uptake genes IRON TRANSPORTER1 (MxIRT1) and FERRIC REDUCTASE OXIDASE 2 (MxFRO2), enhanced ferric chelate reductase (FCR) activity, and promoted active Fe accumulation. Together, these findings reveal a previously uncharacterized MPK6-2-ERF4 signaling module that regulates Fe deficiency responses in apple by modulating ERF4 stability and its interaction with FIT, providing insights into the molecular basis of Fe efficiency and offering potential strategies for breeding Fe-efficient rootstocks.
缺铁是制约苹果在钙质土壤中生长的主要因素。了解缺铁反应的分子机制对提高果树铁利用效率具有重要意义。在本研究中，我们确定了乙烯反应因子4 （MxERF4）是苹果铁缺乏反应的负调控因子。转基因分析显示，在缺铁条件下，过表达MxERF4加剧了叶片黄化，降低了根系铁含量，而RNA干扰（RNAi）系表现出增强的耐受性。我们进一步鉴定了丝裂原活化蛋白激酶（MxMPK6-2）是MxERF4的相互作用物。MxMPK6-2磷酸化MxERF4，降低其蛋白稳定性，促进其降解。MxERF4与关键的铁摄取调节因子Fe - like Fe deficient induced TRANSCRIPTION FACTOR （MxFIT）相互作用，并在根组织中共定位。磷酸化削弱了MxERF4-MxFIT相互作用，从而减轻了对MxFIT-basic Helix-Loop-Helix 38/39 （MxbHLH38/39）复合物形成的抑制。这反过来恢复了铁摄取基因铁转运蛋白1 （MxIRT1）和铁还原酶氧化酶2 （MxFRO2）的激活，增强了铁螯合还原酶（FCR）的活性，促进了铁的活性积累。总之，这些发现揭示了一个以前未被发现的MPK6-2-ERF4信号模块，该信号模块通过调节ERF4的稳定性及其与FIT的相互作用来调节苹果铁缺乏反应，为铁效率的分子基础提供了见解，并为培育铁高效砧木提供了潜在的策略。
{"title":"MPK6-2-mediated phosphorylation of ERF4 releases the Fe uptake regulator FIT and enhances Fe uptake in apple.","authors":"Yue Wu,Qiran Sun,Danrui Zhao,Xu Zhang,Longmei Zhai,Jiahong Lv,Ting Wu,Xinzhong Zhang,Zhenhai Han,Yi Wang","doi":"10.1093/plphys/kiaf657","DOIUrl":"https://doi.org/10.1093/plphys/kiaf657","url":null,"abstract":"Iron (Fe) deficiency is a major limitation to apple (Malus domestica) growth in calcareous soils. Understanding the molecular mechanisms underlying Fe deficiency responses is crucial for improving Fe use efficiency in fruit trees. In this study, we identified the ETHYLENE RESPONSE FACTOR 4 (MxERF4) as a negative regulator of the Fe deficiency response in apple. Transgenic analysis revealed that overexpression of MxERF4 exacerbated leaf chlorosis and reduced root Fe content under Fe-deficient conditions, whereas RNA interference (RNAi) lines exhibited enhanced tolerance. We further identified the MITOGEN-ACTIVATED PROTEIN KINASE (MxMPK6-2) as an interactor of MxERF4. MxMPK6-2 phosphorylates MxERF4, reducing its protein stability and promoting its degradation. MxERF4 interacted with the key Fe uptake regulator FER-LIKE FE DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (MxFIT) and co-localized with it in root tissues. Phosphorylation weakened the MxERF4-MxFIT interaction, thereby relieving the inhibition of MxFIT-basic Helix-Loop-Helix 38/39 (MxbHLH38/39) complex formation. This in turn restored the activation of Fe uptake genes IRON TRANSPORTER1 (MxIRT1) and FERRIC REDUCTASE OXIDASE 2 (MxFRO2), enhanced ferric chelate reductase (FCR) activity, and promoted active Fe accumulation. Together, these findings reveal a previously uncharacterized MPK6-2-ERF4 signaling module that regulates Fe deficiency responses in apple by modulating ERF4 stability and its interaction with FIT, providing insights into the molecular basis of Fe efficiency and offering potential strategies for breeding Fe-efficient rootstocks.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"34 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145777270","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}
Ultraviolet-B (UV-B) radiation negatively affects photosynthesis; however, some studies have also demonstrated positive effects of UV-B radiation on photosynthesis. In cyanobacteria, histidine kinase Hik33 plays an important role in mediating responses to multiple environmental stresses, but whether Hik33 is involved in the positive regulation of photosynthesis by UV-B remains unclear. Here, we successfully established CRISPR-Cpf1-based genetic transformation in the UV-B-tolerant cyanobacterium Nostoc sphaeroides CCNUC1, paving the way for unveiling the regulatory mechanism of UV-B-induced photoacclimation. We constructed a nshik33 knockout mutant that lacked the UV-B-induced positive effects on growth, photosynthetic activity, and cyclic electron flow around photosystem I seen in non-acclimated control cells. We determined that nsHik33 attenuates the phosphorylation of nsRpaB under low UV-B light, thereby upregulating the transcription of photosynthesis-associated genes (such as psbA and psaA, encoding core subunits of photosystems II and I, respectively) in Nostoc sphaeroides CCNUC1. To investigate the conservation of nsHik33 function, we heterologously expressed nshik33 of N. sphaeroides CCNUC1 in the Δhik33 mutant of Synechocystis sp. PCC 6803 and discovered that nsHik33 complements the defective photosynthesis phenotype of Δhik33 mutant cells acclimated to low UV-B. These data indicate that Hik33 plays a crucial role in UV-B-induced photosynthetic acclimation in cyanobacteria.
{"title":"Histidine kinase Hik33 plays a crucial role in UV-B-induced photosynthetic acclimation in cyanobacteria.","authors":"Zhen Chen,Zhen He,Wei-Xin Luo,Zhe Liu,Hai-Feng Xu,Hua-Hua Yue,Fei-Fei Li,Wei-Zhi Li,Chun Chen,Shan Zhang,Kui Xu,Bao-Sheng Qiu,Xiong-Wen Chen","doi":"10.1093/plphys/kiaf661","DOIUrl":"https://doi.org/10.1093/plphys/kiaf661","url":null,"abstract":"Ultraviolet-B (UV-B) radiation negatively affects photosynthesis; however, some studies have also demonstrated positive effects of UV-B radiation on photosynthesis. In cyanobacteria, histidine kinase Hik33 plays an important role in mediating responses to multiple environmental stresses, but whether Hik33 is involved in the positive regulation of photosynthesis by UV-B remains unclear. Here, we successfully established CRISPR-Cpf1-based genetic transformation in the UV-B-tolerant cyanobacterium Nostoc sphaeroides CCNUC1, paving the way for unveiling the regulatory mechanism of UV-B-induced photoacclimation. We constructed a nshik33 knockout mutant that lacked the UV-B-induced positive effects on growth, photosynthetic activity, and cyclic electron flow around photosystem I seen in non-acclimated control cells. We determined that nsHik33 attenuates the phosphorylation of nsRpaB under low UV-B light, thereby upregulating the transcription of photosynthesis-associated genes (such as psbA and psaA, encoding core subunits of photosystems II and I, respectively) in Nostoc sphaeroides CCNUC1. To investigate the conservation of nsHik33 function, we heterologously expressed nshik33 of N. sphaeroides CCNUC1 in the Δhik33 mutant of Synechocystis sp. PCC 6803 and discovered that nsHik33 complements the defective photosynthesis phenotype of Δhik33 mutant cells acclimated to low UV-B. These data indicate that Hik33 plays a crucial role in UV-B-induced photosynthetic acclimation in cyanobacteria.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"21 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145777264","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：