Molecular Plant-microbe Interactions最新文献

{"title":"Suppression of a Transketolase Mutation Leads to Only Partial Restoration of Symbiosis in <i>Sinorhizobium meliloti</i>.","authors":"Sabhjeet Kaur, Justin P Hawkins, Ivan J Oresnik","doi":"10.1094/MPMI-02-25-0017-R","DOIUrl":"10.1094/MPMI-02-25-0017-R","url":null,"abstract":"<p><p>The interaction between <i>Sinorhizobium meliloti</i> and alfalfa is a well-studied model system for symbiotic establishment between rhizobia and legume plants. Proper utilization of carbon sources has been linked with effective symbiotic establishment in <i>S. meliloti</i> strain Rm1021. Previous work has shown that mutation of the gene <i>tktA</i>, which encodes a transketolase involved in the pentose phosphate pathway, resulted in a strain impaired in many biological functions, including the ability to establish symbiosis with alfalfa. Work with this strain revealed the appearance of suppressor mutations that could partially revert the symbiotic phenotype associated with a <i>tktA</i> mutation. Characterization of these suppressor strains showed that carbon phenotypes associated with a mutation in <i>tktA</i> were no longer present and that the production of succinoglycan was partially restored. Central carbon metabolite pools were observed to be different compared with the wild-type and <i>tktA</i> mutant strains. Multiple independent mutations were identified in the gene <i>SMc02340</i>, a Gnt-type negative regulator, upon sequencing. RT-PCR suggested that <i>SMc02340</i> acts as a negative regulator on an operon containing the gene <i>tktB</i>, which becomes upregulated when the suppressor mutation is present or <i>SMc02340</i> is removed. Microscopic analysis revealed a unique symbiotic phenotype. The <i>tktA</i> mutant strain induced root hair curling but could not colonize the apoplastic space. Collectively, the data suggest that the upregulation of <i>tktB</i> can partially bypass some blocks associated with a lesion in <i>tktA</i>, including the colonization of the curled root hair, but cannot fully compensate for the loss of <i>tktA</i>. [Formula: see text] Copyright © 2025 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":"505-517"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586344","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":"Differential Effects of Local dsRNA Application on Systemic Beet Mosaic Virus Resistance in <i>Nicotiana benthamiana</i> and <i>Beta vulgaris</i>.","authors":"Dennis Rahenbrock, Marieke Bode, Mark Varrelmann","doi":"10.1094/MPMI-01-25-0009-R","DOIUrl":"10.1094/MPMI-01-25-0009-R","url":null,"abstract":"<p><p>Beet mosaic virus (BtMV) is one of several viruses infecting sugar beets and was previously managed by controlling the vector <i>Myzus persicae</i> with neonicotinoid seed treatment. Following the ban of this measure in 2019 in Europe, alternative control strategies needed to be researched. One alternative might be the use of RNA interference as a major antiviral defense system. Here, we report the selection of target regions using small RNA high-throughput sequencing of BtMV-infected <i>Beta vulgaris</i> subsp. <i>vulgaris</i> and <i>Nicotiana benthamiana</i> plants, the production of double-stranded RNA (dsRNA), and the effective use of dsRNA in inducing resistance against the mechanically inoculated virus under greenhouse conditions. In <i>Escherichia coli</i> HT115, the dsRNAs produced for BtMV P1 and nuclear inclusion body b (NIb) induced a high level of resistance when sprayed before mechanical BtMV inoculation, resulting in an 80% reduction of symptomatic <i>B. vulgaris</i> and <i>N. benthamiana</i> plants. Stem-loop RT-qPCR showed the systemic distribution of dsRNA-derived small interfering RNA molecules, but the applied dsRNA remained at the site of application and did not spread within the plant. However, when the virus was inoculated on the next upward leaf to the dsRNA application site, no protective effect was observed. Despite this limitation, the results demonstrate the potential of dsRNA as an effective tool for viral protection in sugar beets, thereby establishing a basis for future developments in systemic delivery and broader field applications. [Formula: see text] Copyright © 2025 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":"518-528"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795710","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":"CRISPR/Cas9-Mediated Disruption of <i>CsLIEXP1</i> Reveals Expansin as a Key Susceptibility Factor for Citrus Canker Disease.","authors":"Reinaldo Rodrigues de Souza-Neto, Lídia Nascimento Cavalcante, Isis Gabriela Barbosa Carvalho, Maiara Curtolo, Celso Eduardo Benedetti, Marco Aurélio Takita, Nian Wang, Alessandra Alves de Souza","doi":"10.1094/MPMI-12-24-0151-R","DOIUrl":"10.1094/MPMI-12-24-0151-R","url":null,"abstract":"<p><p>The <i>Citrus sinensis LATERAL ORGAN BOUNDERIES 1</i> (<i>CsLOB1</i>) gene, which is directly induced by the <i>Xanthomonas citri</i> subsp. <i>citri</i> effector PthA4, functions as a transcription factor and citrus canker susceptibility (S) gene. Genome editing of <i>CsLOB1</i> has been shown to confer resistance to citrus canker disease. Previous studies revealed that the citrus <i>CsLOB1-INDUCED EXPANSIN 1</i> gene (<i>CsLIEXP1</i>) is highly and directly upregulated by <i>CsLOB1</i> in <i>Xanthomonas citri</i> subsp. <i>citri</i>-infected plants. Because expansins are associated with cell wall loosening, potentially facilitating bacterial colonization, the <i>CsLOB1-</i>dependent activation of <i>CsLIEXP1</i> is thought to contribute to canker symptoms and disease progression. Thus, <i>CsLIEXP1</i> likely represents a critical canker susceptibility gene. In this study, we employed CRISPR/Cas9 to disrupt the function of <i>CsLIEXP1</i> by modifying its corresponding coding region in <i>Citrus sinensis</i> cultivar 'Hamlin' and evaluated the postinfection responses of edited plants. DNA sequencing confirmed the edition of the <i>CsLIEXP1</i>-edited plant, which exhibited 26.47% of <i>CsLIEXP1</i> edited sequences. Furthermore, <i>CsLIEXP1</i> protein accumulation was reduced in <i>CsLIEXP1</i>-edited plants compared with the wild type when infected with <i>X. citri</i>. Leaves of edited plants inoculated with <i>X. citri</i> showed significantly fewer canker symptoms, with lesions limited to the site of bacterial inoculation and less pronounced cellular hypertrophy compared with control plants. Our results show that <i>CsLIEXP1</i> is a citrus canker S gene that acts downstream of <i>CsLOB1</i>, thus providing new insights into plant-pathogen interactions. [Formula: see text] Copyright © 2025 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":"589-598"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772410","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":"Pleiotropic Phenotypes of the Tomato <i>diageotropica</i> Mutant Enable Resistance to <i>Ralstonia solanacearum</i>.","authors":"Katherine Rivera-Zuluaga, Pratibha Choudhary, Sana Mohammad, Denise Caldwell, Rebecca Leuschen-Kohl, Pete E Pascuzzi, Anjali Iyer-Pascuzzi","doi":"10.1094/MPMI-10-24-0123-R","DOIUrl":"10.1094/MPMI-10-24-0123-R","url":null,"abstract":"<p><p>Quantitative disease resistance (QDR) is the most common form of disease resistance in crops, but it is challenging to understand at the cellular level due to the involvement of many genes and biological processes. <i>Ralstonia solanacearum</i>, the causal agent of bacterial wilt disease, is a destructive plant pathogen of Solanaceous species that is best controlled by quantitatively resistant varieties, but few QDR genes are known. We previously found that a tomato auxin pathway mutant known as <i>diageotropica</i> (<i>dgt</i>) has enhanced resistance to <i>R. solanacearum</i>. Here, we show that, as with wild-type quantitatively resistant tomato plants, resistance in <i>dgt</i> is the result of multiple mechanisms. Mock-inoculated <i>dgt</i> roots have endogenously higher levels of the plant defense hormone salicylic acid (SA). However, the SA-deficient double mutant <i>dgtNahG</i> is still resistant to <i>R. solanacearum</i>, indicating that SA-independent pathways are also required for resistance. Scanning electron microscopy revealed that <i>R. solanacearum</i> colonization of the root xylem is delayed in <i>dgt</i>. We found an increased number of lignified xylem cells and altered root vasculature anatomy in <i>dgt</i>, and <i>dgt</i> root length was not impacted by <i>R. solanacearum</i> treatment. Similar to the wilt-resistant wild-type tomato Hawaii7996, RNA sequencing results suggested that <i>dgt</i> may tolerate <i>R. solanacearum</i>-induced water stress better than the wilt-susceptible parent. Thus, resistance in <i>dgt</i> is due to several pathways, including preactivated SA defenses, physical barriers in the xylem, and an ability to tolerate water stress. The pleiotropic nature of this single mutation appears to mimic quantitative resistance. [Formula: see text] Copyright © 2025 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":"566-578"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144019093","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 Soilborne Fungus <i>Verticillium longisporum</i> and Its Interactions with the Brassicaceous Hosts.","authors":"Vahideh Rafiei, Christina Dixelius, Georgios Tzelepis","doi":"10.1094/MPMI-03-25-0029-IRW","DOIUrl":"10.1094/MPMI-03-25-0029-IRW","url":null,"abstract":"<p><p><i>Verticillium longisporum</i>, a soilborne fungal species, is the causative agent of Verticillium stripe disease in <i>Brassica</i> species and represents a notable threat to agricultural production, particularly in regions where oilseed rape is a major crop, including Europe, North America, and Asia. The microsclerotia of this pathogen can persist in the soil for extended periods, with a potential lifespan of up to a decade, thereby posing a substantial challenge for the complete eradication of the pathogen from infested soil. The genome of <i>V. longisporum</i> is amphidiploid and resulted from the hybridization of <i>V. dahliae</i> (D genotypes) and an unidentified species (A1 genotype). At least three independent hybridization events are estimated to have occurred, resulting in three distinct lineages: A1/D1, A1/D2, and A1/D3. Genome sequence analysis revealed the presence of mating-type idiomorphs, putative cell wall-degrading enzymes, and effectors. However, due to the complexity of the genome, there is a paucity of research on the molecular interactions between <i>V. longisporum</i> and <i>Brassica</i> crops. This review summarizes the extant knowledge regarding the pathogenicity factors that <i>V. longisporum</i> deploys upon infection and the host immune responses against this attack, highlighting aspects that remain to be elucidated and the molecular tools available for studying this interaction. A better understanding of the molecular interactions in this pathosystem will contribute to developing more effective control measures against this disease in <i>Brassica</i> oilseed and cabbage crops. [Formula: see text] Copyright © 2025 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":"497-504"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143990769","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":"Exploration of the Interactions Between <i>Xanthomonas citri</i> subsp. <i>citri-Agrobacterium-</i>Citrus to Improve <i>Agrobacterium-</i>Mediated Transient Expression in Plants.","authors":"Tirtha Lamichhane, Hang Su, Xiaoen Huang, Nian Wang","doi":"10.1094/MPMI-12-24-0164-R","DOIUrl":"10.1094/MPMI-12-24-0164-R","url":null,"abstract":"<p><p><i>Agrobacterium-</i>mediated transient expression (AMTE) is an important tool in plant genetics studies and biotechnology. AMTE remains problematic in citrus and many plant species. Previous research has shown that pretreatment of citrus leaves with <i>Xanthomonas citri</i> subsp. <i>citri</i> (<i>Xcc</i>), which causes citrus canker, significantly improves the AMTE efficacy. Here, we have shown that <i>Xcc</i> promotes AMTE mainly through triggering cell division and upregulating plant cell wall-degrading enzymes. We demonstrate that <i>Xcc</i> improves AMTE via PthA, a transcription activator-like effector known to trigger cell division in citrus, and mutation of <i>pthA4</i> abolished the promoting effect of <i>Xcc.</i> Mutation of the effector (PthA4)-binding element in the promoter region and coding region of <i>CsLOB1</i>, which is known to be directly activated by PthA4, significantly reduced <i>Xcc</i> promotion of AMTE. Mutation of <i>PthA4</i> significantly reduced the expression of cell division-related genes (<i>CDKA</i>, <i>CDKB1-2</i>, and <i>CDKB2-2</i>) compared with wild-type <i>Xcc</i> and the complemented strain. Cell division inhibitor mimosine but not colchicine also significantly decreased <i>Xcc</i> promotion of AMTE. In addition, PthA4 is known to upregulate plant growth hormones auxin (indole-3-acetic acid), gibberellin, and cytokinin, as well as cell wall-degrading enzymes (e.g., cellulase). Exogenous application of indole-3-acetic acid, cytokinin, and cellulase but not gibberellin significantly improved AMTE in leaves of sweet orange, pummelo, Meiwa kumquat, lucky bamboo, and rose mallow. Our study provides a mechanistic understanding of how <i>Xcc</i> promotes AMTE and develops practical measures to improve AMTE via pretreatment with plant hormones (i.e., auxin and cytokinin) and cellulase. [Formula: see text] Copyright © 2025 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":"479-488"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071010","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":"By Hijacking a Host Chaperone, the Bacterial Effector XopAE Disarms Cassava Immunity.","authors":"Meenu Singla-Rastogi","doi":"10.1094/MPMI-06-25-0070-CM","DOIUrl":"https://doi.org/10.1094/MPMI-06-25-0070-CM","url":null,"abstract":"","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":"38 3","pages":"354-355"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529011","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":"Biocontrol of Bacterial Wilt Disease Using Plant-Associated Bacterial Communities in Tomato.","authors":"Eriko Tanaka, Daisuke Umeki, Shota Kido, Rikako Makishima, Yuko Tamaki, Takumi Murakami, Masayuki Fujiwara, Yusuke Saijo","doi":"10.1094/MPMI-09-24-0114-R","DOIUrl":"10.1094/MPMI-09-24-0114-R","url":null,"abstract":"<p><p>Host-protective or disease-suppressive microorganisms are emerging as sustainable solutions for controlling crop diseases, such as bacterial wilt. However, the efficacy of biocontrol strategies is often constrained by limited resilience under varying environmental conditions and interactions with native microbial communities in the field. One major challenge is that introduced biocontrol microbes often face suppression by indigenous microbes due to competitive interactions. Synthetic communities (SynComs) offer a promising alternative strategy. However, conventional approaches to assembling SynComs by combining different microbial isolates often result in antagonism and competition among strains, leading to ineffective and inconsistent outcomes. In this study, we assembled a bacterial wilt-suppressive SynCom for tomato, composed of bacterial isolates derived from co-cultured microbial complexes associated with healthy plants. This SynCom demonstrates significant disease-suppressive effects against <i>Ralstonia pseudosolanacearum</i> in tomato seedlings under both axenic and soil conditions. Additionally, our findings suggest the presence of an optimal SynCom colonization level in plants, which is crucial for effective disease suppression. The SynCom also exhibits direct antibiotic activity and modulates the plant-associated microbiome. Our results provide an effective approach to constructing SynComs with consistent and effective disease-suppressive properties within microbial community contexts. [Formula: see text] Copyright © 2025 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":"411-426"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008293","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":"Distinct Virulence Mechanisms of <i>Burkholderia gladioli</i> in Onion Foliar and Bulb Scale Tissues.","authors":"Sujan Paudel, Yaritza Franco, Mei Zhao, Bhabesh Dutta, Brian H Kvitko","doi":"10.1094/MPMI-10-24-0129-R","DOIUrl":"10.1094/MPMI-10-24-0129-R","url":null,"abstract":"<p><p>Slippery skin of onion caused by <i>Burkholderia gladioli</i> pv. <i>alliicola</i> (Bga) is a common bacterial disease reported from onion-growing regions around the world. Despite the increasing attention in recent years, our understanding of the virulence mechanisms of this pathogen remains limited. In this study, we characterized the predicted genetic determinants of virulence in Bga strain 20GA0385 using a reverse genetics approach. Using the closely related rice pathogen <i>B. glumae</i> as a reference, comparative genomics analysis was performed to identify Bga candidate virulence factors and regulators. Marked and unmarked deletion mutants were generated using allelic exchange, and the mutants were functionally validated using in vitro and in vivo assays. The role of mutants in pathogenic phenotypes was analyzed using onion foliar/seedling necrosis assays, the red scale necrosis assay, and in planta bacterial population counts. The phytotoxin toxoflavin was a major contributor to foliar necrosis and bacterial populations, whereas the type II and type III secretion systems (T2SS/T3SS) were dispensable for foliar symptoms. In onion scale tissue, the T2SS single mutant <i>gspC</i> and its double and triple mutant derivatives all contributed to scale lesion area. Neither the lipocyclopeptide icosalide, toxoflavin, nor T3SS was required for scale symptoms. Our results suggest that the quorum sensing <i>tofIMR</i> system in Bga regulates toxoflavin, T2SS, and T3SS, contributing to onion symptom production. We show that different virulence factors contribute to onion tissue-specific virulence patterns in Bga and that decreases in scale symptoms often do not result in decreased Bga populations in onion tissue. [Formula: see text] Copyright © 2025 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":"427-439"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142951973","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":"Intraspecific Variation and Recent Loss of Ancient, Conserved Effector Genes in the Sudden Oak Death Pathogen <i>Phytophthora ramorum</i>.","authors":"Nicholas C Cauldron, Caroline M Press, Alexandra J Weisberg, Marília Horta Jung, Tamara Corcobado, Joan F Webber, Koji Kageyama, Ayaka Hieno, Hayato Masuya, Seiji Uematsu, Bruno Scanu, Clive M Brasier, Thomas Jung, Jeff H Chang, Niklaus J Grünwald","doi":"10.1094/MPMI-10-24-0131-R","DOIUrl":"10.1094/MPMI-10-24-0131-R","url":null,"abstract":"<p><p>Members of the <i>Phytophthora</i> genus are responsible for many important diseases in agricultural and natural ecosystems. <i>Phytophthora ramorum</i> causes devastating diseases of oak and tanoak stands in U.S. forests and larch in the United Kingdom. The four evolutionary lineages involved express different virulence phenotypes on plant hosts, and characterization of gene content is foundational to understanding the basis for these differences. Recent discovery of <i>P. ramorum</i> at its candidate center of origin in Asia provides a new opportunity for investigating the evolutionary history of the species. We assembled high-quality genome sequences of six <i>P. ramorum</i> isolates representing three lineages from Asia and three causing epidemics in Western U.S. forests. The six genomes were assembled into 13 putative chromosomes. Analysis of structural variation revealed multiple chromosome fusion and fission events. Analysis of putative virulence genes revealed variations in effector gene composition among the sequenced lineages. We further characterized their evolutionary history and inferred a contraction of crinkler-encoding genes in the subclade of <i>Phytophthora</i> containing <i>P. ramorum</i>. There were losses of multiple families and a near complete loss of paralogs in the largest core crinkler family in the ancestor of <i>P. ramorum</i> and sister species <i>P. lateralis</i>. Secreted glycoside hydrolase enzymes showed a similar degree of variation in abundance among genomes of <i>P. ramorum</i> lineages as that observed among several <i>Phytophthora</i> species. We found plasticity among genomes from multiple lineages in a <i>Phytophthora</i> species and provide insights into the evolutionary history of a class of anciently conserved effector genes. [Formula: see text] Copyright © 2025 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":"440-453"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143052758","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}