scholarly journals Spotlight on the Roles of Whitefly Effectors in Insect–Plant Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Diana Naalden ◽  
Paula J. M. van Kleeff ◽  
Sarmina Dangol ◽  
Marieke Mastop ◽  
Rebecca Corkill ◽  
...  
Keyword(s):  
Plant Viruses ◽  
Effector Proteins ◽  
Plant Interactions ◽  
In Planta ◽  
Crop Resistance ◽  
Resistance To Insects ◽  
Wide Range ◽  
Core Concepts ◽  
Phloem Feeding ◽  
Compatible Interactions

The Bemisia tabaci species complex (whitefly) causes enormous agricultural losses. These phloem-feeding insects induce feeding damage and transmit a wide range of dangerous plant viruses. Whiteflies colonize a broad range of plant species that appear to be poorly defended against these insects. Substantial research has begun to unravel how phloem feeders modulate plant processes, such as defense pathways, and the central roles of effector proteins, which are deposited into the plant along with the saliva during feeding. Here, we review the current literature on whitefly effectors in light of what is known about the effectors of phloem-feeding insects in general. Further analysis of these effectors may improve our understanding of how these insects establish compatible interactions with plants, whereas the subsequent identification of plant defense processes could lead to improved crop resistance to insects. We focus on the core concepts that define the effectors of phloem-feeding insects, such as the criteria used to identify candidate effectors in sequence-mining pipelines and screens used to analyze the potential roles of these effectors and their targets in planta. We discuss aspects of whitefly effector research that require further exploration, including where effectors localize when injected into plant tissues, whether the effectors target plant processes beyond defense pathways, and the properties of effectors in other insect excretions such as honeydew. Finally, we provide an overview of open issues and how they might be addressed.

scholarly journals Identification of a putative DNA-binding protein in Arabidopsis that acts as a susceptibility hub and interacts with multiple Pseudomonas syringae effectors

2020 ◽  
Author(s):  
Karl Schreiber ◽  
Jennifer D Lewis
Keyword(s):  
Pseudomonas Syringae ◽  
Transcriptional Profiling ◽  
Effector Proteins ◽  
Ribosomal Protein Genes ◽  
Loss Of Function ◽  
Wild Type ◽  
In Planta ◽  
Arabidopsis Protein ◽  
Wide Range

Phytopathogens use secreted effector proteins to suppress host immunity and promote pathogen virulence, and there is increasing evidence that the host-pathogen interactome comprises a complex network. In an effort to identify novel interactors of the Pseudomonas syringae effector HopZ1a, we performed a yeast two-hybrid screen that identified a previously uncharacterized Arabidopsis protein that we designate HopZ1a Interactor 1 (ZIN1). Additional analyses in yeast and in planta revealed that ZIN1 also interacts with several other P. syringae effectors. We show that an Arabidopsis loss-of-function zin1 mutant is less susceptible to infection by certain strains of P. syringae, while overexpression of ZIN1 results in enhanced susceptibility. Functionally, ZIN1 exhibits topoisomerase-like activity in vitro. Transcriptional profiling of wild-type and zin1 Arabidopsis plants inoculated with P. syringae indicated that while ZIN1 regulates a wide range of pathogen-responsive biological processes, the list of genes more highly expressed in zin1 versus wild-type plants was particularly enriched for ribosomal protein genes. Altogether, these data illuminate ZIN1 as a potential susceptibility hub that interacts with multiple effectors to influence the outcome of plant-microbe interactions.

scholarly journals Genomes and secretomes of Ascomycota fungi reveal diverse functions in plant biomass decomposition and pathogenesis

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jean F. Challacombe ◽  
Cedar N. Hesse ◽  
Lisa M. Bramer ◽  
Lee Ann McCue ◽  
Mary Lipton ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Carbon Sources ◽  
Effector Proteins ◽  
Arid Ecosystems ◽  
Exact Nature ◽  
Plant Interactions ◽  
Symbiotic Associations ◽  
Wide Range ◽  
Arid Grasslands ◽  
Biomass Decomposition

Abstract Background The dominant fungi in arid grasslands and shrublands are members of the Ascomycota phylum. Ascomycota fungi are important drivers in carbon and nitrogen cycling in arid ecosystems. These fungi play roles in soil stability, plant biomass decomposition, and endophytic interactions with plants. They may also form symbiotic associations with biocrust components or be latent saprotrophs or pathogens that live on plant tissues. However, their functional potential in arid soils, where organic matter, nutrients and water are very low or only periodically available, is poorly characterized. Results Five Ascomycota fungi were isolated from different soil crust microhabitats and rhizosphere soils around the native bunchgrass Pleuraphis jamesii in an arid grassland near Moab, UT, USA. Putative genera were Coniochaeta, isolated from lichen biocrust, Embellisia from cyanobacteria biocrust, Chaetomium from below lichen biocrust, Phoma from a moss microhabitat, and Aspergillus from the soil. The fungi were grown in replicate cultures on different carbon sources (chitin, native bunchgrass or pine wood) relevant to plant biomass and soil carbon sources. Secretomes produced by the fungi on each substrate were characterized. Results demonstrate that these fungi likely interact with primary producers (biocrust or plants) by secreting a wide range of proteins that facilitate symbiotic associations. Each of the fungal isolates secreted enzymes that degrade plant biomass, small secreted effector proteins, and proteins involved in either beneficial plant interactions or virulence. Aspergillus and Phoma expressed more plant biomass degrading enzymes when grown in grass- and pine-containing cultures than in chitin. Coniochaeta and Embellisia expressed similar numbers of these enzymes under all conditions, while Chaetomium secreted more of these enzymes in grass-containing cultures. Conclusions This study of Ascomycota genomes and secretomes provides important insights about the lifestyles and the roles that Ascomycota fungi likely play in arid grassland, ecosystems. However, the exact nature of those interactions, whether any or all of the isolates are true endophytes, latent saprotrophs or opportunistic phytopathogens, will be the topic of future studies.

scholarly journals Chromosomal Locus That Affects Pathogenicity of Rhodococcus fascians

2002 ◽  
Vol 184 (4) ◽  
pp. 1112-1120 ◽  
Author(s):  
Danny Vereecke ◽  
Karen Cornelis ◽  
Wim Temmerman ◽  
Mondher Jaziri ◽  
Marc Van Montagu ◽  
...  
Keyword(s):  
Krebs Cycle ◽  
Malate Synthase ◽  
Habitat Modification ◽  
Signal Molecules ◽  
In Planta ◽  
Chromosomal Locus ◽  
Physiological Alterations ◽  
Rhodococcus Fascians ◽  
Wide Range ◽  
Symptomatic Tissue

ABSTRACT The gram-positive plant pathogen Rhodococcus fascians provokes leafy gall formation on a wide range of plants through secretion of signal molecules that interfere with the hormone balance of the host. Crucial virulence genes are located on a linear plasmid, and their expression is tightly controlled. A mutant with a mutation in a chromosomal locus that affected virulence was isolated. The mutation was located in gene vicA, which encodes a malate synthase and is functional in the glyoxylate shunt of the Krebs cycle. VicA is required for efficient in planta growth in symptomatic, but not in normal, plant tissue, indicating that the metabolic requirement of the bacteria or the nutritional environment in plants or both change during the interaction. We propose that induced hyperplasia on plants represents specific niches for the causative organisms as a result of physiological alterations in the symptomatic tissue. Hence, such interaction could be referred to as metabolic habitat modification.

scholarly journals Novel System for the Simultaneous Analysis ofGeminivirus DNA Replication and Plant Interactions in Nicotianabenthamiana

2003 ◽  
Vol 77 (24) ◽  
pp. 13315-13322 ◽  
Author(s):  
Yiguo Hong ◽  
John Stanley ◽  
Rene van Wezel
Keyword(s):  
Defense Mechanism ◽  
Intracellular Localization ◽  
Potato Virus X ◽  
African Cassava Mosaic Virus ◽  
Origin Of Replication ◽  
Amino Acid Residues ◽  
Plant Interactions ◽  
In Planta ◽  
Gfp Fusion Protein ◽  
Host Defense Mechanism

ABSTRACT The origin of replication of African cassava mosaic virus (ACMV) and a gene expression vector based on Potato virus X were exploited to devise an in planta system for functional analysis of the geminivirus replication-associated protein (Rep) in transgenic Nicotiana benthamiana line pOri-2. This line contains an integrated copy of a tandem repeat of the ACMV origin of replication flanking nonviral sequences that can be mobilized and replicated by Rep as an episomal replicon. A Rep-GFP fusion protein can also mobilize and amplify the replicon, facilitating Rep detection in planta. The activity of Rep and its mutants, Rep-mediated host response, and the correlation between Rep intracellular localization and biological functions could be effectively assessed by using this in planta system. Our results indicate that modification of amino acid residues R2, R5, R7 and K11 or H56, L57 and H58 prevent Rep function in replication. This defect correlates with possible loss of Rep nuclear localization and inability to trigger the host defense mechanism resembling a hypersensitive response.

scholarly journals In-field screening for host plant resistance to Delia radicum and Brevicoryne brassicae within selected rapeseed cultivars and new interspecific hybrids

2020 ◽  
Vol 15 (1) ◽  
pp. 711-720
Author(s):  
Janetta Niemann ◽  
Justyna Szwarc ◽  
Jan Bocianowski ◽  
Dorota Weigt ◽  
Marek Mrówczyński
Keyword(s):  
Life Sciences ◽  
Field Trials ◽  
Brevicoryne Brassicae ◽  
Delia Radicum ◽  
Sources Of Resistance ◽  
Cabbage Aphid ◽  
Hybrid Combination ◽  
Resistance To Insects ◽  
Wide Range ◽  
High Level

AbstractRapeseed (Brassica napus) can be attacked by a wide range of pests, for example, cabbage root fly (Delia radicum) and cabbage aphid (Brevicoryne brassicae). One of the best methods of pest management is breeding for insect resistance in rapeseed. Wild genotypes of Brassicaceae and rapeseed cultivars can be used as a source of resistance. In 2017, 2018, and 2019, field trials were performed to assess the level of resistance to D. radicum and B. brassicae within 53 registered rapeseed cultivars and 31 interspecific hybrid combinations originating from the resources of the Department of Genetics and Plant Breeding of Poznań University of Life Sciences (PULS). The level of resistance varied among genotypes and years. Only one hybrid combination and two B. napus cultivars maintained high level of resistance in all tested years, i.e., B. napus cv. Jet Neuf × B. carinata – PI 649096, Galileus, and Markolo. The results of this research indicate that resistance to insects is present in Brassicaceae family and can be transferred to rapeseed cultivars. The importance of continuous improvement of rapeseed pest resistance and the search for new sources of resistance is discussed; furthermore, plans for future investigations are presented.

scholarly journals Multiple cellular compartments engagement in Nicotiana benthamiana-peanut stunt virus-satRNA interactions revealed by systems biology approach

2021 ◽  
Author(s):  
Barbara Wrzesińska ◽  
Agnieszka Zmienko ◽  
Lam Dai Vu ◽  
Ive De Smet ◽  
Aleksandra Obrępalska-Stęplowska
Keyword(s):  
Virus Infection ◽  
Nicotiana Benthamiana ◽  
Cellular Localization ◽  
Plant Interactions ◽  
Satellite Rna ◽  
Functional Connections ◽  
Cell Compartments ◽  
Wide Range ◽  
Peanut Stunt Virus ◽  
Cellular Compartments

Abstract Key message PSV infection changed the abundance of host plant’s transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and cytosol, affecting photosynthesis, translation, transcription, and splicing. Abstract Virus infection is a process resulting in numerous molecular, cellular, and physiological changes, a wide range of which can be analyzed due to development of many high-throughput techniques. Plant RNA viruses are known to replicate in the cytoplasm; however, the roles of chloroplasts and other cellular structures in the viral replication cycle and in plant antiviral defense have been recently emphasized. Therefore, the aim of this study was to analyze the small RNAs, transcripts, proteins, and phosphoproteins affected during peanut stunt virus strain P (PSV-P)–Nicotiana benthamiana interactions with or without satellite RNA (satRNA) in the context of their cellular localization or functional connections with particular cellular compartments to elucidate the compartments most affected during pathogenesis at the early stages of infection. Moreover, the processes associated with particular cell compartments were determined. The ‘omic’ results were subjected to comparative data analyses. Transcriptomic and small RNA (sRNA)–seq data were obtained to provide new insights into PSV-P–satRNA–plant interactions, whereas previously obtained proteomic and phosphoproteomic data were used to broaden the analysis to terms associated with cellular compartments affected by virus infection. Based on the collected results, infection with PSV-P contributed to changes in the abundance of transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and the cytosol, and the most affected processes were photosynthesis, translation, transcription, and mRNA splicing. Furthermore, sRNA-seq and phosphoproteomic analyses indicated that kinase regulation resulted in decreases in phosphorylation levels. The kinases were associated with the membrane, cytoplasm, and nucleus components.

Solid State Materials Chemistry

2021 ◽  
Author(s):  
Patrick M. Woodward ◽  
Pavel Karen ◽  
John S. O. Evans ◽  
Thomas Vogt
Keyword(s):  
Materials Science ◽  
Specific Property ◽  
Integrated Treatment ◽  
Synthesis Methods ◽  
Materials Chemistry ◽  
Wide Range ◽  
Hands On ◽  
Hands On Learning ◽  
Extended Solids ◽  
Core Concepts

This comprehensive textbook provides a modern, self-contained treatment for upper undergraduate and graduate level students. It emphasizes the links between structure, defects, bonding, and properties throughout, and provides an integrated treatment of a wide range of materials, including crystalline, amorphous, organic and nano- materials. Boxes on synthesis methods, characterization tools, and technological applications distil specific examples and support student understanding of materials and their design. The first six chapters cover the fundamentals of extended solids, while later chapters explore a specific property or class of material, building a coherent framework for students to master core concepts with confidence, and for instructors to easily tailor the coverage to fit their own single semester course. With mathematical details given only where they strengthen understanding, 400 original figures and over 330 problems for hands-on learning, this accessible textbook is ideal for courses in chemistry and materials science.

scholarly journals A salivary effector enables whitefly to feed on host plants by eliciting salicylic acid-signaling pathway

2018 ◽  
Vol 116 (2) ◽  
pp. 490-495 ◽  
Author(s):  
Hong-Xing Xu ◽  
Li-Xin Qian ◽  
Xing-Wei Wang ◽  
Ruo-Xuan Shao ◽  
Yue Hong ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Signaling Pathway ◽  
Host Plants ◽  
Salivary Protein ◽  
In Planta ◽  
Protein Protein Interaction ◽  
Salicylic Acid Signaling ◽  
Homeobox Transcription Factor ◽  
Phloem Feeding ◽  
Sa Signaling

Phloem-feeding insects feed on plant phloem using their stylets. While ingesting phloem sap, these insects secrete saliva to circumvent plant defenses. Previous studies have shown that, to facilitate their feeding, many phloem-feeding insects can elicit the salicylic acid- (SA-) signaling pathway and thus suppress effective jasmonic acid defenses. However, the molecular basis for the regulation of the plant's defense by phloem-feeding insects remains largely unknown. Here, we show that Bt56, a whitefly-secreted low molecular weight salivary protein, is highly expressed in the whitefly primary salivary gland and is delivered into host plants during feeding. Overexpression of the Bt56 gene in planta promotes susceptibility of tobacco to the whitefly and elicits the SA-signaling pathway. In contrast, silencing the whitefly Bt56 gene significantly decreases whitefly performance on host plants and interrupts whitefly phloem feeding with whiteflies losing the ability to activate the SA pathway. Protein-protein interaction assays show that the Bt56 protein directly interacts with a tobacco KNOTTED 1-like homeobox transcription factor that decreases whitefly performance and suppresses whitefly-induced SA accumulation. The Bt56 orthologous genes are highly conserved but differentially expressed in different species of whiteflies. In conclusion, Bt56 is a key salivary effector that promotes whitefly performance by eliciting salicylic acid-signaling pathway.

scholarly journals Genome context influences evolutionary flexibility of nearly identical type III effectors in two phytopathogenic Pseudomonads

2021 ◽  
Author(s):  
David A Baltrus ◽  
Qian Feng ◽  
Brian H Kvitko
Keyword(s):  
Pseudomonas Syringae ◽  
Evolutionary Dynamics ◽  
Effector Proteins ◽  
In Planta ◽  
Genomic Context ◽  
Type Iii Effectors ◽  
Type Iii ◽  
Genome Context ◽  
The Impact ◽  
Multiple Type

Integrative Conjugative Elements (ICEs) are replicons that can insert and excise from chromosomal locations in a site specific manner, can conjugate across strains, and which often carry a variety of genes useful for bacterial growth and survival under specific conditions. Although ICEs have been identified and vetted within certain clades of the agricultural pathogen Pseudomonas syringae, the impact of ICE carriage and transfer across the entire P. syringae species complex remains underexplored. Here we identify and vet an ICE (PmaICE-DQ) from P. syringae pv. maculicola ES4326, a strain commonly used for laboratory virulence experiments, demonstrate that this element can excise and conjugate across strains, and contains loci encoding multiple type III effector proteins. Moreover, genome context suggests that another ICE (PmaICE-AOAB) is highly similar in comparison with and found immediately adjacent to PmaICE-DQ within the chromosome of strain ES4326, and also contains multiple type III effectors. Lastly, we present passage data from in planta experiments that suggests that genomic plasticity associated with ICEs may enable strains to more rapidly lose type III effectors that trigger R-gene mediated resistance in comparison to strains where nearly isogenic effectors are not present in ICEs. Taken together, our study sheds light on a set of ICE elements from P. syringae pv. maculicola ES4326 and highlights how genomic context may lead to different evolutionary dynamics for shared virulence genes between strains.

scholarly journals An ancient antimicrobial protein co-opted by a fungal plant pathogen for in planta mycobiome manipulation

2021 ◽  
Author(s):  
Nick Snelders ◽  
Gabriella Petti ◽  
Grardy van den Berg ◽  
Michael Seidl ◽  
Bart Thomma
Keyword(s):  
Life Stage ◽  
Antibacterial Properties ◽  
Plant Evolution ◽  
Effector Proteins ◽  
Plant Colonization ◽  
Antimicrobial Protein ◽  
In Planta ◽  
Antimicrobial Proteins ◽  
Pathogenic Microbes ◽  
Plant Microbiome

Microbes typically secrete a plethora of molecules to promote niche colonization. Soil-dwelling microbes are well-known producers of antimicrobials that are exploited to outcompete microbial co-inhabitants. Also plant pathogenic microbes secrete a diversity of molecules into their environment for niche establishment. Upon plant colonization, microbial pathogens secrete so-called effector proteins that promote disease development. While such effectors are typically considered to exclusively act through direct host manipulation, we recently reported that the soil-borne fungal xylem-colonizing vascular wilt pathogen Verticillium dahliae exploits effector proteins with antibacterial properties to promote host colonization through the manipulation of beneficial host microbiota. Since fungal evolution preceded land plant evolution, we now speculate that a subset of the pathogen effectors involved in host microbiota manipulation evolved from ancient antimicrobial proteins of terrestrial fungal ancestors that served in microbial competition prior to the evolution of plant pathogenicity. Here, we show that V. dahliae has co-opted an ancient antimicrobial protein as effector, named VdAMP3, for mycobiome manipulation in planta. We show that VdAMP3 is specifically expressed to ward off fungal niche competitors during resting structure formation in senescing mesophyll tissues. Our findings indicate that effector-mediated microbiome manipulation by plant pathogenic microbes extends beyond bacteria and also concerns eukaryotic members of the plant microbiome. Finally, we demonstrate that fungal pathogens can exploit plant microbiome-manipulating effectors in a life-stage specific manner, and that a subset of these effectors has evolved from ancient antimicrobial proteins of fungal ancestors that likely originally functioned in manipulation of terrestrial biota.

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