scholarly journals Functional analysis of a Phytophthora host-translocated effector using the yeast model system

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12576
Author(s):  
Avery C. Wilson ◽  
William R. Morgan
Keyword(s):  
Amino Acid ◽  
Plant Pathogens ◽  
Bioinformatics Analysis ◽  
Effector Proteins ◽  
Yeast Cells ◽  
Phosphate Homeostasis ◽  
Rxlr Effectors ◽  
Effector Genes ◽  
Rxlr Effector ◽  
Yeast Genes

Background Phytophthora plant pathogens secrete effector proteins that are translocated into host plant cells during infection and collectively contribute to pathogenicity. A subset of these host-translocated effectors can be identified by the amino acid motif RXLR (arginine, any amino acid, leucine, arginine). Bioinformatics analysis has identified hundreds of putative RXLR effector genes in Phytophthora genomes, but the specific molecular function of most remains unknown. Methods Here we describe initial studies to investigate the use of Saccharomyces cerevisiae as a eukaryotic model to explore the function of Phytophthora RXLR effector proteins. Results and Conclusions Expression of individual RXLR effectors in yeast inhibited growth, consistent with perturbation of a highly conserved cellular process. Transcriptome analysis of yeast cells expressing the poorly characterized P. sojae RXLR effector Avh110 identified nearly a dozen yeast genes whose expression levels were altered greater than two-fold compared to control cells. All five of the most down-regulated yeast genes are normally induced under low phosphate conditions via the PHO4 transcription factor, indicating that PsAvh110 perturbs the yeast regulatory network essential for phosphate homeostasis and suggesting likely PsAvh110 targets during P. sojae infection of its soybean host.

scholarly journals Effectors with different gears: divergence of Ustilago maydis effector genes is associated with their temporal expression pattern during plant infection

2020 ◽  
Author(s):  
Jasper R.L. Depotter ◽  
Weiliang Zuo ◽  
Maike Hansen ◽  
Boqi Zhang ◽  
Mingliang Xu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plant Pathogens ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Intraspecific Diversity ◽  
Close Relative ◽  
Host Immune System ◽  
Gene Repertoire ◽  
Effector Genes ◽  
Amino Acid Divergence

AbstractPlant pathogens secrete a variety of effector proteins that enable host colonization but are also typical pathogen detection targets for the host immune system. Consequently, effector genes encounter high selection pressures, which typically makes them fast evolving. The corn smut pathogen Ustilago maydis has an effector gene repertoire with a dynamic expression across the different disease stages. We determined the amino acid divergence of U. maydis effector candidates with Sporisorium reilianum orthologs, a close relative of U. maydis. Intriguingly, there are two distinct groups of effector candidates, ones with a respective conserved and diverged protein evolution. Conservatively evolving effector genes especially have their peak expression during the (pre-)penetration stages of the disease cycle. In contrast, expression of divergently evolving effector genes generally peaks during fungal proliferation within the host. To test if this interspecific effector diversity corresponds to intraspecific diversity, we sampled and sequenced a diverse collection of U. maydis strains from the most important maize breeding and production regions in China. Effector candidates with a diverged interspecific evolution had more intraspecific amino acid variation than candidates with a conserved evolution. In conclusion, we highlight diversity in evolution within the U. maydis effector repertoire with dynamically and conservatively evolving members.

scholarly journals Effectors with Different Gears: Divergence of Ustilago maydis Effector Genes Is Associated with Their Temporal Expression Pattern during Plant Infection

2020 ◽  
Vol 7 (1) ◽  
pp. 16
Author(s):  
Jasper R. L. Depotter ◽  
Weiliang Zuo ◽  
Maike Hansen ◽  
Boqi Zhang ◽  
Mingliang Xu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plant Pathogens ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Intraspecific Diversity ◽  
Close Relative ◽  
Host Immune System ◽  
Gene Repertoire ◽  
Effector Genes ◽  
Amino Acid Divergence

Plant pathogens secrete a variety of effector proteins that enable host colonization but are also typical pathogen detection targets for the host immune system. Consequently, effector genes encounter high selection pressures, which typically makes them fast evolving. The corn smut pathogen Ustilago maydis has an effector gene repertoire with a dynamic expression across the different disease stages. We determined the amino acid divergence of U. maydis effector candidates with Sporisorium reilianum orthologs, a close relative of U. maydis. Intriguingly, there are two distinct groups of effector candidates, ones with a respective conserved and diverged protein evolution. Conservatively evolving effector genes especially have their peak expression during the (pre-)penetration stages of the disease cycle. In contrast, expression of divergently evolving effector genes generally peaks during fungal proliferation within the host. To test if this interspecific effector diversity corresponds to intraspecific diversity, we sampled and sequenced a diverse collection of U. maydis strains from the most important maize breeding and production regions in China. Effector candidates with a diverged interspecific evolution had more intraspecific amino acid variation than candidates with a conserved evolution. In conclusion, we highlight diversity in evolution within the U. maydis effector repertoire with dynamically and conservatively evolving members.

scholarly journals Recent Progress in RXLR Effector Research

2015 ◽  
Vol 28 (10) ◽  
pp. 1063-1072 ◽  
Author(s):  
Ryan G. Anderson ◽  
Devdutta Deb ◽  
Kevin Fedkenheuer ◽  
John M. McDowell
Keyword(s):  
Comparative Genomics ◽  
Effector Proteins ◽  
Host Protein ◽  
Protein Targets ◽  
Major Function ◽  
Functional Studies ◽  
Rxlr Effectors ◽  
Cell Compartments ◽  
Rxlr Effector ◽  
Bacteria And Fungi

Some of the most devastating oomycete pathogens deploy effector proteins, with the signature amino acid motif RXLR, that enter plant cells to promote virulence. Research on the function and evolution of RXLR effectors has been very active over the decade that has transpired since their discovery. Comparative genomics indicate that RXLR genes play a major role in virulence for Phytophthora and downy mildew species. Importantly, gene-for-gene resistance against these oomycete lineages is based on recognition of RXLR proteins. Comparative genomics have revealed several mechanisms through which this resistance can be broken, most notably involving epigenetic control of RXLR gene expression. Structural studies have revealed a core fold that is present in the majority of RXLR proteins, providing a foundation for detailed mechanistic understanding of virulence and avirulence functions. Finally, functional studies have demonstrated that suppression of host immunity is a major function for RXLR proteins. Host protein targets are being identified in a variety of plant cell compartments. Some targets comprise hubs that are also manipulated by bacteria and fungi, thereby revealing key points of vulnerability in the plant immune network.

scholarly journals Positively selected effector genes and their contribution to virulence in the smut fungus Sporisorium reilianum

2017 ◽  
Author(s):  
Gabriel Schweizer ◽  
Karin Münch ◽  
Gertrud Mannhaupt ◽  
Jan Schirawski ◽  
Regine Kahmann ◽  
...  
Keyword(s):  
Positive Selection ◽  
Plant Pathogens ◽  
Molecular Mechanisms ◽  
Large Fraction ◽  
Gene Families ◽  
Effector Proteins ◽  
Smut Fungi ◽  
Formae Speciales ◽  
Effector Genes ◽  
Sporisorium Reilianum

AbstractPlants and fungi display a broad range of interactions in natural and agricultural ecosystems ranging from symbiosis to parasitism. These ecological interactions result in coevolution between genes belonging to different partners. A well-understood example are secreted fungal effector proteins and their host targets, which play an important role in pathogenic interactions. Biotrophic smut fungi (Basidiomycota) are well-suited to investigate the evolution of plant pathogens, because several reference genomes and genetic tools are available for these species. Here, we used the genomes of Sporisorium reilianum f. sp. zeae and S. reilianum f. sp. reilianum, two closely related formae speciales infecting maize and sorghum, respectively, together with the genomes of Ustilago hordei, Ustilago maydis and Sporisorium scitamineum to identify and characterize genes displaying signatures of positive selection. We identified 154 gene families having undergone positive selection during species divergence in at least one lineage, among which 77% were identified in the two investigated formae speciales of S. reilianum. Remarkably, only 29% of positively selected genes encode predicted secreted proteins. We assessed the contribution to virulence of nine of these candidate effector genes in S. reilianum f. sp. zeae by deleting individual genes, including a homologue of the effector gene pit2 previously characterized in U. maydis. Only the pit2 deletion mutant was found to be strongly reduced in virulence. Additional experiments are required to understand the molecular mechanisms underlying the selection forces acting on the other candidate effector genes, as well as the large fraction of positively selected genes encoding predicted cytoplasmic proteins.

scholarly journals The RXLR Effector PcAvh1 Is Required for Full Virulence of Phytophthora capsici

2019 ◽  
Vol 32 (8) ◽  
pp. 986-1000 ◽  
Author(s):  
Xiao-Ren Chen ◽  
Ye Zhang ◽  
Hai-Yang Li ◽  
Zi-Hui Zhang ◽  
Gui-Lin Sheng ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Ectopic Expression ◽  
Plant Cells ◽  
Effector Proteins ◽  
Bell Pepper ◽  
Broad Host Range ◽  
Virus Induced Gene Silencing ◽  
Rxlr Effector

Plant pathogens employ diverse secreted effector proteins to manipulate host physiology and defense in order to foster diseases. The destructive Phytophthora pathogens encode hundreds of cytoplasmic effectors, which are believed to function inside the plant cells. Many of these cytoplasmic effectors contain the conserved N-terminal RXLR motif. Understanding the virulence function of RXLR effectors will provide important knowledge of Phytophthora pathogenesis. Here, we report the characterization of RXLR effector PcAvh1 from the broad–host range pathogen Phytophthora capsici. Only expressed during infection, PcAvh1 is quickly induced at the early infection stages. CRISPR/Cas9-knockout of PcAvh1 in P. capsici severely impairs virulence while overexpression enhances disease development in Nicotiana benthamiana and bell pepper, demonstrating that PcAvh1 is an essential virulence factor. Ectopic expression of PcAvh1 induces cell death in N. benthamiana, tomato, and bell pepper. Using yeast two-hybrid screening, we found that PcAvh1 interacts with the scaffolding subunit of the protein phosphatase 2A (PP2Aa) in plant cells. Virus-induced gene silencing of PP2Aa in N. benthamiana attenuates resistance to P. capsici and results in dwarfism, suggesting that PP2Aa regulates plant immunity and growth. Collectively, these results suggest that PcAvh1 contributes to P. capsici infection, probably through its interaction with host PP2Aa.

scholarly journals Rpi-amr3 confers resistance to multiple Phytophthora species by recognizing a conserved RXLR effector

2021 ◽  
Author(s):  
Xiao Lin ◽  
Andrea Olave-Achury ◽  
Robert Heal ◽  
Kamil Witek ◽  
Hari S. Karki ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Plant Pathogens ◽  
Nucleotide Binding ◽  
Phytophthora Species ◽  
Crop Plants ◽  
Leucine Rich Repeat ◽  
Nucleotide Binding Domain ◽  
Rxlr Effectors ◽  
Rxlr Effector

Diverse pathogens from the genus Phytophthora cause disease and reduce yields in many crop plants. Although many Resistance to Phytophthora infestans (Rpi) genes effective against potato late blight have been cloned, few have been cloned against other Phytophthora species. Most Rpi genes encode nucleotide-binding domain, leucine-rich repeat- containing (NLR) proteins, that recognize RXLR effectors. However, whether NLR proteins can recognize RXLR effectors from multiple different Phytophthora pathogens has rarely been investigated. Here, we report the effector AVRamr3 from P. infestans that is recognized by Rpi-amr3 from S. americanum. We show here that AVRamr3 is broadly conserved in many different Phytophthora species, and that recognition of AVRamr3 homologs enables resistance against multiple Phytophthora pathogens, including P. parasitica and P. palmivora. Our findings suggest a novel path to identifying R genes against important plant pathogens.

scholarly journals The Pleiades are a cluster of fungal effectors that inhibit host defenses

2021 ◽  
Vol 17 (6) ◽  
pp. e1009641
Author(s):  
Fernando Navarrete ◽  
Nenad Grujic ◽  
Alexandra Stirnberg ◽  
Indira Saado ◽  
David Aleksza ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Functional Characterization ◽  
Rapid Evolution ◽  
Effector Proteins ◽  
In Planta ◽  
E3 Ligases ◽  
Effector Genes ◽  
Ros Burst ◽  
Molecular Patterns

Biotrophic plant pathogens secrete effector proteins to manipulate the host physiology. Effectors suppress defenses and induce an environment favorable to disease development. Sequence-based prediction of effector function is impeded by their rapid evolution rate. In the maize pathogen Ustilago maydis, effector-coding genes frequently organize in clusters. Here we describe the functional characterization of the pleiades, a cluster of ten effector genes, by analyzing the micro- and macroscopic phenotype of the cluster deletion and expressing these proteins in planta. Deletion of the pleiades leads to strongly impaired virulence and accumulation of reactive oxygen species (ROS) in infected tissue. Eight of the Pleiades suppress the production of ROS upon perception of pathogen associated molecular patterns (PAMPs). Although functionally redundant, the Pleiades target different host components. The paralogs Taygeta1 and Merope1 suppress ROS production in either the cytoplasm or nucleus, respectively. Merope1 targets and promotes the auto-ubiquitination activity of RFI2, a conserved family of E3 ligases that regulates the production of PAMP-triggered ROS burst in plants.

scholarly journals The Pleiades cluster of fungal effector genes inhibit host defenses

2019 ◽  
Author(s):  
Fernando Navarrete ◽  
Nenad Grujic ◽  
Alexandra Stirnberg ◽  
David Aleksza ◽  
Michelle Gallei ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Functional Characterization ◽  
Rapid Evolution ◽  
Effector Proteins ◽  
Host Defenses ◽  
E3 Ligases ◽  
Effector Genes ◽  
Ros Burst ◽  
Molecular Patterns

SummaryBiotrophic plant pathogens secrete effector proteins to manipulate the host physiology. Effectors suppress defenses and induce an environment favorable to disease development. Sequence-based prediction of effector function is difficulted by their rapid evolution rate. In the maize pathogen Ustilago maydis, effector-coding genes frequently organize in clusters. Here we describe the functional characterization of the pleiades, a cluster of ten symplastic effectors. Deletion of the pleiades leads to strongly impaired virulence and accumulation of reactive oxygen species (ROS) in infected tissue. Eight of the Pleiades suppress the production of ROS upon perception of pathogen associated molecular patterns (PAMPs). Although genetically redundant, the Pleiades target different host components. The paralogs Taygeta1 and Merope1 suppress ROS production in either the cytoplasm or nucleus, respectively. Merope1 targets and promotes the autoubiquitination activity of RFI2, a conserved family of E3 ligases that regulates the production of PAMP-triggered ROS burst and influences flowering time in plants.

scholarly journals Conserved RxLR Effectors From Oomycetes Hyaloperonospora arabidopsidis and Phytophthora sojae Suppress PAMP- and Effector-Triggered Immunity in Diverse Plants

2018 ◽  
Vol 31 (3) ◽  
pp. 374-385 ◽  
Author(s):  
Devdutta Deb ◽  
Ryan G. Anderson ◽  
Theresa How-Yew-Kin ◽  
Brett M. Tyler ◽  
John M. McDowell
Keyword(s):  
Plant Pathogens ◽  
Phytophthora Species ◽  
Phytophthora Sojae ◽  
Effector Proteins ◽  
Host Cells ◽  
Rxlr Effectors ◽  
Genes Encoding ◽  
Effector Triggered Immunity ◽  
Hyaloperonospora Arabidopsidis ◽  
Diverse Plant

Effector proteins are exported to the interior of host cells by diverse plant pathogens. Many oomycete pathogens maintain large families of candidate effector genes, encoding proteins with a secretory leader followed by an RxLR motif. Although most of these genes are very divergent between oomycete species, several genes are conserved between Phytophthora species and Hyaloperonospora arabidopsidis, suggesting that they play important roles in pathogenicity. We describe a pair of conserved effector candidates, HaRxL23 and PsAvh73, from H. arabidopsidis and P. sojae respectively. We show that HaRxL23 is expressed early during infection of Arabidopsis. HaRxL23 triggers an ecotype-specific defense response in Arabidopsis, suggesting that it is recognized by a host surveillance protein. HaRxL23 and PsAvh73 can suppress pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) in Nicotiana benthamiana and effector-triggered immunity (ETI) in soybean. Transgenic Arabidopsis constitutively expressing HaRxL23 or PsAvh73 exhibit suppression of PTI and enhancement of bacterial and oomycete virulence. Together, our experiments demonstrate that these conserved oomycete RxLR effectors suppress PTI and ETI across diverse plant species.

Sign in / Sign up

Export Citation Format

Share Document