Water hyacinth (Pontederia crassipes), an allotetraploid species, is among the most ecologically successful aquatic plants, exhibiting two remarkable adaptive traits: tristyly, a rare floral polymorphism promoting outcrossing, and inflated petioles (floats) that facilitate buoyancy. However, the genetic and evolutionary mechanisms underlying these traits in a polyploid context remain poorly understood. We assembled a gap-free telomere-to-telomere genome of an M-morph Po. crassipes and integrated whole-genome resequencing, transcriptomic, physiological, and anatomical analyses to investigate its genome evolution, floral polymorphism, and float formation. We detected multiple whole-genome duplication events in the Pontederia lineage. Po. crassipes originated via hybridization between two diploid progenitors and experienced nonreciprocal homoeologous exchanges. The M-morph is associated with a single hemizygous gene, LAZY1-M, and its characteristic long stamen filaments may result from cell elongation mediated by INCREASED LEAF INCLINATION (ILI) genes. By contrast, variation in style length between L- and M-morphs is primarily driven by differences in cell number. In addition, ethylene was identified as a key positive regulator of float formation. Our study provides a comprehensive analysis of the M-locus in a polyploid species, demonstrates its conserved evolutionary origin within Pontederiaceae, and uncovers novel regulatory mechanisms underlying morphological adaptation in aquatic plants.
{"title":"Gap-free genome-based analyses of the origin and adaptation of a globally invasive polyploid hydrophyte.","authors":"Yunming Zhang,Feiqi Yu,Xi Hu,Yuhan Wang,Jingyi Guo,Jingjing Yang,Yali Wang,Hongwei Hou,Xudong Xu","doi":"10.1111/nph.71057","DOIUrl":"https://doi.org/10.1111/nph.71057","url":null,"abstract":"Water hyacinth (Pontederia crassipes), an allotetraploid species, is among the most ecologically successful aquatic plants, exhibiting two remarkable adaptive traits: tristyly, a rare floral polymorphism promoting outcrossing, and inflated petioles (floats) that facilitate buoyancy. However, the genetic and evolutionary mechanisms underlying these traits in a polyploid context remain poorly understood. We assembled a gap-free telomere-to-telomere genome of an M-morph Po. crassipes and integrated whole-genome resequencing, transcriptomic, physiological, and anatomical analyses to investigate its genome evolution, floral polymorphism, and float formation. We detected multiple whole-genome duplication events in the Pontederia lineage. Po. crassipes originated via hybridization between two diploid progenitors and experienced nonreciprocal homoeologous exchanges. The M-morph is associated with a single hemizygous gene, LAZY1-M, and its characteristic long stamen filaments may result from cell elongation mediated by INCREASED LEAF INCLINATION (ILI) genes. By contrast, variation in style length between L- and M-morphs is primarily driven by differences in cell number. In addition, ethylene was identified as a key positive regulator of float formation. Our study provides a comprehensive analysis of the M-locus in a polyploid species, demonstrates its conserved evolutionary origin within Pontederiaceae, and uncovers novel regulatory mechanisms underlying morphological adaptation in aquatic plants.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"6 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368433","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}
Yiling Li,Deyan Wang,Pengchuan Sun,Jiale Zhao,Lanxing Shan,Dafu Ru,Guangpeng Ren,Tao Ma,Susanne S Renner,Jianquan Liu
Among the relatively few flowering plants with strongly heteromorphic XY chromosomes are dioecious species of Hippophae (Elaeagnaceae). To understand the evolution of these sex chromosomes, we generated haplotype-resolved genomes for H. rhamnoides and H. tibetana, carried out ancestral karyotype reconstruction using Elaeagnus mollis (with bisexual flowers) as the outgroup, inferred the location of the sex-linked regions (SLRs), and used transcriptome data to test for dosage compensation. In H. rhamnoides, the X chromosome is 30% larger than the Y and in H. tibetana 15%, a difference primarily due to the accumulation of repetitive sequences on the X and extensive gene loss on the Y in H. rhamnoides. Both sex chromosome pairs have an older (S1, 6.3-7.6 million years ago (Ma)) and a younger stratum (S2, 1.9-2.5 Ma), the latter with more species-specific inversions. The SLRs coincide with the pericentromere regions, which already in the ancestor of Hippophae were greatly enlarged by the insertion of another chromosome. Dosage compensation occurs primarily in floral tissues and mainly through downregulation of female X-specific genes, balancing expression between the sexes in floral tissues. These results add to the growing evidence for SLRs often evolving in pericentromeric regions, which are prone to extensive rearrangements and have low recombination frequencies.
{"title":"Heteromorphic XY chromosomes with pericentromeric recombination suppression in Hippophae (Elaeagnaceae).","authors":"Yiling Li,Deyan Wang,Pengchuan Sun,Jiale Zhao,Lanxing Shan,Dafu Ru,Guangpeng Ren,Tao Ma,Susanne S Renner,Jianquan Liu","doi":"10.1111/nph.71059","DOIUrl":"https://doi.org/10.1111/nph.71059","url":null,"abstract":"Among the relatively few flowering plants with strongly heteromorphic XY chromosomes are dioecious species of Hippophae (Elaeagnaceae). To understand the evolution of these sex chromosomes, we generated haplotype-resolved genomes for H. rhamnoides and H. tibetana, carried out ancestral karyotype reconstruction using Elaeagnus mollis (with bisexual flowers) as the outgroup, inferred the location of the sex-linked regions (SLRs), and used transcriptome data to test for dosage compensation. In H. rhamnoides, the X chromosome is 30% larger than the Y and in H. tibetana 15%, a difference primarily due to the accumulation of repetitive sequences on the X and extensive gene loss on the Y in H. rhamnoides. Both sex chromosome pairs have an older (S1, 6.3-7.6 million years ago (Ma)) and a younger stratum (S2, 1.9-2.5 Ma), the latter with more species-specific inversions. The SLRs coincide with the pericentromere regions, which already in the ancestor of Hippophae were greatly enlarged by the insertion of another chromosome. Dosage compensation occurs primarily in floral tissues and mainly through downregulation of female X-specific genes, balancing expression between the sexes in floral tissues. These results add to the growing evidence for SLRs often evolving in pericentromeric regions, which are prone to extensive rearrangements and have low recombination frequencies.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"75 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368434","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}
Michael B Mueller,Xueying Chen,Casey S Philbin,Christopher S Jeffrey,André Kessler
Trade-offs between induced plant defenses and competitive growth are regarded as being universal. This seems particularly true for often-studied early succession annuals, where exposure to competition often suppresses defense expression. However, whether such trade-offs are universal across plant life histories remains unclear, especially considering recent work demonstrating that the trade-off can be artificially uncoupled. We test the hypothesis that Solidago altissima, a perennial herbaceous plant, naturally uncouples this trade-off by adjusting its investment in chemical defenses when exposed to competitive cues, allowing for persistence in high-competition environments despite herbivore pressure. Using a factorial glasshouse experiment, we manipulated competition cues (far-red light and conspecific neighbors) and insect herbivory to assess impacts on growth, resistance, and secondary metabolite production. S. altissima maintained or even enhanced herbivore-induced resistance in the presence of competition cues. Bioassays revealed reduced herbivore performance on previously damaged plants, particularly when they were exposed to neighbors. Metabolomic profiling showed herbivory-induced production of several secondary metabolite classes. Most notably, we found competition-enhanced production of hydroxycinnamic acids, dominated by 3-O-(E)-feruloylquinic acid, associated with resistance. Our findings challenge the generality of the growth-defense trade-off and highlight the importance of ecological context and life-history strategy in shaping plastic responses.
{"title":"Functional uncoupling of the induced defense-competitive growth trade-off.","authors":"Michael B Mueller,Xueying Chen,Casey S Philbin,Christopher S Jeffrey,André Kessler","doi":"10.1111/nph.71058","DOIUrl":"https://doi.org/10.1111/nph.71058","url":null,"abstract":"Trade-offs between induced plant defenses and competitive growth are regarded as being universal. This seems particularly true for often-studied early succession annuals, where exposure to competition often suppresses defense expression. However, whether such trade-offs are universal across plant life histories remains unclear, especially considering recent work demonstrating that the trade-off can be artificially uncoupled. We test the hypothesis that Solidago altissima, a perennial herbaceous plant, naturally uncouples this trade-off by adjusting its investment in chemical defenses when exposed to competitive cues, allowing for persistence in high-competition environments despite herbivore pressure. Using a factorial glasshouse experiment, we manipulated competition cues (far-red light and conspecific neighbors) and insect herbivory to assess impacts on growth, resistance, and secondary metabolite production. S. altissima maintained or even enhanced herbivore-induced resistance in the presence of competition cues. Bioassays revealed reduced herbivore performance on previously damaged plants, particularly when they were exposed to neighbors. Metabolomic profiling showed herbivory-induced production of several secondary metabolite classes. Most notably, we found competition-enhanced production of hydroxycinnamic acids, dominated by 3-O-(E)-feruloylquinic acid, associated with resistance. Our findings challenge the generality of the growth-defense trade-off and highlight the importance of ecological context and life-history strategy in shaping plastic responses.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"56 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368435","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}
Cristian D Torres,Pirén López-Alaniz,Amaru Magnin,Javier G Puntieri
From a root economics perspective, variation in fine-root morphological traits reflects contrasting strategies of resource acquisition and conservation. Here, we examined how fine-root structural and functional traits are associated with belowground architecture. We analysed coarse-root architecture and fine-root functional traits (specific root length, dry matter content and diameter) in four tap-rooted and four adventitious-rooted perennial herb species from North Patagonian forests. We considered two scales of analysis: entire belowground systems and root modules. Variations in the dry-matter content and specific length of fine roots were stronger among species than between architectural groups. Only for tap-rooted plants, lower specific root length was related to the development of thicker and more branched second-order roots. Dry-matter content of fine roots was positively related to the belowground mass fraction in tap-rooted plants and negatively related to adventitious-rooted plants. At root-module scale, the diameter of fine roots was more variable and more related to the structure of exploratory roots in tap-rooted species. Our multiscale approach strongly suggests that belowground architecture of coarse-root systems constrains fine-root functional strategies. Tap-rooted species exhibited a more integrated and architecturally constrained belowground system than adventitious-rooted species.
{"title":"Root architecture and fine-root economic traits in tap- and adventitious-rooted perennial herbs.","authors":"Cristian D Torres,Pirén López-Alaniz,Amaru Magnin,Javier G Puntieri","doi":"10.1111/nph.71079","DOIUrl":"https://doi.org/10.1111/nph.71079","url":null,"abstract":"From a root economics perspective, variation in fine-root morphological traits reflects contrasting strategies of resource acquisition and conservation. Here, we examined how fine-root structural and functional traits are associated with belowground architecture. We analysed coarse-root architecture and fine-root functional traits (specific root length, dry matter content and diameter) in four tap-rooted and four adventitious-rooted perennial herb species from North Patagonian forests. We considered two scales of analysis: entire belowground systems and root modules. Variations in the dry-matter content and specific length of fine roots were stronger among species than between architectural groups. Only for tap-rooted plants, lower specific root length was related to the development of thicker and more branched second-order roots. Dry-matter content of fine roots was positively related to the belowground mass fraction in tap-rooted plants and negatively related to adventitious-rooted plants. At root-module scale, the diameter of fine roots was more variable and more related to the structure of exploratory roots in tap-rooted species. Our multiscale approach strongly suggests that belowground architecture of coarse-root systems constrains fine-root functional strategies. Tap-rooted species exhibited a more integrated and architecturally constrained belowground system than adventitious-rooted species.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"263 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368436","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 mangrove Avicennia marina thrives in high-salinity intertidal habitat and possesses pneumatophores with lenticels. The roles of pneumatophores in photosynthesis and lenticels in gas exchange are well established. However, their functions in salt excretion remain unclear. This study divided pneumatophores into three zones: aboveground portion (PA) with lenticels, belowground portion (PB), and feeding root (FR). Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) analysis showed sodium (Na) and chlorine (Cl) were the predominant elements in crystals on lenticels, indicative of NaCl. Inductively coupled plasma mass spectrometry and spectrophotometry revealed significant Na+, Cl-, and K+ accumulation in the PA. SEM-EDS and non-invasive micro-test technology (NMT) revealed a salt transport pathway: ions are absorbed through FRs, followed by longitudinal transport via xylem (PB → PA) and lateral translocation through cortical cells to lenticels. Real-time quantitative polymerase chain reaction showed predominant expression of Na+ transporter genes (SOS1, NHX1, and HKT1) in the PB, facilitating upward transport. Salt-excretion efficiency increased with the degree of lenticel maturation and habitat salinity. PA-specific expressions of aquaporin genes (TIP1:3, PIP2:2, and PIP1:2) and salt-transport-related genes (AKT1 and CLC-c) suggest their roles in maintaining water-salt relation during salt excretion via lenticels. This work establishes a coordinated salt management model in A. marina pneumatophores, integrating root uptake, transport, and lenticel-mediated excretion, redefining the excretory function of lenticels.
{"title":"Salt excretion: a new function of lenticels on pneumatophores of the mangrove Avicennia marina.","authors":"He-Zi Huang,Zhao-Yu Guo,Yu-Chen Zhang,Liang Jin,Li-Han Zhuang,Lin-Jiao Chen,Han-Xin Zheng,Xing-Yue Hong,Han-Chen Tang,Jia-Kun Liu,Hai-Lei Zheng,Xue-Yi Zhu","doi":"10.1111/nph.71061","DOIUrl":"https://doi.org/10.1111/nph.71061","url":null,"abstract":"The mangrove Avicennia marina thrives in high-salinity intertidal habitat and possesses pneumatophores with lenticels. The roles of pneumatophores in photosynthesis and lenticels in gas exchange are well established. However, their functions in salt excretion remain unclear. This study divided pneumatophores into three zones: aboveground portion (PA) with lenticels, belowground portion (PB), and feeding root (FR). Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) analysis showed sodium (Na) and chlorine (Cl) were the predominant elements in crystals on lenticels, indicative of NaCl. Inductively coupled plasma mass spectrometry and spectrophotometry revealed significant Na+, Cl-, and K+ accumulation in the PA. SEM-EDS and non-invasive micro-test technology (NMT) revealed a salt transport pathway: ions are absorbed through FRs, followed by longitudinal transport via xylem (PB → PA) and lateral translocation through cortical cells to lenticels. Real-time quantitative polymerase chain reaction showed predominant expression of Na+ transporter genes (SOS1, NHX1, and HKT1) in the PB, facilitating upward transport. Salt-excretion efficiency increased with the degree of lenticel maturation and habitat salinity. PA-specific expressions of aquaporin genes (TIP1:3, PIP2:2, and PIP1:2) and salt-transport-related genes (AKT1 and CLC-c) suggest their roles in maintaining water-salt relation during salt excretion via lenticels. This work establishes a coordinated salt management model in A. marina pneumatophores, integrating root uptake, transport, and lenticel-mediated excretion, redefining the excretory function of lenticels.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"6 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368317","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}
Alexandra J Wright,J English,C Guimaraes-Steinicke
Climate change is increasing global temperatures, increasing atmospheric drying, and driving more severe and frequent drought. Plants can cool and humidify microclimates through sensible and latent heat exchange. Higher diversity plant communities can modify microclimates more strongly than lower diversity plant communities, creating the potential for strong biodiversity-climate feedbacks. Here, we review the physical and physiological mechanisms that drive these diversity-microclimate patterns, catalogue the magnitude of these trends across ecosystem types, and explore how microclimate feedbacks can explain the relationship between biodiversity and ecosystem functioning. We identify key areas where more research is needed (e.g. the role of belowground traits that drive latent heat exchange). This research is essential for understanding how biodiversity and climate are linked at micro- and macroscales.
{"title":"Diversity affects microclimate temperature and humidity: an overview of the evidence and major unanswered questions.","authors":"Alexandra J Wright,J English,C Guimaraes-Steinicke","doi":"10.1111/nph.71030","DOIUrl":"https://doi.org/10.1111/nph.71030","url":null,"abstract":"Climate change is increasing global temperatures, increasing atmospheric drying, and driving more severe and frequent drought. Plants can cool and humidify microclimates through sensible and latent heat exchange. Higher diversity plant communities can modify microclimates more strongly than lower diversity plant communities, creating the potential for strong biodiversity-climate feedbacks. Here, we review the physical and physiological mechanisms that drive these diversity-microclimate patterns, catalogue the magnitude of these trends across ecosystem types, and explore how microclimate feedbacks can explain the relationship between biodiversity and ecosystem functioning. We identify key areas where more research is needed (e.g. the role of belowground traits that drive latent heat exchange). This research is essential for understanding how biodiversity and climate are linked at micro- and macroscales.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"31 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147359043","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}
Vinavi A Gamage,Mariola Usovsky,Anser Mahmood,Elizabeth De Meyer,Bishnu Dhital,Clinton G Meinhardt,Qijian Song,Lesa J Beamer,Andrew M Scaboo,Melissa G Mitchum
Soybean (Glycine max) plants counteract soybean cyst nematode (SCN, Heterodera glycines Ichinohe) infection through an impairment of soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (α-SNAP) - NSF interactions and vesicular trafficking leading to cellular toxicity in response to nematode feeding. Through the use of a bi-parental mapping population from a cross between the SCN-resistant soybean cultivars Pickett × Peking, a major QTL on chromosome 14 was mapped to a confidence interval containing the GmSNAP14 gene. SCN-resistant genotypes were found to carry one of two variant GmSNAP14 alleles harboring either a deletion or an insertion in GmSNAP14. Expression of full-length transcripts was absent or markedly lower in plants carrying these alleles when compared to susceptible plants. Additionally, the generation of deleted and/or alternatively spliced isoforms coding for GmSNAP14 C-terminal variant proteins was pronounced in resistant plants, suggesting that SCN resistance may result from a combination of diminished GmSNAP14 expression and GmSNAP14 protein variants. CRISPR/Cas9-mediated knockout of GmSNAP14 enhanced resistance to SCN, consistent with susceptibility gene behavior indicating GmSNAP14 as a potential nematode virulence target. Our findings can be leveraged through the use of genome editing and conventional breeding techniques utilizing native alleles to develop resistant soybean cultivars.
{"title":"GmSNAP14: a key contributor to soybean cyst nematode resistance in soybean.","authors":"Vinavi A Gamage,Mariola Usovsky,Anser Mahmood,Elizabeth De Meyer,Bishnu Dhital,Clinton G Meinhardt,Qijian Song,Lesa J Beamer,Andrew M Scaboo,Melissa G Mitchum","doi":"10.1111/nph.71037","DOIUrl":"https://doi.org/10.1111/nph.71037","url":null,"abstract":"Soybean (Glycine max) plants counteract soybean cyst nematode (SCN, Heterodera glycines Ichinohe) infection through an impairment of soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (α-SNAP) - NSF interactions and vesicular trafficking leading to cellular toxicity in response to nematode feeding. Through the use of a bi-parental mapping population from a cross between the SCN-resistant soybean cultivars Pickett × Peking, a major QTL on chromosome 14 was mapped to a confidence interval containing the GmSNAP14 gene. SCN-resistant genotypes were found to carry one of two variant GmSNAP14 alleles harboring either a deletion or an insertion in GmSNAP14. Expression of full-length transcripts was absent or markedly lower in plants carrying these alleles when compared to susceptible plants. Additionally, the generation of deleted and/or alternatively spliced isoforms coding for GmSNAP14 C-terminal variant proteins was pronounced in resistant plants, suggesting that SCN resistance may result from a combination of diminished GmSNAP14 expression and GmSNAP14 protein variants. CRISPR/Cas9-mediated knockout of GmSNAP14 enhanced resistance to SCN, consistent with susceptibility gene behavior indicating GmSNAP14 as a potential nematode virulence target. Our findings can be leveraged through the use of genome editing and conventional breeding techniques utilizing native alleles to develop resistant soybean cultivars.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"199 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147346260","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}
Drought is a major environmental factor restricting plant growth and productivity. Putrescine, a small polyamine, is known to enhance drought tolerance, but the role of key genes in the ornithine-derived pathway and their upstream regulators remains unclear. PoODC, encoding Paeonia ostii ornithine decarboxylase, was strongly upregulated under drought stress in P. ostii. Silencing PoODC reduced, while overexpression in tobacco increased putrescine accumulation and drought tolerance. Its transcription was repressed by PoDPBF4, a basic leucine zipper (bZIP) transcription factor binding to the abscisic acid response element (ABRE) element in the PoODC promoter, which negatively regulated putrescine accumulation and drought tolerance. PoDPBF4 physically interacted with PoPP2A, a drought-inducible protein phosphatase, which dephosphorylated PoDPBF4 at Ser92. This modification promoted PoDPBF4 degradation via the 26S proteasome pathway, reducing its protein stability and weakening its repression of PoODC. Also, silencing PoPP2A impaired drought tolerance, confirming its positive role in drought adaptation. These findings reveal a novel drought-responsive regulatory module in which PoPP2A dephosphorylates PoDPBF4, relieving repression of PoODC and enhancing putrescine biosynthesis. This study provides insights into the post-translational regulation of polyamine metabolism and identifies a potential genetic target for improving drought tolerance in perennial woody plants.
{"title":"Dephosphorylation of DPBF4 by PP2A promotes drought tolerance by regulating putrescine biosynthesis in tree peony.","authors":"Yuting Luan,Yuxuan Zhang,Xuan Zhao,Jun Tao,Daqiu Zhao","doi":"10.1111/nph.71038","DOIUrl":"https://doi.org/10.1111/nph.71038","url":null,"abstract":"Drought is a major environmental factor restricting plant growth and productivity. Putrescine, a small polyamine, is known to enhance drought tolerance, but the role of key genes in the ornithine-derived pathway and their upstream regulators remains unclear. PoODC, encoding Paeonia ostii ornithine decarboxylase, was strongly upregulated under drought stress in P. ostii. Silencing PoODC reduced, while overexpression in tobacco increased putrescine accumulation and drought tolerance. Its transcription was repressed by PoDPBF4, a basic leucine zipper (bZIP) transcription factor binding to the abscisic acid response element (ABRE) element in the PoODC promoter, which negatively regulated putrescine accumulation and drought tolerance. PoDPBF4 physically interacted with PoPP2A, a drought-inducible protein phosphatase, which dephosphorylated PoDPBF4 at Ser92. This modification promoted PoDPBF4 degradation via the 26S proteasome pathway, reducing its protein stability and weakening its repression of PoODC. Also, silencing PoPP2A impaired drought tolerance, confirming its positive role in drought adaptation. These findings reveal a novel drought-responsive regulatory module in which PoPP2A dephosphorylates PoDPBF4, relieving repression of PoODC and enhancing putrescine biosynthesis. This study provides insights into the post-translational regulation of polyamine metabolism and identifies a potential genetic target for improving drought tolerance in perennial woody plants.","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"251 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147329184","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) is a transition metal necessary for achieving essential physiological processes throughout the plant lifecycle. In Arabidopsis thaliana, secreting Fe-mobilizing coumarins (FMC) is a key mechanism enabling roots to acquire nonbioavailable Fe present in soils. Here, we unveil the pivotal role played by NRT1/PTR FAMILY 7.2 (NPF7.2) in coumarin secretion by conducting phenotypic analyses of NPF7.2 loss-of-function mutants, NPF7.2 expression-localization analyses and direct transport assay of NPF7.2 protein with coumarin compounds using yeast cells. NPF7.2 loss-of-function impairs coumarin secretion and Fe acquisition in Arabidopsis seedlings, and the corresponding mutants are hypersensitive to Fe deficiency. NPF7.2 protein colocalizes with the main coumarin exporter, PDR9 (PLEIOTROPIC DRUG RESISTANCE PROTEIN 9), in both cortex and epidermis cell layers in root areas where coumarin secretion occurs. A site-specific accumulation of fraxin, a storage form of fraxetin, in root peripheral tissues is disturbed in the mutants under Fe deficiency. When expressed in yeast cells, NPF7.2 protein has an uptake activity for fraxetin and scopoletin, a major FMC and its precursor, respectively. However, fraxin and scopolin, their storage form, are not transported. We propose that NPF7.2 facilitates PDR9-mediated FMC secretion from the epidermis into the rhizosphere by the cellular loading of coumarins from apoplastic spaces, leading to optimal Fe acquisition.
铁（Fe）是在整个植物生命周期中实现基本生理过程所必需的过渡金属。拟南芥（Arabidopsis thaliana）分泌铁动员香豆素（FMC）是根系获取土壤中非生物可利用铁的关键机制。本研究通过对NPF7.2功能缺失突变体进行表型分析、NPF7.2表达定位分析以及利用酵母细胞对NPF7.2蛋白与香豆素化合物的直接转运试验，揭示了NRT1/PTR FAMILY 7.2 （NPF7.2）在香豆素分泌中的关键作用。NPF7.2功能缺失损害拟南芥幼苗香豆素分泌和铁获取，相应突变体对缺铁敏感。NPF7.2蛋白与香豆素主要输出蛋白PDR9 （PLEIOTROPIC DRUG RESISTANCE protein 9）共定位于香豆素分泌的根区皮层和表皮细胞层。在缺铁的突变体中，根外周组织中特定位点的蜡蛋白积累（蜡蛋白的一种储存形式）受到干扰。当在酵母细胞中表达时，NPF7.2蛋白分别对主要的FMC和前体东莨菪素具有摄取活性。然而，蜡质和东莨菪碱，它们的储存形式，不运输。我们认为NPF7.2促进pdr9介导的FMC从表皮分泌到根际，通过胞外空间香豆素的细胞负荷，从而获得最佳的铁。
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