Phytopathology最新文献

{"title":"Effects and Mechanisms of Sodium Nitroprusside, Spermidine, and Coumarin Addition In Vitro on <i>Epichloë sinensis</i>.","authors":"Yang Luo, Pei Tian","doi":"10.1094/PHYTO-09-25-0312-R","DOIUrl":"https://doi.org/10.1094/PHYTO-09-25-0312-R","url":null,"abstract":"<p><p><i>Epichloë sinensis</i> forms mutualistic symbiosis with the Chinese native grass <i>Festuca sinensis</i>. However, the mechanisms by which <i>E. sinensis</i> responds to host-derived defense signals remain unclear. To explore these responses, three compounds, sodium nitroprusside, spermidine, and coumarin, were added to a potato dextrose broth (PDB) medium to mimic host defense-related signals. Their effects on the growth, antioxidant capacity, and gene expression of three <i>E. sinensis</i> strains (1, 2, and 84F) isolated from different ecotypes of <i>F. sinensis</i> were identified. The results showed that in PDB, certain concentrations of sodium nitroprusside, spermidine, and coumarin treatments significantly promoted the growth of the three <i>E. sinensis</i> strains (<i>P</i> < 0.05) and significantly increased the total antioxidant capacity, superoxide anion scavenging ability, and hydroxyl radical scavenging ability of culture filtrate (<i>P</i> < 0.05). Most of the sodium nitroprusside and spermidine treatments significantly increased the nitric oxide (NO) concentration in the mycelia of these three <i>E. sinensis</i> strains (<i>P</i> < 0.05), except for the 1.0 mM spermidine treatment, which significantly reduced the NO concentration of strain 84F (<i>P</i> < 0.05). Three coumarin treatments significantly increased the NO concentration in the mycelia of strain 2 (<i>P</i> < 0.05) but significantly reduced the NO concentration of strain 84F (<i>P</i> < 0.05), and 0.68 mM coumarin treatment significantly reduced the NO concentration of strain 1 (<i>P</i> < 0.05). Structural equation modeling supported the hypothesis that exogenous additives affect mycelial biomass through the superoxide anion radical scavenging ability and provided moderate support for additives affecting growth through hydroxyl radical scavenging ability. These three compounds also affected the gene expression of <i>E. sinensis</i> strain 84F, with 135 differentially expressed genes (DEGs) detected in all of the comparisons. Functional annotation revealed that these DEGs were significantly enriched in \"amino sugar and nucleotide sugar metabolism,\" \"biosynthesis of antibiotics,\" \"biosynthesis of amino acids,\" \"sulfur metabolism,\" and \"cellular iron ion homeostasis.\" In addition, these three compounds regulated the expression of 59 antioxidant-related genes and 31 NO synthesis-related genes of <i>E. sinensis</i>. These results suggest that <i>E. sinensis</i> is sensitive to host defense-related signals and can adjust its antioxidant capacity and key metabolic pathways in response, reflecting its physiological adaptability under in vitro conditions.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO09250312R"},"PeriodicalIF":3.1,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147842048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aggressiveness of Subspecies and Sequence Types of <i>Xylella fastidiosa</i> and Plant Response in <i>Nicotiana benthamiana</i>.","authors":"Aniol Buisac, Beatriz Gascón, Emilio Montesinos, Laura Montesinos","doi":"10.1094/PHYTO-11-25-0366-R","DOIUrl":"10.1094/PHYTO-11-25-0366-R","url":null,"abstract":"<p><p>The aggressiveness of 17 <i>Xylella fastidiosa</i> strains, representing different subspecies and sequence types (STs), was studied in the surrogated host <i>Nicotiana benthamiana</i> by analysis of the population levels and symptom dynamics, dose-effect relationships, and transcriptomic response of the plant. Colonization of all strains was observed after 7 days postinoculation (dpi), and the first symptoms appeared after 14 dpi. Differences in patterns of population dynamics and symptom development were observed between strains, and there was neither a relationship between population growth and symptom severity nor between strains of the same subspecies and STs. Strains IVIA 5387, DeDonno, CN28, and GP18 showed a typical S-shaped dose-effect curve, and the minimum infective dose in <i>N. benthamiana</i> was established at 300 CFU/plant for all strains. The plant response to infection by subsp. <i>pauca</i> ST53 strains DeDonno, CN28, and GP18 was studied in relation to the expression of defense genes. A strain-dependent modulation depending on time was observed, in which CN28 infection showed the highest gene overexpression (12 of 19 genes) and DeDonno the lowest (8 of 19 genes). At 4 dpi, all strains upregulated the genes <i>PR1</i>, <i>PR1a</i>, and <i>ERF1</i> and downregulated the <i>PDF1.2</i> gene, whereas at 30 dpi, most of the genes were downregulated, especially the pathogenesis-related genes, suggesting an immune evasion by the pathogen. Our findings are expected to provide valuable insights into the interaction between <i>X. fastidiosa</i> and its hosts, highlighting the importance of considering differences in aggressiveness among strains and in plant response.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO11250366R"},"PeriodicalIF":3.1,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146150407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic Enhancement of Soybean Resistance to Cyst Nematodes via Chemical Modulation of Salicylic Acid-Gibberellic Acid Crosstalk.","authors":"Esmaeil Miraeiz, Megha Rai, Andrew Bent, Matthew E Hudson","doi":"10.1094/PHYTO-10-25-0344-R","DOIUrl":"10.1094/PHYTO-10-25-0344-R","url":null,"abstract":"<p><p>Soybean cyst nematode (SCN, <i>Heterodera glycines</i>) causes major yield losses, and <i>Rhg1</i> locus-mediated genetic resistance is becoming less effective. Hormonal signaling pathways, particularly salicylic acid (SA) and gibberellic acid (GA), are increasingly implicated in nematode resistance, but their use in plant protection remains underexplored. Here, we tested exogenous application of chemical modulators of these pathways for effects on SCN resistance and dependence on the presence or absence of <i>Rhg1-b</i>.<i> </i>We found that foliar application of the SA mimic acibenzolar-S-methyl (ASM) or the systemic acquired resistance mediator pipecolic acid (Pip) conferred strong, genotype-independent resistance, comparable to genetic resistance at <i>Rhg1</i>. Combining ASM with the GA biosynthesis inhibitor paclobutrazol (PBZ) synergistically enhanced protection, reducing cyst formation by 39.2% and effectively making plants moderately resistant to SCN. These effects were observed in the susceptible cultivar Williams 82, as well as across near-isogenic lines with varying <i>Rhg1</i> copy numbers. ASM alone boosted resistance in resistant <i>Rhg1-b</i> and susceptible <i>Rhg1-c</i> backgrounds, whereas PBZ provided additional benefits only in <i>Rhg1-c</i>, revealing genotype-specific interactions between hormonal signaling and host resistance. Targeted modulation of SA and GA pathways thus provides an effective and sustainable strategy to suppress SCN, complementing and extending the durability of genetic resistance. [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":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO10250344R"},"PeriodicalIF":3.1,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147309371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing the Origin of <i>Xylella fastidiosa</i> subspecies <i>pauca</i> ST53 Strains in France.","authors":"Amandine Cunty, Anne-Laure Boutigny, Bruno Legendre, Valérie Olivier, Déborah Merda","doi":"10.1094/PHYTO-04-25-0124-R","DOIUrl":"10.1094/PHYTO-04-25-0124-R","url":null,"abstract":"<p><p><i>Xylella fastidiosa</i> is a plant-pathogenic bacterium native to the Americas. It has a wide host range and causes significant diseases in economically important crops, including grapevines, citrus, and olive trees. Since 2013, this bacterium has been detected in Europe and other countries of the Mediterranean basin, leading to the identification of several subspecies (<i>multiplex</i>, <i>fastidiosa</i>, and <i>pauca</i>) and sequence types (STs) in various plant species in Italy, France, the Balearic Islands and mainland Spain, Portugal, Israel, and Lebanon. This study focuses on genomic analyses of the subspecies <i>pauca</i> ST53 strains detected in France. ST53 was identified (i) on intercepted coffee plants in the Pays-de-la-Loire region in 2014 and 2015 and (ii) on two infected host plants collected in Menton in the Provence-Alpes-Côte d'Azur region in 2015 and 2019. As an efficient and promising alternative to cell culture, the targeted enrichment method developed specifically to capture <i>X. fastidiosa</i> gDNA was applied to obtain the whole genome. Phylogenetic and genomic comparisons were carried out to compare the ST53 genomic sequences of the samples from France with a range of <i>X. fastidiosa</i> subspecies <i>pauca</i> genomic sequences from public databases, including ST53 from Italy and Costa Rica. The results obtained from these different approaches revealed close genetic relatedness between the strains. A tip-dating analysis and transmission tree were performed, supporting the hypothesis that some ST53 strains from France may be related to the same introduction event as the Italian strains.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO04250124R"},"PeriodicalIF":3.1,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146100529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the Dynamics of <i>Pantoea ananatis</i>: Isolation and Plant Responses.","authors":"Samuel de Paula, Scott Belmar, Mitchell Giebler, Ana Carla Ferreira, Bruna Ronning, Yulin Jia, Rodrigo Pedrozo, Jan E Leach, Emily Luna, Camila Nicolli","doi":"10.1094/PHYTO-12-25-0394-SA","DOIUrl":"10.1094/PHYTO-12-25-0394-SA","url":null,"abstract":"<p><p><i>Pantoea ananatis</i> was first reported infecting rice in the United States in 2021, causing leaf blight in research plots in Arkansas. In 2024, two breeding lines exhibited leaf blight symptoms in research plots at the Rice Research and Extension Center, Stuttgart, AR. This study aimed to recover new <i>P. ananatis</i> isolates and characterize their pathogenicity in rice, as well as their ability to induce plant responses in rice, tobacco, and onion. Isolates were obtained from seeds of symptomatic plants using a <i>Pantoea</i> genus-specific agar protocol and confirmed by PCR and sequencing of 16S rRNA and <i>gyrB</i> genes. <i>P. ananatis</i> isolates were infiltrated into tobacco and rice plants and inoculated in onion to determine their ability to elicit hypersensitive or necrotic responses. Notably, isolate PP105 consistently triggered a necrotic response in rice, tobacco, and onion, suggesting distinct pathogenicity mechanisms compared with the other isolates. Overall, this study enhanced the understanding of <i>P. ananatis</i> characterization in rice and alternative model hosts while highlighting challenges and raising new questions for future research.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO12250394SA"},"PeriodicalIF":3.1,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146100592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host Specificity Among Three Downy Mildew Pathogens (<i>Hyaloperonospora</i> spp.) in Brassicaceae Species in Central Coastal California.","authors":"Kallol Das, Emily M Locke-Paddon, Reilly Blair, Kyle G Brasier, Charlie Dowling, Shunping Ding","doi":"10.1094/PHYTO-06-25-0226-R","DOIUrl":"10.1094/PHYTO-06-25-0226-R","url":null,"abstract":"<p><p>Oomycetes in the genus <i>Hyaloperonospora</i> cause severe downy mildew that threatens the quality and yield of leafy vegetables in the Brassicaceae family. During 2022 and 2023, infected plant samples were collected from multiple fields across California's Central Coast, and a total of 26 downy mildew pathogen isolates were obtained. Morphological characteristics and molecular analyses based on internal transcribed spacer rDNA and <i>cox</i>2 mtDNA gene sequences identified the isolates as <i>Hyaloperonospora brassicae</i>, <i>H. diplotaxidis</i>, and <i>H. erucae</i>. To further evaluate the host specificity of these pathogens, one representative isolate from each species was selected and inoculated onto a group of commonly grown Brassicaceae crops. <i>H. brassicae</i>, originally isolated from <i>Brassica oleracea</i>, caused 45.8% disease severity in <i>B. oleracea</i>, whereas disease severity was significantly lower on wild arugula (<i>Diplotaxis tenuifolia</i>, 1.5%) and cultivated arugula (<i>Eruca vesicaria</i>, 0.0%). Similarly, <i>H. diplotaxidis</i>, originally isolated from wild arugula, caused 26.3% disease severity in wild arugula, compared with 2.0% on cultivated arugula and 0.3% in <i>B. oleracea</i>. <i>H. erucae</i>, derived from cultivated arugula, caused 10.4% disease severity on cultivated arugula, 1.4% on wild arugula, and only 0.6% on <i>B. oleracea</i>. This study underscores the host specificity of downy mildew pathogens while also suggesting a potential risk of cross-infection under favorable conditions. These findings may help growers optimize their cropping systems to enhance downy mildew management in the field.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"707-718"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145763689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Metabolomic and Transcriptomic Analysis Reveals the Mechanism of Dappled Fruit Formation in Hop Stunt Viroid-Infected Sweet Cherry.","authors":"Li Xu, Yue Tan, Peiyuan Zeng, Xiaojuan Zong, Hairong Wei","doi":"10.1094/PHYTO-07-25-0249-R","DOIUrl":"10.1094/PHYTO-07-25-0249-R","url":null,"abstract":"<p><p>Sweet cherry (<i>Prunus avium</i>) is a commercially vital fruit crop in China. Hop stunt viroid (HSVd) infection in sweet cherry causes dappled fruit. This study investigated the mechanism of dappled fruit formation in HSVd-infected sweet cherry using integrated metabolomics and transcriptomics. Dappled and non-dappled peel tissues were sampled at the color change and ripening stages. Ultra-performance liquid chromatography-tandem mass spectrometry identified 181 flavonoid metabolites, with peonidin-3-O-rutinoside, cyanidin-3-O-glucoside, peonidin-3-O-glucoside, cyanidin-3-O-arabinoside, cyanidin 3-xyloside, and cinchonain Ic being significantly enriched in dappled areas. RNA-seq revealed 3,287 differentially expressed genes, with <i>PaCHS</i>, <i>PaCHI</i>, <i>PaDFR</i>, and <i>PaANS</i> upregulated in dappled areas at the early stage, correlating with anthocyanin accumulation. KEGG enrichment highlighted anthocyanin and flavonoid biosynthesis pathways as central to pigmentation. This study suggests that HSVd disrupts anthocyanin biosynthesis to induce dappled pigmentation, offering novel insights into viroid-host interactions affecting fruit color in sweet cherry.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO07250249R"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145918288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Planta Transcriptomics of <i>Xanthomonas albilineans</i> Reveals Early Adaptations to the Nutrient-Limited Xylem Environment of Sugarcane.","authors":"Marcelo Marques Zerillo, Henrique Moura Dias, Juliane K Ishida, Dora T Bonadio, Paula Cristina Gasparezzo Turrini, Andressa Peres Bini, Raquel Paulini Miranda, Claudia Barros Monteiro-Vitorello, Luis Eduardo Aranha Camargo, Silvana Creste, Marie-Anne Van Sluys","doi":"10.1094/PHYTO-06-25-0201-R","DOIUrl":"10.1094/PHYTO-06-25-0201-R","url":null,"abstract":"<p><p><i>Xanthomonas albilineans</i> causes leaf scald disease in sugarcane, leading to white streaks on leaves, stunted growth, and potentially plant death. With the smallest genome in the genus, its compact size likely reflects adaptation to a specialized lifestyle. Here, we present the first in planta transcriptome of <i>X. albilineans</i>, obtained 48 h postinoculation using dual RNA-seq-a technically demanding approach due to minimal bacterial load relative to host material. Despite only 0.05% of the more than 40 billion sequenced bases corresponding to the bacterial cells, we successfully recovered and analyzed its gene expression. Compared with the transcriptome in vitro, we found that during early infection, the bacteria targets sugarcane-specific cell wall components, facilitating tissue invasion. Notably, transcriptomic data suggest that <i>X. albilineans</i> may utilize a distinct metabolic route for the catabolism of lignin-derived compounds, funneling aromatic intermediates into central metabolism through the protocatechuate pathway. This may represent an adaptation to plant-derived aromatic substrates not previously described in other <i>Xanthomonas</i> species. The upregulation of chemotaxis and motility genes indicates active systemic colonization, and phosphorelay systems enhance environmental adaptation. Bacterial fitness is also supported by production of albicidin and upregulation of type IV secretion system (T4SS) and some T5SS genes, whereas T3SS SPI-1 is inactive during early infection. These findings underscore the bacterium's reliance on specific metabolic genes to degrade sugarcane's recalcitrant wall, thrive in the xylem, and migrate to other tissues. Understanding its genomic arsenal and gene expression in sugarcane provides valuable insights for managing leaf scald disease and mitigating impact on production.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"672-683"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145794573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First Record of <i>Pantoea conspicua</i> Bacteria Isolated from <i>Hypera brunneipennis</i> and Its Ability for Biocontrol of Root-Knot Nematodes in Tomato Plants.","authors":"Rehab Y Ghareeb, Eman El-Argawy, Amal A Mohamed, Alshimaa Saber Abd-Elmegeed, Mahmoud H Ghozlan","doi":"10.1094/PHYTO-12-25-0382-SA","DOIUrl":"10.1094/PHYTO-12-25-0382-SA","url":null,"abstract":"<p><p>Root-knot nematodes (<i>Meloidogyne</i> spp.) are among the most destructive agricultural obligate endoparasites worldwide, causing substantial yield losses across numerous crops. Current management options are limited, and the overuse of chemical nematicides poses serious risks to human health and the environment. In this study, a bacterial isolate was investigated as a biocontrol agent against <i>Meloidogyne incognita,</i> identified as <i>Pantoea conspicua</i> strain PC (GeneBank accession ON203125) based on 16S rRNA (ribosomal RNA) gene sequencing. Exposure of second-stage juveniles (J2s) caused mortality rates of 67.9, 94.7, 97.7, and 99.3% in <i>M. incognita</i> at 12, 24, 48, and 96 h after exposure to a 100% concentration of bacterial filtrate, respectively. In comparison, bacterial pellets resulted in 18.5, 51.8, 62.9, and 82.9% mortality at the same time intervals. Both the bacterial filtrate and pellets significantly inhibited egg hatchability in vitro. A greenhouse experiment demonstrated that tomato plants treated with the bacterial filtrate or pellets exhibited marked improvements in root and shoot growth parameters. Specifically, the bacterial filtrate reduced the number of galls, eggs, and egg masses per gram of root by 93.12, 97.9, and 79.9%, respectively, along with a 92.7% decrease in J2s per 250 g of soil. Overall, <i>P. conspicua</i> strain PC demonstrated high potential as a biocontrol agent, offering advantages in its mode of action, efficacy, and contribution to ongoing nematode management while also reducing the environmental impact and supporting integrated pest management strategies.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"PHYTO12250382SA"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146132771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The <i>SGE1</i> Homolog of <i>Fusarium oxysporum</i> f. sp. <i>rapae</i> Is a Pathogenicity Factor and Required for Full Stress Resistance of Chlamydospores.","authors":"Cheng-Yu Tsai, Chih-Li Wang","doi":"10.1094/PHYTO-08-25-0279-R","DOIUrl":"10.1094/PHYTO-08-25-0279-R","url":null,"abstract":"<p><p><i>Fusarium oxysporum</i> f. sp. <i>conglutinans</i>, <i>F. oxysporum</i> f. sp. <i>rapae</i>, <i>F. oxysporum</i> f. sp. <i>raphani</i>, and <i>F. oxysporum</i> f. sp. <i>matthiolae</i> can cause yellows disease of economically important species in the Brassicaceae family. Among these, <i>F. oxysporum</i> f. sp. <i>rapae</i> induces yellows in leaf mustard and Chinese cabbage. <i>SGE1</i> (secreted-in-xylem [SIX] gene expression 1) is a transcription factor characterized by the presence of the WOPR box domain. Homologs of <i>SGE1</i> in other <i>Fusarium</i> species play a crucial role in virulence and regulate the expression of SIX effector genes. However, the role of the <i>SGE1</i> homolog in <i>F. oxysporum</i> f. sp. <i>rapae</i> (<i>FoRP-SGE1</i>) in pathogenesis and fungal development remains unexplored. To investigate its function in regulating pathogenicity and fungal development, gene knockout mutants of <i>FoRP-SGE1</i> (Δ<i>FoRP-SGE1</i>) were generated and validated. Δ<i>FoRP-SGE1</i> showed a reduction in conidiation but normal colony growth and conidial germination. Notably, Δ<i>FoRP-SGE1</i> completely lost pathogenicity in both leaf mustard and <i>Arabidopsis thaliana</i>, but it retained the ability to colonize leaf mustard plants, indicating that <i>FoRP-SGE1</i> is a key pathogenicity factor. Expression of <i>SIX9</i> and <i>SIX14</i> was significantly diminished in Δ<i>FoRP-SGE1</i>. Furthermore, most chlamydospores of Δ<i>FoRP-SGE1</i> lacked the outermost fibrillose coat. Germination of Δ<i>FoRP-SGE1</i> chlamydospores was also impaired under various stress conditions, including osmotic stress, drought, UV exposure, and fluazinam toxicity. This study presents, for the first time, the role of a <i>Fusarium SGE1</i> homolog in the morphology and persistence of chlamydospores. Collectively, our findings suggest that <i>FoRP-SGE1</i> is a critical pathogenicity factor in the leaf mustard-<i>F. oxysporum</i> f. sp. <i>rapae</i> and Arabidopsis-<i>F. oxysporum</i> f. sp. <i>rapae</i> pathosystems and is involved in the development of the fibrillose coat of chlamydospores and their resistance to environmental stresses.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"776-787"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146012190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}