scholarly journals A Phytophthora capsici effector suppresses plant immunity via interaction with EDS1

2020 ◽  
Vol 21 (4) ◽  
pp. 502-511 ◽  
Author(s):  
Qi Li ◽  
Ji Wang ◽  
Tian Bai ◽  
Ming Zhang ◽  
Yuling Jia ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Phytophthora Capsici

scholarly journals A Phytophthora capsici RXLR effector manipulates plant immunity by targeting RAB proteins and disturbing vesicle-mediated protein trafficking pathway

2021 ◽  
Author(s):  
Tianli Li ◽  
Gan Ai ◽  
Xiaowei Fu ◽  
Jin Liu ◽  
Hai Zhu ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Functional Characterization ◽  
Ectopic Expression ◽  
Defense Responses ◽  
Infection Process ◽  
Small Gtpase ◽  
Rab Proteins ◽  
Rxlr Effector

The oomycete pathogen Phytophthora capsici encodes hundreds of RXLR effectors to enter plant cells and suppress host defense responses. Only few of them are conserved across different strains and species. Such ‘core effectors’ may target hub immunity pathways that are essential during Phytophthora pathogens interacting with their hosts. However, the underlying mechanisms of core RXLRs-mediated host immunity manipulation are largely unknown. Here, we report the functional characterization of a P. capsici RXLR effector, RXLR242. RXLR242 expression is highly induced during the infection process. Its ectopic expression in Nicotiana benthamiana promotes Phytophthora infection. RXLR242 physically interacts with a group of RAB proteins, which belong to the small GTPase family and function in specifying transport pathways in the intracellular membrane trafficking system. RXLR242 impedes the secretion of PATHOGENESIS-RELATED 1 (PR1) protein to the apoplast by interfering the formation of RABE1-7-labeled vesicles. Further analysis indicated that such phenomenon is resulted from competitive binding of RXLR242 to RABE1-7. RXLR242 also interferes trafficking of the membrane-located receptor FLAGELLIN-SENSING 2 (FLS2) through competitively interacting with RABA4-3. Taken together, our work demonstrates that RXLR242 manipulates plant immunity by targeting RAB proteins and disturbing vesicle-mediated protein transporting pathway in plant hosts.

scholarly journals A Phytophthora sojae CRN effector mediates phosphorylation and degradation of plant aquaporin proteins to suppress host immune signaling

2021 ◽  
Vol 17 (3) ◽  
pp. e1009388
Author(s):  
Gan Ai ◽  
Qingyue Xia ◽  
Tianqiao Song ◽  
Tianli Li ◽  
Hai Zhu ◽  
...  
Keyword(s):  
Higher Plants ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Kinase Domain ◽  
Phytophthora Sojae ◽  
Effector Proteins ◽  
Ros Accumulation ◽  
Oomycete Pathogen ◽  
Cellular Defenses

Phytophthora genomes encode a myriad of Crinkler (CRN) effectors, some of which contain putative kinase domains. Little is known about the host targets of these kinase-domain-containing CRNs and their infection-promoting mechanisms. Here, we report the host target and functional mechanism of a conserved kinase CRN effector named CRN78 in a notorious oomycete pathogen, Phytophthora sojae. CRN78 promotes Phytophthora capsici infection in Nicotiana benthamiana and enhances P. sojae virulence on the host plant Glycine max by inhibiting plant H2O2 accumulation and immunity-related gene expression. Further investigation reveals that CRN78 interacts with PIP2-family aquaporin proteins including NbPIP2;2 from N. benthamiana and GmPIP2-13 from soybean on the plant plasma membrane, and membrane localization is necessary for virulence of CRN78. Next, CRN78 promotes phosphorylation of NbPIP2;2 or GmPIP2-13 using its kinase domain in vivo, leading to their subsequent protein degradation in a 26S-dependent pathway. Our data also demonstrates that NbPIP2;2 acts as a H2O2 transporter to positively regulate plant immunity and reactive oxygen species (ROS) accumulation. Phylogenetic analysis suggests that the phosphorylation sites of PIP2 proteins and the kinase domains of CRN78 homologs are highly conserved among higher plants and oomycete pathogens, respectively. Therefore, this study elucidates a conserved and novel pathway used by effector proteins to inhibit host cellular defenses by targeting and hijacking phosphorylation of plant aquaporin proteins.

scholarly journals Virulence strategies of an insect herbivore and oomycete plant pathogen converge on host E3 SUMO ligase SIZ1 to suppress plant immunity

2020 ◽  
Author(s):  
S. Liu ◽  
C.J.G. Lenoir ◽  
T.M.M.M. Amaro ◽  
P.A. Rodriguez ◽  
E. Huitema ◽  
...  
Keyword(s):  
Immune Responses ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Negative Regulator ◽  
Herbivorous Insect ◽  
Post Translational Modifications ◽  
Sumo Ligase ◽  
Small Set ◽  
Oomycete Pathogen ◽  
Host Target

AbstractPlant parasites must colonise and reproduce on plants to survive. In most cases, active immune responses, triggered by (conserved) microbe-encoded molecules keep invaders at bay. Post-translational modifications (PTMs) of proteins are vital for contextual regulation and integration of plant immune responses. Pathogens and pests secrete proteins (effectors) to interfere with plant immunity through modification of host target functions and disruption of immune signalling networks. Importantly, molecular virulence strategies of distinct pathogens converge on a small set of regulators with central roles in plant immunity. The extent of convergence between pathogen and herbivorous insect virulence strategies is largely unexplored. Here we report that effectors from the oomycete pathogen, Phytophthora capsici, and the major aphid pest, Myzus persicae target the host immune regulator SIZ1, an E3 SUMO ligase. SIZ1-regulated immunity in Arabidopsis against bacterial pathogens is known to require the resistance protein SNC1, and signalling components PAD4 and EDS1. We show that SIZ1 functions as a negative regulator of plant immunity to aphids and an oomycete pathogen. However, this immune regulation is independent of SNC1, PAD4 and EDS1-signalling pointing to the presence of a novel SIZ1-mediated immune signalling route. Our results suggest convergence of distinct pathogen and pest virulence strategies on an E3 SUMO ligase that negatively regulates plant immunity.

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.

A Phytophthora capsici RXLR effector targets and inhibits the central immune kinases to suppress plant immunity

2021 ◽  
Author(s):  
Xiangxiu Liang ◽  
Yazhou Bao ◽  
Meixiang Zhang ◽  
Dandan Du ◽  
Shaofei Rao ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Rxlr Effector

scholarly journals Phytophthora capsici CBM1‐containing protein CBP3 is an apoplastic effector with plant immunity‐inducing activity

2021 ◽  
Author(s):  
Zhiyuan Yin ◽  
Nan Wang ◽  
Weiwei Duan ◽  
Lei Pi ◽  
Danyu Shen ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Phytophthora Capsici

scholarly journals Type 2 Nep1-Like Proteins from the Biocontrol Oomycete Pythium oligandrum Suppress Phytophthora capsici Infection in Solanaceous Plants

2021 ◽  
Vol 7 (7) ◽  
pp. 496
Author(s):  
Kun Yang ◽  
Xiaohua Dong ◽  
Jialu Li ◽  
Yi Wang ◽  
Yang Cheng ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Control Plant ◽  
Plant Diseases ◽  
In Planta ◽  
Pythium Oligandrum ◽  
Suppression Effect ◽  
Peptide Pattern ◽  
Solanaceous Plants

As a non-pathogenic oomycete, the biocontrol agent Pythium oligandrum is able to control plant diseases through direct mycoparasite activity and boosting plant immune responses. Several P. oligandrum elicitors have been found to activate plant immunity as microbe-associated molecular patterns (MAMPs). Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are a group of MAMPs widely distributed in eukaryotic and prokaryotic plant pathogens. However, little is known about their distribution and functions in P. oligandrum and its sister species Pythium periplocum. Here, we identified a total of 25 NLPs from P. oligandrum (PyolNLPs) and P. periplocum (PypeNLPs). Meanwhile, we found that PyolNLPs/PypeNLPs genes cluster in two chromosomal segments, and our analysis suggests that they expand by duplication and share a common origin totally different from that of pathogenic oomycetes. Nine PyolNLPs/PypeNLPs induced necrosis in Nicotiana benthamiana by agroinfiltration. Eight partially purified PyolNLPs/PypeNLPs were tested for their potential biocontrol activity. PyolNLP5 and PyolNLP7 showed necrosis-inducing activity in N. benthamiana via direct protein infiltration. At sufficient concentrations, they both significantly reduced disease severity and suppressed the in planta growth of Phytophthora capsici in solanaceous plants including N. benthamiana (tobacco), Solanum lycopersicum (tomato) and Capsicum annuum (pepper). Our assays suggest that the Phytophthora suppression effect of PyolNLP5 and PyolNLP7 is irrelevant to reactive oxygen species (ROS) accumulation. Instead, they induce the expression of antimicrobial plant defensin genes, and the induction depends on their conserved nlp24-like peptide pattern. This work demonstrates the biocontrol role of two P. oligandrum NLPs for solanaceous plants, which uncovers a novel approach of utilizing NLPs to develop bioactive formulae for oomycete pathogen control with no ROS-caused injury to plants.

Plant immunity: Born to cheat

Nature China ◽  
2008 ◽  
Author(s):  
Wei Zeng
Keyword(s):  
Plant Immunity
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