51
|
van der Burgh AM, Joosten MHAJ. Plant Immunity: Thinking Outside and Inside the Box. Trends Plant Sci 2019; 24:587-601. [PMID: 31171472 DOI: 10.1016/j.tplants.2019.04.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 05/23/2023]
Abstract
Models are extensively used to describe the coevolution of plants and microbial attackers. Such models distinguish between different classes of plant immune responses, based on the type of danger signal that is recognized or on the strength of the defense response that the danger signal provokes. However, recent molecular and biochemical advances have shown that these dichotomies are blurred. With molecular proof in hand, we propose here to abandon the current classification of plant immune responses, and to define the different forms of plant immunity solely based on the site of microbe recognition - either extracellular or intracellular. Using this spatial partition, our 'spatial immunity model' facilitates a broadly inclusive, but clearly distinguishing nomenclature to describe immune signaling in plant-microbe interactions.
Collapse
Affiliation(s)
- Aranka M van der Burgh
- Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
| |
Collapse
|
52
|
Yu H, Bao H, Zhang Z, Cao Y. Immune Signaling Pathway during Terminal Bacteroid Differentiation in Nodules. Trends Plant Sci 2019; 24:299-302. [PMID: 30772172 DOI: 10.1016/j.tplants.2019.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Plant innate immunity plays an important role in regulating symbiotic associations with rhizobia, including during rhizobial infection, rhizobial colonization, and bacteroid differentiation in leguminous plants. Here we propose that an immune signaling pathway similar to plant pattern-triggered immunity (PTI) is required for the regulation of bacteroid differentiation in Medicago truncatula nodules.
Collapse
Affiliation(s)
- Haixiang Yu
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Hanbin Bao
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhongming Zhang
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yangrong Cao
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| |
Collapse
|
53
|
Huang PY, Zhang J, Jiang B, Chan C, Yu JH, Lu YP, Chung K, Zimmerli L. NINJA-associated ERF19 negatively regulates Arabidopsis pattern-triggered immunity. J Exp Bot 2019; 70:1033-1047. [PMID: 30462256 PMCID: PMC6363091 DOI: 10.1093/jxb/ery414] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 11/19/2018] [Indexed: 05/07/2023]
Abstract
Recognition of microbe-associated molecular patterns (MAMPs) derived from invading pathogens by plant pattern recognition receptors (PRRs) initiates a subset of defense responses known as pattern-triggered immunity (PTI). Transcription factors (TFs) orchestrate the onset of PTI through complex signaling networks. Here, we characterized the function of ERF19, a member of the Arabidopsis thaliana ethylene response factor (ERF) family. ERF19 was found to act as a negative regulator of PTI against Botrytis cinerea and Pseudomonas syringae. Notably, overexpression of ERF19 increased plant susceptibility to these pathogens and repressed MAMP-induced PTI outputs. In contrast, expression of the chimeric dominant repressor ERF19-SRDX boosted PTI activation, conferred increased resistance to the fungus B. cinerea, and enhanced elf18-triggered immunity against bacteria. Consistent with a negative role for ERF19 in PTI, MAMP-mediated growth inhibition was weakened or augmented in lines overexpressing ERF19 or expressing ERF19-SRDX, respectively. Using biochemical and genetic approaches, we show that the transcriptional co-repressor Novel INteractor of JAZ (NINJA) associates with and represses the function of ERF19. Our work reveals ERF19 as a novel player in the mitigation of PTI, and highlights a potential role for NINJA in fine-tuning ERF19-mediated regulation of Arabidopsis innate immunity.
Collapse
Affiliation(s)
- Pin-Yao Huang
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
- Howard Hughes Medical Institute, New York University Langone School of Medicine, New York, NY, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Langone School of Medicine, New York, NY, USA
| | - Jingsong Zhang
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Beier Jiang
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Ching Chan
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Jhong-He Yu
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Pin Lu
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - KwiMi Chung
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Ibaraki, Japan
| | - Laurent Zimmerli
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
- Correspondence:
| |
Collapse
|
54
|
Abstract
Plant-parasitic nematodes (PPNs), such as root-knot nematodes (RKNs) and cyst nematodes (CNs), are among the most devastating pests in agriculture. RKNs and CNs induce redifferentiation of root cells into feeding cells, which provide water and nutrients to these nematodes. Plants trigger immune responses to PPN infection by recognizing PPN invasion through several different but complementary systems. Plants recognize pathogen-associated molecular patterns (PAMPs) sderived from PPNs by cell surface-localized pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI). Plants can also recognize tissue and cellular damage caused by invasion or migration of PPNs through PRR-based recognition of damage-associated molecular patterns (DAMPs). Resistant plants have the added ability to recognize PPN effectors via intracellular nucleotide-binding domain leucine-rich repeat (NLR)-type immune receptors, leading to NLR-triggered immunity. Some PRRs may also recognize apoplastic PPN effectors and induce PTI. Plant immune responses against PPNs include the secretion of anti-nematode enzymes, the production of anti-nematode compounds, cell wall reinforcement, production of reactive oxygen species and nitric oxide, and hypersensitive response-mediated cell death. In this review, we summarize the recognition mechanisms for PPN infection and what is known about PPN-induced immune responses in plants.
Collapse
Affiliation(s)
- Kazuki Sato
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Yasuhiro Kadota
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- *Correspondence: Yasuhiro Kadota, ; Ken Shirasu,
| | - Ken Shirasu
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Graduate School of Science, University of Tokyo, Bunkyo, Japan
- *Correspondence: Yasuhiro Kadota, ; Ken Shirasu,
| |
Collapse
|
55
|
Liu Z, Beskrovnaya P, Melnyk RA, Hossain SS, Khorasani S, O'Sullivan LR, Wiesmann CL, Bush J, Richard JD, Haney CH. A Genome-Wide Screen Identifies Genes in Rhizosphere-Associated Pseudomonas Required to Evade Plant Defenses. mBio 2018; 9:e00433-18. [PMID: 30401768 DOI: 10.1128/mBio.00433-18] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
While rhizosphere bacteria hold the potential to improve plant health and fitness, little is known about the bacterial genes required to evade host immunity. Using a model system consisting of Arabidopsis and a beneficial Pseudomonas sp. isolate, we identified bacterial genes required for both rhizosphere fitness and for evading host immune responses. This work advances our understanding of how evasion of host defenses contributes to survival in the rhizosphere. Pseudomonas fluorescens and related plant root (“rhizosphere”)-associated species contribute to plant health by modulating defenses and facilitating nutrient uptake. To identify bacterial fitness determinants in the rhizosphere of the model plant Arabidopsis thaliana, we performed a high-throughput transposon sequencing (Tn-Seq) screen using the biocontrol and growth-promoting strain Pseudomonas sp. WCS365. The screen, which was performed in parallel on wild-type and immunocompromised Arabidopsis plants, identified 231 genes that increased fitness in the rhizosphere of wild-type plants. A subset of these genes decreased fitness in the rhizosphere of immunocompromised plants. We hypothesized that these genes might be involved in avoiding plant defenses and verified 7 Pseudomonas sp. WCS365 candidate genes by generating clean deletions. We found that two of these deletion mutants, ΔmorA (encoding a putative diguanylate cyclase/phosphodiesterase) and ΔspuC (encoding a putrescine aminotransferase), formed enhanced biofilms and inhibited plant growth. We found that mutants ΔspuC and ΔmorA induced pattern-triggered immunity (PTI) as measured by induction of an Arabidopsis PTI reporter and FLS2/BAK1-dependent inhibition of plant growth. We show that MorA acts as a phosphodiesterase to inhibit biofilm formation, suggesting a possible role in biofilm dispersal. We found that both putrescine and its precursor arginine promote biofilm formation that is enhanced in the ΔspuC mutant, which cannot break down putrescine, suggesting that putrescine might serve as a signaling molecule in the rhizosphere. Collectively, this work identified novel bacterial factors required to evade plant defenses in the rhizosphere.
Collapse
|
56
|
Zhou B, Zeng L. The Tomato U-Box Type E3 Ligase PUB13 Acts With Group III Ubiquitin E2 Enzymes to Modulate FLS2-Mediated Immune Signaling. Front Plant Sci 2018; 9:615. [PMID: 29868071 PMCID: PMC5952000 DOI: 10.3389/fpls.2018.00615] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/18/2018] [Indexed: 06/01/2023]
Abstract
In Arabidopsis and rice, the ubiquitin ligase PUB13-mediated protein degradation plays a significant role in plant pattern-triggered immunity (PTI) and flowering time control. The Arabidopsis PUB13 has been shown to attenuate the pattern recognition receptor FLS2-mediated immune signaling by ubiquitinating FLS2 and consequently promoting its degradation by the 26S proteasome. Nevertheless, the cognate ubiquitin-conjugating enzymes (E2) with which PUB13 acts to modulate FLS2-mediated PTI are unknown. To address this question, we investigate here the tomato (Solanum lycopersicum) homolog of PUB13, SlPUB13 by utilizing the recently characterized complete set of tomato E2s. Of the 13 groups of tomato E2s, only members in group III are found to interact and act with SlPUB13. Knocking-down of the group III E2 genes enhances callose deposition and induction of the RbohB gene in the immunity-associated, early oxidative burst after flg22 treatment. The group III E2s are also found to work with SlPUB13 to ubiquitinate FLS2 in vitro and are required for PUB13-mediated degradation of FLS2 in vivo upon flg22 treatment, suggesting an essential role for group III E2s in the modulation of FLS2-mediated immune signaling by PUB13. Additionally, another immunity-associated E3, NtCMPG1 is shown to also work specifically with members of group III E2 in the in vitro ubiquitination assay, which implies the group III E2 enzymes may cooperate with many E3 ligases to regulate different aspects of PTI. Taken together, these data corroborate the notion that group III E2 enzymes play an important role in PTI and build a foundation for further functional and mechanistic characterization of tomato PUB13.
Collapse
|
57
|
Duba A, Goriewa-Duba K, Wachowska U. A Review of the Interactions between Wheat and Wheat Pathogens: Zymoseptoria tritici, Fusarium spp. and Parastagonospora nodorum. Int J Mol Sci 2018; 19:E1138. [PMID: 29642627 PMCID: PMC5979484 DOI: 10.3390/ijms19041138] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/24/2018] [Accepted: 04/06/2018] [Indexed: 12/11/2022] Open
Abstract
Zymoseptoria tritici is a hemibiotrophic pathogen which causes Septoria leaf blotch in wheat. The pathogenesis of the disease consists of a biotrophic phase and a necrotrophic phase. The pathogen infects the host plant by suppressing its immune response in the first stage of infection. Hemibiotrophic pathogens of the genus Fusarium cause Fusarium head blight, and the necrotrophic Parastagonosporanodorum is responsible for Septoria nodorum blotch in wheat. Cell wall-degrading enzymes in plants promote infections by necrotrophic and hemibiotrophic pathogens, and trichothecenes, secondary fungal metabolites, facilitate infections caused by fungi of the genus Fusarium. There are no sources of complete resistance to the above pathogens in wheat. Defense mechanisms in wheat are controlled by many genes encoding resistance traits. In the wheat genome, the characteristic features of loci responsible for resistance to pathogenic infections indicate that at least several dozen genes encode resistance to pathogens. The molecular interactions between wheat and Z. tritici, P. nodorum and Fusarium spp. pathogens have been insufficiently investigated. Most studies focus on the mechanisms by which the hemibiotrophic Z. tritici suppresses immune responses in plants and the role of mycotoxins and effector proteins in infections caused by P. nodorum and Fusarium spp. fungi. Trichothecene glycosylation and effector proteins, which are involved in defense responses in wheat, have been described at the molecular level. Recent advances in molecular biology have produced interesting findings which should be further elucidated in studies of molecular interactions between wheat and fungal pathogens. The Clustered Regularly-Interspaced Short Palindromic Repeats/ CRISPR associated (CRISPR/Cas) system can be used to introduce targeted mutations into the wheat genome and confer resistance to selected fungal diseases. Host-induced gene silencing and spray-induced gene silencing are also useful tools for analyzing wheat-pathogens interactions which can be used to develop new strategies for controlling fungal diseases.
Collapse
Affiliation(s)
- Adrian Duba
- Department of Entomology, Phytopathology and Molecular Diagnostics, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 17, 10-719 Olsztyn, Poland.
| | - Klaudia Goriewa-Duba
- Department of Plant Breeding and Seed Production, University of Warmia and Mazury in Olsztyn, pl. Łódzki 3, 10-724 Olsztyn, Poland.
| | - Urszula Wachowska
- Department of Entomology, Phytopathology and Molecular Diagnostics, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 17, 10-719 Olsztyn, Poland.
| |
Collapse
|
58
|
Li Y, Zhang Y, Wang Q, Wang T, Cao X, Zhao Z, Zhao S, Xu Y, Xiao Z, Li J, Fan J, Yang H, Huang F, Xiao S, Wang W. RESISTANCE TO POWDERY MILDEW8.1 boosts pattern-triggered immunity against multiple pathogens in Arabidopsis and rice. Plant Biotechnol J 2018; 16. [PMID: 28640974 PMCID: PMC5787827 DOI: 10.1111/pbi.12782] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The Arabidopsis gene RESISTANCE TO POWDERY MILDEW8.1 (RPW8.1) confers resistance to virulent fungal and oomycete pathogens that cause powdery mildew and downy mildew, respectively. However, the underlying mechanism remains unclear. Here, we show that ectopic expression of RPW8.1 boosts pattern-triggered immunity (PTI) resulting in enhanced resistance against different pathogens in both Arabidopsis and rice. In Arabidopsis, transcriptome analysis revealed that ectopic expression of RPW8.1-YFP constitutively up-regulates expression of many pathogen-associated molecular pattern (PAMP-)-inducible genes. Consistently, upon PAMP application, the transgenic line expressing RPW8.1-YFP exhibited more pronounced PTI responses such as callose deposition, production of reactive oxygen species, expression of defence-related genes and hypersensitive response-like cell death. Accordingly, the growth of a virulent bacterial pathogen was significantly inhibited in the transgenic lines expressing RPW8.1-YFP. Conversely, impairment of the PTI signalling pathway from PAMP cognition to the immediate downstream relay of phosphorylation abolished or significantly compromised RPW8.1-boosted PTI responses. In rice, heterologous expression of RPW8.1-YFP also led to enhanced resistance to the blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) and the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). Taken together, our data suggest a surprising mechanistic connection between RPW8.1 function and PTI, and demonstrate the potential of RPW8.1 as a transgene for engineering disease resistance across wide taxonomic lineages of plants.
Collapse
Affiliation(s)
- Yan Li
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
- Collaborative Innovation Center for Hybrid Rice in Yangtze River BasinSichuan Agricultural UniversityChengduChina
| | - Yong Zhang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Qing‐Xia Wang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Ting‐Ting Wang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Xiao‐Long Cao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Zhi‐Xue Zhao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Sheng‐Li Zhao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Yong‐Ju Xu
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Zhi‐Yuan Xiao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Jin‐Lu Li
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Jing Fan
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
- Collaborative Innovation Center for Hybrid Rice in Yangtze River BasinSichuan Agricultural UniversityChengduChina
| | - Hui Yang
- College of Agronomy and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Fu Huang
- College of Agronomy and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
| | - Shunyuan Xiao
- Institute of Bioscience and Biotechnology ResearchDepartment of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMDUSA
| | - Wen‐Ming Wang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengduChina
- Collaborative Innovation Center for Hybrid Rice in Yangtze River BasinSichuan Agricultural UniversityChengduChina
| |
Collapse
|
59
|
Leibman-Markus M, Pizarro L, Bar M, Coaker G, Avni A. NRC proteins - a critical node for pattern and effector mediated signaling. Plant Signal Behav 2018; 13:e1507404. [PMID: 30110243 PMCID: PMC6149469 DOI: 10.1080/15592324.2018.1507404] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 07/25/2018] [Indexed: 05/20/2023]
Abstract
Plants are constantly exposed to numerous diverse microbes and pests. They lack an adaptive immune system and rely on innate immunity to perceive and ward off potential pathogens. The plant immune system enables plants to overcome invading microorganisms, and can be defined as highly successful in this regard. Nevertheless, specialized pathogens are able to overcome structural barriers, preformed defenses, innate immunity and are a persistent threat to crop and food supplies worldwide. The rapidly growing world population results in massive demands for agricultural products and reliable crop yields. Therefore, the ability to precisely manipulate plant immunity to resist diverse diseases holds significant promise for enhancing crop production.
Collapse
Affiliation(s)
| | - Lorena Pizarro
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Maya Bar
- Department of Plant Pathology and Weed Research, ARO, Volcani Center, Rishon LeZion, Israel
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, California, USA
| | - Adi Avni
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
- CONTACT Adi Avni School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
60
|
Underwood W, Somerville SC. Phosphorylation is required for the pathogen defense function of the Arabidopsis PEN3 ABC transporter. Plant Signal Behav 2017; 12:e1379644. [PMID: 28910579 PMCID: PMC5647949 DOI: 10.1080/15592324.2017.1379644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 09/11/2017] [Indexed: 05/18/2023]
Abstract
The Arabidopsis PEN3 ABC transporter accumulates at sites of pathogen detection, where it is involved in defense against a number of pathogens. Perception of PAMPs by pattern recognition receptors initiates recruitment of PEN3 and also leads to PEN3 phosphorylation at multiple amino acid residues. Whether PAMP-induced phosphorylation of PEN3 is important for its defense function or focal recruitment has not been addressed. In this study, we evaluated the role of PEN3 phosphorylation in modulating the localization and defense function of the transporter. We report that PEN3 phosphorylation is critical for its function in defense, but dispensable for recruitment to powdery mildew penetration sites. These results indicate that PAMP-induced phosphorylation is likely to regulate the transport activity of PEN3.
Collapse
Affiliation(s)
- William Underwood
- Energy Biosciences Institute, University of California, Berkeley, CA, USA
- USDA-ARS Sunflower and Plant Biology Research Unit, Red River Valley Agricultural Research Center, Fargo, ND, USA
- CONTACT William Underwood USDA-ARS Sunflower and Plant Biology Research Unit, Northern Crop Science Laboratory, 1605 Albrecht Blvd N, Fargo 58102-2765, ND, USA
| | - Shauna C. Somerville
- Energy Biosciences Institute, University of California, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| |
Collapse
|
61
|
Lee DS, Kim YC, Kwon SJ, Ryu CM, Park OK. The Arabidopsis Cysteine-Rich Receptor-Like Kinase CRK36 Regulates Immunity through Interaction with the Cytoplasmic Kinase BIK1. Front Plant Sci 2017; 8:1856. [PMID: 29163585 PMCID: PMC5663720 DOI: 10.3389/fpls.2017.01856] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/11/2017] [Indexed: 05/20/2023]
Abstract
Receptor-like kinases are important signaling components that regulate a variety of cellular processes. In this study, an Arabidopsis cDNA microarray analysis led to the identification of the cysteine-rich receptor-like kinase CRK36 responsive to the necrotrophic fungal pathogen, Alternaria brassicicola. To determine the function of CRK36 in plant immunity, T-DNA-insertion knockdown (crk36) and overexpressing (CRK36OE) plants were prepared. CRK36OE plants exhibited increased hypersensitive cell death and ROS burst in response to avirulent pathogens. Treatment with a typical pathogen-associated molecular pattern, flg22, markedly induced pattern-triggered immune responses, notably stomatal defense, in CRK36OE plants. The immune responses were weakened in crk36 plants. Protein-protein interaction assays revealed the in vivo association of CRK36, FLS2, and BIK1. CRK36 enhanced flg22-triggered BIK1 phosphorylation, which showed defects with Cys mutations in the DUF26 motifs of CRK36. Disruption of BIK1 and RbohD/RbohF genes further impaired CRK36-mediated stomatal defense. We propose that CRK36, together with BIK1 and NADPH oxidases, may form a positive activation loop that enhances ROS burst and leads to the promotion of stomatal immunity.
Collapse
Affiliation(s)
- Dong Sook Lee
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Young Cheon Kim
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Sun Jae Kwon
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, KRIBB, Daejeon, South Korea
| | - Ohkmae K. Park
- Department of Life Sciences, Korea University, Seoul, South Korea
- *Correspondence: Ohkmae K. Park
| |
Collapse
|
62
|
Mbengue M, Bourdais G, Gervasi F, Beck M, Zhou J, Spallek T, Bartels S, Boller T, Ueda T, Kuhn H, Robatzek S. Clathrin-dependent endocytosis is required for immunity mediated by pattern recognition receptor kinases. Proc Natl Acad Sci U S A 2016; 113:11034-9. [PMID: 27651493 PMCID: PMC5047200 DOI: 10.1073/pnas.1606004113] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sensing of potential pathogenic bacteria is of critical importance for immunity. In plants, this involves plasma membrane-resident pattern recognition receptors, one of which is the FLAGELLIN SENSING 2 (FLS2) receptor kinase. Ligand-activated FLS2 receptors are internalized into endosomes. However, the extent to which these spatiotemporal dynamics are generally present among pattern recognition receptors (PRRs) and their regulation remain elusive. Using live-cell imaging, we show that at least three other receptor kinases associated with plant immunity, PEP RECEPTOR 1/2 (PEPR1/2) and EF-TU RECEPTOR (EFR), internalize in a ligand-specific manner. In all cases, endocytosis requires the coreceptor BRI1-ASSOCIATED KINASE 1 (BAK1), and thus depends on receptor activation status. We also show the internalization of liganded FLS2, suggesting the transport of signaling competent receptors. Trafficking of activated PRRs requires clathrin and converges onto the same endosomal vesicles that are also shared with the hormone receptor BRASSINOSTERIOD INSENSITIVE 1 (BRI1). Importantly, clathrin-dependent endocytosis participates in plant defense against bacterial infection involving FLS2-mediated stomatal closure and callose deposition, but is uncoupled from activation of the flagellin-induced oxidative burst and MAP kinase signaling. In conclusion, immunity mediated by pattern recognition receptors depends on clathrin, a critical component for the endocytosis of signaling competent receptors into a common endosomal pathway.
Collapse
Affiliation(s)
- Malick Mbengue
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom
| | | | - Fabio Gervasi
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom; Fruit Tree Research Center, Council for Agricultural Research and Economics, 00134 Rome, Italy
| | - Martina Beck
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom
| | - Ji Zhou
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom
| | - Thomas Spallek
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom
| | - Sebastian Bartels
- Zürich-Basel Plant Science Center, Department of Environmental Sciences, Botany, University of Basel, CH-4056 Basel, Switzerland
| | - Thomas Boller
- Zürich-Basel Plant Science Center, Department of Environmental Sciences, Botany, University of Basel, CH-4056 Basel, Switzerland
| | - Takashi Ueda
- National Institute for Basic Biology, Aichi 444-8585, Japan
| | - Hannah Kuhn
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom; Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, 52056 Aachen, Germany
| | - Silke Robatzek
- The Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom;
| |
Collapse
|
63
|
Abstract
Pathogen-associated molecular pattern-triggered immunity (PTI) builds one of the first layers of plant disease resistance. In susceptible plants, PTI is overcome by adapted pathogens. This can be achieved by suppression of PTI with the help of pathogen virulence effectors. However, effectors may also contribute to modification of host metabolism or cell architecture to ensure successful pathogenesis. Barley responds to treatment with the pathogen-associated molecular patterns flg22 or chitin with phosphorylation of mitogen-activated protein kinases and an oxidative burst. RAC/ROP GTPases can act as positive or negative modulators of these plant immune responses. The RAC/ROP GTPase RACB is a powdery mildew susceptibility factor of barley. However, RACB apparently does not negatively control early PTI responses but functions in polar cell development during invasion of the pathogen into living host epidermal cells. Here, we further discuss the incomplete picture of PTI in Triticeae.
Collapse
Affiliation(s)
- Ralph Hückelhoven
- Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- CONTACT Ralph Hückelhoven
| | - Anna Seidl
- Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| |
Collapse
|
64
|
Teixeira MA, Wei L, Kaloshian I. Root-knot nematodes induce pattern-triggered immunity in Arabidopsis thaliana roots. New Phytol 2016; 211:276-87. [PMID: 26892116 DOI: 10.1111/nph.13893] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/10/2016] [Indexed: 05/08/2023]
Abstract
Root-knot nematodes (RKNs; Meloidogyne spp.) are plant parasites with a broad host range causing great losses worldwide. To parasitize their hosts, RKNs establish feeding sites in roots known as giant cells. The majority of work studying plant-RKN interactions in susceptible hosts addresses establishment of the giant cells and there is limited information on the early defense responses. Here we characterized early defense or pattern-triggered immunity (PTI) against RKNs in Arabidopsis thaliana. To address PTI, we evaluated known canonical PTI signaling mutants with RKNs and investigated the expression of PTI marker genes after RKN infection using both quantitative PCR and β-glucuronidase reporter transgenic lines. We showed that PTI-compromised plants have enhanced susceptibility to RKNs, including the bak1-5 mutant. BAK1 is a common partner of distinct receptors of microbe- and damage-associated molecular patterns. Furthermore, our data indicated that nematode recognition leading to PTI responses involves camalexin and glucosinolate biosynthesis. While the RKN-induced glucosinolate biosynthetic pathway was BAK1-dependent, the camalexin biosynthetic pathway was only partially dependent on BAK1. Combined, our results indicate the presence of BAK1-dependent and -independent PTI against RKNs in A. thaliana, suggesting the existence of diverse nematode recognition mechanisms.
Collapse
Affiliation(s)
- Marcella A Teixeira
- Department of Nematology, University of California, Riverside, CA, 92521, USA
| | - Lihui Wei
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Isgouhi Kaloshian
- Department of Nematology, University of California, Riverside, CA, 92521, USA
- Institute of Integrative Genome Biology, University of California, Riverside, CA, USA
| |
Collapse
|
65
|
Liu C, Pedersen C, Schultz-Larsen T, Aguilar GB, Madriz-Ordeñana K, Hovmøller MS, Thordal-Christensen H. The stripe rust fungal effector PEC6 suppresses pattern-triggered immunity in a host species-independent manner and interacts with adenosine kinases. New Phytol 2016. [PMID: 27252028 DOI: 10.1111/nph.14034] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/25/2016] [Indexed: 05/20/2023]
Abstract
We identified a wheat stripe rust (Puccinia striiformis) effector candidate (PEC6) with pattern-triggered immunity (PTI) suppression function and its corresponding host target. PEC6 compromised PTI host species-independently. In Nicotiana benthamiana, it hampers reactive oxygen species (ROS) accumulation and callose deposition induced by Pseudomonas fluorescens. In Arabidopsis, plants expressing PEC6 were more susceptible to Pseudomonas syringae pv. tomato (Pto) DC3000 ΔAvrPto/ΔAvrPtoB. In wheat, PEC6-suppression of P. fluorescens-elicited PTI was revealed by the fact that it allowed activation of effector-triggered immunity by Pto DC3000. Knocking down of PEC6 expression by virus-mediated host-induced gene silencing decreased the number of rust pustules, uncovering PEC6 as an important pathogenicity factor. PEC6, overexpressed in plant cells without its signal peptide, was localized to the nucleus and cytoplasm. A yeast two-hybrid assay showed that PEC6 interacts with both wheat and Arabidopsis adenosine kinases (ADKs). Knocking down wheat ADK expression by virus-induced gene silencing reduced leaf growth and enhanced the number of rust pustules, indicating that ADK is important in plant development and defence. ADK plays essential roles in regulating metabolism, cytokinin interconversion and methyl transfer reactions, and our data propose a model where PEC6 may affect one of these processes by targeting ADK to favour fungal growth.
Collapse
Affiliation(s)
- Changhai Liu
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Carsten Pedersen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Torsten Schultz-Larsen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Geziel B Aguilar
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Kenneth Madriz-Ordeñana
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Mogens S Hovmøller
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, DK-4200, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| |
Collapse
|
66
|
Yeh YH, Chang YH, Huang PY, Huang JB, Zimmerli L. Enhanced Arabidopsis pattern-triggered immunity by overexpression of cysteine-rich receptor-like kinases. Front Plant Sci 2015; 6:322. [PMID: 26029224 PMCID: PMC4429228 DOI: 10.3389/fpls.2015.00322] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 04/23/2015] [Indexed: 05/19/2023]
Abstract
Upon recognition of microbe-associated molecular patterns (MAMPs) such as the bacterial flagellin (or the derived peptide flg22) by pattern-recognition receptors (PRRs) such as the FLAGELLIN SENSING2 (FLS2), plants activate the pattern-triggered immunity (PTI) response. The L-type lectin receptor kinase-VI.2 (LecRK-VI.2) is a positive regulator of Arabidopsis thaliana PTI. Cysteine-rich receptor-like kinases (CRKs) possess two copies of the C-X8-C-X2-C (DUF26) motif in their extracellular domains and are thought to be involved in plant stress resistance, but data about CRK functions are scarce. Here, we show that Arabidopsis overexpressing the LecRK-VI.2-responsive CRK4, CRK6, and CRK36 demonstrated an enhanced PTI response and were resistant to virulent bacteria Pseudomonas syringae pv. tomato DC3000. Notably, the flg22-triggered oxidative burst was primed in CRK4, CRK6, and CRK36 transgenics and up-regulation of the PTI-responsive gene FLG22-INDUCED RECEPTOR-LIKE 1 (FRK1) was potentiated upon flg22 treatment in CRK4 and CRK6 overexpression lines or constitutively increased by CRK36 overexpression. PTI-mediated callose deposition was not affected by overexpression of CRK4 and CRK6, while CRK36 overexpression lines demonstrated constitutive accumulation of callose. In addition, Pst DC3000-mediated stomatal reopening was blocked in CRK4 and CRK36 overexpression lines, while overexpression of CRK6 induced constitutive stomatal closure suggesting a strengthening of stomatal immunity. Finally, bimolecular fluorescence complementation and co-immunoprecipitation analyses in Arabidopsis protoplasts suggested that the plasma membrane localized CRK4, CRK6, and CRK36 associate with the PRR FLS2. Association with FLS2 and the observation that overexpression of CRK4, CRK6, and CRK36 boosts specific PTI outputs and resistance to bacteria suggest a role for these CRKs in Arabidopsis innate immunity.
Collapse
Affiliation(s)
| | | | | | | | - Laurent Zimmerli
- *Correspondence: Laurent Zimmerli, Institute of Plant Biology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan
| |
Collapse
|
67
|
Zhang H, Huang L, Dai Y, Liu S, Hong Y, Tian L, Huang L, Cao Z, Li D, Song F. Arabidopsis AtERF15 positively regulates immunity against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea. Front Plant Sci 2015; 6:686. [PMID: 26388886 PMCID: PMC4559647 DOI: 10.3389/fpls.2015.00686] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/20/2015] [Indexed: 05/18/2023]
Abstract
Upon pathogen infection, activation of immune response requires effective transcriptional reprogramming that regulates inducible expression of a large set of defense genes. A number of ethylene-responsive factor transcription factors have been shown to play critical roles in regulating immune responses in plants. In the present study, we explored the functions of Arabidopsis AtERF15 in immune responses against Pseudomonas syringae pv. tomato (Pst) DC3000, a (hemi)biotrophic bacterial pathogen, and Botrytis cinerea, a necrotrophic fungal pathogen. Expression of AtERF15 was induced by infection of Pst DC3000 and B. cinerea and by treatments with salicylic acid (SA) and methyl jasmonate. Biochemical assays demonstrated that AtERF15 is a nucleus-localized transcription activator. The AtERF15-overexpressing (AtERF15-OE) plants displayed enhanced resistance while the AtERF15-RNAi plants exhibited decreased resistance against Pst DC3000 and B. cinerea. Meanwhile, Pst DC3000- or B. cinerea-induced expression of defense genes was upregulated in AtERF15-OE plants but downregulated in AtERF15-RNAi plants, as compared to the expression in wild type plants. In response to infection with B. cinerea, the AtERF15-OE plants accumulated less reactive oxygen species (ROS) while the AtERF15-RNAi plants accumulated more ROS. The flg22- and chitin-induced oxidative burst was abolished and expression levels of the pattern-triggered immunity-responsive genes AtFRK1 and AtWRKY53 were suppressed in AtER15-RNAi plants upon treatment with flg22 or chitin. Furthermore, SA-induced defense response was also partially impaired in the AtERF15-RNAi plants. These data demonstrate that AtERF15 is a positive regulator of multiple layers of the immune responses in Arabidopsis.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Fengming Song
- *Correspondence: Fengming Song, National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China,
| |
Collapse
|
68
|
Gupta R, Lee SE, Agrawal GK, Rakwal R, Park S, Wang Y, Kim ST. Understanding the plant-pathogen interactions in the context of proteomics-generated apoplastic proteins inventory. Front Plant Sci 2015; 6:352. [PMID: 26082784 PMCID: PMC4451336 DOI: 10.3389/fpls.2015.00352] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 05/03/2015] [Indexed: 05/14/2023]
Abstract
The extracellular space between cell wall and plasma membrane acts as the first battle field between plants and pathogens. Bacteria, fungi, and oomycetes that colonize the living plant tissues are encased in this narrow region in the initial step of infection. Therefore, the apoplastic region is believed to be an interface which mediates the first crosstalk between host and pathogen. The secreted proteins and other metabolites, derived from both host and pathogen, interact in this apoplastic region and govern the final relationship between them. Hence, investigation of protein secretion and apoplastic interaction could provide a better understanding of plant-microbe interaction. Here, we are briefly discussing the methods available for the isolation and normalization of the apoplastic proteins, as well as the current state of secretome studies focused on the in-planta interaction between the host and the pathogen.
Collapse
Affiliation(s)
- Ravi Gupta
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National UniversityMiryang, South Korea
| | - So Eui Lee
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National UniversityMiryang, South Korea
| | - Ganesh K. Agrawal
- Research Laboratory for Biotechnology and BiochemistryKathmandu, Nepal
- Global Research Arch for Developing Education (GRADE), Academy Private LimitedBirgunj, Nepal
| | - Randeep Rakwal
- Research Laboratory for Biotechnology and BiochemistryKathmandu, Nepal
- Global Research Arch for Developing Education (GRADE), Academy Private LimitedBirgunj, Nepal
- Organization for Educational Initiatives, University of TsukubaTsukuba, Japan
- Faculty of Health and Sport Sciences, Tsukuba International Academy for Sport Studies, University of TsukubaTsukuba, Japan
| | - Sangryeol Park
- Bio-crop Development Division, National Academy of Agricultural Science, Rural Development AdministrationJeonju, South Korea
| | - Yiming Wang
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding ResearchCologne, Germany
- *Correspondence: Sun Tae Kim, Department of Plant Bioscience, Pusan National University, Miryang 627-706, South Korea
| | - Sun T. Kim
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National UniversityMiryang, South Korea
- Yiming Wang, Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne weg 10, Cologne 50829, Germany
| |
Collapse
|
69
|
Abstract
Plants are constantly exposed to potentially pathogenic microbes present in their surrounding environment. Due to the activation of the pattern-triggered immunity (PTI) response that largely relies on accurate detection of pathogen- or microbe-associated molecular patterns by pattern-recognition receptors (PRRs), plants are resistant to the majority of potential pathogens. However, adapted pathogens may avoid recognition or repress plant PTI and resulting diseases significantly affect crop yield worldwide. PTI provides protection against a wide range of pathogens. Reinforcement of PTI through genetic engineering may thus generate crops with broad-spectrum field resistance. In this review, new approaches based on fundamental discoveries in PTI to improve crop immunity are discussed. Notably, we highlight recent studies describing the interfamily transfer of PRRs or key regulators of PTI signaling.
Collapse
Affiliation(s)
- Pin-Yao Huang
- Department of Life Science, National Taiwan UniversityTaipei, Taiwan
- Institute of Plant Biology, National Taiwan UniversityTaipei, Taiwan
| | - Laurent Zimmerli
- Department of Life Science, National Taiwan UniversityTaipei, Taiwan
- Institute of Plant Biology, National Taiwan UniversityTaipei, Taiwan
| |
Collapse
|
70
|
Huang PY, Yeh YH, Liu AC, Cheng CP, Zimmerli L. The Arabidopsis LecRK-VI.2 associates with the pattern-recognition receptor FLS2 and primes Nicotiana benthamiana pattern-triggered immunity. Plant J 2014; 79:243-55. [PMID: 24844677 DOI: 10.1111/tpj.12557] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 04/24/2014] [Accepted: 05/06/2014] [Indexed: 05/27/2023]
Abstract
Pattern-triggered immunity (PTI) is broad spectrum and manipulation of PTI is believed to represent an attractive way to engineer plants with broad-spectrum disease resistance. PTI is activated upon perception of microbe-associated molecular patterns (MAMPs) by pattern-recognition receptors (PRRs). We have recently demonstrated that the L-type lectin receptor kinase-VI.2 (LecRK-VI.2) positively regulates Arabidopsis thaliana PTI. Here we show through in vitro pull-down, bimolecular fluorescence complementation and co-immunoprecipitation analyses that LecRK-VI.2 associates with the PRR FLS2. We also demonstrated that LecRK-VI.2 from the cruciferous plant Arabidopsis remains functional after interfamily transfer to the Solanaceous plant Nicotiana benthamiana. Wild tobacco plants ectopically expressing LecRK-VI.2 were indeed more resistant to virulent hemi-biotrophic and necrotrophic bacteria, but not to the fungal pathogen Botrytis cinerea suggesting that, as with Arabidopsis, the LecRK-VI.2 protective effect in N. benthamiana is bacteria specific. Ectopic expression of LecRK-VI.2 in N. benthamiana primed PTI-mediated reactive oxygen species production, mitogen-activated protein kinase (MAPK) activity, callose deposition and gene expression upon treatment with the MAMP flagellin. Our findings identified LecRK-VI.2 as a member of the FLS2 receptor complex and suggest that heterologous expression of components of PRR complexes can be used as tools to engineer plant disease resistance to bacteria.
Collapse
Affiliation(s)
- Pin-Yao Huang
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | | | | | | | | |
Collapse
|
71
|
Liu X, Grabherr HM, Willmann R, Kolb D, Brunner F, Bertsche U, Kühner D, Franz-Wachtel M, Amin B, Felix G, Ongena M, Nürnberger T, Gust AA. Host-induced bacterial cell wall decomposition mediates pattern-triggered immunity in Arabidopsis. eLife 2014; 3:e01990. [PMID: 24957336 PMCID: PMC4103680 DOI: 10.7554/elife.01990] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 06/20/2014] [Indexed: 12/22/2022] Open
Abstract
Peptidoglycans (PGNs) are immunogenic bacterial surface patterns that trigger immune activation in metazoans and plants. It is generally unknown how complex bacterial structures such as PGNs are perceived by plant pattern recognition receptors (PRRs) and whether host hydrolytic activities facilitate decomposition of bacterial matrices and generation of soluble PRR ligands. Here we show that Arabidopsis thaliana, upon bacterial infection or exposure to microbial patterns, produces a metazoan lysozyme-like hydrolase (lysozyme 1, LYS1). LYS1 activity releases soluble PGN fragments from insoluble bacterial cell walls and cleavage products are able to trigger responses typically associated with plant immunity. Importantly, LYS1 mutant genotypes exhibit super-susceptibility to bacterial infections similar to that observed on PGN receptor mutants. We propose that plants employ hydrolytic activities for the decomposition of complex bacterial structures, and that soluble pattern generation might aid PRR-mediated immune activation in cell layers adjacent to infection sites.
Collapse
Affiliation(s)
- Xiaokun Liu
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Heini M Grabherr
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Roland Willmann
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Dagmar Kolb
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Frédéric Brunner
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Ute Bertsche
- Department of Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Daniel Kühner
- Department of Microbial Genetics, University of Tübingen, Tübingen, Germany
| | | | - Bushra Amin
- Medical and Natural Sciences Research Centre, University of Tübingen, Tübingen, Germany
| | - Georg Felix
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Marc Ongena
- Wallon Centre for Industrial Biology, University of Liege-Gembloux Agro-Bio Tech, Gembloux, Belgium
| | - Thorsten Nürnberger
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Andrea A Gust
- Department of Plant Biochemistry, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| |
Collapse
|
72
|
Zhou J, Wu S, Chen X, Liu C, Sheen J, Shan L, He P. The Pseudomonas syringae effector HopF2 suppresses Arabidopsis immunity by targeting BAK1. Plant J 2014; 77:235-45. [PMID: 24237140 PMCID: PMC4224013 DOI: 10.1111/tpj.12381] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/21/2013] [Accepted: 11/11/2013] [Indexed: 05/18/2023]
Abstract
Pseudomonas syringae delivers a plethora of effector proteins into host cells to sabotage immune responses and modulate physiology to favor infection. The P. syringae pv. tomato DC3000 effector HopF2 suppresses Arabidopsis innate immunity triggered by multiple microbe-associated molecular patterns (MAMP) at the plasma membrane. We show here that HopF2 possesses distinct mechanisms for suppression of two branches of MAMP-activated MAP kinase (MAPK) cascades. In addition to blocking MKK5 (MAPK kinase 5) activation in the MEKK1 (MAPK kinase kinase 1)/MEKKs-MKK4/5-MPK3/6 cascade, HopF2 targets additional component(s) upstream of MEKK1 in the MEKK1-MKK1/2-MPK4 cascade and the plasma membrane-localized receptor-like cytoplasmic kinase BIK1 and its homologs. We further show that HopF2 directly targets BAK1, a plasma membrane-localized receptor-like kinase that is involved in multiple MAMP signaling. The interaction between BAK1 and HopF2 and between two other P. syringae effectors, AvrPto and AvrPtoB, was confirmed in vivo and in vitro. Consistent with BAK1 as a physiological target of AvrPto, AvrPtoB and HopF2, the strong growth defects or lethality associated with ectopic expression of these effectors in wild-type Arabidopsis transgenic plants were largely alleviated in bak1 mutant plants. Thus, our results provide genetic evidence to show that BAK1 is a physiological target of AvrPto, AvrPtoB and HopF2. Identification of BAK1 as an additional target of HopF2 virulence not only explains HopF2 suppression of multiple MAMP signaling at the plasma membrane, but also supports the notion that pathogen virulence effectors act through multiple targets in host cells.
Collapse
Affiliation(s)
- Jinggeng Zhou
- Department of Biochemistry and Biophysics, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
| | - Shujing Wu
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
- State key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, Laboratory of Apple Molecular Biology and Biotechnology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an 271018, China
| | - Xin Chen
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
| | - Chenglong Liu
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
| | - Jen Sheen
- Department of Genetics, Harvard Medical School, and Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, MA 02114, USA
| | - Libo Shan
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
| | - Ping He
- Department of Biochemistry and Biophysics, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843
| |
Collapse
|