Phytopathology最新文献

Integrating Multi-Omics Data Reveals the Mechanism of Action of the Antifungal Agent Ferimzone Against the Tea Leaf Spot Pathogen Didymella segeticola. 整合多组学数据揭示抗真菌剂Ferimzone对茶叶斑疹病原菌的作用机制

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-24 DOI: 10.1094/PHYTO-10-25-0350-R

Yuancan Shi, Jinhui Xu, Xiaotong Feng, Yueyue Zheng, Jun Zhang, Wenjin Xie, Shujing Yu, Zhuo Chen

{"title":"Integrating Multi-Omics Data Reveals the Mechanism of Action of the Antifungal Agent Ferimzone Against the Tea Leaf Spot Pathogen Didymella segeticola.","authors":"Yuancan Shi, Jinhui Xu, Xiaotong Feng, Yueyue Zheng, Jun Zhang, Wenjin Xie, Shujing Yu, Zhuo Chen","doi":"10.1094/PHYTO-10-25-0350-R","DOIUrl":"10.1094/PHYTO-10-25-0350-R","url":null,"abstract":"Tea leaf spot, caused by Didymella segeticola, is prevalent in many tea-growing regions of China and has a significant negative impact on both tea yield and quality. Ferimzone, as an uncoupler, demonstrates antimicrobial activity against various pathogens; however, its inhibitory mechanism remains poorly understood. The present study found that it effectively inhibited several phytopathogenic fungi. Specifically, the half-maximal effective concentration (EC50) for D. segeticola hyphae was 58.48 μg/ml. Microstructural analyses revealed that ferimzone caused several changes in the hyphae, including shortened inter-septum distances, hyphal swelling, accumulation of hyphal contents, and inhibition of new hyphal growth. Transcriptomic, proteomic, and metabolomic analyses indicated that ferimzone affects hyphal energy production, metabolic processes, biosynthesis of biomolecules, and material transport. Molecular docking and molecular dynamics simulations demonstrated that ferimzone binds to the candidate target protein pyruvate carboxylase (PC), with a predicted binding free energy of -7.9 kcal/mol. Microscale thermophoresis and surface plasmon resonance assays confirmed that ferimzone binds directly to PC. The dissociation constant (Kd) for the ferimzone-PC interaction was significantly lower than that observed for its structural analog fluazinam, indicating that ferimzone exhibits a higher binding affinity for this fungal target. Furthermore, ferimzone inhibited the mitochondrial membrane potential of the hyphae, with this effect becoming more pronounced as the dose increased. It is likely that ferimzone targets PC in the hyphae, disrupting energy metabolism and ultimately impairing hyphal growth. Several formulations of ferimzone, including osthole, exhibited enhanced inhibitory activity, suggesting promising potential for controlling tea leaf spot caused by D. segeticola.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1389-1404"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147639613","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

Untargeted Metabolomics Reveals the Dynamic and Time-Dependent 'Hass' Avocado Response to Stem-End Rot Infection at Harvest and Post-Storage. 非靶向代谢组学揭示了“哈斯”鳄梨在收获和储存后对茎端腐病的动态和时间依赖性反应。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-24 DOI: 10.1094/PHYTO-01-26-0013-R

Valentina Valencia Bernal, Amancio de Souza, Fatemeh Khodadadi

{"title":"Untargeted Metabolomics Reveals the Dynamic and Time-Dependent 'Hass' Avocado Response to Stem-End Rot Infection at Harvest and Post-Storage.","authors":"Valentina Valencia Bernal, Amancio de Souza, Fatemeh Khodadadi","doi":"10.1094/PHYTO-01-26-0013-R","DOIUrl":"10.1094/PHYTO-01-26-0013-R","url":null,"abstract":"Stem-end rot (SER), caused by Botryosphaeriaceae fungi, is an important postharvest disease in avocados. However, the metabolic processes shaping fruit-pathogen interactions during postharvest ripening remain poorly understood, particularly following cold storage. This study evaluated the impact of postharvest ripening and pathogen infection on the fruit metabolome, specifically comparing how a 35-day cold storage period alters these metabolic responses relative to freshly harvested, unripe fruit. 'Hass' avocados were inoculated with Neofusicoccum luteum both immediately after harvest and after 35 days of cold storage (5°C). Fruit samples were collected at 0, 24, 48, and 96 h postinoculation and analyzed using untargeted ultra-high-performance liquid chromatography-mass spectrometry, alongside firmness and dry matter measurements. Multivariate analyses indicated that cold storage altered the baseline fruit metabolome, with subsequent SER infection driving additional changes over time. Metabolomic changes were largely driven by lipid-associated metabolites, reflecting possible remodeling of membrane-associated lipids during cold storage and infection. Sphingolipids such as phytosphingosine and sphinganine consistently accumulated in infected fruit, especially after storage, suggesting involvement in stress and fruit-pathogen responses during disease progression. In addition to the lipid changes, a smaller set of non-lipid metabolites, such as eicosanoids, indoles, and various terpenoid forms, were also differentially abundant across treatments. These findings indicate that cold storage preconditions the avocado metabolome and influences the metabolomic landscape accompanying subsequent SER infection. To the best of our knowledge, this is the first study to characterize the avocado metabolome in both intact and SER-infected fruit under postharvest, cold storage conditions.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1493-1507"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147874982","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

Colletotrichum Species Causing Glomerella Leaf Spot and Bitter Rot of Apple in Georgia and Their Resistance to QoI Fungicides. 乔治亚州苹果肾小球斑病和苦腐病病原菌及其对QoI杀菌剂的抗性

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-24 DOI: 10.1094/PHYTO-01-26-0028-R

Jonathan Henson, Philip M Brannen, Marin Talbot Brewer

{"title":"Colletotrichum Species Causing Glomerella Leaf Spot and Bitter Rot of Apple in Georgia and Their Resistance to QoI Fungicides.","authors":"Jonathan Henson, Philip M Brannen, Marin Talbot Brewer","doi":"10.1094/PHYTO-01-26-0028-R","DOIUrl":"10.1094/PHYTO-01-26-0028-R","url":null,"abstract":"Glomerella leaf spot (GLS) and bitter rot, caused by Colletotrichum species, are two of the most economically damaging diseases of apple (Malus domestica) in the southeastern United States. However, the causal species and their resistance to fungicides have not been well established in Georgia. We surveyed nine orchards in the Georgia apple-growing region in 2023 to identify the Colletotrichum species responsible for these two diseases and to assess their resistance to quinone outside inhibitor (QoI) fungicides. A total of 252 isolates were identified to species, revealing that bitter rot was caused by C. chrysophilum, C. fioriniae, C. fructicola, and C. siamense, with frequencies varying by orchard. In contrast, GLS was dominated by C. fructicola (86%) and, in some orchards, by C. chrysophilum. Sequencing of the cytochrome b (cytb) gene showed that the G143A mutation, which confers complete QoI resistance, was present in all species but was especially common in C. fructicola (96%) and C. siamense (63%). Several isolates were heteroplasmic for cytb intron variants as well as for G143A, which could only be detected using multiple, genotype-specific primer sets for each isolate, emphasizing that careful detection is required in future studies. Mycelium inhibition assays confirmed that G143A conferred resistance in vitro, as most G143A isolates (98.8%) were classified as resistant using a discriminatory dose of pyraclostrobin, whereas most wild-type isolates (97.7%) remained sensitive. Overall, these findings indicate that QoI fungicides are unlikely to control GLS in Georgia and will be ineffective for bitter rot at many locations.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1480-1492"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147988840","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

Evolutionary Changes in Tomato Yellow Leaf Curl Virus Associated with Widespread Ty-1 Use in Japan. 与日本广泛使用Ty-1相关的番茄黄卷叶病毒的进化变化

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-03 DOI: 10.1094/PHYTO-03-26-0062-R

Misaki Nakajima, Moeno Shimoide, Nadya Syafira Pohan, Rui Yamasaki, Rieko Niwa, Suzuna Tsunoda, Myeonghwan Kwak, Eui-Joon Kil, Sota Koeda

{"title":"Evolutionary Changes in Tomato Yellow Leaf Curl Virus Associated with Widespread Ty-1 Use in Japan.","authors":"Misaki Nakajima, Moeno Shimoide, Nadya Syafira Pohan, Rui Yamasaki, Rieko Niwa, Suzuna Tsunoda, Myeonghwan Kwak, Eui-Joon Kil, Sota Koeda","doi":"10.1094/PHYTO-03-26-0062-R","DOIUrl":"10.1094/PHYTO-03-26-0062-R","url":null,"abstract":"Tomato yellow leaf curl virus (TYLCV) is a major global threat to tomato production. In Japan, TYLCV Israel (IL) and Mild (Mld) strains have predominated since 1996, and resistance breeding has relied extensively on Ty-1. To assess whether long-term deployment of Ty-1 has shaped viral evolution, we conducted the first nationwide, multiyear survey of TYLCV diversity in Japan. From 2022 to 2025, 294 symptomatic samples were collected from 13 prefectures, of which 203 tested positive for TYLCV. Phylogenetic analyses of 182 partial TYLCV sequences revealed that although most isolates clustered within the canonical IL or Mld strains, distinct noncanonical Mld isolates have emerged and persisted regionally. Full-length genome sequencing showed that representative noncanonical isolates (Rec71 and Rec103) are recombinants between TYLCV-Mld and honeysuckle yellow vein virus, with recombination breakpoints in the intergenic region and replication-associated genes. Virus infectious clone assays demonstrated that Rec103 is highly virulent (equivalent to IS76-like isolate) and Ty-1-mediated resistance is only partially effective. In contrast, Ty-2 effectively conferred resistance against Rec103, despite its putative major parent, TYLCV-Mld, being known to overcome Ty-2 resistance. Given the widespread cultivation of Ty-1-bearing varieties in Japan, these findings provide evidence of host resistance-driven viral adaptation. Collectively, our results reveal ongoing TYLCV evolution under host genetic selection and highlight the evolutionary risks of relying on a single resistance gene, underscoring the importance of diversified, strategically deployed resistance sources for durable, robust disease management. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1508-1518"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148056136","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

Detection of Palm Lethal Yellowing Phytoplasma in the Salivary Glands of Nesomyndus maculatus and Asymptomatic Bismarck Palms from Madagascar. 马达加斯加无症状俾斯麦棕榈和斑点Nesomyndus maculatus棕榈致黄植物原体唾液腺的检测。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-10 DOI: 10.1094/PHYTO-03-26-0082-R

Brian W Bahder, Miangaly R Ratsimbazafy, Safidinirina A Randretsiferana, Rasolondalao H Hasinjaka, Melody Bloch, Jeremy Lane, Ericka E Helmick, Daniel R Swale, Mbolarinosy R Rakotomalala, Fabian Pilet

{"title":"Detection of Palm Lethal Yellowing Phytoplasma in the Salivary Glands of Nesomyndus maculatus and Asymptomatic Bismarck Palms from Madagascar.","authors":"Brian W Bahder, Miangaly R Ratsimbazafy, Safidinirina A Randretsiferana, Rasolondalao H Hasinjaka, Melody Bloch, Jeremy Lane, Ericka E Helmick, Daniel R Swale, Mbolarinosy R Rakotomalala, Fabian Pilet","doi":"10.1094/PHYTO-03-26-0082-R","DOIUrl":"10.1094/PHYTO-03-26-0082-R","url":null,"abstract":"Palm lethal yellowing phytoplasmas (PLYPs) are plant pathogens that cause fatal infections in various palm species in tropical regions. The only confirmed vector of these pathogens is Haplaxius crudus Van Duzee (Hemiptera: Cixiidae), a planthopper found in the Neotropics and parts of North America. The recent identification of a new PLYP in Madagascar, 'Candidatus Phytoplasma katsepyensis', was the impetus for vector studies. In 2024, an expedition was launched to document planthopper diversity on palms in Madagascar, where phytoplasmas had previously been observed, to identify putative vectors. Insect specimens belonging to the genus Nesomyndus (Hemiptera: Cixiidae) were collected in relatively high abundance (n = 101) and later determined to represent three species: N. australis, N. maculatus, and N. madagascarensis. Additionally, five coconut palms tested positive by qPCR for phytoplasma among the sites surveyed. Among all specimens of all three species, only 9 out of 61 specimens of N. maculatus were positive for phytoplasma based on qPCR and high-resolution melt curve analysis, with four of these nine specimens having detectable levels of phytoplasma in the salivary glands by digital PCR. All positive specimens were collected from a single site. The detection of the phytoplasma in the salivary glands provides strong evidence that N. maculatus is a competent vector of a phytoplasma strain affecting coconuts in Madagascar. Future efforts will determine if the other species are also capable of acquiring the phytoplasma and evaluate critical details of the transmission cycle.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1414-1423"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138770","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

Controlled Activation of Auxilin-Like Protein 1 Triggers Cell Death-Associated Disease Resistance to Xanthomonas oryzae pv. oryzae in Rice. 调控激活生长素样蛋白1触发细胞对水稻黄单胞菌的死亡相关疾病抗性水稻中的稻谷。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-07-21 DOI: 10.1094/PHYTO-12-25-0380-R

A-Ram Jeong, Hyeran Moon, Oh-Kyu Kwon, Chang-Jin Park

{"title":"Controlled Activation of Auxilin-Like Protein 1 Triggers Cell Death-Associated Disease Resistance to Xanthomonas oryzae pv. oryzae in Rice.","authors":"A-Ram Jeong, Hyeran Moon, Oh-Kyu Kwon, Chang-Jin Park","doi":"10.1094/PHYTO-12-25-0380-R","DOIUrl":"10.1094/PHYTO-12-25-0380-R","url":null,"abstract":"Auxilin-like proteins (ALPs) are type III J-proteins that participate in clathrin-mediated endocytosis. In rice (Oryza sativa), an ALP, OsALP1, has been identified, but its precise role in immunity and potential for application remain largely unknown. Here, we investigated OsALP1 and its close homolog OsALP2 to elucidate their roles in rice defense. OsALP1 and OsALP2 share high sequence similarity and similar overexpression phenotypes, including spontaneous cell death and enhanced resistance to Xanthomonas oryzae pv. oryzae (Xoo). Notably, OsALP1 transcript levels were higher than those of OsALP2 in the tissues and developmental stages examined in this study, suggesting that OsALP1 is the predominant functional ALP in rice. To separate OsALP1-mediated resistance from its detrimental growth effects, we established a dexamethasone (DEX)-inducible expression system enabling temporal activation of OsALP1 in planta. DEX-induced OsALP1 expression conferred enhanced resistance to Xoo but increased susceptibility to the necrotrophic fungus Rhizoctonia solani, revealing lifestyle-dependent outcomes of immune-associated cell death. These findings provide a controllable framework for deploying OsALP1-based disease resistance while minimizing growth costs.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1458-1465"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147974793","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

Phloem Sucrose Osmoregulation and Vector Competence in the Asian Citrus Psyllid, the Vector of Huanglongbing. 黄龙冰病媒柑橘木虱韧皮部蔗糖渗透调节及媒介能力研究。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-21 DOI: 10.1094/PHYTO-05-26-0152-RVW

Nabil Killiny

{"title":"Phloem Sucrose Osmoregulation and Vector Competence in the Asian Citrus Psyllid, the Vector of Huanglongbing.","authors":"Nabil Killiny","doi":"10.1094/PHYTO-05-26-0152-RVW","DOIUrl":"10.1094/PHYTO-05-26-0152-RVW","url":null,"abstract":"Phloem-feeding insects, including the Asian citrus psyllid (Diaphorina citri), navigate one of the most osmotically challenging diets in nature, the sugar-rich phloem sap. Maintaining osmotic homeostasis is critical for survival, development, and vector competence, particularly in transmitting 'Candidatus Liberibacter asiaticus', the causal agent of citrus greening disease or huanglongbing (HLB). This review synthesizes current knowledge on the physiological, biochemical, and behavioral adaptations that enable D. citri to cope with extreme osmotic pressures. Key strategies include sucrose hydrolysis and conversion into glucose, fructose, and trehalose, as well as redistribution via the hemolymph, and efficient excretion of honeydew, which varies structurally and chemically across different developmental stages and sexes. These adaptations support prolonged phloem feeding, facilitate dual-lifestyle pathogen survival in both phloem and hemolymph, and directly enhance 'Ca. L. asiaticus' acquisition and transmission efficiency. Honeydew as an indicator for feeding behavior, host suitability, and susceptibility to insecticides is also highlighted. Finally, emerging approaches to disrupt osmoregulation, including RNAi-mediated interference with sugar metabolism and water transport, which may provide innovative avenues for integrated management of D. citri and mitigation of HLB spread, are discussed.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1348-1356"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148353236","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

AG-5 II: A Novel Rhizoctonia solani Anastomosis Subgroup of AG-5 on Legumes and Sugar Beet in Sweden. AG-5 II：瑞典豆科和甜菜上一个新的茄根丝核菌吻合亚群。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-10 DOI: 10.1094/PHYTO-09-25-0299-R

Shirley Marcou, Mariann Wikström, Lars Persson, Raf Verdoodt, Sara Ragnarsson, Josefin Wikström, Monica Höfte

{"title":"AG-5 II: A Novel Rhizoctonia solani Anastomosis Subgroup of AG-5 on Legumes and Sugar Beet in Sweden.","authors":"Shirley Marcou, Mariann Wikström, Lars Persson, Raf Verdoodt, Sara Ragnarsson, Josefin Wikström, Monica Höfte","doi":"10.1094/PHYTO-09-25-0299-R","DOIUrl":"10.1094/PHYTO-09-25-0299-R","url":null,"abstract":"This study focuses on 81 Rhizoctonia solani anastomosis group (AG)-5 isolates collected from various field crops, primarily Pisum sativum (pea), in southern Sweden and other Nordic countries since 2015. Using rDNA internal transcribed spacer (rDNA-ITS) sequencing and classical hyphal anastomosis assays, two distinct subgroups of AG-5, named AG-5 I and AG-5 II, were identified. ITS analysis revealed that the 34 AG-5 II isolates (42% of all AG-5 isolates) exhibited higher intra-isolate polymorphism, with numerous insertions and double peaks, suggesting ongoing evolutionary changes and a greater diversity of ITS regions within nuclei. In contrast, tef1-α sequences of a representative subset of AG-5 isolates showed fewer polymorphisms, higher bootstrap support, and clearer clustering of the two subgroups, highlighting the stability of this marker for phylogenetic inference. Pathogenicity assays showed that AG-5 II caused more severe epicotyl discoloration in pea and faba bean, and AG-5 I was associated with a higher incidence of damping-off in sugar beet. AG-5 II also displayed higher tolerance to fludioxonil, but the broader ecological and evolutionary significance of this observation requires further investigation. In conclusion, this work provides the first report on the subdivision of AG-5 into two subgroups, AG-5 I and the evolving AG-5 II. rDNA-ITS and tef1-α markers together allow for robust delineation of these subgroups, which differ in pathogenicity and fungicide tolerance, emphasizing their relevance for crop disease management.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1466-1479"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147779339","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

Race Characterization of the Stripe Rust Pathogen in Canada from 2020 to 2024 and Long-Term CYP51 Mutation Analysis. 2020 - 2024年加拿大条锈病病原的小种特征及CYP51长期突变分析

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-08-10 DOI: 10.1094/PHYTO-02-26-0058-R

Bohan Wei, Ryan Gourlie, Mohamed Hafez, Rhodesia Celoy, Stephen Strelkov, Reem Aboukhaddour

{"title":"Race Characterization of the Stripe Rust Pathogen in Canada from 2020 to 2024 and Long-Term CYP51 Mutation Analysis.","authors":"Bohan Wei, Ryan Gourlie, Mohamed Hafez, Rhodesia Celoy, Stephen Strelkov, Reem Aboukhaddour","doi":"10.1094/PHYTO-02-26-0058-R","DOIUrl":"10.1094/PHYTO-02-26-0058-R","url":null,"abstract":"Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst) remains a major threat to global wheat production. In Canada, long-term collection of Pst isolates since 1984 provides a unique perspective on pathogen evolution over four decades. This study extends previous race structure analyses by characterizing 73 isolates collected since 2020 from wheat, barley, and wild barley. Among 56 wheat-infecting isolates, 23 races were identified, including 16 new races (C90 to C105). The predominant races C17 and C43 and the newly emerged C96 accounted for 50% of isolates, with C96 likely evolving stepwise from C43 through acquisition of virulence to cultivar Tyee (YrTye); this cultivar was resistant in previous years. Alberta remains a hotspot of Pst diversity (14 races), whereas Saskatchewan showed lower diversity (5 races). Most isolates were virulent to Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yr43, Yr44, YrTr1, and YrExp2, whereas Yr5 and Yr15 remained undefeated; Yr1, Yr10, Yr24, Yr32, and YrSP conferred resistance to most of the isolates. Cultivated barley-derived isolates infected both wheat and barley and displayed distinct virulence profiles, suggesting interspecific adaptation and possible hybridization with P. striiformis f. sp. hordei (Psh). Additionally, analysis of the Cyp51 gene revealed the presence of a nonsynonymous mutation Y134F in one Psh isolate but its absence across tested Pst populations over the past 40 years in Canada, signifying potential evolution of fungicide tolerance or fitness adaptation in barley-infecting form.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1437-1446"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148194843","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

Microscopic Atlas of Citrus Huanglongbing Unravels Its Sequential Disease Development Mechanism. 黄龙冰柑桔显微图谱揭示其序贯疾病发生机制。

IF 3.4 2区农林科学

Phytopathology Pub Date : 2026-09-01 Epub Date: 2026-07-20 DOI: 10.1094/PHYTO-01-26-0019-R

Diann S Achor, Camila Ribeiro, Jinyun Li, Nian Wang

{"title":"Microscopic Atlas of Citrus Huanglongbing Unravels Its Sequential Disease Development Mechanism.","authors":"Diann S Achor, Camila Ribeiro, Jinyun Li, Nian Wang","doi":"10.1094/PHYTO-01-26-0019-R","DOIUrl":"10.1094/PHYTO-01-26-0019-R","url":null,"abstract":"Citrus huanglongbing (HLB), caused by the phloem-colonizing 'Candidatus Liberibacter asiaticus' (CLas), is a devastating disease worldwide. CLas systemically infects all organs containing phloem. How CLas causes pathogenicity in different organs remains poorly understood. Here, we conducted transmission electron microscope and light microscope analyses of different organs in a grove and greenhouse at four time points over a year. Compared with the healthy controls, increased phloem cell death was observed in CLas-positive tissues, including leaf, fruit albedo, pedicel, and columella, as well as bark tissues of the branches and trunk, but not in root and seed coat tissues. CLas infection causes more phloem callose deposition in leaf, fruit albedo, pedicel, and columella, as well as bark tissues of the branches and trunk, but not, or to a lesser extent, in root and seed coat tissues. Our data demonstrate that CLas triggers phloem cell death and callose deposition in photosynthetic tissues but not, or to a lesser extent, in nonphotosynthetic tissues. CLas infection also caused starch accumulation in mature leaves and branch bark and starch depletion in roots. Our data have revealed the sequential order of HLB disease development. CLas triggers phloem cell death and callose deposition, which cause phloem transportation blockage and subsequent starch accumulation in leaves. Starch accumulation leads to chloroplast degeneration and subsequent blotchy mottling and yellowing symptoms. Root decay mainly results from carbon starvation, which further contributes to HLB symptom development, such as nutrient deficiency, tree decline, and death. In sum, CLas causes disease effects on photosynthetic and nonphotosynthetic tissues via distinct mechanisms. [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.","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":" ","pages":"1367-1377"},"PeriodicalIF":3.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148536861","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}

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