Planta最新文献

{"title":"GhSCL5, a GRAS transcription factor from cotton, positively regulates drought tolerance by modulating phytohormone signaling and carbon metabolism.","authors":"Duofu Shan, Xin Zhang, Haijuan Wang, Xingyue Zhong, Yongxue Xie, Kunduziayi Kudelaiti, Aixia Han, Wanwan Fu, Xilin Wang, Yanlong Yang, Jingbo Zhang","doi":"10.1007/s00425-026-05138-0","DOIUrl":"https://doi.org/10.1007/s00425-026-05138-0","url":null,"abstract":"<p><strong>Main conclusion: </strong>In this study, we functionally characterized the GRAS transcription factor gene GhSCL5 in upland cotton. Transcriptome analysis, RT-qPCR validation, and public transcriptome data from the CottonOmics database demonstrated that the expression of GhSCL5 was significantly induced by exogenous γ-polyglutamic acid (γ-PGA), polyethylene glycol (PEG)-simulated drought, and natural drought conditions. These results indicate that GhSCL5 participates in the drought stress response of cotton. Drought is a major abiotic stress limiting cotton production. The GRAS protein family participates in plant development and abiotic stress responses, but the roles of many cotton GRAS members remain unclear. Here, we characterized GhSCL5, a GRAS family gene in upland cotton (Gossypium hirsutum) whose expression was induced by natural drought, polyethylene glycol (PEG), and exogenous γ-polyglutamic acid (γ-PGA). Silencing GhSCL5 by virus-induced gene silencing (VIGS) reduced cotton drought tolerance, as indicated by decreased catalase (CAT) and peroxidase (POD) activities, lower proline (Pro) accumulation and leaf relative water content (RWC), and increased malondialdehyde (MDA) content under drought stress. Conversely, heterologous overexpression of GhSCL5 in Arabidopsis thaliana enhanced drought tolerance and maintained longer primary roots under mannitol-induced osmotic stress. Transcriptome profiling identified 7061 differentially expressed genes (DEGs) in GhSCL5-silenced cotton leaves under drought stress, comprising 3140 upregulated and 3921 downregulated genes. Notably, upregulated DEGs were enriched in pathways, including plant-pathogen interaction, plant hormone signal transduction, the plant MAPK signaling pathway, amino sugar and nucleotide sugar metabolism, phenylpropanoid biosynthesis, and arginine and proline metabolism, while downregulated DEGs were enriched in photosynthesis, plant hormone signal transduction, starch and sucrose metabolism, carbon fixation in photosynthetic organisms, glyoxylate and dicarboxylate metabolism, and photosynthesis-antenna protein. Importantly, the plant hormone signal transduction pathway was enriched with both upregulated and downregulated DEGs, suggesting that this pathway may represent a significant component of the transcriptional response. Within the plant hormone signal transduction pathway, genes associated with abscisic acid (ABA) and auxin were the most abundant, which indicates that these two hormonal systems might be key factors in the response associated with GhSCL5. Collectively, these findings suggest that GhSCL5 may contribute to drought tolerance through processes related to antioxidant defense, osmotic adjustment, and carbon metabolism, with transcriptomic evidence suggesting a potential involvement of ABA and Auxin signaling.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148897760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A genetic access to plant cell axis formation.","authors":"Thomas Berleth, Christian S Hardtke, Jim Mattson, Gerhard K H Przemeck","doi":"10.1007/s00425-026-05112-w","DOIUrl":"10.1007/s00425-026-05112-w","url":null,"abstract":"","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13541976/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148887993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strigolactone (GR24) promotes arbuscular mycorrhizal colonization and wheat root growth.","authors":"Maryam Moosavi, Reza Khorassani, Reza Tavakkol Afshari","doi":"10.1007/s00425-026-05139-z","DOIUrl":"https://doi.org/10.1007/s00425-026-05139-z","url":null,"abstract":"<p><strong>Main conclusion: </strong>GR24 enhances wheat performance by optimizing plant-arbuscular mycorrhizal fungi (AMF) interactions. Signaling molecules such as strigolactones (SLs) play essential regulatory roles in the rhizosphere by facilitating plant-soil communication and strengthening plant-microbe interactions. These molecules are crucial for promoting AMF colonization and the stable establishment of a symbiotic association, thereby supporting plant adaptation under stress conditions. This study aimed to evaluate the potential of seed priming with the synthetic strigolactone analogue GR24 to enhance AMF colonization, nutrient uptake, and the morpho-physiological performance of wheat. A factorial experiment was conducted in a completely randomized design under greenhouse conditions, with four GR24 concentrations (0, 2.5, 5, and 10 μM) and two AMF inoculation treatments (with and without AMF). Results showed that the addition of 5 μM GR24 combined with AMF significantly enhanced plant growth and physiological performance. Specifically, total dry weight (TDW), total chlorophyll content, stomatal conductance, photosynthetic rate, and the uptake of N, K, Fe, and Zn increased by 41%, 31%, 50%, 42%, 42.88%, 39%, 69.69%, and 69.81%, respectively. In addition, application of 5 μM GR24 increased phosphorus (P) uptake by 19.42% compared with the control. These findings suggest that an appropriate concentration of GR24 enhances phosphorus uptake, while its combined application with AMF further improves nutrient acquisition, physiological performance, and overall plant growth in wheat.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148875462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PAE8 and PAE9 double mutant reduces auxin and alters resistance against selected bacteria and fungi in Arabidopsis thaliana.","authors":"Rawan M Ahmad, Nehaya Al-Karablieh, Kholoud M Alananbeh, Haya Abdallah, Wafa' Salhieh, Osama Alkhasoneh, Khaldoun J Al-Hadid","doi":"10.1007/s00425-026-05137-1","DOIUrl":"https://doi.org/10.1007/s00425-026-05137-1","url":null,"abstract":"<p><strong>Main conclusion: </strong>PAE8 and PAE9 double mutants reduce auxin concentration and enhance Arabidopsis thaliana resistance in a pathogen-dependent manner. Pectin O-acetylation is a key plant cell wall modification that influences developmental processes and stress responses. pectin acetylesterases (PAEs) are cell wall-modifying enzymes that are responsible for removing the acetyl group from pectin. In this study, we investigated the roles of PAE8 and PAE9 in regulating pectin O-acetylation, auxin concentration, and plant defense in Arabidopsis thaliana rosette leaves. Quantitative real-time PCR (qPCR) was conducted to evaluate the transcriptional profiles of PAE8 and PAE9 in 3- to 8-week-old rosette leaves that represent successive vegetative developmental stages, showing maximum expression at week 8 for both genes. The double mutant plants (pae8/pae9) showed significantly higher cell wall acetylation levels compared to the wild-type plants (Col-0) across all examined developmental stages. Indole-3-acetic acid (IAA) concentration was reduced in pae8/pae9 compared to Col-0 at week 8. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed a significant difference in cell wall acetylation between Col-0 and pae8/pae9. Detached leaf assay for 8-week-old rosette leaves demonstrated that pae8/pae9 plants exhibit enhanced resistance to Fusarium oxysporum, Macrophomina phaseolina, Aspergillus flavus, Pseudomonas viridiflava, and Pectobacterium carotovorum, whereas the bacterial growth of Pseudomonas syringae pv. tomato and Pectobacterium atrosepticum was not significantly different from Col-0 under the tested conditions. Together, altered pectin structure and reduced auxin concentration in pae8/pae9 may contribute to pathogen-dependent resistance although auxin's direct role remains to be determined. These findings highlight PAE8 and PAE9 as key regulators of pectin O-acetylation and suggest a potential link between cell wall acetylation, reduced IAA concentration, and pathogen-dependent defense responses.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148875500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerating iron biofortification in millets: progress, challenges, and future prospects.","authors":"A R Sree Rathna, Stanislaus Antony Ceasar","doi":"10.1007/s00425-026-05141-5","DOIUrl":"https://doi.org/10.1007/s00425-026-05141-5","url":null,"abstract":"<p><strong>Main conclusion: </strong>Integrating conventional breeding, omics, and CRISPR-based genome editing can overcome genetic and antinutrient constraints, enabling efficient iron biofortification of millets for sustainable and nutrition-secure food systems. Iron (Fe) deficiency remains one of the most widespread forms of micronutrient malnutrition. Biofortification of staple crops has emerged as a particularly sustainable and scalable strategy to combat this issue. Millets are nutrient-dense staple cereals with exceptional nutritional quality and climate resilience. However, genetic variations and the presence of antinutrients limit Fe content in millets, which highlights the necessity of advancing biofortification strategies. This review examines the present state of multi-dimensional strategies and discusses the future prospects for efficient iron biofortification in millets. We analyzed the efforts made for Fe biofortification in millets, ranging from conventional breeding practices to next-generation molecular approaches. Recent advances in omics have enhanced understanding of Fe uptake, transport, and storage in millets. Furthermore, CRISPR/Cas-based genome editing is discussed for the regulated expression of key Fe-transporter genes and targeted knockout of genes responsible for antinutrients. A multidisciplinary approach is essential to develop high-yielding and Fe-rich millet varieties that can contribute to sustainable nutrition security.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148866285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear diversity in Charophyceae revealed by fluorescence staining and its implications for genome size estimation.","authors":"Julien Böhm, Julia Peters, Klaus Herburger, Hendrik Schubert","doi":"10.1007/s00425-026-05085-w","DOIUrl":"10.1007/s00425-026-05085-w","url":null,"abstract":"<p><strong>Main conclusion: </strong>We established a protocol for reliable nuclear visualization in Charophyceae, revealed diverse nuclear organization across cell types and species, and identified suitable cells for genome size estimation via flow cytometry. Charophyceae are multicellular green algae closely related to land plants and are established model systems for understanding plant evolution. Yet key cellular parameters like genome size remain poorly characterized. We combined fluorescence microscopy, transmission electron microscopy (TEM), and flow cytometry to characterize nuclear diversity across cell types and species of Characeae and to identify a cell type suitable for genome size estimation. Among three DNA-intercalating fluorochromes, propidium iodide labeled nuclei most reliably. Nuclear morphology varied widely across cell types: mononucleated cells were found in vegetative apical cells, the coronula of oogonia, and spermatogenous filaments of antheridia, whereas multinucleation predominated in other tissues, e.g., cortical cells, spine cells, stipulodes and rhizoids. Nuclei in Chara hispida showed a significant gradient in cross-sectional area along the thallus axis. In the apical internodes, nuclei were larger and more heterogeneous, whereas in the basal internodes they were smaller and more uniform, which is consistent with possible endopolyploidy. TEM confirmed the nuclear identity of crescent-shaped structures. Relatively large nuclei were found in rhizoids and spine cells. Only Sphaerochara canadensis showed an organized nuclei pattern. Whole-thallus preparations did not yield a defined nuclear peak by flow cytometry, but antheridia of Chara tomentosa produced a sharp peak, from which a genome size of 5.32 pg (1C) was estimated. The protocol established here provides a simple, reproducible framework for visualizing nuclei and estimating genome size in Charophyceae, and helps address longstanding questions in this group, such as the mechanisms and functions of multinucleation, the site of meiosis, and genome evolution.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13525061/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148851427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FAST-TRACE: delineating tissue-specific cis-regulatory activities in the cadmium/zinc hyperaccumulator Sedum plumbizincicola.","authors":"Yanlan Mo, Yixin Zhang, Xiaotong Wu, Huan Liu, Wenzhong Xu, Longhua Wu","doi":"10.1007/s00425-026-05136-2","DOIUrl":"https://doi.org/10.1007/s00425-026-05136-2","url":null,"abstract":"<p><strong>Main conclusion: </strong>FAST-TRACE is a transient expression system for rapid homologous promoter analysis in Sedum plumbizincicola, enabling identification of critical regulatory regions and a MYB transcription factor, SpTRB4, that activates the SpHMA3 promoter. Investigating the SpHMA3 promoter in Sedum plumbizincicola is essential to elucidate the molecular regulatory mechanisms underlying the above-ground metal detoxification. Given that generating stably transformed plants is time-consuming and costly, an efficient, low-cost method for the preliminary promoter activity assessment is needed. Here, we present FAST-TRACE (Fast Agrobacterium-mediated Spatio-Temporal Regulatory Activity and Cis-element Evaluation), a rapid transient transformation method for leaf tissues mediated by Agrobacterium tumefaciens. Following optimization (OD₆₀₀= 0.8), qualitative and quantitative measurements of promoter activity can be obtained within 2-3 days. Using FAST-TRACE, we systematically evaluated the promoter responses to multiple stimuli, including abscisic acid (ABA), salicylic acid (SA), methyl jasmonate (MeJA), and light/dark conditions. The LUC/REN ratios showed strong correlation with the transcript levels of endogenous SpHMA3, SpCAX3, and SpNRAMP3, confirming the accuracy of this system in reflecting native expression dynamics. Truncation analysis identified two critical regions: deletion of the P1-P2 segment (- 1303 to -1054) reduced activity by 2.5-fold, indicating the presence of positive regulatory elements, while the P5-P6 region (- 303 to -54) displayed highly activity and is enriched in core promoter and regulatory motifs, including GATA motifs, MYB and MYC binding sites, suggesting its critical role in transcriptional regulation. Notably, yeast one-hybrid screening using the P1-P2 region as bait identified a MYB transcription factor, SpTRB4, which directly activated the SpHMA3 promoter by approximately 3.7-fold in homologous S. plumbizincicola leaves. FAST-TRACE was successfully applied to Sedum alfredii and Nicotiana tabacum, and extended to subcellular localization. In conclusion, the scalability and simplicity of FAST-TRACE make it a practical attractive alternative for both qualitative and quantitative promoter analysis using luciferase reporters.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148831237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"More is not always better: phosphorus context shapes the effectiveness of single-strain and consortium plant growth-promoting bacteria in tomato.","authors":"Alice Ferreira Alves, Mónica Yorlady Alzate Zuluaga, Talita de Oliveira Caretta, Sonia Monterisi, Fernando Dini Andreote, Stefano Cesco, Youry Pii","doi":"10.1007/s00425-026-05134-4","DOIUrl":"10.1007/s00425-026-05134-4","url":null,"abstract":"<p><strong>Main conclusion: </strong>Phosphorus availability determines whether single or consortium PGPB maximize tomato performance, demonstrating that rational inoculant design should prioritize functional complementarity over increasing microbial complexity. Phosphorus (P) availability is a major constraint for crop development and productivity, and beneficial bacteria are increasingly proposed to enhance plant P-acquisition efficiency. However, their comparative performance remains variable across studies and experimental contexts. This study investigated whether single plant growth-promoting bacteria (PGPB) strains and a defined bacterial consortium differentially modulate P nutrition and early growth of tomato under contrasting P availability. Tomato plants were grown hydroponically in a factorial design combining single-strain inoculations (Azospirillum brasilense, Pantoea agglomerans, Priestia aryabhattai), a defined consortium, and a non-inoculated control under five P regimes differing in concentration and chemical form (soluble vs. insoluble). Plant growth and root architecture traits were evaluated alongside ionomics and targeted expression analysis of SlPHT1 transporters, thus linking plant performance with nutrient status and regulation. Results indicated that P. agglomerans showed the most stable benefits under soluble P, while A. brasilense strongly promoted adaptive root and transporter responses under moderate limitation. P. aryabhattai induced subtler growth effects but reshaped nutrient associations, particularly with insoluble P. By contrast, the consortium did not consistently outperform single strains and showed clear advantages only when insoluble P was the sole source. Overall, these findings demonstrate that the effectiveness of single versus multi-strain inoculation is strongly context-dependent and emerges from the interaction between P availability, strain identity, and plant response integration. Accordingly, effective consortia should be designed based on functional complementarity and balance, rather than on increasing inoculant complexity, as overlapping PGP traits may lead to non-additive or even counterproductive effects.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13506622/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148819306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Knockdown of Arabidopsis RUS4 impacts pollen coat formation by affecting flavonoid and lipid metabolism.","authors":"Ting-Ting Zhang, Li-Qian Yuan, Hong-Wei Zhu, Shu-Qing Zhao","doi":"10.1007/s00425-026-05135-3","DOIUrl":"https://doi.org/10.1007/s00425-026-05135-3","url":null,"abstract":"<p><strong>Main conclusion: </strong>The DUF647 family member RUS4 contributes to pollen coat formation in Arabidopsis by modulating transcript levels of key genes for flavonoid and lipid metabolism. RUS4 encodes a member of the broadly conserved DUF647 domain-containing protein family that is distributed across eukaryotes. We have previously shown that artificial microRNA knockdown Arabidopsis RUS4 lines (known as amiR-RUS4) exhibit reduced male fertility due to reduced pollen viability, decreased pollen germination rate, and impaired pollen tube growth. However, amiR-RUS4 plants exhibit a previously uncharacterized phenotype in pollen coat formation, which was investigated in the present study. Scanning electron microscopy and transmission electron microscopy analyses revealed that amiR-RUS4 pollen grains exhibit abnormal pollen wall structure and defective pollen coat deposition. Confocal observation of DPBA and Nile Red double-stained pollen grains indicated less accumulation of lipids and flavonoids in the pollen coat of amiR-RUS4 plants compared with wild type. Quantitative image analysis confirmed significantly lower fluorescence signal intensities of both DPBA and Nile Red in amiR-RUS4 pollen relative to the wild type. Consistently, the expression of flavonol metabolic genes was down-regulated in amiR-RUS4 stamens. Moreover, the transcript abundance of several pollen coat extracellular lipases (EXLs) genes was substantially reduced in amiR-RUS4 flower buds. Similarly, the expression of two 3-ketoacyl-CoA synthase genes KCS5 and KCS6, which are responsible for the biosynthesis of very-long-chain fatty acids in the pollen coat, was also altered in amiR-RUS4 flower buds. Taken together, these results suggest that RUS4 is involved in pollen coat formation in Arabidopsis by modulating the expression of key genes for flavonoid and lipid metabolism. This study advances our understanding of the biological functions of DUF647 family genes during plant pollen development.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148813547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualization of auxin responses during vine twining in Ipomoea nil and the functional role of the subapical hook in this process.","authors":"Yu Takarada, Tomoe Yofune, Sae Yamauchi, Miyuki Funamoto, Kaho Teramachi, Tsuyoshi Kaneta","doi":"10.1007/s00425-026-05133-5","DOIUrl":"https://doi.org/10.1007/s00425-026-05133-5","url":null,"abstract":"<p><strong>Main conclusion: </strong>This study suggests that hook-shaped bending associated with properly regulated auxin response patterns in the subapical region may contribute to the maintenance of twining in morning glory vines. The twining behavior demonstrated by vine plants represents an important morphogenetic adaptation essential to their survival; however, the physiological mechanisms driving this response remain largely unknown. To elucidate the role of auxin in vine twining in morning glory (Ipomoea nil), we generated and investigated transgenic morning glory carrying the GUS reporter gene under an auxin-responsive promoter, which enabled the identification of the localization of auxin responses through color development. Strong GUS activity, indicating auxin response, was observed at the hook-shaped bend in the subapical region of the vine. In many cases, the GUS activity was circumferentially biased in this region when the shoot apex was either descending to form a hook or maintaining a downward orientation. Treatment of vines with N-(1-naphthyl)phthalamic acid (NPA), an auxin transport inhibitor, resulted in the suppression of circumnutation, twining, and hook formation. Ectopically strong auxin responses were observed in the subapical region of these NPA-treated vines. In addition, unilateral application of the synthetic auxin NAA to the vine induced bending with the treated side on the outside of the curve. These results suggest that auxin response patterns in the subapical region are associated with circumnutation, twining, and hook formation, although the specificity of pharmacological treatments is limited. Local treatment of the subapical region of the vine with PCIB, an auxin-competitive inhibitor, resulted in temporary hook relaxation, detachment from the support, and resumption of exploratory circumnutation in certain individuals. These findings suggest that the hook in the subapical region of the vine contributes to maintaining twining.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"264 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}