Journal of Experimental Botany最新文献

{"title":"Tracing the Evolutionary Origins of Jasmonate Signaling: Co-Evolution of Oxylipin Metabolism and Hormone Perception in the Green Lineage.","authors":"Andrea Chini, Guillermo H Jimenez-Aleman, Roberto Solano","doi":"10.1093/jxb/erag527","DOIUrl":"https://doi.org/10.1093/jxb/erag527","url":null,"abstract":"<p><p>Jasmonates constitute a central class of lipid-derived signaling molecules that regulate plant defense, development, and environmental adaptation. Although jasmonic acid (JA) and its bioactive conjugate jasmonoyl-L-isoleucine (JA-Ile) are well characterized in angiosperms, recent evolutionary, biochemical, and structural studies have revealed that jasmonate signaling predates the origin of land plants. Jasmonates occur in streptophyte algae but are absent from chlorophytes, indicating that jasmonate biosynthesis evolved in the last common ancestor of streptophytes. However, the molecular nature, perception mechanisms, and biological functions of jasmonates have undergone profound changes during plant evolution. During terrestrialization, the recruitment of a pre-existing transcriptional regulatory network by a newly evolved COI1 receptor module established the canonical COI1/JAZ signaling system. Early diverging land plants employed dn-OPDA, a JA precursor, as the ancestral ligand, which was progressively replaced by JA amino acid conjugates such as JA-Ile in vascular plants. Here, we synthesize current evidence supporting a stepwise evolutionary model progressively shaping the COI1/JAZ-dependent hormone pathway. We discuss how (bio)chemical diversification of oxylipins, co-evolution of receptors and ligands, and the emergence of JA-Ile in vascular plants enabled the expansion, specificity, and systemic integration of jasmonate signaling as a requirement for plant terrestrialization.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cell wall polymer interactions, rather than polysaccharide fine structure, underlie recalcitrance in energy cane varieties.","authors":"Adriana Grandis, Débora Pagliuso, Marina C M Martins, Anne Elizabeth Harman-Ware, Nicholas C Carpita, Marcos S Buckeridge","doi":"10.1093/jxb/erag494","DOIUrl":"https://doi.org/10.1093/jxb/erag494","url":null,"abstract":"<p><p>Second-generation bioethanol production from lignocellulosic biomass has driven the development of high-fiber sugarcane varieties known as energy canes, which combine high tillering, high biomass accumulation, lower sucrose, and improved agronomic performance. However, energy canes have been reported to be more recalcitrant to enzymatic saccharification. We compared biomass and cell wall composition, non-cellulosic polysaccharide extractability, and saccharification efficiency in two energy cane varieties, Vertix V2 and Vertix V3, and sugarcane. Sugarcane contained three times as much sucrose and less fiber than energy canes. After removing soluble sugars from the biomass, reduced digestibility became evident in the two energy cane varieties, particularly in V2. Saccharification increased with alkali and doubled after acidic sodium chlorite treatments. Although the main polysaccharides and linkage structures were broadly conserved across genotypes, minor changes were observed in their relative abundance and extractability. Glucuronoarabinoxylans (GAX) were the predominant wall polysaccharides (72%), while pectins [homogalacturonan (HG) and rhamnogalacturonan I (RG-I), each 1%], arabinan side-groups (4-6%), glucomannans (1%), and xyloglucan (2-4%) occurred in smaller proportions. Sugarcane contained higher abundances of xyloglucan, β-glucan, glucomannan, and arabinan, whereas energy canes had higher HG and RG-I. Chlorite oxidation solubilized GAX and RG-I, indicating that polymers are associated with phenylpropanoids and contribute to wall recalcitrance. The contrasting saccharification behavior of the sugarcane and energy cane varieties examined here appears to arise not from major changes in polysaccharide fine structure, but from differences in biomass allocation, phenylpropanoid abundance, extractability, and molecular interactions among cellulose, matrix polysaccharides, and phenylpropanoids within the cell wall. Understanding these properties in relation to enzyme-mediated disassembly is fundamental to accessing grass walls and improving biomass saccharification.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149216186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhizobial type III effectors as regulators of root-nodule symbiosis in legumes.","authors":"Alicia Camuel, Albin Teulet, Pablo Del Cerro","doi":"10.1093/jxb/erag528","DOIUrl":"https://doi.org/10.1093/jxb/erag528","url":null,"abstract":"<p><p>The rhizobia-legume nitrogen-fixing symbiosis begins when plants perceive rhizobial Nod factors (NF), activating the Common Symbiosis Signalling Pathway (CSSP) that drives nodule organogenesis. Rhizobia also inject Type III effectors (T3E) into host cells through a Type III Secretion System (T3SS) related to those of pathogenic bacteria. These effectors were long viewed only as suppressors of plant immunity and determinants of host compatibility, but this picture has changed. Recent studies revealed that rhizobial effectors (known as Nodulation Outer Proteins, Nops) such as NopT, NopM, NopL, NopP and NopZ directly target NF receptors or associated kinases, thereby regulating CSSP activation. The effector-triggering nodulation proteins (ET-Nods), a separate class of T3Es found in various Bradyrhizobium species, can activate nodule organogenesis independently of NF perception by rewiring host transcriptional and SUMOylation-based signalling. We trace the evolutionary origins of these activities, which may derive either from redirection of ancestral immune-targeting effectors toward symbiotic functions or from rhizobium-specific innovations. We ask whether the T3SS contributed to nodulation. We then consider what this interference means for the host, ranging from reinforced partner choice to partial loss of host control, and argue that rhizobial effectors have evolved as specialised modulators that converge on the signalling hubs governing symbiosis.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149207137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfite dynamics affect drought tolerance and water status in Arabidopsis and tomato.","authors":"Kusum Khatri, Jaykumar Patel, Aizat Bekturova, Poonam Tiwari, Tesfaye Asmare Sisay, Babita Choudhary, Dominic Standing, Beery Yaakov, Simon Barak, Veronika Turečková, Miroslav Strnad, Moshe Sagi","doi":"10.1093/jxb/erag344","DOIUrl":"10.1093/jxb/erag344","url":null,"abstract":"<p><p>Previously, we showed that altered sulfite homeostasis led to higher water loss in sulfite oxidase (SO) RNA interference (Ri) plants than in Arabidopsis wild type (WT) after sulfite infiltration into rosette leaves. In contrast, SO overexpression (OE) and adenosine-5'-phosphosulfate reductase 2 (apr2) knockout (KO) resulted in lower water loss than in WT. Accordingly, sulfite homeostasis and drought tolerance under prolonged drought in Arabidopsis and tomato (Rheinlands Ruhm) were investigated. SO Ri mutants displayed the most severe wilting and water loss, accompanied by sulfite accumulation due to reduced SO expression. In contrast, SO OE, apr2 KO, apr2 KO/SO OE, and gene-edited lines, including sulfite reductase (SiR) OEC2+SO OEC2 and SiR OEC4/SO OE, maintained higher relative water content by enhancing sulfite oxidation and reduction. Elevated sulfite in SO Ri mutants acted as an antagonist to abscisic acid (ABA), as despite accumulating higher ABA than all other genotypes, SO Ri plants displayed the lowest relative water content, consistent with sulfite suppressing ABA signal transduction through impaired by Pyrobactin resistance 1-like 5 (PYL5) and enhanced ABA negative feedback by Highly ABA-induced PP2C gene 2 (HAI2). SO and SiR overexpression also increased hydrogen sulfide and cysteine levels, contributing to drought resilience. Tomato lines also reflected these patterns in SO OE, SiR OE, and SiR OE/SO OE, showing reduced sulfite and improved relative water content compared with WT. Overall, coordinated regulation of SO, SiR, and APR2 maintains sulfite homeostasis, mitigating drought-induced damage and enhancing water retention across species by directly limiting sulfite accumulation and relieving sulfite-driven antagonism of ABA signal transduction.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6756-6773"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13672997/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148421567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rethinking wound signaling in plant development: the epigenetic and metabolic nexus of jasmonate-mediated bud activation.","authors":"Puyuan Liu, Rishikesh P Bhalerao, Qinsong Yang, Guolei Li","doi":"10.1093/jxb/erag346","DOIUrl":"10.1093/jxb/erag346","url":null,"abstract":"","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6307-6310"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148436951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The transcriptional regulator MOS1 attenuates salinity stress-induced seed germination inhibition via negative feedback regulation of ABA signaling in Arabidopsis.","authors":"Yafei Xu, Xiaoyu Chen, Lujing Luo, Jie Huang, Fangning Zhu, Zhixue Wang, Dianxing Wu, Lilan Hong, Ning Zhang","doi":"10.1093/jxb/erag305","DOIUrl":"10.1093/jxb/erag305","url":null,"abstract":"<p><p>Seed germination is inhibited by salt stress, and this inhibition is known to be mainly mediated by the plant hormone abscisic acid (ABA). Whether and how this inhibition is fine-tuned is not fully understood. Here, we identified MODIFIER OF snc1-1 (MOS1) as an attenuator of salt-induced inhibition of seed germination. MOS1 expression was induced by salt, and this induction was partly dependent on ABA biosynthesis and signaling. The mos1 mutant showed hypersensitivity to salt stress during seed germination compared with the wild type, accompanied by higher ABA accumulation and stronger salt-induced expression of ABA biosynthesis and signaling genes. Genetic analysis suggested that MOS1 limits both salt-induced ABA biosynthesis and ABA responsiveness. Moreover, ABI5 directly activated MOS1 expression, whereas ABI5 transcripts and protein accumulated to higher levels in mos1 under salt stress. In addition, MOS1 expression was inhibited by the germination-promoting hormone gibberellin (GA), and MOS1 helped maintain GA biosynthesis. Together, these findings suggest that MOS1 attenuates salt-induced inhibition of seed germination, at least in part, through ABI5-linked negative feedback regulation of ABA signaling and modulation of GA biosynthesis.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6672-6688"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148277680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The pentatricopeptide repeat protein EMBRYO DEFECTIVE 1417 is required for chloroplast RNA editing and intron splicing in Arabidopsis.","authors":"Chu Zeng, Tonghui Wu, Jinling Su, Qingsong Jiao, Ting Jia, Xueyun Hu","doi":"10.1093/jxb/erag362","DOIUrl":"10.1093/jxb/erag362","url":null,"abstract":"<p><p>Post-transcriptional RNA processing is essential for chloroplast biogenesis. The pentatricopeptide repeat (PPR) protein EMBRYO DEFECTIVE 1417 (EMB1417), which contains only two PPR motifs, was previously shown to be required for splicing of rpoC1 and ycf3.2 transcripts in chloroplasts. Here, we demonstrate that chemical-induced silencing of EMB1417 results in a yellow-leaf phenotype with markedly reduced chlorophyll content. RNA sequencing analyses revealed that EMB1417 is indispensable for efficient C-to-U editing at multiple sites, including rpoA-200, clpP-559, petL-5, psbZ-50, accD-1568, and ndhD-2. Protein-protein interaction assays demonstrated that EMB1417 physically interacts with multiple RNA editing cofactors, MORF2/8/9 and DG409, thereby facilitating RNA editing in chloroplasts. Strikingly, disruption of EMB1417 significantly also severely impairs the splicing of group II introns in ndhB, petB, and petD transcripts. We further identified a direct interaction between EMB1417 and the splicing factor CFM3A. These findings establish that EMB1417 participates in chloroplast RNA processing, providing critical insights into the mechanisms of RNA editing and splicing during chloroplast development.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6436-6449"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orchestral maneuvers: integrated cytokinin and gibberellin signals regulate flowering.","authors":"Grace A Johnston, Cristiana T Argueso","doi":"10.1093/jxb/erag474","DOIUrl":"https://doi.org/10.1093/jxb/erag474","url":null,"abstract":"","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":"77 19","pages":"6303-6306"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bending and squeezing: gradual electric potentials encode mechanical stimuli in poplar.","authors":"Erwan Tinturier, Éric Badel, Nathalie Leblanc-Fournier, Geoffroy Guéna, Yoël Forterre, Jean-Louis Julien","doi":"10.1093/jxb/erag329","DOIUrl":"10.1093/jxb/erag329","url":null,"abstract":"<p><p>Mechanical stimuli such as wind elicit rapid electrical signals in plants, yet the mechanisms underlying these responses remain poorly understood. Here, we investigated the electrophysiological responses of young poplar trees to controlled stem bending. We identified a gradual potential (GP), distinct from classical action potentials, whose attenuation and propagation distance depend strongly on stimulus speed and intensity. While the maximal GP amplitude recorded near the bending site remained stable across stimulation conditions, slower or gentler flexions resulted in faster spatial decay and shorter propagation distances. Similar GP responses were elicited by stem bending and by direct root pressurization, indicating a coupling between hydraulic perturbations and electrical signaling. Although GP propagation and attenuation are consistent with a diffusive pressure signal, key features-such as the invariance of peak amplitude at the generation site and progressive waveform narrowing-cannot be explained by hydraulic diffusion alone and point to a nonlinear transduction process. Together, these results constrain the biophysical mechanisms underlying mechanically induced electrical signaling in trees and provide a framework for future studies addressing their physiological relevance.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6541-6554"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148404827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining a high-caliber chromosome-level genome and root single-cell atlas resolves genetic diversity and root development in Olea europaea subsp. cuspidata.","authors":"Wenjun Hu, Chenkai Jiang, Qian Zhao, Wei Wang, Xue Li, Hongling Lu, Lin Chen, Song Gao, Fei Xu, Guoxin Shen, Shenlong Zhu, Ying Fu, Erli Niu","doi":"10.1093/jxb/erag311","DOIUrl":"10.1093/jxb/erag311","url":null,"abstract":"<p><p>Olea europaea subsp. cuspidata, a subspecies of olive trees, stands out for its remarkable stress tolerance, and commonly serves as a rootstock that enhances olive oil yield. To explore its genomic and cellular underpinnings for potential breeding applications, a chromosome-scale genome assembly and a root-specific single-cell atlas of O. europaea subsp. cuspidata was resolved. Using a combined survey evaluation strategy along with PacBio CLR and Hi-C sequencing technologies, a total genome of 1.62 Gb was obtained (23 chromosomes; N50: 55.72 Mb). Phylogenetic analysis revealed that Oleaceae plants diverged ∼17.2 million years ago (Mya), with O. europaea subsp. cuspidata splitting from other O. europaea lineages ∼5.7 Mya. It is genetically closer to the cultivated olive O. europaea subsp. europaea cv. Arbequina than to the wild olive O. europaea subsp. europaea var. sylvestris. Additionally, a dynamic molecular map of olive roots was generated at single-cell resolution to reconstruct the continuous root cell differentiation and developmental trajectory. This helps to unravel key regulatory genes in olive root development and adaptation to the external environment. This study explored the diversity of olive trees at genomic and root cellular levels, with insights to support the theoretical basis for enhanced stress tolerance, aiding the global introduction and promotion of olive trees.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6450-6467"},"PeriodicalIF":6.5,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148317391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}