Pub Date : 2024-10-02DOI: 10.1094/PHYTO-10-23-0378-KC
Leon M Hodgson, Francisco J Lopez-Ruiz, Mark R Gibberd, Geoff J Thomas, Ayalsew Zerihun
The effectiveness of fungicides to control foliar fungal crop diseases is being diminished by the increasing spread of resistances to fungicides. One approach that may help to maintain efficacy is remediation of resistant populations by sensitive ones. However, the success of such approaches can be compromised by re-incursion of resistance through aerial spore dispersal; although, knowledge of localized gene flow is lacking. Here, we report on a replicated mark-release-recapture field experiment with several treatments set up to study spore-dispersal-mediated gene flow of a mutated allele that confers demethylase inhibitor resistance in Pyrenophora teres f. teres (Ptt). Artificial inoculation of the host, barley (Hordeum vulgare), was successful across the 12-ha trial, where the introduced sensitive- and resistant-populations were, respectively, 6- and 13-fold the DNA concentration of the native Ptt population. Subsequent disease pressure remained low which hampered spread of the epidemic to such extent that gene flow was not detected at, or beyond 2.5 m from source points. In the absence of gene flow, plots were assessed for treatment effects; fungicide applied to populations that contained 14.3% of allele mutation increased in frequency to 24.5%, whereas sensitive populations had no change in structure. Untreated controls of native Ptt population remained genetically stable, yet untreated controls that were inoculated with sensitive Ptt had half the resistance frequency of the native population structure. The trial demonstrates the potential for management to remediate fungicide resistant pathogen populations, where localized gene flow is minimal; to safeguard chemical crop protection into the future.
由于对杀真菌剂的抗药性日益扩散,杀真菌剂控制作物叶部真菌病害的效果正在减弱。一种有助于保持药效的方法是用敏感种群补救抗药性种群。然而,这种方法的成功可能会因抗药性通过气生孢子传播再次扩散而受到影响;不过,目前还缺乏关于局部基因流的知识。在此,我们报告了一项重复的标记-释放-再捕获田间试验,该试验设置了几种处理方法,以研究孢子散播所介导的基因流,该基因流是一种突变的等位基因,它赋予了赤潮镰刀菌(Ptt)对去甲基化酶抑制剂的抗性。对宿主大麦(Hordeum vulgare)的人工接种在 12 公顷的试验中取得了成功,引入的敏感种群和抗性种群的 DNA 浓度分别是本地 Ptt 种群的 6 倍和 13 倍。随后的病害压力仍然很低,阻碍了疫病的传播,以至于在距离源点 2.5 米处或更远的地方都检测不到基因流。在没有基因流动的情况下,对地块的处理效果进行了评估;对含有 14.3% 等位基因变异的种群施用杀菌剂后,其变异频率增加到 24.5%,而敏感种群的结构没有变化。未处理的本地 Ptt 种群对照组在遗传上保持稳定,而接种了敏感 Ptt 的未处理对照组的抗性频率只有本地种群结构的一半。该试验表明,在局部基因流动最小的情况下,管理部门有可能对具有杀真菌剂抗性的病原体种群进行补救,以保障未来的化学作物保护。
{"title":"Field-scale gene flow of fungicide resistance in <i>Pyrenophora teres</i> f. <i>teres</i> and the effect of selection pressure on the population structure.","authors":"Leon M Hodgson, Francisco J Lopez-Ruiz, Mark R Gibberd, Geoff J Thomas, Ayalsew Zerihun","doi":"10.1094/PHYTO-10-23-0378-KC","DOIUrl":"https://doi.org/10.1094/PHYTO-10-23-0378-KC","url":null,"abstract":"<p><p>The effectiveness of fungicides to control foliar fungal crop diseases is being diminished by the increasing spread of resistances to fungicides. One approach that may help to maintain efficacy is remediation of resistant populations by sensitive ones. However, the success of such approaches can be compromised by re-incursion of resistance through aerial spore dispersal; although, knowledge of localized gene flow is lacking. Here, we report on a replicated mark-release-recapture field experiment with several treatments set up to study spore-dispersal-mediated gene flow of a mutated allele that confers demethylase inhibitor resistance in <i>Pyrenophora teres</i> f. <i>teres</i> (<i>Ptt</i>). Artificial inoculation of the host, barley (<i>Hordeum vulgare</i>), was successful across the 12-ha trial, where the introduced sensitive- and resistant-populations were, respectively, 6- and 13-fold the DNA concentration of the native <i>Ptt</i> population. Subsequent disease pressure remained low which hampered spread of the epidemic to such extent that gene flow was not detected at, or beyond 2.5 m from source points. In the absence of gene flow, plots were assessed for treatment effects; fungicide applied to populations that contained 14.3% of allele mutation increased in frequency to 24.5%, whereas sensitive populations had no change in structure. Untreated controls of native <i>Ptt</i> population remained genetically stable, yet untreated controls that were inoculated with sensitive <i>Ptt</i> had half the resistance frequency of the native population structure. The trial demonstrates the potential for management to remediate fungicide resistant pathogen populations, where localized gene flow is minimal; to safeguard chemical crop protection into the future.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142366279","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}
Rice blast is one of the most hazardous diseases affecting rice production. Previously, we discovered that the Atp2 protein of Rhodopseudomonas palustris could significantly inhibit the appressorium formation and pathogenicity of Magnaporthe oryzae. However, the molecular mechanism of this fungus has remained unknown. This study revealed that Atp2 can enter the cell and interact with the ribosomal protein MoRpl12 of M. oryzae, directly affecting the expression of the MoRpl12 protein. Silencing the MoRPL12 gene can affect cell wall integrity, growth, conidiogenesis, and fungal pathogenicity. The quantitative reverse transcription PCR results showed significant changes in the expression of conidiation-related genes in the MoRPL12 gene-silenced mutants or in the Atp2 protein-treated plants. We further found that Atp2 treatment can influence the expression of ribosomal-related genes, such as RPL, in M. oryzae. Our study revealed a novel antifungal mechanism by which the Atp2 protein binds to the ribosomal protein MoRpl12 and inhibits the pathogenicity of rice blast fungus, providing a new potential target for rice blast prevention and control.
{"title":"<i>Rhodopseudomonas palustris</i> Atp2 Protein Exerts Antifungal Effects by Targeting the Ribosomal Protein MoRpl12 in <i>Magnaporthe oryzae</i>.","authors":"Chunyan Chen, Xiyang Wu, Qiang Huang, Yingfei Qin, Chenggang Li, Xin Zhang, Pei Wang, Xinqiu Tan, Yong Liu, Yue Chen, Deyong Zhang","doi":"10.1094/PHYTO-05-24-0169-R","DOIUrl":"https://doi.org/10.1094/PHYTO-05-24-0169-R","url":null,"abstract":"<p><p>Rice blast is one of the most hazardous diseases affecting rice production. Previously, we discovered that the Atp2 protein of <i>Rhodopseudomonas palustris</i> could significantly inhibit the appressorium formation and pathogenicity of <i>Magnaporthe oryzae.</i> However, the molecular mechanism of this fungus has remained unknown. This study revealed that Atp2 can enter the cell and interact with the ribosomal protein MoRpl12 of <i>M. oryzae</i>, directly affecting the expression of the MoRpl12 protein. Silencing the <i>MoRPL12</i> gene can affect cell wall integrity, growth, conidiogenesis, and fungal pathogenicity. The quantitative reverse transcription PCR results showed significant changes in the expression of conidiation-related genes in the <i>MoRPL12</i> gene-silenced mutants or in the Atp2 protein-treated plants. We further found that Atp2 treatment can influence the expression of ribosomal-related genes, such as <i>RPL</i>, in <i>M. oryzae</i>. Our study revealed a novel antifungal mechanism by which the Atp2 protein binds to the ribosomal protein MoRpl12 and inhibits the pathogenicity of rice blast fungus, providing a new potential target for rice blast prevention and control.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142366278","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}
Pub Date : 2024-09-30DOI: 10.1094/PHYTO-10-23-0391-KC
Liuliu Yang, Yu Sun, Lin Sun, Zehao Wang, Jie Feng, Yue Liang
Plant diseases impact the production of all kinds of crops, resulting in significant economic losses worldwide. Timely and accurate detection of plant pathogens is crucial for surveillance and management of plant diseases. In recent years, loop-mediated isothermal amplification (LAMP) has become a popular method for pathogen detection and disease diagnosis due to the advantages of its simple instrument requirement and constant reaction temperature. In this review, we provide an overview of current research on LAMP, including the reaction system, design of primers, selection of target regions, visualization of amplicons, and application of LAMP on the detection of all major groups of plant pathogens. We also discuss plant pathogens for which LAMP is yet to be developed, potential improvements of plant disease diagnosis, and disadvantages that need to be considered.
{"title":"Application of loop-mediated isothermal amplification (LAMP) in plant pathogen detection.","authors":"Liuliu Yang, Yu Sun, Lin Sun, Zehao Wang, Jie Feng, Yue Liang","doi":"10.1094/PHYTO-10-23-0391-KC","DOIUrl":"https://doi.org/10.1094/PHYTO-10-23-0391-KC","url":null,"abstract":"<p><p>Plant diseases impact the production of all kinds of crops, resulting in significant economic losses worldwide. Timely and accurate detection of plant pathogens is crucial for surveillance and management of plant diseases. In recent years, loop-mediated isothermal amplification (LAMP) has become a popular method for pathogen detection and disease diagnosis due to the advantages of its simple instrument requirement and constant reaction temperature. In this review, we provide an overview of current research on LAMP, including the reaction system, design of primers, selection of target regions, visualization of amplicons, and application of LAMP on the detection of all major groups of plant pathogens. We also discuss plant pathogens for which LAMP is yet to be developed, potential improvements of plant disease diagnosis, and disadvantages that need to be considered.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352511","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}
Pub Date : 2024-09-30DOI: 10.1094/PHYTO-05-24-0162-R
Stephen Muhindi, Wendy Zellner, Shin-Yi Marzano, Jennifer Boldt, Scott Leisner
Silicon (Si) supplementation permits plants to better deter infection. Supplementing hydroponically-propagated Nicotiana tabacum with 1 mM potassium silicate (K2SiO3) reduced necrotic lesion development on detached leaves by both Botrytis cinerea and Sclerotinia sclerotiorum. Previously, a family of Si-induced genes was identified in N. tabacum. These genes were members of the Solanaceous Histidine-Rich Defensin (HRD) superfamily and were termed NtHRD1s (the first identified family of Nicotiana tabacum Histidine-Rich Defensins). Defensins were originally identified to participate in innate immunity. Thus, the NtHRD1s were tested for antimicrobial effects on plant pathogens. Transient expression of NtHRD1 genes within Nicotiana benthamiana leaves restricted the development of necrotic lesions caused by B. cinerea and S. sclerotiorum. Thus, the NtHRD1s may be an additional Si-responsive factor conferring beneficial effects on plants.
补充硅(Si)可使植物更好地阻止感染。在水培烟草中添加 1 mM 硅酸钾(K2SiO3)可减少灰霉病菌和硬皮病菌在脱落叶片上造成的坏死病变。此前,在 N. tabacum 中发现了一个 Si- 诱导基因家族。这些基因是茄科组氨酸富防御素(HRD)超家族的成员,被称为 NtHRD1s(第一个确定的烟草组氨酸富防御素家族)。防御素最初被认定参与先天性免疫。因此,我们测试了 NtHRD1s 对植物病原体的抗菌作用。NtHRD1 基因在烟草叶片中的瞬时表达限制了由 B. cinerea 和 S. sclerotiorum 引起的坏死病变的发展。因此,NtHRD1s 可能是对植物有益的另一种 Si- 反应因子。
{"title":"Transient Expression of <i>Nicotiana tabacum</i> Silicon-Induced Histidine-Rich Defensins in <i>Nicotiana benthamiana</i> Limits Necrotic Lesion Development Caused by Phytopathogenic Fungi.","authors":"Stephen Muhindi, Wendy Zellner, Shin-Yi Marzano, Jennifer Boldt, Scott Leisner","doi":"10.1094/PHYTO-05-24-0162-R","DOIUrl":"https://doi.org/10.1094/PHYTO-05-24-0162-R","url":null,"abstract":"<p><p>Silicon (Si) supplementation permits plants to better deter infection. Supplementing hydroponically-propagated <i>Nicotiana tabacum</i> with 1 mM potassium silicate (K<sub>2</sub>SiO<sub>3</sub>) reduced necrotic lesion development on detached leaves by both <i>Botrytis cinerea</i> and <i>Sclerotinia sclerotiorum</i>. Previously, a family of Si-induced genes was identified in <i>N. tabacum</i>. These genes were members of the Solanaceous <i>Histidine-Rich Defensin</i> (HRD) superfamily and were termed NtHRD1s (the first identified family of <i>Nicotiana tabacum</i> Histidine-Rich Defensins). Defensins were originally identified to participate in innate immunity. Thus, the NtHRD1s were tested for antimicrobial effects on plant pathogens. Transient expression of <i>NtHRD1</i> genes within <i>Nicotiana benthamiana</i> leaves restricted the development of necrotic lesions caused by <i>B. cinerea</i> and <i>S. sclerotiorum</i>. Thus, the NtHRD1s may be an additional Si-responsive factor conferring beneficial effects on plants.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352513","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}
Bursaphelenchus xylophilus (pine wood nematode, PWN), a migratory plant-parasitic nematode, acts as an etiological agent, inflicting considerable damage to pine forests worldwide. Plant immunity constitutes a crucial factor in resisting various pathogenic invasions. The primary defensive responses of host pines against PWN infection encompass terpene accumulation, defense response-related gene expression, and programmed cell death. Venom allergen-like proteins (VAPs), as potential effectors, are instrumental in facilitating the successful colonization of PWNs. In this study, we investigated the inhibition of B. xylophilus VAP (BxVAP1) expression by RNA interference in vitro. Following BxVAP1 silencing, the reproduction rate and migration rate of the PWN population in Pinus massoniana decreased, the expression of the α-pinene synthase gene was induced, other terpene synthase and pathogenesis-related genes were inhibited and delayed, the peak times and levels of terpene-related substances were changed, and the degree of cavitation in P. massoniana was diminished. Transient expression of BxVAP1 in Nicotiana benthamiana revealed that BxVAP1 was expressed in both the cell membrane and nucleus, inducing programmed cell death and the expression of pathogen-associated molecular pattern-triggered immunity marker genes (NbAcre31 and NbPTI5). This study is the first to demonstrate that silencing the BxVAP1 gene affects host defense responses, including terpenoid metabolism in P. massoniana, and that BxVAP1 can be recognized by N. benthamiana as an effector to trigger its innate immunity, expanding our understanding of the parasitic mechanism of B. xylophilus.
{"title":"<i>Bursaphelenchus xylophilus</i> Venom Allergen-Like Protein BxVAP1, Triggering Plant Defense-Related Programmed Cell Death, Plays an Important Role in Regulating <i>Pinus massoniana</i> Terpene Defense Responses.","authors":"Yuqian Feng, Yongxia Li, Zhenkai Liu, Xuan Wang, Wei Zhang, Dongzhen Li, Xiaojian Wen, Xingyao Zhang","doi":"10.1094/PHYTO-01-24-0026-R","DOIUrl":"https://doi.org/10.1094/PHYTO-01-24-0026-R","url":null,"abstract":"<p><p><i>Bursaphelenchus xylophilus</i> (pine wood nematode, PWN), a migratory plant-parasitic nematode, acts as an etiological agent, inflicting considerable damage to pine forests worldwide. Plant immunity constitutes a crucial factor in resisting various pathogenic invasions. The primary defensive responses of host pines against PWN infection encompass terpene accumulation, defense response-related gene expression, and programmed cell death. Venom allergen-like proteins (VAPs), as potential effectors, are instrumental in facilitating the successful colonization of PWNs. In this study, we investigated the inhibition of <i>B. xylophilus</i> VAP (<i>BxVAP1</i>) expression by RNA interference in vitro. Following <i>BxVAP1</i> silencing, the reproduction rate and migration rate of the PWN population in <i>Pinus massoniana</i> decreased, the expression of the α-pinene synthase gene was induced, other terpene synthase and pathogenesis-related genes were inhibited and delayed, the peak times and levels of terpene-related substances were changed, and the degree of cavitation in <i>P. massoniana</i> was diminished. Transient expression of BxVAP1 in <i>Nicotiana benthamiana</i> revealed that BxVAP1 was expressed in both the cell membrane and nucleus, inducing programmed cell death and the expression of pathogen-associated molecular pattern-triggered immunity marker genes (<i>NbAcre31</i> and <i>NbPTI5</i>). This study is the first to demonstrate that silencing the <i>BxVAP1</i> gene affects host defense responses, including terpenoid metabolism in <i>P. massoniana</i>, and that BxVAP1 can be recognized by <i>N. benthamiana</i> as an effector to trigger its innate immunity, expanding our understanding of the parasitic mechanism of <i>B. xylophilus</i>.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352509","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}
Pub Date : 2024-09-25DOI: 10.1094/PHYTO-04-24-0129-R
Jun-Jun Liu, Richard A Sniezko, Sydney Houston, Genoa Alger, Jodie Krakowski, Anna W Schoettle, Robert Sissons, Arezoo Zamany, Holly Williams, Benjamin Rancourt, Angelia Kegley
The coevolution of virulence reduces the effectiveness of host resistance to pathogens, posing a direct threat to forest species and their key ecosystem functions. This exacerbates the threat to limber pine (Pinus flexilis), an endangered species in Canada due to rapid declines mainly driven by white pine blister rust (WPBR) as caused by Cronartium ribicola. We present the first report on a new C. ribicola virulent race (designated vcr4) that overcomes limber pine major gene (Cr4) resistance (MGR). Field surveys found that three parental trees (pf-503, pf-508 and pf-2015-0070) were cankered with WPBR in Alberta, but their progenies showed MGR-related phenotypic segregation post-inoculation of avirulent race (Avcr4). Genotyping of their progenies using Cr4-linked DNA markers and genome-wide association study (GWAS) provided additional support that these cankered parental trees had Cr4-controlled MGR. To confirm the presence of vcr4, aeciospores were collected from the cankered pf-503 tree to inoculate resistant seedlings that had survived prior inoculation using Avcr4 race, as well as seedlings of two US seed parents, one previously confirmed with MGR (Cr4) and one non-MGR, respectively. All inoculated seedlings showed clear stem symptoms, confirming the virulent race is vcr4. These results provide insights into evolution of C. ribicola virulence, and reinforces caution on deployment of Cr4-controlled MGR. The information will be useful for designing a breeding program for durable resistance by layering both R genes with quantitative trait loci (QTLs) for resistance to WPBR in North America.
{"title":"A New Threat to Limber Pine (<i>Pinus flexilis</i>) Restoration in Alberta and Beyond: First Documentation of a <i>Cronartium ribicola</i> race (<i>vcr4</i>) Virulent to <i>Cr4</i>-Controlled Major Gene Resistance.","authors":"Jun-Jun Liu, Richard A Sniezko, Sydney Houston, Genoa Alger, Jodie Krakowski, Anna W Schoettle, Robert Sissons, Arezoo Zamany, Holly Williams, Benjamin Rancourt, Angelia Kegley","doi":"10.1094/PHYTO-04-24-0129-R","DOIUrl":"https://doi.org/10.1094/PHYTO-04-24-0129-R","url":null,"abstract":"<p><p>The coevolution of virulence reduces the effectiveness of host resistance to pathogens, posing a direct threat to forest species and their key ecosystem functions. This exacerbates the threat to limber pine (<i>Pinus flexilis</i>), an endangered species in Canada due to rapid declines mainly driven by white pine blister rust (WPBR) as caused by <i>Cronartium ribicola</i>. We present the first report on a new <i>C. ribicola</i> virulent race (designated <i>vcr4</i>) that overcomes limber pine major gene (<i>Cr4</i>) resistance (MGR). Field surveys found that three parental trees (pf-503, pf-508 and pf-2015-0070) were cankered with WPBR in Alberta, but their progenies showed MGR-related phenotypic segregation post-inoculation of avirulent race (<i>Avcr4</i>). Genotyping of their progenies using <i>Cr4</i>-linked DNA markers and genome-wide association study (GWAS) provided additional support that these cankered parental trees had <i>Cr4</i>-controlled MGR. To confirm the presence of <i>vcr4</i>, aeciospores were collected from the cankered pf-503 tree to inoculate resistant seedlings that had survived prior inoculation using <i>Avcr4</i> race, as well as seedlings of two US seed parents, one previously confirmed with MGR (<i>Cr4</i>) and one non-MGR, respectively. All inoculated seedlings showed clear stem symptoms, confirming the virulent race is <i>vcr4</i>. These results provide insights into evolution of <i>C. ribicola</i> virulence, and reinforces caution on deployment of <i>Cr4</i>-controlled MGR. The information will be useful for designing a breeding program for durable resistance by layering both R genes with quantitative trait loci (QTLs) for resistance to WPBR in North America.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352510","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}
Pub Date : 2024-09-25DOI: 10.1094/PHYTO-05-24-0154-R
WenWen Li, FeiFei Liu, ShuaiFei Chen, Michael J Wingfield, Tuan A Duong
Calonectria pseudoreteaudii causes a serious and widespread disease known as Calonectria leaf blight in Eucalyptus plantations of southern China. Little is known regarding the population biology or reproductive biology of this pathogen in the affected areas. The aims of this study were to investigate the genetic diversity, population structure and the reproductive mode of C. pseudoreteaudii from affected Eucalyptus plantations of southern China. Ten polymorphic SSR markers were developed for the species, and were used to genotype 311 isolates from eight populations. The mating types of all isolates were identified using the MAT gene primers. The results revealed a high level of genetic diversity of the pathogen in all investigated populations. Of the 90 multilocus genotypes detected, ten were shared between at least two populations. With the exception of one population from HuiZhou, GuangDong (7HZ), the most dominant genotype was shared in seven remaining populations. DAPC and population differentiation analyses showed that the 7HZ population was well differentiated from the others and that there was no significant differentiation between the remaining populations. AMOVA suggested that most molecular variation was within populations (86%). Index of association analysis was consistent with a predominantly asexual life cycle for C. pseudoreteaudii in the studied regions. Although both mating types were detected in seven of the eight populations, the MAT1-1/MAT1-2 ratios in these populations deviated significantly from the 1:1 ratio expected in a randomly mating population.
{"title":"High genetic diversity and limited regional population differentiation in populations of <i>Calonectria pseudoreteaudii</i> from <i>Eucalyptus</i> plantations.","authors":"WenWen Li, FeiFei Liu, ShuaiFei Chen, Michael J Wingfield, Tuan A Duong","doi":"10.1094/PHYTO-05-24-0154-R","DOIUrl":"https://doi.org/10.1094/PHYTO-05-24-0154-R","url":null,"abstract":"<p><p><i>Calonectria pseudoreteaudii</i> causes a serious and widespread disease known as Calonectria leaf blight in <i>Eucalyptus</i> plantations of southern China. Little is known regarding the population biology or reproductive biology of this pathogen in the affected areas. The aims of this study were to investigate the genetic diversity, population structure and the reproductive mode of <i>C. pseudoreteaudii</i> from affected <i>Eucalyptus</i> plantations of southern China. Ten polymorphic SSR markers were developed for the species, and were used to genotype 311 isolates from eight populations. The mating types of all isolates were identified using the <i>MAT</i> gene primers. The results revealed a high level of genetic diversity of the pathogen in all investigated populations. Of the 90 multilocus genotypes detected, ten were shared between at least two populations. With the exception of one population from HuiZhou, GuangDong (7HZ), the most dominant genotype was shared in seven remaining populations. DAPC and population differentiation analyses showed that the 7HZ population was well differentiated from the others and that there was no significant differentiation between the remaining populations. AMOVA suggested that most molecular variation was within populations (86%). Index of association analysis was consistent with a predominantly asexual life cycle for <i>C. pseudoreteaudii</i> in the studied regions. Although both mating types were detected in seven of the eight populations, the <i>MAT1-1</i>/<i>MAT1-2</i> ratios in these populations deviated significantly from the 1:1 ratio expected in a randomly mating population.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352512","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}
Pine wilt disease (PWD) is caused by pine wood nematode (PWN, Bursaphelenchus xylophilus) and significantly impacts pine forest ecosystems globally. This study focuses on Pinus massoniana, an important timber and oleoresin resource in China, and is highly susceptible to PWN. However, the defense mechanism of pine trees in response to PWN remains unclear. Addressing the complexities of PWD, influenced by diverse factors like bacteria, fungi, and environment, we established a reciprocal system between PWN and P. massoniana seedlings under aseptic conditions. Utilizing combined second and third-generation sequencing technologies, we identified 3,718 differentially expressed genes post-PWN infection. Transcript analysis highlighted the activation of defense mechanisms via stilbenes, salicylic acid and jasmonic acid pathways, terpene synthesis, and induction of pathogenesis-related proteins and resistance genes, predominantly at 72 hours post-infection. Notably, terpene synthesis pathways, particularly the mevalonate pathway, were crucial in defense, suggesting their significance in P. massoniana's response to PWN. This comprehensive transcriptome profiling offers insights into P. massoniana's intricate defense strategies against PWN under aseptic conditions laid a foundation for future functional analyses of key resistance genes.
{"title":"Unraveling <i>Pinus massoniana</i>'s defense mechanisms against <i>Bursaphelenchus xylophilus</i> under aseptic conditions: A transcriptomic analysis.","authors":"Jinghui Zhu, Kean-Jin Lim, Tianyu Fang, Chen Zhang, Jianren Ye, Li-Hua Zhu","doi":"10.1094/PHYTO-06-24-0180-R","DOIUrl":"https://doi.org/10.1094/PHYTO-06-24-0180-R","url":null,"abstract":"<p><p>Pine wilt disease (PWD) is caused by pine wood nematode (PWN, <i>Bursaphelenchus xylophilus</i>) and significantly impacts pine forest ecosystems globally. This study focuses on <i>Pinus massoniana</i>, an important timber and oleoresin resource in China, and is highly susceptible to PWN. However, the defense mechanism of pine trees in response to PWN remains unclear. Addressing the complexities of PWD, influenced by diverse factors like bacteria, fungi, and environment, we established a reciprocal system between PWN and <i>P. massoniana</i> seedlings under aseptic conditions. Utilizing combined second and third-generation sequencing technologies, we identified 3,718 differentially expressed genes post-PWN infection. Transcript analysis highlighted the activation of defense mechanisms via stilbenes, salicylic acid and jasmonic acid pathways, terpene synthesis, and induction of pathogenesis-related proteins and resistance genes, predominantly at 72 hours post-infection. Notably, terpene synthesis pathways, particularly the mevalonate pathway, were crucial in defense, suggesting their significance in <i>P. massoniana</i>'s response to PWN. This comprehensive transcriptome profiling offers insights into <i>P. massoniana</i>'s intricate defense strategies against PWN under aseptic conditions laid a foundation for future functional analyses of key resistance genes.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142293751","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}
Pub Date : 2024-09-16DOI: 10.1094/PHYTO-02-24-0064-R
Md Musharaf Hossain, Edel Pérez López, Christopher D Todd, Yangdou Wei, Peta C Bonham-Smith
Plasmodiophora brassicae is an obligate biotroph that causes clubroot disease in cruciferous plants, including canola and Arabidopsis. In contrast to most known bacterial, oomycete and fungal pathogens that colonize at the host apoplastic space, the protist P. brassicae establishes an intracellular colonization within various types of root cells and secretes a plethora of effector proteins to distinct cellular compartments favourable for survival and growth of the pathogen during pathogenesis. Identification and functional characterization of P. brassicae effectors has been hampered by the limited understanding of this unique pathosystem. Here, we report a P. brassicae effector, PbPE23, containing a Ser/Thr kinase domain, that induces necrosis after heterologous expression by leaf infiltration in both host and non-host plants. While PbPE23 is an active kinase, the kinase activity itself is not required for triggering the necrosis in plants. PbPE23 shows a nucleocytoplasmic localization in Nicotiana benthamiana and its N-terminal 25TPdPAQKQ32 sequence, resembling the contiguous hydrophilic TPAP motif and Q-rich region in many Nep1-like proteins (NLPs) from plant-associated microbes, is required for the induction of necrosis. Further, transcript profiling of PbPE23 reveals its high expression at the transition stages from primary to secondary infection, suggesting its potential involvement in the development of clubroot disease.
{"title":"<i>Plasmodiophora brassicae</i> effector PbPE23 induces necrotic responses in both host and non-host plants.","authors":"Md Musharaf Hossain, Edel Pérez López, Christopher D Todd, Yangdou Wei, Peta C Bonham-Smith","doi":"10.1094/PHYTO-02-24-0064-R","DOIUrl":"https://doi.org/10.1094/PHYTO-02-24-0064-R","url":null,"abstract":"<p><p><i>Plasmodiophora brassicae</i> is an obligate biotroph that causes clubroot disease in cruciferous plants, including canola and Arabidopsis. In contrast to most known bacterial, oomycete and fungal pathogens that colonize at the host apoplastic space, the protist <i>P. brassicae</i> establishes an intracellular colonization within various types of root cells and secretes a plethora of effector proteins to distinct cellular compartments favourable for survival and growth of the pathogen during pathogenesis. Identification and functional characterization of <i>P. brassicae</i> effectors has been hampered by the limited understanding of this unique pathosystem. Here, we report a <i>P. brassicae</i> effector, PbPE23, containing a Ser/Thr kinase domain, that induces necrosis after heterologous expression by leaf infiltration in both host and non-host plants. While PbPE23 is an active kinase, the kinase activity itself is not required for triggering the necrosis in plants. PbPE23 shows a nucleocytoplasmic localization in <i>Nicotiana benthamiana</i> and its N-terminal <sup>25</sup>TPdPAQKQ<sup>32</sup> sequence, resembling the contiguous hydrophilic TPAP motif and Q-rich region in many Nep1-like proteins (NLPs) from plant-associated microbes, is required for the induction of necrosis. Further, transcript profiling of <i>PbPE23</i> reveals its high expression at the transition stages from primary to secondary infection, suggesting its potential involvement in the development of clubroot disease.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142293749","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}
Pub Date : 2024-09-16DOI: 10.1094/PHYTO-07-24-0206-R
Robbert van Himbeeck, Eline Laura Binnebösz, Deisy Amora, Michele Gottardi, Jaap-Jan Willig, Stefan Geisen, Johannes Helder
Potato cyst nematodes (PCN) are notorious pathogens in all major potato production areas worldwide. Mainly due to the low mobility of this soil pathogen, PCN infestations are mostly observed as patches ('foci') that only cover a fraction of the acreage. In-field pre-symptomatic localization of this pathogen is valuable as it would allow for the localized application of control measures. Although the mapping of foci is technically feasible, it is unpractical as it would take the analysis of numerous soil samples. We investigated whether chlorophyll fluorescence (Chl-F) could be suitable as a rapid, non-destructive method for early PCN detection. To this end, the impact of four Globodera pallida densities on the Chl-F of tomato was investigated in a phenotyping greenhouse for 26 days. Furthermore, classical plant performance indicators biomass and root surface area were compared with Chl-F. Thermal dissipation ('NPQ_Lss') and actual photosynthetic rate ('QY_Lss') responded at 1 DPI, while QY_Lss was most sensitive to low PCN infection levels. Chl-F parameters responded more readily to PCN infection than biomass and root surface area. The efficiency of photosystem II (QY_max) and the potential activity of photosystem II (Fv/Fo) initially increased at low PCN infection levels, whereas a sharp decrease was observed at higher infestation levels. Hence, our data suggest that low PCN levels promoted plant performance before becoming detrimental at higher levels. While Chl-F allowed for early and sensitive PCN detection, it remains to be investigated whether these signals can be distinguished from those produced by other below-ground stressors in the field.
{"title":"Non-invasive, pre-symptomatic detection of potato cyst nematode infection in tomato using chlorophyll fluorescence analysis.","authors":"Robbert van Himbeeck, Eline Laura Binnebösz, Deisy Amora, Michele Gottardi, Jaap-Jan Willig, Stefan Geisen, Johannes Helder","doi":"10.1094/PHYTO-07-24-0206-R","DOIUrl":"https://doi.org/10.1094/PHYTO-07-24-0206-R","url":null,"abstract":"<p><p>Potato cyst nematodes (PCN) are notorious pathogens in all major potato production areas worldwide. Mainly due to the low mobility of this soil pathogen, PCN infestations are mostly observed as patches ('foci') that only cover a fraction of the acreage. In-field pre-symptomatic localization of this pathogen is valuable as it would allow for the localized application of control measures. Although the mapping of foci is technically feasible, it is unpractical as it would take the analysis of numerous soil samples. We investigated whether chlorophyll fluorescence (Chl-F) could be suitable as a rapid, non-destructive method for early PCN detection. To this end, the impact of four <i>Globodera pallida</i> densities on the Chl-F of tomato was investigated in a phenotyping greenhouse for 26 days. Furthermore, classical plant performance indicators biomass and root surface area were compared with Chl-F. Thermal dissipation ('NPQ_Lss') and actual photosynthetic rate ('QY_Lss') responded at 1 DPI, while QY_Lss was most sensitive to low PCN infection levels. Chl-F parameters responded more readily to PCN infection than biomass and root surface area. The efficiency of photosystem II (QY_max) and the potential activity of photosystem II (Fv/Fo) initially increased at low PCN infection levels, whereas a sharp decrease was observed at higher infestation levels. Hence, our data suggest that low PCN levels promoted plant performance before becoming detrimental at higher levels. While Chl-F allowed for early and sensitive PCN detection, it remains to be investigated whether these signals can be distinguished from those produced by other below-ground stressors in the field.</p>","PeriodicalId":20410,"journal":{"name":"Phytopathology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142293750","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}