Phytopathology最新文献_第5页

Population Genomic Analysis of Two Independent Clonal Invasions of the Sudden Oak Death Pathogen into One Forest. 橡树猝死病菌两次独立无性系入侵同一森林的种群基因组分析。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-28 DOI: 10.1094/PHYTO-10-24-0329-FI

Nicholas C Cauldron, Hazel A Daniels, Jared M LeBoldus, Niklaus J Grünwald

{"title":"Population Genomic Analysis of Two Independent Clonal Invasions of the Sudden Oak Death Pathogen into One Forest.","authors":"Nicholas C Cauldron, Hazel A Daniels, Jared M LeBoldus, Niklaus J Grünwald","doi":"10.1094/PHYTO-10-24-0329-FI","DOIUrl":"https://doi.org/10.1094/PHYTO-10-24-0329-FI","url":null,"abstract":"Upon introduction, clonal pathogen populations are expected to go through a genetic bottleneck followed by gradual clonal divergence. Two distinct and purely clonal lineages of the sudden oak death pathogen Phytophthora ramorum recently emerged in forests in the Western United States, providing the unique opportunity to study a naturally replicated invasion into the same ecosystem. We characterized population genomic patterns during early invasion using whole genome sequencing of two P. ramorum clonal lineages sampled in the first five years following their detection. We re-sequenced genomes from populations of two dominant clonal lineages, NA1 (n=134; 2001-2005) and EU1 (n=160; 2015-2019), and obtained 106,070 high-quality SNPs in genic regions. Our results are consistent with the hypothesis of one introduction for each lineage. The NA1 population had a wider distribution of pairwise genetic distances than EU1 and higher genetic diversity, though neither NA1 nor EU1 populations clustered clearly by year. There was significant correlation between genetic distance and geographic distance for NA1 (p = 0.042), but not for EU1 (p = 0.402). The genetic diversity in NA1 is strongly driven by loss of heterozygous positions, which impacted more than one-third of the sampled NA1 population. However, loss of heterozygosity was rare in EU1. This work provides novel insights into the invasion biology and dynamics of clonal plant pathogens in natural ecosystems.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144161503","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}

引用次数: 0

Soil Temperature and Moisture Conditions Affect the Recovery and Sporulation Capacity of Phytophthora ramorum from Infested Rhododendron Leaf Disks. 土壤温湿度条件对侵染杜鹃叶片疫霉恢复和产孢能力的影响。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-28 DOI: 10.1094/PHYTO-02-25-0056-R

Ebba K Peterson, Niklaus J Grünwald, Jennifer L Parke

{"title":"Soil Temperature and Moisture Conditions Affect the Recovery and Sporulation Capacity of Phytophthora ramorum from Infested Rhododendron Leaf Disks.","authors":"Ebba K Peterson, Niklaus J Grünwald, Jennifer L Parke","doi":"10.1094/PHYTO-02-25-0056-R","DOIUrl":"https://doi.org/10.1094/PHYTO-02-25-0056-R","url":null,"abstract":"The invasive pathogen Phytophthora ramorum persists within nurseries, potentially within buried, infested leaf debris. To determine how the environment - notably soil temperature and moisture levels - affects the epidemiological risk of soil inoculum reserves, we performed laboratory assays assessing how variable conditions impact pathogen survival and its capacity to sporulate. We first established that incubating inoculum at 4°C increases the number of sporangia produced from infested rhododendron leaf disks. In a second experiment, inoculum was incubated in soil at a range of temperature (6.7, 14, 20, or 28°C) and soil moisture (approximating 0, -40, or -400 kPa) conditions for up to 18 weeks. Our ability to culture P. ramorum was only negatively affected by the warmest and driest regimes. In contrast, the capacity to sporulate was affected over a much wider range of conditions, whereby declines in sporulation potential were observed over time from inoculum incubated at both 20 and 28°C in all soil moisture conditions. However, subsequent incubation of this inoculum at 4°C for an additional seven weeks restored sporulation potential, at times exceeding pre-incubation levels. These results are consistent with field-observations that P. ramorum becomes more biologically active after exposure to cooler temperatures, and highlights the risk soilborne inoculum poses during some times of the year. Disinfestation of soils through artificially high heat is likely required to prevent recurrent infections within nurseries from soilborne sources, and thus prevent the further spread of this invasive pathogen.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144161408","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}

引用次数: 0

Emerging Xanthomonas prunicola Strains Cause Bacterial Leaf Necrosis of Wheat. 新出现的prunicola黄单胞菌引起小麦细菌性叶片坏死。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-28 DOI: 10.1094/PHYTO-02-25-0044-R

Felipe Clavijo, Veronica Roman-Reyna, Rebecca D Curland, Ruth Dill-Macky, Jonathan M Jacobs, Carolina Leoni, Lucía Coimbra, Silvia Pereyra, María I Siri

{"title":"Emerging Xanthomonas prunicola Strains Cause Bacterial Leaf Necrosis of Wheat.","authors":"Felipe Clavijo, Veronica Roman-Reyna, Rebecca D Curland, Ruth Dill-Macky, Jonathan M Jacobs, Carolina Leoni, Lucía Coimbra, Silvia Pereyra, María I Siri","doi":"10.1094/PHYTO-02-25-0044-R","DOIUrl":"https://doi.org/10.1094/PHYTO-02-25-0044-R","url":null,"abstract":"Xanthomonas prunicola, initially described as a nectarine pathogen, has emerged as the causal agent of a new wheat disease, Bacterial Leaf Necrosis (BLN). This study compares X. prunicola strains isolated from wheat fields in Uruguay and the United States to nectarine-associated strains using genomic and pathogenicity analyses to identify factors driving host specificity. Pathogenicity assays revealed clear differences between the two groups: while X. prunicola wheat-associated strains caused distinct dry necrosis lesions in wheat; the reference strain isolated from nectarine failed to induce any symptoms in this host. Surprisingly, most of the wheat strains elicited water-soaking symptoms in Prunus persica, similar to those caused by the X. prunicola strain isolated from nectarine. Complete high-quality genomes were obtained for the six selected X. prunicola strains. Genomic analyses confirmed their identification and revealed that wheat-associated strains form a distinct phylogenomic cluster separated from nectarine-associated strains. Comparative analyses identified key differences, including a functional Type VI Secretion System (T6SS), absent in nectarine strains, and unique Type III effectors, XopR and XopW, potentially linked to wheat pathogenicity. These findings underscore the importance of understanding the epidemiology of this emerging pathogen, transmission pathways, and host specificity to mitigate its impact on wheat production and develop targeted control strategies.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144174663","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}

引用次数: 0

Characterization of Mycotoxin and Furanoterpenoid Production by Fusarium Species Infecting Sweetpotato. 甘薯镰刀菌产生真菌毒素和呋喃萜类的特性研究。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-28 DOI: 10.1094/PHYTO-01-25-0031-R

U Bhatta, J R Standish, O Baars, L M Quesada-Ocampo

{"title":"Characterization of Mycotoxin and Furanoterpenoid Production by Fusarium Species Infecting Sweetpotato.","authors":"U Bhatta, J R Standish, O Baars, L M Quesada-Ocampo","doi":"10.1094/PHYTO-01-25-0031-R","DOIUrl":"https://doi.org/10.1094/PHYTO-01-25-0031-R","url":null,"abstract":"Sweetpotato (Ipomoea batatas) production is threatened by Fusarium root rot, which can lead to substantial yield losses and contamination with mycotoxins and phytotoxins. This study investigated the production of mycotoxins by different Fusarium species and isolates in vitro and in vivo, as well as furanoterpenoid compounds produced by sweetpotato in response to Fusarium infection and wounding. Among 37 Fusarium isolates tested, only four Fusarium proliferatum isolates (AS050, AS116, JS603 and NM229) produced significant levels of fumonisins B1 and B2 in sweetpotato roots, with NM229 exhibiting the highest mycotoxin concentrations. Notably, fumonisin production differed between in vivo and in vitro conditions. In sweetpotato roots, fumonisin concentrations for NM229 decreased over time, while in liquid culture, concentrations increased. The other isolates produced minimal amounts of fumonisins, with no significant changes over time in either condition. An untargeted metabolomics analysis showed several putative furanoterpenoids, both wounding-induced and Fusarium-specific. Wounding alone triggered production of certain furanoterpenoids, while Fusarium infections, particularly F. denticulatum infections resulted in the highest levels of phytotoxins, including ipomeamarone, 4-hydroxymyoporone, 1-ipomeanol, and 4-ipomeanol. Fusarium acuminatum, F. commune, and F. proliferatum isolates induced some additional putative furanoterpenoids based on observed similar fragmentation patterns. These findings highlight the complex interaction between mechanical damage and Fusarium infection in stimulating phytotoxin production in sweetpotato and emphasize the importance of effective disease management strategies. The detection of high fumonisin levels, exceeding FDA guidelines for human food (2-4 ppm), underscores the need for monitoring and controlling Fusarium infections in sweetpotato production.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144161496","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}

引用次数: 0

Integrative Elements Repeatedly Captured the Phaseolotoxin Biosynthesis Gene Cluster and Invaded Pseudomonas syringae Multiple Times. 整合元件多次捕获相毒素生物合成基因簇，多次入侵丁香假单胞菌。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-28 DOI: 10.1094/PHYTO-01-25-0017-R

Luiz Orlando de Oliveira, Hugo Vianna Silva Rody, Selene Aguilera, Jesus Murillo

{"title":"Integrative Elements Repeatedly Captured the Phaseolotoxin Biosynthesis Gene Cluster and Invaded Pseudomonas syringae Multiple Times.","authors":"Luiz Orlando de Oliveira, Hugo Vianna Silva Rody, Selene Aguilera, Jesus Murillo","doi":"10.1094/PHYTO-01-25-0017-R","DOIUrl":"https://doi.org/10.1094/PHYTO-01-25-0017-R","url":null,"abstract":"Phaseolotoxin is a virulence factor of Pseudomonas amygdali pv. phaseolicola (Pph) and P. syringae pv. actinidiae (Psa). Herein, we explore the evolutionary history of a genomic island (Tox island) composed of an integrative element (GInt) carrying the 23-gene cluster (Pht cluster) for biosynthesis of phaseolotoxin and toxin resistance. Our analyses indicate that the Pht cluster has been acquired, either naked or associated with a GInt, on seven independent occasions by four phylogroups of the P. syringae complex (Pph, Psa, P. caricapapayae, and P. syringae pv. syringae) and the phylogenetically distant rhizobacterium Pseudomonas sp. JAI115. The Pht cluster was independently captured by three distinct GInt elements, suggesting specific mechanisms for gene capture. Once acquired, the Tox island tends to be stably maintained, evolving with the genome. The likely evolutionary trajectory of the Tox island within Pph and Psa involved: i) acquisition by Pph; ii) transfer of the Tox island from Pph to Psa biovar 1; iii) independent acquisition from unknown sources of a different version of the Tox island by Psa biovar 1, generating a second toxigenic lineage; 4) independent acquisition from unknown sources of a third version of the Tox island by Psa biovar 6; and 5) replacement of the Tox island in Pph by a distantly related GInt, generating nontoxigenic isolates. These findings underscore the potential role of phaseolotoxin in bacterial fitness and contribute to our understanding of the evolutionary dynamics of mobile genetic elements and virulence evolution in bacterial plant pathogens.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144161497","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}

引用次数: 0

Role of Organic Amendment Composition and Soil Texture in Modulating Volatile Fatty Acids, Fe/Mn Reduction, and Fusarium oxysporum Suppression During Anaerobic Soil Disinfestation in Neutral to Alkaline Soils. 有机改进剂组成和土壤质地在中性至碱性土壤厌氧消毒过程中对挥发性脂肪酸、铁/锰还原和尖孢镰刀菌抑制的调节作用

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-21 DOI: 10.1094/PHYTO-12-24-0423-R

James Littrell, Bonnie H Ownley, Zachariah R Hansen, Kimberly D Gwinn, David M Butler

{"title":"Role of Organic Amendment Composition and Soil Texture in Modulating Volatile Fatty Acids, Fe/Mn Reduction, and Fusarium oxysporum Suppression During Anaerobic Soil Disinfestation in Neutral to Alkaline Soils.","authors":"James Littrell, Bonnie H Ownley, Zachariah R Hansen, Kimberly D Gwinn, David M Butler","doi":"10.1094/PHYTO-12-24-0423-R","DOIUrl":"https://doi.org/10.1094/PHYTO-12-24-0423-R","url":null,"abstract":"Less hazardous alternatives to soil fumigants for suppressing soilborne pathogens such as pathogenic isolates within the Fusarium oxysporum (Fo) species complex that cause black root rot of strawberry are urgently needed. A promising alternative is anaerobic soil disinfestation (ASD), in which anaerobic fermentation is induced in soil, leading to production of pathogen-suppressing reduced metal cations (Fe2+, Mn2+) and volatile fatty acids (VFAs) before planting. However, little is known about how interactions between amendment composition, soil texture, and neutral to alkaline soil pH influences Fo suppression via soil biogeochemistry. Suppression of Fo was investigated in soil-based ASD incubation mesocosm trials where Fo-inoculated soils with initial neutral pH (sand, sandy loam, and silty clay) were amended with lime (0.1% CaCO3) or unamended, and amended (1% w/w) with five amendment mixtures of soybean protein isolate (SPI) and dried molasses (DM) (100/0%, 75/25%, 50/50%, 25/75% or 0/100%) for a range of protein: carbohydrate ratios (0.1:1 to 32:1), to initiate ASD treatments. Post-ASD, soil chemical properties were measured, including VFA and Fe2+/Mn2+ concentrations, and Fo inoculum viability was assessed. Total soil VFA and Fe2+/Mn2+ concentrations were influenced by ASD amendment composition and soil texture, with the highest VFA concentrations resulting from high protein amendments and the highest Mn2+ concentrations observed in sandy loam and silty clay soils. Fo viability was reduced in all amended treatments, but finer soil textures were associated with lower Fo suppression. Our results highlight the importance of soil texture and amendment composition in influencing ASD effectiveness in neutral to alkaline soils.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111853","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}

引用次数: 0

Development of a Minireplicon for Grapevine leafroll-associated virus 1 and Genetic Analyses of Sequences in the 5' Non-Translated Region Required for Replication. 葡萄叶卷相关病毒1微型复制子的研制及复制所需5'非翻译区序列的遗传分析。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-19 DOI: 10.1094/PHYTO-12-24-0380-R

Arunabha Mitra, Sridhar Jarugula, Rayapeti A Naidu

{"title":"Development of a Minireplicon for Grapevine leafroll-associated virus 1 and Genetic Analyses of Sequences in the 5' Non-Translated Region Required for Replication.","authors":"Arunabha Mitra, Sridhar Jarugula, Rayapeti A Naidu","doi":"10.1094/PHYTO-12-24-0380-R","DOIUrl":"https://doi.org/10.1094/PHYTO-12-24-0380-R","url":null,"abstract":"Grapevine leafroll-associated virus 1 (GLRaV-1, genus Ampelovirus, family Closteroviridae) has a monopartite RNA genome with size varying among genetic variants between 18,731 and 18,946 nucleotides (nt) and a 5' non-translated region (5'-NTR), varying in length between 857 and 922 nt. This study was undertaken to examine the role of the 5'-NTR in GLRaV-1 replication. For this purpose, a minireplicon cDNA clone, consisting of the 5'-NTR, the replicase gene module, the green fluorescent protein (GFP) reporter gene, and the 3'-NTR, was constructed. Functionality of the minireplicon was validated by GFP fluorescence and the presence of GFP-specific mRNA transcripts by Northern blot hybridization and RT-qPCR assays in Nicotiana benthamiana leaves agro-coinfiltrated with silencing suppressors. The minireplicon retained functionality when its 5'-NTR was exchanged with corresponding sequences from distinct genetic variants of GLRaV-1. In contrast, the minireplicon of GLRaV-1 was non-functional when its 5'-NTR sequence was swapped with corresponding sequences from other GLRaV species. Deletion mutations in the 5'-NTR indicated that the first 32 nt at the 5'-terminus of the genome are essential for replication of the minireplicon. In silico-predicted secondary structure of the 5'-terminal 32-nt sequence showed two stem-loop structures and mutations that altered these secondary structures or compensatory mutations preserving the secondary structures failed to retain functionality of the minireplicon, suggesting that the nucleotide sequence, rather than any higher order secondary structures in this genomic region, is important for replication.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144102491","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}

引用次数: 0

Isolation, Phylogenetic Inferences, and Early Diversification of Xylella fastidiosa subsp. fastidiosa in Cova da Beira Region, Portugal. 苛养木杆菌亚种的分离、系统发育推断及早期分化。葡萄牙Cova da Beira地区的fastidiosa。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-15 DOI: 10.1094/PHYTO-01-25-0009-R

Eva Garcia, Alexandra K Kahn, Cristiana Rodrigues, Alexandra Camelo, Christophe Espirito Santo, Helvecio D Coletta-Filho, Rodrigo P P Almeida, Joana Costa

{"title":"Isolation, Phylogenetic Inferences, and Early Diversification of Xylella fastidiosa subsp. fastidiosa in Cova da Beira Region, Portugal.","authors":"Eva Garcia, Alexandra K Kahn, Cristiana Rodrigues, Alexandra Camelo, Christophe Espirito Santo, Helvecio D Coletta-Filho, Rodrigo P P Almeida, Joana Costa","doi":"10.1094/PHYTO-01-25-0009-R","DOIUrl":"https://doi.org/10.1094/PHYTO-01-25-0009-R","url":null,"abstract":"The introduction of Xylella fastidiosa, a plant pathogen with a broad host range, poses a significant threat to agriculture and natural ecosystems. We analysed six X. fastidiosa subsp. fastidiosa strains obtained from the Beira Interior region of Portugal, an area known for fruit production. Whole-genome sequencing and phylogenetic analyses were performed to genetically characterize these strains and determine their origin. The results suggest that these outbreak-demarcated areas originated from a single introduction event traced back to California, USA. All six strains belong to subspecies fastidiosa, sequence type ST1, which has been reported to infect a variety of economically important crops, including cherry, plum, almond, and grapevine. A molecular clock analysis estimated that the introduction occurred between 2010 and 2020 (95% HPD 1999 - 2022), with the strains forming a clade that diverged circa 2020. The findings underscore the importance of continued surveillance in both agricultural and unmanaged ecosystems, as the presence and potential impact of X. fastidiosa on Portuguese landscapes remain largely unknown.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144079730","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}

引用次数: 0

Unraveling the Environmental Drivers of Phyllachora maydis Spore Release and Dispersal Using Spore Trapping and qPCR. 利用孢子捕获和qPCR技术揭示毛叶蚜孢子释放和扩散的环境驱动因素。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-15 DOI: 10.1094/PHYTO-01-25-0027-R

Jill C Check, Janette L Jacobs, Peyton J Phillips, Emily M Roggenkamp, Jaime Willbur, Martin I Chilvers

{"title":"Unraveling the Environmental Drivers of Phyllachora maydis Spore Release and Dispersal Using Spore Trapping and qPCR.","authors":"Jill C Check, Janette L Jacobs, Peyton J Phillips, Emily M Roggenkamp, Jaime Willbur, Martin I Chilvers","doi":"10.1094/PHYTO-01-25-0027-R","DOIUrl":"https://doi.org/10.1094/PHYTO-01-25-0027-R","url":null,"abstract":"Phyllachora maydis, the causal agent of tar spot of corn, is an emerging disease in the United States and Canada. This study aims to improve our understanding of P. maydis spore release and dispersal by utilizing spore trapping and quantitative PCR to assess the relationship between spore capture and environmental conditions. Burkard and rotating-arm air samplers were deployed in Michigan corn fields with natural disease pressure from 2021 to 2023. Correlation analysis and mixed-effects logistic regression were applied to examine the impact of environmental factors on spore capture. Through an exhaustive screening of candidate logistic regression models, results indicated that spore quantity is significantly negatively correlated with daily summaries of minimum temperature (P<0.05, τ=-0.24), mean temperature (P<0.05, τ=-0.25), maximum precipitation rate (P<0.05, τ=-0.33) and durations of temperature between 16.6 to 23ºC and relative humidity over 85% (P<0.001, τ=-0.27). Logistic regression models frequently incorporated temperature and humidity predictors, and the best performing model used daily averages of mean temperature and maximum humidity to discriminate presence and absence of spore detection, achieving a balanced accuracy of 85%. Across all site-years, spore traps did not detect P. maydis spores prior to the visible detection of tar spot symptoms but did detect spores before tar spot incidence reached 100%. Through this study, the environmental drivers of spore release and dispersal were described to fill current knowledge gaps in the tar spot disease cycle. Additionally, a methodology for the capture and molecular quantification of airborne P. maydis spores is described which will benefit future research.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144079693","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}

引用次数: 0

A Soil-Borne Virus Modifies the Root System Architecture of a Plant Host via a Single Amino Acid and Influences Nematode Transmission. 一种土壤传播的病毒通过单个氨基酸修饰植物宿主的根系结构并影响线虫的传播。

IF 2.6 2区农林科学

Phytopathology Pub Date : 2025-05-15 DOI: 10.1094/PHYTO-03-25-0105-R

Brandon G Roy, Gérard Demangeat, Sophie Meyer, Claude Gertz, Véronique Komar, Isabelle R Martin, Marc F Fuchs

{"title":"A Soil-Borne Virus Modifies the Root System Architecture of a Plant Host via a Single Amino Acid and Influences Nematode Transmission.","authors":"Brandon G Roy, Gérard Demangeat, Sophie Meyer, Claude Gertz, Véronique Komar, Isabelle R Martin, Marc F Fuchs","doi":"10.1094/PHYTO-03-25-0105-R","DOIUrl":"https://doi.org/10.1094/PHYTO-03-25-0105-R","url":null,"abstract":"Grapevine fanleaf virus (GFLV) is the main causative agent of fanleaf degeneration disease. Transmission of GFLV is exclusively accomplished by the ectoparasitic dagger nematode Xiphinema index in a non-circulative, non-propagative mode. Previous studies of GFLV-host interactions revealed strain- and viral amino acid-specific changes to the root system architecture (RSA) in Nicotiana benthamiana. Here, a two-step assay first revealed the suitability of N. benthamiana in comparison to Vitis sp. for the transmission of GFLV by X. index. Then, a novel one-step assay revealed strain- and viral amino acid-specific differences in transmission between wildtype GFLV strains F13 and GHu, and their respective mutants with single residue changes to position 802 of the putative RNA-dependent RNA polymerase (protein 1EPol*/Sd). Higher transmission rates were obtained with asymptomatic mutant GFLV-GHu 1EK802G (33.33%,16/48) versus symptomatic wildtype GFLV-GHu (25.53%, 12/47) and with asymptomatic wildtype GFLV-F13 (75%, 30/40) versus symptomatic mutant GFLV-F13 1EG802K (51.28%, 20/39). These results documented that X. index-mediated transmission is influenced by the GFLV strain and the identity of the amino acid in position 802 of protein 1EPol*/Sd with a glycine favoring transmission and a lysine reducing transmission. As expected, GFLV transmission was significantly correlated with differences in RSA traits such as the number of root tips and total root length, but not to GFLV titer in X. index or in roots of donor plants. This is the first report of a soil-borne virus modifying both the RSA of a plant host and transmission by its dagger nematode via a single viral amino acid.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144079724","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}

引用次数: 0