{"title":"Resolving <i>Fusarium</i>: Current Status of the Genus.","authors":"Brett A Summerell","doi":"10.1146/annurev-phyto-082718-100204","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100204","url":null,"abstract":"<p><p>The fungal genus <i>Fusarium</i> is one of the most important groups of plant-pathogenic fungi and affects a huge diversity of crops in all climatic zones across the globe. In addition, it is also a human pathogen and produces several extremely important mycotoxins in food products that have deleterious effects on livestock and humans. These fungi have been plagued over the past century by different perspectives of what constitutes the genus <i>Fusarium</i> and how many species occur within the genus. Currently, there are conflicting views on the generic boundaries and what defines a species that impact disease diagnosis, management, and biosecurity legislation. An approach to defining and identifying <i>Fusarium</i> that places the needs of the community of users (especially, in this case, phytopathologists) to the forefront is presented in this review.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"323-339"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37349782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niklaus J Grünwald, Jared M LeBoldus, Richard C Hamelin
{"title":"Ecology and Evolution of the Sudden Oak Death Pathogen <i>Phytophthora ramorum</i>.","authors":"Niklaus J Grünwald, Jared M LeBoldus, Richard C Hamelin","doi":"10.1146/annurev-phyto-082718-100117","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100117","url":null,"abstract":"<p><p>The sudden oak and sudden larch death pathogen <i>Phytophthora ramorum</i> emerged simultaneously in the United States on oak and in Europe on <i>Rhododendron</i> in the 1990s. This pathogen has had a devastating impact on larch plantations in the United Kingdom as well as mixed conifer and oak forests in the Western United States. Since the discovery of this pathogen, a large body of research has provided novel insights into the emergence, epidemiology, and genetics of this pandemic. Genetic and genomic resources developed for <i>P. ramorum</i> have been instrumental in improving our understanding of the epidemiology, evolution, and ecology of this disease. The recent reemergence of EU1 in the United States and EU2 in Europe and the discovery of <i>P. ramorum</i> in Asia provide renewed impetus for research on the sudden oak death pathogen.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"301-321"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37349781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pathways of DNA Transfer to Plants from <i>Agrobacterium tumefaciens</i> and Related Bacterial Species.","authors":"Benoît Lacroix, Vitaly Citovsky","doi":"10.1146/annurev-phyto-082718-100101","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100101","url":null,"abstract":"<p><p>Genetic transformation of host plants by <i>Agrobacterium tumefaciens</i> and related species represents a unique model for natural horizontal gene transfer. Almost five decades of studying the molecular interactions between <i>Agrobacterium</i> and its host cells have yielded countless fundamental insights into bacterial and plant biology, even though several steps of the DNA transfer process remain poorly understood. <i>Agrobacterium</i> spp. may utilize different pathways for transferring DNA, which likely reflects the very wide host range of <i>Agrobacterium</i>. Furthermore, closely related bacterial species, such as rhizobia, are able to transfer DNA to host plant cells when they are provided with <i>Agrobacterium</i> DNA transfer machinery and T-DNA. Homologs of <i>Agrobacterium</i> virulence genes are found in many bacterial genomes, but only one non-<i>Agrobacterium</i> bacterial strain, <i>Rhizobium etli</i> CFN42, harbors a complete set of virulence genes and can mediate plant genetic transformation when carrying a T-DNA-containing plasmid.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"231-251"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37349785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>Fusarium graminearum</i> Trichothecene Mycotoxins: Biosynthesis, Regulation, and Management.","authors":"Yun Chen, H Corby Kistler, Zhonghua Ma","doi":"10.1146/annurev-phyto-082718-100318","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100318","url":null,"abstract":"<p><p>Fusarium head blight (FHB) of small grain cereals caused by <i>Fusarium graminearum</i> and other <i>Fusarium</i> species is an economically important plant disease worldwide. <i>Fusarium</i> infections not only result in severe yield losses but also contaminate grain with various mycotoxins, especially deoxynivalenol (DON). With the complete genome sequencing of <i>F. graminearum</i>, tremendous progress has been made during the past two decades toward understanding the basis for DON biosynthesis and its regulation. Here, we summarize the current understanding of DON biosynthesis and the effect of regulators, signal transduction pathways, and epigenetic modifications on DON production and the expression of biosynthetic <i>TRI</i> genes. In addition, strategies for controlling FHB and DON contamination are reviewed. Further studies on these biosynthetic and regulatory systems will provide useful knowledge for developing novel management strategies to prevent FHB incidence and mycotoxin accumulation in cereals.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"15-39"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37075522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shree P Thapa, Edward W Davis, Qingyang Lyu, Alexandra J Weisberg, Danielle M Stevens, Christopher R Clarke, Gitta Coaker, Jeff H Chang
{"title":"The Evolution, Ecology, and Mechanisms of Infection by Gram-Positive, Plant-Associated Bacteria.","authors":"Shree P Thapa, Edward W Davis, Qingyang Lyu, Alexandra J Weisberg, Danielle M Stevens, Christopher R Clarke, Gitta Coaker, Jeff H Chang","doi":"10.1146/annurev-phyto-082718-100124","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100124","url":null,"abstract":"<p><p>Gram-positive bacteria are prominent members of plant-associated microbial communities. Although many are hypothesized to be beneficial, some are causative agents of economically important diseases of crop plants. Because the features of Gram-positive bacteria are fundamentally different relative to those of Gram-negative bacteria, the evolution and ecology as well as the mechanisms used to colonize and infect plants also differ. Here, we discuss recent advances in our understanding of Gram-positive, plant-associated bacteria and provide a framework for future research directions on these important plant symbionts.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"341-365"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37126816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christopher R Clarke, Michael P Timko, John I Yoder, Michael J Axtell, James H Westwood
{"title":"Molecular Dialog Between Parasitic Plants and Their Hosts.","authors":"Christopher R Clarke, Michael P Timko, John I Yoder, Michael J Axtell, James H Westwood","doi":"10.1146/annurev-phyto-082718-100043","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100043","url":null,"abstract":"Parasitic plants steal sugars, water, and other nutrients from host plants through a haustorial connection. Several species of parasitic plants such as witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) are major biotic constraints to agricultural production. Parasitic plants are understudied compared with other major classes of plant pathogens, but the recent availability of genomic and transcriptomic data has accelerated the rate of discovery of the molecular mechanisms underpinning plant parasitism. Here, we review the current body of knowledge of how parasitic plants sense host plants, germinate, form parasitic haustorial connections, and suppress host plant immune responses. Additionally, we assess whether parasitic plants fit within the current paradigms used to understand the molecular mechanisms of microbial plant-pathogen interactions. Finally, we discuss challenges facing parasitic plant research and propose the most urgent questions that need to be answered to advance our understanding of plant parasitism.","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"279-299"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37349783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Revisiting the Concept of Host Range of Plant Pathogens.","authors":"Cindy E Morris, Benoît Moury","doi":"10.1146/annurev-phyto-082718-100034","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100034","url":null,"abstract":"<p><p>Strategies to manage plant disease-from use of resistant varieties to crop rotation, elimination of reservoirs, landscape planning, surveillance, quarantine, risk modeling, and anticipation of disease emergences-all rely on knowledge of pathogen host range. However, awareness of the multitude of factors that influence the outcome of plant-microorganism interactions, the spatial and temporal dynamics of these factors, and the diversity of any given pathogen makes it increasingly challenging to define simple, all-purpose rules to circumscribe the host range of a pathogen. For bacteria, fungi, oomycetes, and viruses, we illustrate that host range is often an overlapping continuum-more so than the separation of discrete pathotypes-and that host jumps are common. By setting the mechanisms of plant-pathogen interactions into the scales of contemporary land use and Earth history, we propose a framework to assess the frontiers of host range for practical applications and research on pathogen evolution.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"63-90"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37411442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Durability of Quantitative Resistance in Crops: Greater Than We Know?","authors":"Christina Cowger, James K M Brown","doi":"10.1146/annurev-phyto-082718-100016","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100016","url":null,"abstract":"<p><p>Quantitative resistance (QR) to crop diseases has usually been much more durable than major-gene, effector-triggered resistance. It has been observed that the effectiveness of some QR has eroded as pathogens adapt to it, especially when deployment is extensive and epidemics occur regularly, but it generally declines more slowly than effector-triggered resistance. Changes in aggressiveness and specificity of diverse pathogens on cultivars with QR have been recorded, along with experimental data on fitness costs of pathogen adaptation to QR, but there is little information about molecular mechanisms of adaptation. Some QR has correlated or antagonistic effects on multiple diseases. Longitudinal data on cultivars' disease ratings in trials over several years can be used to assess the significance of QR for durable resistance in crops. It is argued that published data likely underreport the durability of QR, owing to publication bias. The implications of research on QR for plant breeding are discussed.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"253-277"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37341359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aude Cerutti, Alain Jauneau, Patrick Laufs, Nathalie Leonhardt, Martin H Schattat, Richard Berthomé, Jean-Marc Routaboul, Laurent D Noël
{"title":"Mangroves in the Leaves: Anatomy, Physiology, and Immunity of Epithemal Hydathodes.","authors":"Aude Cerutti, Alain Jauneau, Patrick Laufs, Nathalie Leonhardt, Martin H Schattat, Richard Berthomé, Jean-Marc Routaboul, Laurent D Noël","doi":"10.1146/annurev-phyto-082718-100228","DOIUrl":"https://doi.org/10.1146/annurev-phyto-082718-100228","url":null,"abstract":"Hydathodes are organs found on aerial parts of a wide range of plant species that provide almost direct access for several pathogenic microbes to the plant vascular system. Hydathodes are better known as the site of guttation, which is the release of droplets of plant apoplastic fluid to the outer leaf surface. Because these organs are only described through sporadic allusions in the literature, this review aims to provide a comprehensive view of hydathode development, physiology, and immunity by compiling a historic and contemporary bibliography. In particular, we refine the definition of hydathodes. We illustrate their important roles in the maintenance of plant osmotic balance, nutrient retrieval, and exclusion of deleterious chemicals from the xylem sap. Finally, we present our current understanding of the infection of hydathodes by adapted vascular pathogens and the associated plant immune responses.","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"57 ","pages":"91-116"},"PeriodicalIF":10.2,"publicationDate":"2019-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-082718-100228","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37248981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanisms Underlying Establishment of Arbuscular Mycorrhizal Symbioses.","authors":"Jeongmin Choi, William Summers, Uta Paszkowski","doi":"10.1146/annurev-phyto-080516-035521","DOIUrl":"https://doi.org/10.1146/annurev-phyto-080516-035521","url":null,"abstract":"<p><p>Most land plants engage in mutually beneficial interactions with arbuscular mycorrhizal (AM) fungi, the fungus providing phosphate and nitrogen in exchange for fixed carbon. During presymbiosis, both organisms communicate via oligosaccharides and butenolides. The requirement for a rice chitin receptor in symbiosis-induced lateral root development suggests that cell division programs operate in inner root tissues during both AM and nodule symbioses. Furthermore, the identification of transcription factors underpinning arbuscule development and degeneration reemphasized the plant's regulatory dominance in AM symbiosis. Finally, the finding that AM fungi, as lipid auxotrophs, depend on plant fatty acids (FAs) to complete their asexual life cycle revealed the basis for fungal biotrophy. Intriguingly, lipid metabolism is also central for asexual reproduction and interaction of the fungal sister clade, the Mucoromycotina, with endobacteria, indicative of an evolutionarily ancient role for lipids in fungal mutualism.</p>","PeriodicalId":8251,"journal":{"name":"Annual review of phytopathology","volume":"56 ","pages":"135-160"},"PeriodicalIF":10.2,"publicationDate":"2018-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-phyto-080516-035521","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10578418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}