Molecular Plant-microbe Interactions最新文献

{"title":"Exploring the Root Response to Multiple Stressors: Mechanisms Underlying Kiwifruit Vine Decline Syndrome (KVDS) Development.","authors":"Micol Guaschino, Heidi Hargarten, Christopher Cook, Huiting Zhang, Loren Honaas, Tracey Somera, Davide Spadaro","doi":"10.1094/MPMI-02-26-0017-R","DOIUrl":"https://doi.org/10.1094/MPMI-02-26-0017-R","url":null,"abstract":"<p><p>First reported in Italy in 2012, Kiwifruit Vine Decline Syndrome (KVDS) has emerged as a major threat to <i>Actinidia deliciosa</i> vines in the Mediterranean region, significantly impacting kiwifruit production. Infection with biotic agents alone (e.g., <i>Phytopythium vexans</i>) has proven insufficient to reproduce KVDS symptoms, with studies suggesting root flooding as a key factor in KVDS development. To date, research has provided insights into the response of <i>A. deliciosa</i> to individual stress factors; however, little is known about how these plants cope with stress combinations. We characterized the transcriptome response of <i>Actinidia deliciosa</i> cv. Hayward over time under biotic stress (inoculation with <i>P. vexans</i>), abiotic stress (root flooding), and their combination, mimicking KVDS development. This study reveals that although typical flooding responses (e.g., anaerobic metabolism shift, ethylene signaling) were present under combined stress, the overall transcriptomic profile was distinct and not predictable from individual stress responses. Notably, in the presence of flooding key biotic defense mechanisms were suppressed, including phenylpropanoid biosynthesis and auxin signaling, despite their upregulation during infection with <i>P. vexans</i> alone. These results suggest that KVDS may involve an interaction between stressors, in which abiotic stress responses could come at the cost of plant defense mechanisms.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147729396","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":"Dual Involvement of Potyviral VPg-Interacting Protein (PVIP) and Eukaryotic Translation Initiation Factor Components with Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus Resistance in <i>Phaseolus vulgaris</i>.","authors":"Fulgencio Espejel, Natzul Santoyo, Gloria Santana, Gabriela Toomer, Jorge Acosta-Gallegos, Matthew W Blair, Laura Silva-Rosales, Masoud Naderpour","doi":"10.1094/MPMI-07-25-0086-R","DOIUrl":"https://doi.org/10.1094/MPMI-07-25-0086-R","url":null,"abstract":"<p><p>Two independent recessive genes, <i>bc</i>-<i>1</i> and <i>bc-</i>2, in <i>Phaseolus vulgaris</i> confer resistance to the systemic movement of bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV). To identify candidate genes for these loci, homologs of <i>Arabidopsis thaliana PVIP1</i> and <i>PVIP2</i>, which encode potyviral VPg-interacting proteins, were cloned from <i>P</i>. <i>vulgaris</i> genotypes. The eukaryotic translation initiation factor <i>eIF4E</i> was also cloned. We identified 2 alleles of <i>PvPVIP1</i>, 12 alleles of <i>PvPVIP2</i> (<i>PvPVIP2¹</i> to <i>PvPVIP2¹²</i>), 2 previously reported <i>eIF4E¹</i> and <i>eIF4E³</i> alleles, and a novel <i>eIF4E⁵</i> allele. Predicted PvPVIP2 and PveIF4E proteins differed from their wild-type homologs by one to four amino acids and one deletion, distinguishing most resistant (<i>bc-1¹</i>) from susceptible (<i>BC-1¹</i>) cultivars. Resistance to BCMV and/or BCMNV in several genotypes correlated with co-occurrence of mutated <i>eIF4E</i> and <i>PvPVIP2</i> alleles. An F₂ population segregating for <i>PvPVIP2²/PvPVIP2³</i> and <i>eIF4E³</i> alleles was analyzed for resistance to BCMV-NL1 and BCMNV-NL3 variants. Plants were genotyped using two <i>cleaved amplified polymorphic sequence</i> (<i>CAPS</i>) markers, <i>PVIP2-Hpa</i>II and <i>eIF4E-Rsa</i>I, as well as BCMV-resistant markers <i>SW13</i> and <i>ROC11</i>. F₂ plants homozygous for <i>PveIF4E³</i> and <i>PvPVIP2²/PvPVIP³</i> alleles and positive for the <i>ROC11</i> marker were resistant to both viruses. In-silico protein-protein interaction studies confirmed PvPVIP2 and BCMV-VPg as biological counterparts. <i>PvPVIP2</i> gene mapped on linkage group 8, a new position for virus resistance. This study expands understanding of recessive viral resistances in plants by correlating <i>PveIF4E</i> and <i>PvPVIP2</i> and suggests that <i>CAPS</i> markers could aid in common bean breeding. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI07250086R"},"PeriodicalIF":3.4,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147654406","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":"<i>Fusarium oxysporum</i> f. sp. <i>vasinfectum</i> Race 4 (Fov4) <i>FNP1</i>, a Nonribosomal Peptide Synthetase Gene, Plays an Important Role in Cotton Fusarium Wilt.","authors":"Huan Zhang, Yi Zhou, Caleb Oliver Bedsole, Won Bo Shim","doi":"10.1094/MPMI-01-26-0004-R","DOIUrl":"10.1094/MPMI-01-26-0004-R","url":null,"abstract":"<p><p>Fusarium wilt, caused by <i>Fusarium oxysporum</i> f. sp. <i>vasinfectum</i> (Fov), is one of the most destructive early-season cotton diseases worldwide. The recent emergence of the highly virulent Fov race 4 (Fov4) and its aggressiveness have raised significant concerns for the U.S. cotton industry. Unlike predominant Fov races in U.S. cotton production, which require root-knot nematodes to cause damage, Fov4 is known to infect cotton independent of nematodes. However, the molecular mechanisms of Fov4 virulence in cotton are not clearly understood. Secondary metabolites are often identified as the culprits in pathogen virulence toward plant hosts. To investigate these factors in Fov4, we analyzed the genomes of Fov1 and Fov4 using Fungal antiSMASH and identified a Fov4-specific nonribosomal peptide synthetase gene, <i>FNP1</i>. To investigate its function, we generated an <i>FNP1</i> knockout mutant using the CRISPR-Cas9 approach. Growth assays revealed that the mutant exhibited significantly attenuated hyphal production on media containing cotton roots as the sole carbon source, increased sensitivity to cell stress agents, and lagged spore germination. Furthermore, the mutant exhibited a defect in cotton root rot virulence and a significant decrease in fusaric acid production. Microscopic observation of the GFP-labeled <i>FNP1</i> deletion mutant showed impeded infection progression in cotton roots compared with the wild type. RNA-seq analysis further revealed extensive transcriptional reprogramming in the <i>FNP1</i> deletion mutant, supporting a regulatory role for <i>FNP1</i> in fusaric acid biosynthesis and broader metabolic networks. Gene complementation restored the observed defects, confirming that <i>FNP1</i> is critical for Fov4 virulence, hyphal development, fusaric acid production, and stress responses. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI01260004R"},"PeriodicalIF":3.4,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147321861","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":"The Virulence Gene <i>ToxB</i> Is Both Amplified and Disrupted by Transposons in the Wheat Pathogen <i>Pyrenophora tritici-repentis</i>.","authors":"Ryan Gourlie, Megan C McDonald, Mohamed Hafez, Reem Aboukhaddour","doi":"10.1094/MPMI-01-26-0003-R","DOIUrl":"https://doi.org/10.1094/MPMI-01-26-0003-R","url":null,"abstract":"<p><p>Mechanisms that drive virulence gene duplication in plant pathogenic fungi remain poorly understood. In <i>Pyrenophora tritici-repentis</i> (<i>Ptr</i>), responsible for tan spot of wheat, <i>ToxB</i> is a multicopy virulence gene encoding a proteinaceous necrotrophic effector. <i>ToxB</i> exhibits a virulence dosage effect, where higher copy numbers are associated with increased disease severity. In this work, we sought to resolve a 25-year old question as to what drove the proliferation of <i>ToxB</i> within <i>Ptr</i>. To investigate this, 23 long-read assemblies were generated and analyzed from a collection of globally distributed isolates with various <i>ToxB</i> copy numbers, with a specific focus on regions containing <i>ToxB</i>. Extensive comparative alignments identified a Helitron-like element, <i>ToxB-HLE</i>, that appears to be driving the duplication of <i>ToxB</i> in an accessory region of chromosome 4. This region is entirely absent in isolates lacking <i>ToxB</i> or its nonfunctional homolog <i>toxb</i>. In addition to gene amplification by transposons, multiple independent transposon insertion events were identified in several isolates that disrupted the <i>ToxB</i> open reading frame creating inactive <i>toxb</i> haplotypes. This study provides strong evidence supporting the hypothesis that transposons play dual roles in the rapid evolution of fungal pathogenicity by both amplifying and disrupting a key virulence gene in a globally distributed plant pathogen.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147639456","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":"Modes of Action and in Planta Antifungal Activity of <i>Olea europaea</i> Defensin OefDef1.1-Derived Peptide Variant.","authors":"Ruby Tiwari, S Hamsa, James Godwin, Meenakshi Tetorya, Emery Usher, Dilip Shah","doi":"10.1094/MPMI-10-25-0149-R","DOIUrl":"10.1094/MPMI-10-25-0149-R","url":null,"abstract":"<p><p>Peptide-based biopesticides represent a promising strategy for sustainable disease control in agriculture. Synthetic antifungal peptides incorporating the γ-core motif of plant defensins offer multiple modes of action (MoAs) and potential as biofungicides. We investigated a synthetic short-chain variant of the olive defensin OefDef1.1 for antifungal activity, structure-function relationships, and MoAs against <i>Botrytis cinerea</i>, a necrotrophic pathogen causing gray mold disease in fruits and vegetables. A disulfide-bridged peptide, GMAOe1C_V1*, derived from OefDef1.1 (G32-Y53) modified with hydrophobic amino acid substitutions inhibited <i>B. cinerea</i> growth <i>in vitro</i> and reduced lesion formation in detached leaves. Foliar application of GMAOe1C_V1* suppressed disease symptoms in pepper plants. Mechanistically, GMAOe1C_V1* rapidly permeabilized the fungal plasma membrane and accumulated in vacuole, triggering vacuolar expansion and cell death. It also inhibited protein synthesis <i>in vitro</i> and <i>in vivo</i>, suggesting a role as a translation inhibitor. Alanine scanning mutagenesis of the non-disulfide-bridged variant identified the ⁷RHSKH¹¹ motif as essential for antifungal activity. Circular dichroism revealed an unstructured conformation with minimal secondary structure. Transcriptomic analysis of GMAOe1C_V1*-treated <i>B. cinerea</i> showed downregulation of genes involved in mitochondrial function and amino acid biosynthesis. These findings demonstrate the potential of an olive defensin-derived peptide as a bio-inspired antifungal agent with multifaceted MoAs for crop protection. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI10250149R"},"PeriodicalIF":3.4,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147434407","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 Nuclear Effector of <i>Magnaporthe oryzae</i> Targets a Mitogen-Activated Protein Kinase to Suppress Basal Plant Defense.","authors":"Anastasios Samaras, Evagelia Daskalaki, Shridhar Jambagi, Moses Biruma, Christina Dixelius, Georgios Tzelepis","doi":"10.1094/MPMI-02-26-0019-SC","DOIUrl":"10.1094/MPMI-02-26-0019-SC","url":null,"abstract":"<p><p>The fungal pathogen <i>Magnaporthe oryzae</i> poses a major threat to the global production of cereals such as rice, wheat, and millets. Similar to other fungal pathogens, it secretes effector proteins to manipulate host immune responses, enabling successful colonization and infection. In this study, <i>M. oryzae</i> strains were collected from diseased finger millet plants and wild grasses in Uganda. A candidate effector gene-<i>Mo2928Fm</i>-was identified from a highly virulent finger millet strain and found to be strongly induced at 2 days postinoculation, suggesting a role in the early infection process. In silico analysis indicated that <i>Mo2928Fm</i> is present only in a subset of <i>M. oryzae</i> genomes and encodes a protein with two domains connected by a serine-rich linker. Confocal microscopy confirmed its nuclear localization in host cells, and gene deletion significantly reduced fungal virulence. Transient expression of <i>Mo2928Fm</i> suppressed the transcription of key plant immune response genes. Further analyses also revealed a potential interaction between Mo2928Fm and the plant mitogen-activated protein kinase 3 (MAPK3) protein. Based on these findings, we propose that the Mo2928Fm-MAPK3 complex interferes with basal plant immune signaling and promotes susceptibility to blast disease. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI02260019SC"},"PeriodicalIF":3.4,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147365875","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":"<i>Rpp2</i> Encodes a TIR-NBS-WH-LRR Protein That Confers Resistance to <i>Phakopsora pachyrhizi</i> in Soybean.","authors":"Katerina L Holan, Nicole C Thunes, Lori M Lincoln, Amy Wright, Brian Diers, Ricardo V Abdelnoor, Jamie A O'Rourke, Steven A Whitham, Kerry F Pedley, Michelle A Graham","doi":"10.1094/MPMI-02-26-0013-R","DOIUrl":"https://doi.org/10.1094/MPMI-02-26-0013-R","url":null,"abstract":"<p><p>The obligate biotrophic fungus <i>Phakopsora pachyrhizi</i> Syd. & P. Syd., the causal agent of soybean rust, is among the most formidable pathogens of soybean (<i>Glycine max</i> [L.] Merr.). The pathogen is now established in all major soybean growing areas of the world and presents a significant impediment to global soybean production. Most soybean germplasm is susceptible, enabling the fungus to penetrate and colonize the leaf tissue, causing tan-colored necrotic lesions to form at the site of infection. Severe infection reduces photosynthesis and causes premature defoliation, which ultimately decreases crop yield and seed quality. Eight genetic loci, <i>Rpp1/Rpp1b</i> to <i>Rpp7</i> and <i>Rpp6907</i>, that confer race-specific resistance to <i>P. pachyrhizi</i> (<i>Rpp</i>) have been identified. <i>Rpp2</i> was identified and characterized in the soybean accession PI 230970 and fine-mapped to a 188.1 kb interval on chromosome 16, a region predicted to contain several toll/interleukin-1 receptor nucleotide-binding leucine-rich repeat (TIR-NLR) genes. To identify <i>Rpp2</i>, we constructed a bacterial artificial chromosome (BAC) library from the resistant soybean accession PI 230970. Sequencing BACs that span the <i>Rpp2</i> locus identified fourteen candidate genes with homology to the TIR-NLR family of resistance genes with integrated winged-helix (WH) domains. Of these, seven are predicted to encode full-length R proteins. Co-silencing the <i>Rpp2</i> candidate genes compromised resistance in soybean accession PI 230970. Gene expression analysis suggests that a single gene, <i>Rpp2C7_PI</i>, which shares greatest homology to <i>Rpp2C6_Wms82</i> (Glyma.16G136600) in the Williams 82 reference genome, is responsible for <i>Rpp2</i>-mediated resistance.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147593354","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":"Lanthanide-Dependent Methanol Dehydrogenase XoxF Confers a Competitive Advantage to <i>Sinorhizobium meliloti</i> During Symbiosis with <i>Medicago sativa</i>.","authors":"Olivia N Walser, Enish Pathak, Angel I Banuelos, Silvia Rossbach","doi":"10.1094/MPMI-08-25-0110-R","DOIUrl":"10.1094/MPMI-08-25-0110-R","url":null,"abstract":"<p><p>The recent discovery of the lanthanide (Ln)-dependent methanol dehydrogenase (Ln-MDH) XoxF has expanded the spectrum of bacteria recognized for methylotrophic metabolism. Many bacteria, including rhizobia, have historically escaped being categorized as methylotrophs because they exclusively produce XoxF-type Ln-MDHs and entirely lack the long-studied calcium-dependent MDH MxaFI. We report that the XoxF-type Ln-MDH encoded by the <i>smb20173</i> gene is the sole MDH that supports methylotrophic growth of <i>Sinorhizobium meliloti</i>. The lanthanides that consistently supported growth of <i>S</i>. <i>meliloti</i> in minimal media with methanol included lanthanum, cerium, praseodymium, and neodymium. Based on genome, whole-transcriptome, and mutant phenotype analyses, we propose a metabolic model for Ln-dependent methylotrophy in <i>S</i>. <i>meliloti</i> wherein oxidation of one-carbon compounds, such as methanol, generate the reducing power needed to assimilate carbon via the Calvin-Benson-Bassham cycle. By investigating how these newfound insights into lanthanides reshape our understanding of the methylotrophic capabilities of rhizobia, we explored how methanol produced by plants has the potential to create a nutritional niche in the rhizosphere. Using a <i>Medicago sativa</i> (alfalfa) nodule occupancy assay, we found that a <i>xoxF</i> mutant strain was outcompeted by the wild-type strain only when lanthanides were available, suggesting that Ln-dependent methylotrophy promotes an efficient rhizobia-legume symbiosis. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI08250110R"},"PeriodicalIF":3.4,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146106267","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":"Comparative Transcriptome Profiling of <i>Nicotiana benthamiana</i> Plants Infected with Potato Mop-Top Virus and Its Mutant Lacking a Gene for the 8K Protein Underlines the Role of Chloroplasts During Infection.","authors":"Shweta Roy, Katalin Nemes, Ganapathi Varma Saripella, Ramesh Raju Vetukuri, Abu Bakar Siddique, Eugene I Savenkov","doi":"10.1094/MPMI-10-25-0146-R","DOIUrl":"10.1094/MPMI-10-25-0146-R","url":null,"abstract":"<p><p>Potato mop-top virus (PMTV) is a significant pathogen causing potato \"spraing\" disease worldwide. The PMTV 8K protein functions as a weak viral suppressor of RNA silencing (VSR), has viroporin activity, and plays a role in pathogenicity by promoting viral long-distance movement and modulating host responses. Uniquely, PMTV can establish systemic infection in the absence of the 8K protein, though the infection is slightly delayed. To elucidate the molecular mechanisms underlying PMTV-host interactions, we conducted comprehensive RNA-seq analysis comparing wild-type PMTV with a mutant lacking the <i>8K</i> gene (PMTV-Δ8K) in <i>Nicotiana benthamiana</i>. Our transcriptomic analysis shows that wild-type PMTV and PMTV-Δ8K elicit largely distinct transcriptional responses in the host, with more unique than shared differentially expressed genes. The analysis also revealed extensive reprogramming of metabolic pathways, stress responses, and defense mechanisms. Notably, wild-type PMTV induced more defense-related transcription factors, including 27 <i>WRKY</i> genes compared with 8 in PMTV-Δ8K infections. RNA-silencing pathway genes displayed distinct expression patterns, with <i>AGO2</i>, <i>RDR1</i>, and <i>AGO-MEL1</i> showing notably enhanced upregulation (up to 9.7-fold) in PMTV-Δ8K infections. Functional analysis identified chloroplast-associated genes <i>GNS2</i>, <i>CHUP1</i>, and <i>KIN5l</i> as host restriction factors. Virus-induced gene silencing experiments confirmed that GNS2 and CHUP1 restrict viral accumulation under both infection scenarios (wild-type PMTV and PMTV-Δ8K), and localization studies revealed that the TGB2 protein and GNS2 colocalize at chloroplast structures. These findings provide insights into PMTV pathogenesis, suggest that 8K is a multifunctional protein operating through diverse mechanisms, and advance understanding of viral suppression strategies. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI10250146R"},"PeriodicalIF":3.4,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125837","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":"The RING-Type Ubiquitin Ligase XBAT35.2 Positively Modulates Plant Immunity by Promoting FLS2 Protein Accumulation.","authors":"Yi Zhang, Chaofeng Wang, Bangjun Zhou, Pooja Verma, Sadia Hamera, Lirong Zeng","doi":"10.1094/MPMI-02-26-0015-R","DOIUrl":"10.1094/MPMI-02-26-0015-R","url":null,"abstract":"<p><p>Pattern-triggered immunity (PTI) serves as a critical frontline defense in plants, initiated by the recognition of pathogen- or microbe-associated molecular patterns by cell-surface pattern recognition receptors (PRRs). The PRR FLAGELLIN-SENSING 2 (FLS2), which perceives bacterial flagellin (flg22), is essential for plant defense against bacterial pathogens. In this study, we demonstrate that the Arabidopsis ubiquitin ligase (E3) XBAT35.2 positively regulates FLS2-mediated PTI by modulating FLS2 protein stability. XBAT35 belongs to an Arabidopsis E3 ligase family that features an ankyrin-repeat (ANK)-RING domain architecture and is highly homologous to tomato XBSL35 (<u>XB3</u> ortholog <u>5</u> in <i><u>S</u>olanum <u>l</u>ycopersicum</i>), an interactor of the tomato E2 enzyme Fni3 that has been implicated in Lys63-linked ubiquitination and plant immunity. The <i>XBAT35</i> transcript undergoes alternative splicing, giving rise to two isoforms, XBAT35.1 and XBAT35.2. Unlike XBAT34 and XBAT35.1, XBAT35.2 was shown to function in plant immunity against the bacterial pathogen <i>Pseudomonas syringae</i> pv. <i>tomato</i> strain DC3000. Overexpression of XBAT35.2 increases FLS2 protein accumulation without affecting BAK1 levels, and the <i>xbat35</i> null mutant exhibits enhanced flg22-induced FLS2 degradation. XBAT35.2 is localized to the plasma membrane (PM) and the Golgi apparatus, interacting with FLS2, BAK1, and BIK1 at the PM in vivo via its ANK domain. Treatment with flg22 strengthens XBAT35.2 interactions with FLS2 and BAK1 but reduces its association with BIK1. Notably, XBAT35.2 does not ubiquitinate FLS2 in vitro. These findings suggest that XBAT35.2 contributes to plant PTI by modulating FLS2 protein stability, presumably without directly ubiquitinating FLS2, and likely also facilitates early FLS2-mediated immune signaling. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"MPMI02260015R"},"PeriodicalIF":3.4,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147344741","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}