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Midgley KA, van den Berg N, Backer R, Swart V. Identification of Phytophthora cinnamomi CRN effectors and their roles in manipulating cell death during Persea americana infection. BMC Genomics 2024; 25:435. [PMID: 38698341 PMCID: PMC11064341 DOI: 10.1186/s12864-024-10358-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 04/26/2024] [Indexed: 05/05/2024] Open
Abstract
The oomycete Phytophthora cinnamomi is a devastating plant pathogen with a notably broad host range. It is the causal agent of Phytophthora root rot (PRR), arguably the most economically important yield-limiting disease in Persea americana (avocado). Despite this, our understanding of the mechanisms P. cinnamomi employs to infect and successfully colonize avocado remains limited, particularly regarding the pathogen's ability to maintain its biotrophic and necrotrophic lifestyles during infection. The pathogen utilises a large repertoire of effector proteins which function in facilitating and establishing disease in susceptible host plants. Crinkling and necrosis effectors (CRN/Crinklers) are suspected to manipulate cell death to aid in maintenance of the pathogens biotrophic and necrotrophic lifestyles during different stages of infection. The current study identified 25 P. cinnamomi CRN effectors from the GKB4 genome using an HMM profile and assigned putative function to them as either cell death inducers or suppressors. Function was assigned to 10 PcinCRNs by analysing their RNA-seq expression profiles, relatedness to other functionally characterised Phytophthora CRNs and tertiary protein predictions. The full-length coding sequences for these PcinCRNs were confirmed by Sanger sequencing, six of which were found to have two divergent alleles. The presence of alleles indicates that the proteins encoded may perform contradicting functions in cell death manipulation, or function in different host plant species. Overall, this study provides a foundation for future research on P. cinnamomi infection and cell death manipulation mechanisms.
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Affiliation(s)
- Kayla A Midgley
- Hans Merensky Chair in Avocado Research, Department of Biochemistry; Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Noëlani van den Berg
- Hans Merensky Chair in Avocado Research, Department of Biochemistry; Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Robert Backer
- Hans Merensky Chair in Avocado Research, Department of Biochemistry; Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Velushka Swart
- Hans Merensky Chair in Avocado Research, Department of Biochemistry; Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa.
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2
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Severin S, Gratacap MP, Bouvet L, Borret M, Kpotor AO, Chicanne G, Xuereb JM, Viaud J, Payrastre B. Phosphoinositides take a central stage in regulating blood platelet production and function. Adv Biol Regul 2024; 91:100992. [PMID: 37793962 DOI: 10.1016/j.jbior.2023.100992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023]
Abstract
Blood platelets are produced by megakaryocytes through a complex program of differentiation and play a critical role in hemostasis and thrombosis. These anucleate cells are the target of antithrombotic drugs that prevent them from clumping in cardiovascular disease conditions. Platelets also significantly contribute to various aspects of physiopathology, including interorgan communications, healing, inflammation, and thromboinflammation. Their production and activation are strictly regulated by highly elaborated mechanisms. Among them, those involving inositol lipids have drawn the attention of researchers. Phosphoinositides represent the seven combinatorially phosphorylated forms of the inositol head group of inositol lipids. They play a crucial role in regulating intracellular mechanisms, such as signal transduction, actin cytoskeleton rearrangements, and membrane trafficking, either by generating second messengers or by directly binding to specific domains of effector proteins. In this review, we will explore how phosphoinositides are implicated in controlling platelet production by megakaryocytes and in platelet activation processes. We will also discuss the diversity of phosphoinositides in platelets, their role in granule biogenesis and maintenance, as well as in integrin signaling. Finally, we will address the discovery of a novel pool of phosphatidylinositol 3-monophosphate in the outerleaflet of the plasma membrane of human and mouse platelets.
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Affiliation(s)
- Sonia Severin
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Marie-Pierre Gratacap
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Laura Bouvet
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Maxime Borret
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Afi Oportune Kpotor
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Gaëtan Chicanne
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Jean-Marie Xuereb
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Julien Viaud
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France
| | - Bernard Payrastre
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297 and Université Paul Sabatier, F-31432, Toulouse, France; Laboratoire d'Hématologie, Centre de Référence des Pathologies Plaquettaires, Centre Hospitalier Universitaire de Toulouse Rangueil, F-31432, Toulouse, France.
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3
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Mujalli A, Viaud J, Severin S, Gratacap MP, Chicanne G, Hnia K, Payrastre B, Terrisse AD. Exploring the Role of PI3P in Platelets: Insights from a Novel External PI3P Pool. Biomolecules 2023; 13:biom13040583. [PMID: 37189331 DOI: 10.3390/biom13040583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/10/2023] [Accepted: 03/19/2023] [Indexed: 05/17/2023] Open
Abstract
Phosphoinositides (PIs) play a crucial role in regulating intracellular signaling, actin cytoskeleton rearrangements, and membrane trafficking by binding to specific domains of effector proteins. They are primarily found in the membrane leaflets facing the cytosol. Our study demonstrates the presence of a pool of phosphatidylinositol 3-monophosphate (PI3P) in the outer leaflet of the plasma membrane of resting human and mouse platelets. This pool of PI3P is accessible to exogenous recombinant myotubularin 3-phosphatase and ABH phospholipase. Mouse platelets with loss of function of class III PI 3-kinase and class II PI 3-kinase α have a decreased level of external PI3P, suggesting a contribution of these kinases to this pool of PI3P. After injection in mouse, or incubation ex vivo in human blood, PI3P-binding proteins decorated the platelet surface as well as α-granules. Upon activation, these platelets were able to secrete the PI3P-binding proteins. These data sheds light on a previously unknown external pool of PI3P in the platelet plasma membrane that recognizes PI3P-binding proteins, leading to their uptake towards α-granules. This study raises questions about the potential function of this external PI3P in the communication of platelets with the extracellular environment, and its possible role in eliminating proteins from the plasma.
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Affiliation(s)
- Abdulrahman Mujalli
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Julien Viaud
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Sonia Severin
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Marie-Pierre Gratacap
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Gaëtan Chicanne
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Karim Hnia
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
| | - Bernard Payrastre
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
- Laboratoire d'Hématologie, Centre de Référence des Pathologies Plaquettaires, Centre Hospitalier Universitaire de Toulouse Rangueil, F-31432 Toulouse Cedex, France
| | - Anne-Dominique Terrisse
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), INSERM UMR-1297, Université Paul Sabatier, F-31432 Toulouse Cedex, France
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Yang K, Yan Q, Wang Y, Zhu W, Wang X, Li X, Peng H, Zhou Y, Jing M, Dou D. Engineering crop Phytophthora resistance by targeting pathogen-derived PI3P for enhanced catabolism. PLANT COMMUNICATIONS 2023; 4:100460. [PMID: 36217305 PMCID: PMC10030320 DOI: 10.1016/j.xplc.2022.100460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/24/2022] [Accepted: 10/06/2022] [Indexed: 05/04/2023]
Abstract
Phytophthora pathogens lead to numerous economically damaging plant diseases worldwide, including potato late blight caused by P. infestans and soybean root rot caused by P. sojae. Our previous work showed that Phytophthora pathogens may generate abundant phosphatidylinositol 3-phosphate (PI3P) to promote infection via direct association with RxLR effectors. Here, we designed a disease control strategy for metabolizing pathogen-derived PI3P by expressing secreted Arabidopsis thaliana phosphatidylinositol-4-phosphate 5-kinase 1 (AtPIP5K1), which can phosphorylate PI3P to PI(3,4)P2. We fused AtPIP5K1 with the soybean PR1a signal peptide (SP-PIP5K1) to enable its secretion into the plant apoplast. Transgenic soybean and potato plants expressing SP-PIP5K1 showed substantially enhanced resistance to various P. sojae and P. infestans isolates, respectively. SP-PIP5K1 significantly reduced PI3P accumulation during P. sojae and soybean interaction. Knockout or inhibition of PI3 kinases (PI3Ks) in P. sojae compromised the resistance mediated by SP-PIP5K1, indicating that SP-PIP5K1 action requires a supply of pathogen-derived PI3P. Furthermore, we revealed that SP-PIP5K1 can interfere with the action of P. sojae mediated by the RxLR effector Avr1k. This novel disease control strategy has the potential to confer durable broad-spectrum Phytophthora resistance in plants through a clear mechanism in which catabolism of PI3P interferes with RxLR effector actions.
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Affiliation(s)
- Kun Yang
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiang Yan
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China; Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Nanjing 210095, China
| | - Yi Wang
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenyi Zhu
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodan Wang
- College of Plant Protection, China Agricultural University, Beijing 100091, China
| | - Xiaobo Li
- Crops Research Institute, Guangdong Academy of Agricultural Sciences/Guangdong Provincial Key Laboratory of Crop Genetic Improvement, Guangdong, Guangzhou 510640, China
| | - Hao Peng
- Department of Plant Pathology, Washington State University, Pullman, WA 99164, USA
| | - Yang Zhou
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Maofeng Jing
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China.
| | - Daolong Dou
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China; College of Plant Protection, China Agricultural University, Beijing 100091, China.
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Yang Y, Liu X, Guo W, Liu W, Shao W, Zhao J, Li J, Dong Q, Ma L, He Q, Li Y, Han J, Lei X. Testing the polar auxin transport model with a selective plasma membrane H + -ATPase inhibitor. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1229-1245. [PMID: 35352470 DOI: 10.1111/jipb.13256] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Auxin is unique among plant hormones in that its function requires polarized transport across plant cells. A chemiosmotic model was proposed to explain how polar auxin transport is derived by the H+ gradient across the plasma membrane (PM) established by PM H+ -adenosine triphosphatases (ATPases). However, a classical genetic approach by mutations in PM H+ -ATPase members did not result in the ablation of polar auxin distribution, possibly due to functional redundancy in this gene family. To confirm the crucial role of PM H+ -ATPases in the polar auxin transport model, we employed a chemical genetic approach. Through a chemical screen, we identified protonstatin-1 (PS-1), a selective small-molecule inhibitor of PM H+ -ATPase activity that inhibits auxin transport. Assays with transgenic plants and yeast strains showed that the activity of PM H+ -ATPases affects auxin uptake as well as acropetal and basipetal polar auxin transport. We propose that PS-1 can be used as a tool to interrogate the function of PM H+ -ATPases. Our results support the chemiosmotic model in which PM H+ -ATPase itself plays a fundamental role in polar auxin transport.
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Affiliation(s)
- Yongqing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaohui Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Wei Guo
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Wei Liu
- Department of Dermatology, Peking University First Hospital, Beijing, 100034, China
| | - Wei Shao
- Iomics Biosciences Inc., Beijing, 100102, China
| | - Jun Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Junhong Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Qing Dong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Liang Ma
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Qun He
- College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yingzhang Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jianyong Han
- College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaoguang Lei
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
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6
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Yang Y, Zhao Y, Zheng W, Zhao Y, Zhao S, Wang Q, Bai L, Zhang T, Huang S, Song C, Yuan M, Guo Y. Phosphatidylinositol 3-phosphate regulates SCAB1-mediated F-actin reorganization during stomatal closure in Arabidopsis. THE PLANT CELL 2022; 34:477-494. [PMID: 34850207 PMCID: PMC8773959 DOI: 10.1093/plcell/koab264] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/22/2021] [Indexed: 05/20/2023]
Abstract
Stomatal movement is critical for plant responses to environmental changes and is regulated by the important signaling molecule phosphatidylinositol 3-phosphate (PI3P). However, the molecular mechanism underlying this process is not well understood. In this study, we show that PI3P binds to stomatal closure-related actin-binding protein1 (SCAB1), a plant-specific F-actin-binding and -bundling protein, and inhibits the oligomerization of SCAB1 to regulate its activity on F-actin in guard cells during stomatal closure in Arabidopsis thaliana. SCAB1 binds specifically to PI3P, but not to other phosphoinositides. Treatment with wortmannin, an inhibitor of phosphoinositide kinase that generates PI3P, leads to an increase of the intermolecular interaction and oligomerization of SCAB1, stabilization of F-actin, and retardation of F-actin reorganization during abscisic acid (ABA)-induced stomatal closure. When the binding activity of SCAB1 to PI3P is abolished, the mutated proteins do not rescue the stability and realignment of F-actin regulated by SCAB1 and the stomatal closure in the scab1 mutant. The expression of PI3P biosynthesis genes is consistently induced when the plants are exposed to drought and ABA treatments. Furthermore, the binding of PI3P to SCAB1 is also required for vacuolar remodeling during stomatal closure. Our results illustrate a PI3P-regulated pathway during ABA-induced stomatal closure, which involves the mediation of SCAB1 activity in F-actin reorganization.
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Affiliation(s)
| | | | | | - Yang Zhao
- Shanghai Center for Plant Stress Biology, CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shuangshuang Zhao
- Key Life Science College, Laboratory of Plant Stress, Shandong Normal University, Jinan 250014, China
| | - Qiannan Wang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Li Bai
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Tianren Zhang
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Shanjin Huang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Chunpeng Song
- Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng 475001, China
| | - Ming Yuan
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
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Yang Y, Han X, Ma L, Wu Y, Liu X, Fu H, Liu G, Lei X, Guo Y. Dynamic changes of phosphatidylinositol and phosphatidylinositol 4-phosphate levels modulate H +-ATPase and Na +/H + antiporter activities to maintain ion homeostasis in Arabidopsis under salt stress. MOLECULAR PLANT 2021; 14:2000-2014. [PMID: 34339895 DOI: 10.1016/j.molp.2021.07.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/20/2021] [Accepted: 07/27/2021] [Indexed: 05/28/2023]
Abstract
Plant metabolites are dynamically modified and distributed in response to environmental changes. However, it is poorly understood how metabolic change functions in plant stress responses. Maintaining ion homeostasis under salt stress requires coordinated activation of two types of central regulators: plasma membrane (PM) H+-ATPase and Na+/H+ antiporter. In this study, we used a bioassay-guided isolation approach to identify endogenous small molecules that affect PM H+-ATPase and Na+/H+ antiporter activities and identified phosphatidylinositol (PI), which inhibits PM H+-ATPase activity under non-stress conditions in Arabidopsis by directly binding to the C terminus of the PM H+-ATPase AHA2. Under salt stress, the phosphatidylinositol 4-phosphate-to-phosphatidylinositol (PI4P-to-PI) ratio increased, and PI4P bound and activated the PM Na+/H+ antiporter. PI prefers binding to the inactive form of PM H+-ATPase, while PI4P tends to bind to the active form of the Na+/H+ antiporter. Consistent with this, pis1 mutants, with reduced levels of PI, displayed increased PM H+-ATPase activity and salt stress tolerance, while the pi4kβ1 mutant, with reduced levels of PI4P, displayed reduced PM Na+/H+ antiporter activity and salt stress tolerance. Collectively, our results reveal that the dynamic change between PI and PI4P in response to salt stress in Arabidopsis is crucial for maintaining ion homeostasis to protect plants from unfavorable environmental conditions.
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Affiliation(s)
- Yongqing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiuli Han
- College of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Liang Ma
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yujiao Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiao Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Haiqi Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Guoyong Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaoguang Lei
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| | - Yan Guo
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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Zhou Y, Yang K, Yan Q, Wang X, Cheng M, Si J, Xue X, Shen D, Jing M, Tyler BM, Dou D. Targeting of anti-microbial proteins to the hyphal surface amplifies protection of crop plants against Phytophthora pathogens. MOLECULAR PLANT 2021; 14:1391-1403. [PMID: 33965632 DOI: 10.1016/j.molp.2021.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 03/14/2021] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
Phytophthora pathogens are a persistent threat to the world's commercially important agricultural crops, including potato and soybean. Current strategies aim at reducing crop losses rely mostly on disease-resistance breeding and chemical pesticides, which can be frequently overcome by the rapid adaptive evolution of pathogens. Transgenic crops with intrinsic disease resistance offer a promising alternative and continue to be developed. Here, we explored Phytophthora-derived PI3P (phosphatidylinositol 3-phosphate) as a novel control target, using proteins that bind this lipid to direct secreted anti-microbial peptides and proteins (AMPs) to the surface of Phytophthora pathogens. In transgenic Nicotiana benthamiana, soybean, and potato plants, significantly enhanced resistance to different pathogen isolates was achieved by expression of two AMPs (GAFP1 or GAFP3 from the Chinese medicinal herb Gastrodia elata) fused with a PI3P-specific binding domain (FYVE). Using the soybean pathogen P. sojae as an example, we demonstrated that the FYVE domain could boost the activities of GAFPs in multiple independent assays, including those performed in vitro, in vivo, and in planta. Mutational analysis of P. sojae PI3K1 and PI3K2 genes of this pathogen confirmed that the enhanced activities of the targeted GAFPs were correlated with PI3P levels in the pathogen. Collectively, our study provides a new strategy that could be used to confer resistance not only to Phytophthora pathogens in many plants but also potentially to many other kinds of plant pathogens with unique targets.
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Affiliation(s)
- Yang Zhou
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Yang
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiang Yan
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodan Wang
- College of Plant Protection, China Agricultural University, Beijing 100091, China
| | - Ming Cheng
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Jierui Si
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xue Xue
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Danyu Shen
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Maofeng Jing
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China.
| | - Brett M Tyler
- Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
| | - Daolong Dou
- Key Laboratory of Plant Immunity, College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China; College of Plant Protection, China Agricultural University, Beijing 100091, China.
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9
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Cavaco AR, Matos AR, Figueiredo A. Speaking the language of lipids: the cross-talk between plants and pathogens in defence and disease. Cell Mol Life Sci 2021; 78:4399-4415. [PMID: 33638652 PMCID: PMC11073031 DOI: 10.1007/s00018-021-03791-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/21/2021] [Accepted: 02/12/2021] [Indexed: 12/26/2022]
Abstract
Lipids and fatty acids play crucial roles in plant immunity, which have been highlighted over the past few decades. An increasing number of studies have shown that these molecules are pivotal in the interactions between plants and their diverse pathogens. The roles played by plant lipids fit in a wide spectrum ranging from the first physical barrier encountered by the pathogens, the cuticle, to the signalling pathways that trigger different immune responses and expression of defence-related genes, mediated by several lipid molecules. Moreover, lipids have been arising as candidate biomarkers of resistance or susceptibility to different pathogens. Studies on the apoplast and extracellular vesicles have been highlighting the possible role of lipids in the intercellular communication and the establishment of systemic acquired resistance during plant-pathogen interactions. From the pathogen perspective, lipid metabolism and specific lipid molecules play pivotal roles in the pathogen's life cycle completion, being crucial during recognition by the plant and evasion from the host immune system, therefore potentiating infection. Studies conducted in the last years have contributed to a better understanding of the language of lipids during the cross-talk between plants and pathogens. However, it is essential to continue exploring the knowledge brought up to light by transcriptomics and proteomics studies towards the elucidation of lipid signalling processes during defence and disease. In this review, we present an updated overview on lipids associated to plant-pathogen interactions, exploiting their roles from the two sides of this battle.
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Affiliation(s)
- Ana Rita Cavaco
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Science, University of Lisbon, Lisbon, Portugal
| | - Ana Rita Matos
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Science, University of Lisbon, Lisbon, Portugal
| | - Andreia Figueiredo
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Science, University of Lisbon, Lisbon, Portugal.
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10
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Organize, Don't Agonize: Strategic Success of Phytophthora Species. Microorganisms 2020; 8:microorganisms8060917. [PMID: 32560346 PMCID: PMC7355776 DOI: 10.3390/microorganisms8060917] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
Plants are constantly challenged by various environmental stressors ranging from abiotic-sunlight, elevated temperatures, drought, and nutrient deficits, to biotic factors-microbial pathogens and insect pests. These not only affect the quality of harvest but also the yield, leading to substantial annual crop losses, worldwide. Although plants have a multi-layered immune system, phytopathogens such as species of the oomycete genus Phytophthora, can employ elaborate mechanisms to breach this defense. For the last two decades, researchers have focused on the co-evolution between Phytophthora and interacting hosts to decouple the mechanisms governing their molecular associations. This has provided a comprehensive understanding of the pathobiology of plants affected by oomycetes. Ultimately, this is important for the development of strategies to sustainably improve agricultural production. Therefore, this paper discusses the present-day state of knowledge of the strategic mode of operation employed by species of Phytophthora for successful infection. Specifically, we consider motility, attachment, and host cell wall degradation used by these pathogenic species to obtain nutrients from their host. Also discussed is an array of effector types from apoplastic (hydrolytic proteins, protease inhibitors, elicitins) to cytoplastic (RxLRs, named after Arginine-any amino acid-Leucine-Arginine consensus sequence and CRNs, for CRinkling and Necrosis), which upon liberation can subvert the immune response and promote diseases in plants.
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11
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Lu S, Yu J, Ma L, Dou D. Two phosphatidylinositol 3-kinase components are involved in interactions between Nicotiana benthamiana and Phytophthora by regulating pathogen effectors and host cell death. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:293-302. [PMID: 32054565 DOI: 10.1071/fp19155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Phosphatidylinositol 3-phosphate (PtdIns(3)P) has been reported to regulate different physiological processes in plants. PtdIns(3)P is synthesised by the phosphatidylinositol 3-kinase (PI3K) complex which includes common subunits of vacuolar protein sorting (VPS)15, VPS30 and VPS34. Here, we characterised the roles of the important genes NbVPS15, -30 and -34 encoding PI3K components during interactions between Nicotiana benthamiana and Phytophthora pathogens. NbVPS15 and NbVPS34 were upregulated during infection, and plants deficient in these two genes displayed higher resistance to two different Phytophthora pathogens. Silencing NbVPS15 and NbVPS34 decreased the content of PtdIns(3)P in plant cells and the stability of three RxLR (containing the characteristic amino-terminal motif of arginine-X-leucine-arginine, X is any amino acid) effectors. Furthermore, NbVPS15, -30 and -34 were essential for autolysosome formation during Phytophthora capsici infection and limiting programmed cell death (PCD) induced by effectors and elicitors. Taken together, these findings suggest that NbVPS15 and NbVPS34 play a critical role in the resistance of N. benthamiana to Phytophthora pathogens by regulating PtdIns(3)P contents and host PCD.
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Affiliation(s)
- Shan Lu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China; and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; and Corresponding author.
| | - Jia Yu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Lina Ma
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
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12
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Han X, Yang Y, Zhao F, Zhang T, Yu X. An improved protein lipid overlay assay for studying lipid-protein interactions. PLANT METHODS 2020; 16:33. [PMID: 32165912 PMCID: PMC7060618 DOI: 10.1186/s13007-020-00578-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/28/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Lipids perform multiple functions in the cell, and lipid-protein interactions play a key role in metabolism. Although various techniques have been developed to study lipid-protein interactions, the interacting protein partners that bind to most lipids remain unknown. The protein lipid overlay (PLO) assay has revealed numerous lipid-protein interactions, but its application suffers from unresolved technical issues. RESULTS Herein, we found that blocking proteins may interfere with interactions between lipids and their binding proteins if a separate blocking step is carried out before the incubation step in the PLO assay. To overcome this, we modified the PLO assay by combining an incubation step alongside the blocking step. Verification experiments included phosphatidylinositol-3-phosphate (PI3P) and its commercially available interacting protein G302, C18:1, C18:2, C18:3 and the Arabidopsis plasma membrane H+-ATPase (PM H+-ATPase) AHA2 C-terminus, phosphatidylglycerol (PG) and AtROP6, and phosphatidylserine (PS) and the AHA2 C-terminus. The lipid-protein binding signal in the classical PLO (CPLO) assay was weak and not reproducible, but the modified PLO (MPLO) assay displayed significantly improved sensitivity and reproducibility. CONCLUSIONS This work identified a limitation of the CPLO assay, and both sensitivity and reproducibility were improved in the modified assay, which could prove to be more effective for investigating lipid-protein interactions.
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Affiliation(s)
- Xiuli Han
- College of Life Sciences, Shandong University of Technology, Zibo, 255049 China
| | - Yongqing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193 China
| | - Fengyun Zhao
- College of Life Sciences, Shandong University of Technology, Zibo, 255049 China
| | - Tianren Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193 China
| | - Xiang Yu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193 China
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13
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Li T, Wang Q, Feng R, Li L, Ding L, Fan G, Li W, Du Y, Zhang M, Huang G, Schäfer P, Meng Y, Tyler BM, Shan W. Negative regulators of plant immunity derived from cinnamyl alcohol dehydrogenases are targeted by multiple Phytophthora Avr3a-like effectors. THE NEW PHYTOLOGIST 2019. [PMID: 31436314 DOI: 10.1111/nph.16139] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/15/2019] [Indexed: 05/21/2023]
Abstract
Oomycete pathogens secrete numerous effectors to manipulate host immunity. While some effectors share a conserved structural fold, it remains unclear if any have conserved host targets. Avr3a-like family effectors, which are related to Phytophthora infestans effector PiAvr3a and are widely distributed across diverse clades of Phytophthora species, were used to study this question. By using yeast-two-hybrid, bimolecular fluorescence complementation and co-immunoprecipitation assays, we identified members of the plant cinnamyl alcohol dehydrogenase 7 (CAD7) subfamily as targets of multiple Avr3a-like effectors from Phytophthora pathogens. The CAD7 subfamily has expanded in plant genomes but lost the lignin biosynthetic activity of canonical CAD subfamilies. In turn, we identified CAD7s as negative regulators of plant immunity that are induced by Phytophthora infection. Moreover, AtCAD7 was stabilized by Avr3a-like effectors and involved in suppression of pathogen-associated molecular pattern-triggered immunity, including callose deposition, reactive oxygen species burst and WRKY33 expression. Our results reveal CAD7 subfamily proteins as negative regulators of plant immunity that are exploited by multiple Avr3a-like effectors to promote infection in different host plants.
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Affiliation(s)
- Tingting Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Qinhu Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ruirui Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Licai Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Liwen Ding
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guangjin Fan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Weiwei Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yu Du
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Meixiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guiyan Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Patrick Schäfer
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK
- Warwick Integrative Synthetic Biology Centre, University of Warwick, Coventry, CV4 7AL, UK
| | - Yuling Meng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Brett M Tyler
- Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Weixing Shan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
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14
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Noman A, Aqeel M, Lou Y. PRRs and NB-LRRs: From Signal Perception to Activation of Plant Innate Immunity. Int J Mol Sci 2019; 20:ijms20081882. [PMID: 30995767 PMCID: PMC6514886 DOI: 10.3390/ijms20081882] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/02/2019] [Accepted: 04/10/2019] [Indexed: 12/11/2022] Open
Abstract
To ward off pathogens and pests, plants use a sophisticated immune system. They use pattern-recognition receptors (PRRs), as well as nucleotide-binding and leucine-rich repeat (NB-LRR) domains, for detecting nonindigenous molecular signatures from pathogens. Plant PRRs induce local and systemic immunity. Plasma-membrane-localized PRRs are the main components of multiprotein complexes having additional transmembrane and cytosolic kinases. Topical research involving proteins and their interactive partners, along with transcriptional and posttranscriptional regulation, has extended our understanding of R-gene-mediated plant immunity. The unique LRR domain conformation helps in the best utilization of a surface area and essentially mediates protein–protein interactions. Genome-wide analyses of inter- and intraspecies PRRs and NB-LRRs offer innovative information about their working and evolution. We reviewed plant immune responses with relevance to PRRs and NB-LRRs. This article focuses on the significant functional diversity, pathogen-recognition mechanisms, and subcellular compartmentalization of plant PRRs and NB-LRRs. We highlight the potential biotechnological application of PRRs and NB-LRRs to enhance broad-spectrum disease resistance in crops.
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Affiliation(s)
- Ali Noman
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310027, China.
- Department of Botany, Government College University, Faisalabad 38000, Pakistan.
| | - Muhammad Aqeel
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Science, Lanzhou University, Lanzhou 730000, China.
| | - Yonggen Lou
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310027, China.
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15
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Liu L, Xu L, Jia Q, Pan R, Oelmüller R, Zhang W, Wu C. Arms race: diverse effector proteins with conserved motifs. PLANT SIGNALING & BEHAVIOR 2019; 14:1557008. [PMID: 30621489 PMCID: PMC6351098 DOI: 10.1080/15592324.2018.1557008] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Effector proteins play important roles in the infection by pathogenic oomycetes and fungi or the colonization by endophytic and mycorrhizal fungi. They are either translocated into the host plant cells via specific translocation mechanisms and function in the host's cytoplasm or nucleus, or they reside in the apoplast of the plant cells and act at the extracellular host-microbe interface. Many effector proteins possess conserved motifs (such as the RXLR, CRN, LysM, RGD, DELD, EAR, RYWT, Y/F/WXC or CFEM motifs) localized in their N- or C-terminal regions. Analysis of the functions of effector proteins, especially so-called "core effectors", is crucial for the understanding of pathogenicity/symbiosis mechanisms and plant defense strategies, and helps to develop breeding strategies for pathogen-resistant cultivars, and to increase crop yield and quality as well as abiotic stress resistance. This review summarizes current knowledge about these effector proteins with the conversed motifs and their involvement in pathogenic or mutualistic plant/fungal interactions.
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Affiliation(s)
- Liping Liu
- College of Horticulture & Gardening, Yangtze University, Jingzhou, China
| | - Le Xu
- Hubei Collaborative Innovation Center for Grain Industry/Research Center of Crop Stresses Resistance Technologies, Yangtze University, Jingzhou, China
| | - Qie Jia
- College of Horticulture & Gardening, Yangtze University, Jingzhou, China
| | - Rui Pan
- Hubei Collaborative Innovation Center for Grain Industry/Research Center of Crop Stresses Resistance Technologies, Yangtze University, Jingzhou, China
| | - Ralf Oelmüller
- Plant Physiology, Matthias-Schleiden-Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich-Schiller-University Jena, Jena, Germany
| | - Wenying Zhang
- Hubei Collaborative Innovation Center for Grain Industry/Research Center of Crop Stresses Resistance Technologies, Yangtze University, Jingzhou, China
- CONTACT Wenying Zhang Hubei Collaborative Innovation Center for Grain Industry/Research Center of Crop Stresses Resistance Technologies, Yangtze University, Jingzhou 434025, China; Chu Wu College of Horticulture & Gardening, Yangtze University, Jingzhou 434025, China
| | - Chu Wu
- College of Horticulture & Gardening, Yangtze University, Jingzhou, China
- Institute of Plant Ecology and Environmental Restoration, Yangtze University, Jingzhou, China
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16
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Zhang X, He D, Zhao Y, Cheng X, Zhao W, Taylor IA, Yang J, Liu J, Peng YL. A positive-charged patch and stabilized hydrophobic core are essential for avirulence function of AvrPib in the rice blast fungus. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:133-146. [PMID: 29989241 DOI: 10.1111/tpj.14023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 06/20/2018] [Indexed: 05/09/2023]
Abstract
Fungal avirulence effectors, a key weapon utilized by pathogens to promote their infection, are recognized by immune receptors to boost host R gene-mediated resistance. Many avirulence effectors share sparse sequence homology to proteins with known functions, and their molecular and biochemical functions together with the evolutionary relationship among different members remain largely unknown. Here, the crystal structure of AvrPib, an avirulence effector from Magnaporthe oryzae, was determined and showed a high degree of similarity to the M. oryzae Avrs and ToxB (MAX) effectors. Compared with other MAX effectors, AvrPib has a distinct positive-charge patch formed by five positive-charged residues (K29, K30, R50, K52 and K70) on the surface. These five key residues were essential to avirulence function of AvrPib and affected its nuclear localization into host cells. Moreover, residues V39 and V58, which locate in the hydrophobic core of the structure, cause loss of function of AvrPib by single-point mutation in natural isolates. In comparison with the wild-type AvrPib, the V39A or V58A mutations resulted in a partial or entire loss of secondary structure elements. Taken together, our results suggest that differences in the surface charge distribution of avirulence proteins could be one of the major bases for the variation in effector-receptor specificity, and that destabilization of the hydrophobic core is one of the major mechanisms employed by AvrPib for the fungus to evade recognition by resistance factors in the host cell.
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Affiliation(s)
- Xin Zhang
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Dan He
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Yanxiang Zhao
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xilan Cheng
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Wensheng Zhao
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Jun Yang
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Junfeng Liu
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - You-Liang Peng
- Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
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17
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Trusch F, Loebach L, Wawra S, Durward E, Wuensch A, Iberahim NA, de Bruijn I, MacKenzie K, Willems A, Toloczko A, Diéguez-Uribeondo J, Rasmussen T, Schrader T, Bayer P, Secombes CJ, van West P. Cell entry of a host-targeting protein of oomycetes requires gp96. Nat Commun 2018; 9:2347. [PMID: 29904064 PMCID: PMC6002402 DOI: 10.1038/s41467-018-04796-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/11/2018] [Indexed: 12/02/2022] Open
Abstract
The animal-pathogenic oomycete Saprolegnia parasitica causes serious losses in aquaculture by infecting and killing freshwater fish. Like plant-pathogenic oomycetes, S. parasitica employs similar infection structures and secretes effector proteins that translocate into host cells to manipulate the host. Here, we show that the host-targeting protein SpHtp3 enters fish cells in a pathogen-independent manner. This uptake process is guided by a gp96-like receptor and can be inhibited by supramolecular tweezers. The C-terminus of SpHtp3 (containing the amino acid sequence YKARK), and not the N-terminal RxLR motif, is responsible for the uptake into host cells. Following translocation, SpHtp3 is released from vesicles into the cytoplasm by another host-targeting protein where it degrades nucleic acids. The effector translocation mechanism described here, is potentially also relevant for other pathogen-host interactions as gp96 is found in both animals and plants.
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Grants
- BB/E007120/1 Biotechnology and Biological Sciences Research Council
- BB/G012075/1 Biotechnology and Biological Sciences Research Council
- Biotechnology and Biological Sciences Research Council (BBSRC)
- Deutsche Forschungsgemeinschaft (German Research Foundation)
- Our work is supported by the [European Community's] Seventh Framework Programme [FP7/2007-2013] under grant agreement no [238550] (LL, JDU, CJS, PvW); BBSRC [BBE007120/1, BB/J018333/1 and BB/G012075/1] (FT, IdB, CJS, SW, PvW); Newton Global partnership Award [BB/N005058/1] (FT, PvW), the University of Aberdeen (ADT, TR, CJS, PvW) and Deutsche Forschungsgemeinschaft [CRC1093] (PB, TS). We would like to acknowledge the Ministry of Higher Education Malaysia for funding INA. We would like to thank Brian Haas for his bioinformatics support. We would like to acknowledge Neil Gow and Johannes van den Boom for critical reading of the manuscript. We would like to acknowledge Svetlana Rezinciuc for technical help with pH-studies.
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Affiliation(s)
- Franziska Trusch
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Lars Loebach
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Stephan Wawra
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- Botanical Institute, Genetical Institute, University of Cologne, Cologne, 50674, Germany
| | - Elaine Durward
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Andreas Wuensch
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Nurul Aqilah Iberahim
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- School of Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Terengganu, Malaysia
| | - Irene de Bruijn
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- Netherlands Institute for Ecology (NIOO), Wageningen, 6708 PB, Netherlands
| | - Kevin MacKenzie
- Microscopy and Histology Facility, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Ariane Willems
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Aleksandra Toloczko
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | | | - Tim Rasmussen
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
| | - Thomas Schrader
- Organic Chemistry, University of Duisburg-Essen, Essen, 45117, Germany
| | - Peter Bayer
- Structural and Medicinal Biochemistry, Centre for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, 45117, Germany
| | - Chris J Secombes
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK
- Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - Pieter van West
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK.
- International Centre for Aquaculture Research and Development (ICARD), University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, UK.
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18
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Han X, Shi Y, Liu G, Guo Y, Yang Y. Activation of ROP6 GTPase by Phosphatidylglycerol in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2018; 9:347. [PMID: 29599797 PMCID: PMC5862815 DOI: 10.3389/fpls.2018.00347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 03/01/2018] [Indexed: 05/05/2023]
Abstract
Plant Rho-like GTPases (ROPs) are switch-like proteins which play essential roles in controlling cell polarity development and cellular activities. ROPs are regulated by many factors, such as auxin, light, and RopGEFs and RopGAPs proteins. However, it has not been reported yet whether small molecules play a role in the regulation of ROP activity. Here, we showed that AtROP6 specially bound to a phospholipid, phosphatidylglycerol (PG), by the protein-lipid overlay and liposome sedimentation assays, and further MST assay gave a dissociation constant (Kd) of 4.8 ± 0.4 μM for binding of PG to His-AtROP6. PG profile analysis in Arabidopsis revealed that PG existed both in leaves and roots but with distinctive fatty acyl chain patterns. By evaluating AtROP6 activity using RIC1 effector binding-based assay, we found that PG stimulated AtROP6 activity. In the FM4-64 uptake experiment, PG inhibited AtROP6-mediated endocytosis process. By evaluating internalization of PIN2, PG was shown to regulate endocytosis process coordinately with NAA. Further root gravitropism experiment revealed that PG enhanced the AtROP6-mediated root gravity response. These results suggest that the phospholipid PG physically binds AtROP6, stimulates its activity and influences AtROP6-mediated root gravity response in Arabidopsis.
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Bournaud C, Gillet FX, Murad AM, Bresso E, Albuquerque EVS, Grossi-de-Sá MF. Meloidogyne incognita PASSE-MURAILLE (MiPM) Gene Encodes a Cell-Penetrating Protein That Interacts With the CSN5 Subunit of the COP9 Signalosome. FRONTIERS IN PLANT SCIENCE 2018; 9:904. [PMID: 29997646 PMCID: PMC6029430 DOI: 10.3389/fpls.2018.00904] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/07/2018] [Indexed: 05/11/2023]
Abstract
The pathogenicity of phytonematodes relies on secreted virulence factors to rewire host cellular pathways for the benefits of the nematode. In the root-knot nematode (RKN) Meloidogyne incognita, thousands of predicted secreted proteins have been identified and are expected to interact with host proteins at different developmental stages of the parasite. Identifying the host targets will provide compelling evidence about the biological significance and molecular function of the predicted proteins. Here, we have focused on the hub protein CSN5, the fifth subunit of the pleiotropic and eukaryotic conserved COP9 signalosome (CSN), which is a regulatory component of the ubiquitin/proteasome system. We used affinity purification-mass spectrometry (AP-MS) to generate the interaction network of CSN5 in M. incognita-infected roots. We identified the complete CSN complex and other known CSN5 interaction partners in addition to unknown plant and M. incognita proteins. Among these, we described M. incognita PASSE-MURAILLE (MiPM), a small pioneer protein predicted to contain a secretory peptide that is up-regulated mostly in the J2 parasitic stage. We confirmed the CSN5-MiPM interaction, which occurs in the nucleus, by bimolecular fluorescence complementation (BiFC). Using MiPM as bait, a GST pull-down assay coupled with MS revealed some common protein partners between CSN5 and MiPM. We further showed by in silico and microscopic analyses that the recombinant purified MiPM protein enters the cells of Arabidopsis root tips in a non-infectious context. In further detail, the supercharged N-terminal tail of MiPM (NTT-MiPM) triggers an unknown host endocytosis pathway to penetrate the cell. The functional meaning of the CSN5-MiPM interaction in the M. incognita parasitism is discussed. Moreover, we propose that the cell-penetrating properties of some M. incognita secreted proteins might be a non-negligible mechanism for cell uptake, especially during the steps preceding the sedentary parasitic phase.
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Affiliation(s)
- Caroline Bournaud
- Embrapa Genetic Resources and Biotechnology, Brasília, Brazil
- *Correspondence: Caroline Bournaud
| | | | - André M. Murad
- Embrapa Genetic Resources and Biotechnology, Brasília, Brazil
| | - Emmanuel Bresso
- Université de Lorraine, Centre National de la Recherche Scientifique, Inria, Laboratoire Lorrain de Recherche en Informatique et ses Applications, Nancy, France
| | | | - Maria F. Grossi-de-Sá
- Embrapa Genetic Resources and Biotechnology, Brasília, Brazil
- Post-Graduation Program in Genomic Science and Biotechnology, Universidade Católica de Brasília, Brasília, Brazil
- Maria F. Grossi-de-Sá
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20
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Lo Presti L, Kahmann R. How filamentous plant pathogen effectors are translocated to host cells. CURRENT OPINION IN PLANT BIOLOGY 2017; 38:19-24. [PMID: 28460240 DOI: 10.1016/j.pbi.2017.04.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/05/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
The interaction of microbes with "signature" plants is largely governed by secreted effector proteins, which serve to dampen plant defense responses and modulate host cell processes. Secreted effectors can function either in the apoplast or within plant cell compartments. How oomycetes and fungi translocate their effectors to plant cells is still poorly understood and controversial. While most oomycete effectors share a common 'signature' that was proposed to mediate their uptake via endocytosis, fungal effectors display no conserved motifs at the primary amino acid sequence level. Here we summarize current knowledge in the field of oomycete and fungal effector uptake and highlight emerging themes that may unite rather than set apart these unrelated filamentous pathogens.
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Affiliation(s)
- Libera Lo Presti
- Max Planck Institute for Terrestrial Microbiology, Dept. Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Dept. Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany.
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Shen D, Li Q, Sun P, Zhang M, Dou D. Intrinsic disorder is a common structural characteristic of RxLR effectors in oomycete pathogens. Fungal Biol 2017; 121:911-919. [PMID: 29029698 DOI: 10.1016/j.funbio.2017.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 07/05/2017] [Accepted: 07/21/2017] [Indexed: 01/31/2023]
Abstract
Intrinsic disorder is common in nature and has been studied to play important biological roles in bacterial effectors. However, disorder in oomycete RxLR effectors has not been investigated previously and the roles are unknown. Our results of PONDR VL-XT disorder analysis showed that predicted oomycete RxLR effectors were significantly more disordered than other effectors and secretome. The distribution of disorder content presented preference that RxLR-dEER regions were enriched in disordered residues, suggesting potential role of disorder in effector translocation. In contrast, the disorder content was depleted in the C-terminal regions, especially for W/Y/L motifs. We also found that around 42 % of putative RxLR proteins were predicted to contain at least one α-helix-forming molecular recognition feature (α-MoRF), and most α-MoRFs were located in the C-terminal regions. Furthermore, both of the disorder mutants of PsAvh18 and PcAvh207 lost the cell death-inducing activity, indicating the potential important role of disordered structure in RxLR effector function. Overall, these results demonstrate that intrinsic disorder is a common characteristic of oomycete RxLR proteins, and we postulate that such structure feature may be important for effector translocation or function. This study extends our understanding of RxLR effectors in protein structures, and opens up new directions to explore novel mechanisms of oomycete RxLR effectors.
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Affiliation(s)
- Danyu Shen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qingling Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peng Sun
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Meixiang Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
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22
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Han X, Yang Y, Wu Y, Liu X, Lei X, Guo Y. A bioassay-guided fractionation system to identify endogenous small molecules that activate plasma membrane H+-ATPase activity in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2951-2962. [PMID: 28582540 PMCID: PMC5853834 DOI: 10.1093/jxb/erx156] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/08/2017] [Indexed: 05/13/2023]
Abstract
Plasma membrane (PM) H+-ATPase is essential for plant growth and development. Various environmental stimuli regulate its activity, a process that involves many protein cofactors. However, whether endogenous small molecules play a role in this regulation remains unknown. Here, we describe a bio-guided isolation method to identify endogenous small molecules that regulate PM H+-ATPase activity. We obtained crude extracts from Arabidopsis seedlings with or without salt treatment and then purified them into fractions based on polarity and molecular mass by repeated column chromatography. By evaluating the effect of each fraction on PM H+-ATPase activity, we found that fractions containing the endogenous, free unsaturated fatty acids oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3) extracted from salt-treated seedlings stimulate PM H+-ATPase activity. These results were further confirmed by the addition of exogenous C18:1, C18:2, or C18:3 in the activity assay. The ssi2 mutant, with reduced levels of C18:1, C18:2, and C18:3, displayed reduced PM H+-ATPase activity. Furthermore, C18:1, C18:2, and C18:3 directly bound to the C-terminus of the PM H+-ATPase AHA2. Collectively, our results demonstrate that the binding of free unsaturated fatty acids to the C-terminus of PM H+-ATPase is required for its activation under salt stress. The bio-guided isolation model described in this study could enable the identification of new endogenous small molecules that modulate essential protein functions, as well as signal transduction, in plants.
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Affiliation(s)
- Xiuli Han
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- National Institute of Biological Sciences, Beijing, China
| | - Yongqing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yujiao Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiaohui Liu
- National Institute of Biological Sciences, Beijing, China
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xiaoguang Lei
- National Institute of Biological Sciences, Beijing, China
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Yan Guo
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
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Anderson C, Khan MA, Catanzariti AM, Jack CA, Nemri A, Lawrence GJ, Upadhyaya NM, Hardham AR, Ellis JG, Dodds PN, Jones DA. Genome analysis and avirulence gene cloning using a high-density RADseq linkage map of the flax rust fungus, Melampsora lini. BMC Genomics 2016; 17:667. [PMID: 27550217 PMCID: PMC4994203 DOI: 10.1186/s12864-016-3011-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/11/2016] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Rust fungi are an important group of plant pathogens that cause devastating losses in agricultural, silvicultural and natural ecosystems. Plants can be protected from rust disease by resistance genes encoding receptors that trigger a highly effective defence response upon recognition of specific pathogen avirulence proteins. Identifying avirulence genes is crucial for understanding how virulence evolves in the field. RESULTS To facilitate avirulence gene cloning in the flax rust fungus, Melampsora lini, we constructed a high-density genetic linkage map using single nucleotide polymorphisms detected in restriction site-associated DNA sequencing (RADseq) data. The map comprises 13,412 RADseq markers in 27 linkage groups that together span 5860 cM and contain 2756 recombination bins. The marker sequences were used to anchor 68.9 % of the M. lini genome assembly onto the genetic map. The map and anchored assembly were then used to: 1) show that M. lini has a high overall meiotic recombination rate, but recombination distribution is uneven and large coldspots exist; 2) show that substantial genome rearrangements have occurred in spontaneous loss-of-avirulence mutants; and 3) identify the AvrL2 and AvrM14 avirulence genes by map-based cloning. AvrM14 is a dual-specificity avirulence gene that encodes a predicted nudix hydrolase. AvrL2 is located in the region of the M. lini genome with the lowest recombination rate and encodes a small, highly-charged proline-rich protein. CONCLUSIONS The M. lini high-density linkage map has greatly advanced our understanding of virulence mechanisms in this pathogen by providing novel insights into genome variability and enabling identification of two new avirulence genes.
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Affiliation(s)
- Claire Anderson
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 2601 Australia
| | - Muhammad Adil Khan
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 2601 Australia
- Current address: ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
| | - Ann-Maree Catanzariti
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 2601 Australia
| | - Cameron A. Jack
- ANU Bioinformatics Consulting Unit, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Acton, ACT 2601 Australia
| | - Adnane Nemri
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601 Australia
- Current address: KWS SAAT SE, Grimsehlstraße 31, Einbeck, 37574 Germany
| | | | | | - Adrienne R. Hardham
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 2601 Australia
| | | | - Peter N. Dodds
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601 Australia
| | - David A. Jones
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 2601 Australia
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24
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Contributions of host cellular trafficking and organization to the outcomes of plant-pathogen interactions. Semin Cell Dev Biol 2016; 56:163-173. [DOI: 10.1016/j.semcdb.2016.05.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 05/16/2016] [Accepted: 05/20/2016] [Indexed: 11/23/2022]
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25
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Oomycete interactions with plants: infection strategies and resistance principles. Microbiol Mol Biol Rev 2016; 79:263-80. [PMID: 26041933 DOI: 10.1128/mmbr.00010-15] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Oomycota include many economically significant microbial pathogens of crop species. Understanding the mechanisms by which oomycetes infect plants and identifying methods to provide durable resistance are major research goals. Over the last few years, many elicitors that trigger plant immunity have been identified, as well as host genes that mediate susceptibility to oomycete pathogens. The mechanisms behind these processes have subsequently been investigated and many new discoveries made, marking a period of exciting research in the oomycete pathology field. This review provides an introduction to our current knowledge of the pathogenic mechanisms used by oomycetes, including elicitors and effectors, plus an overview of the major principles of host resistance: the established R gene hypothesis and the more recently defined susceptibility (S) gene model. Future directions for development of oomycete-resistant plants are discussed, along with ways that recent discoveries in the field of oomycete-plant interactions are generating novel means of studying how pathogen and symbiont colonizations overlap.
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26
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Sonah H, Deshmukh RK, Bélanger RR. Computational Prediction of Effector Proteins in Fungi: Opportunities and Challenges. FRONTIERS IN PLANT SCIENCE 2016; 7:126. [PMID: 26904083 PMCID: PMC4751359 DOI: 10.3389/fpls.2016.00126] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/23/2016] [Indexed: 05/20/2023]
Abstract
Effector proteins are mostly secretory proteins that stimulate plant infection by manipulating the host response. Identifying fungal effector proteins and understanding their function is of great importance in efforts to curb losses to plant diseases. Recent advances in high-throughput sequencing technologies have facilitated the availability of several fungal genomes and 1000s of transcriptomes. As a result, the growing amount of genomic information has provided great opportunities to identify putative effector proteins in different fungal species. There is little consensus over the annotation and functionality of effector proteins, and mostly small secretory proteins are considered as effector proteins, a concept that tends to overestimate the number of proteins involved in a plant-pathogen interaction. With the characterization of Avr genes, criteria for computational prediction of effector proteins are becoming more efficient. There are 100s of tools available for the identification of conserved motifs, signature sequences and structural features in the proteins. Many pipelines and online servers, which combine several tools, are made available to perform genome-wide identification of effector proteins. In this review, available tools and pipelines, their strength and limitations for effective identification of fungal effector proteins are discussed. We also present an exhaustive list of classically secreted proteins along with their key conserved motifs found in 12 common plant pathogens (11 fungi and one oomycete) through an analytical pipeline.
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Affiliation(s)
| | | | - Richard R. Bélanger
- Département de Phytologie, Faculté des Sciences de l’Agriculture et de l’Alimentation, Centre de Recherche en Horticulture, Université Laval, QuébecQC, Canada
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27
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Export of malaria proteins requires co-translational processing of the PEXEL motif independent of phosphatidylinositol-3-phosphate binding. Nat Commun 2016; 7:10470. [PMID: 26832821 PMCID: PMC4740378 DOI: 10.1038/ncomms10470] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 12/09/2015] [Indexed: 11/08/2022] Open
Abstract
Plasmodium falciparum exports proteins into erythrocytes using the Plasmodium export element (PEXEL) motif, which is cleaved in the endoplasmic reticulum (ER) by plasmepsin V (PMV). A recent study reported that phosphatidylinositol-3-phosphate (PI(3)P) concentrated in the ER binds to PEXEL motifs and is required for export independent of PMV, and that PEXEL motifs are functionally interchangeable with RxLR motifs of oomycete effectors. Here we show that the PEXEL does not bind PI(3)P, and that this lipid is not concentrated in the ER. We find that RxLR motifs cannot mediate export in P. falciparum. Parasites expressing a mutated version of KAHRP, with the PEXEL motif repositioned near the signal sequence, prevented PMV cleavage. This mutant possessed the putative PI(3)P-binding residues but is not exported. Reinstatement of PEXEL to its original location restores processing by PMV and export. These results challenge the PI(3)P hypothesis and provide evidence that PEXEL position is conserved for co-translational processing and export.
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28
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The phospholipid code: a key component of dying cell recognition, tumor progression and host-microbe interactions. Cell Death Differ 2015; 22:1893-905. [PMID: 26450453 DOI: 10.1038/cdd.2015.122] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 02/06/2023] Open
Abstract
A significant effort is made by the cell to maintain certain phospholipids at specific sites. It is well described that proteins involved in intracellular signaling can be targeted to the plasma membrane and organelles through phospholipid-binding domains. Thus, the accumulation of a specific combination of phospholipids, denoted here as the 'phospholipid code', is key in initiating cellular processes. Interestingly, a variety of extracellular proteins and pathogen-derived proteins can also recognize or modify phospholipids to facilitate the recognition of dying cells, tumorigenesis and host-microbe interactions. In this article, we discuss the importance of the phospholipid code in a range of physiological and pathological processes.
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29
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Bioinformatics Analysis Reveals Abundant Short Alpha-Helices as a Common Structural Feature of Oomycete RxLR Effector Proteins. PLoS One 2015; 10:e0135240. [PMID: 26252511 PMCID: PMC4529148 DOI: 10.1371/journal.pone.0135240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 07/20/2015] [Indexed: 11/19/2022] Open
Abstract
RxLR effectors represent one of the largest and most diverse effector families in oomycete plant pathogens. These effectors have attracted enormous attention since they can be delivered inside the plant cell and manipulates host immunity. With the exceptions of a signal peptide and the following RxLR-dEER and C-terminal W/Y/L motifs identified from the sequences themselves, nearly no functional domains have been found. Recently, protein structures of several RxLRs were revealed to comprise alpha-helical bundle repeats. However, approximately half of all RxLRs lack obvious W/Y/L motifs, which are associated with helical structures. In this study, secondary structure prediction of the putative RxLR proteins was performed. We found that the C-terminus of the majority of these RxLR proteins, irrespective of the presence of W/Y/L motifs, contains abundant short alpha-helices. Since a large-scale experimental determination of protein structures has been difficult to date, results of the current study extend our understanding on the oomycete RxLR effectors in protein secondary structures from individual members to the entire family. Moreover, we identified less alpha-helix-rich proteins from secretomes of several oomycete and fungal organisms in which RxLRs have not been identified, providing additional evidence that these organisms are unlikely to harbor RxLR-like proteins. Therefore, these results provide additional information that will aid further studies on the evolution and functional mechanisms of RxLR effectors.
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30
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Blondeau K, Blaise F, Graille M, Kale SD, Linglin J, Ollivier B, Labarde A, Lazar N, Daverdin G, Balesdent MH, Choi DHY, Tyler BM, Rouxel T, van Tilbeurgh H, Fudal I. Crystal structure of the effector AvrLm4-7 of Leptosphaeria maculans reveals insights into its translocation into plant cells and recognition by resistance proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:610-24. [PMID: 26082394 DOI: 10.1111/tpj.12913] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 06/02/2015] [Accepted: 06/08/2015] [Indexed: 05/13/2023]
Abstract
The avirulence gene AvrLm4-7 of Leptosphaeria maculans, the causal agent of stem canker in Brassica napus (oilseed rape), confers a dual specificity of recognition by two resistance genes (Rlm4 and Rlm7) and is strongly involved in fungal fitness. In order to elucidate the biological function of AvrLm4-7 and understand the specificity of recognition by Rlm4 and Rlm7, the AvrLm4-7 protein was produced in Pichia pastoris and its crystal structure was determined. It revealed the presence of four disulfide bridges, but no close structural analogs could be identified. A short stretch of amino acids in the C terminus of the protein, (R/N)(Y/F)(R/S)E(F/W), was well-conserved among AvrLm4-7 homologs. Loss of recognition of AvrLm4-7 by Rlm4 is caused by the mutation of a single glycine to an arginine residue located in a loop of the protein. Loss of recognition by Rlm7 is governed by more complex mutational patterns, including gene loss or drastic modifications of the protein structure. Three point mutations altered residues in the well-conserved C-terminal motif or close to the glycine involved in Rlm4-mediated recognition, resulting in the loss of Rlm7-mediated recognition. Transient expression in Nicotiana benthamiana (tobacco) and particle bombardment experiments on leaves from oilseed rape suggested that AvrLm4-7 interacts with its cognate R proteins inside the plant cell, and can be translocated into plant cells in the absence of the pathogen. Translocation of AvrLm4-7 into oilseed rape leaves is likely to require the (R/N)(Y/F)(R/S)E(F/W) motif as well as an RAWG motif located in a nearby loop that together form a positively charged region.
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Affiliation(s)
- Karine Blondeau
- I2BC, Université Paris-Saclay, CEA, CNRS, Université Paris Sud, UMR9198, Bât 430, F-91405, Orsay, France
| | - Françoise Blaise
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Marc Graille
- I2BC, Université Paris-Saclay, CEA, CNRS, Université Paris Sud, UMR9198, Bât 430, F-91405, Orsay, France
| | - Shiv D Kale
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Juliette Linglin
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Bénédicte Ollivier
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Audrey Labarde
- I2BC, Université Paris-Saclay, CEA, CNRS, Université Paris Sud, UMR9198, Bât 430, F-91405, Orsay, France
| | - Noureddine Lazar
- I2BC, Université Paris-Saclay, CEA, CNRS, Université Paris Sud, UMR9198, Bât 430, F-91405, Orsay, France
| | - Guillaume Daverdin
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Marie-Hélène Balesdent
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Danielle H Y Choi
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, 24061, USA
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, 97331, USA
| | - Brett M Tyler
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, 24061, USA
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, 97331, USA
| | - Thierry Rouxel
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
| | - Herman van Tilbeurgh
- I2BC, Université Paris-Saclay, CEA, CNRS, Université Paris Sud, UMR9198, Bât 430, F-91405, Orsay, France
| | - Isabelle Fudal
- INRA, UMR 1290 INRA-AgroParisTech BIOGER, Avenue Lucien Brétignières, F-78850, Thiverval-Grignon, France
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31
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Experimental approaches to investigate effector translocation into host cells in the Ustilago maydis/maize pathosystem. Eur J Cell Biol 2015; 94:349-58. [PMID: 26118724 DOI: 10.1016/j.ejcb.2015.06.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The fungus Ustilago maydis is a pathogen that establishes a biotrophic interaction with Zea mays. The interaction with the plant host is largely governed by more than 300 novel, secreted protein effectors, of which only four have been functionally characterized. Prerequisite to examine effector function is to know where effectors reside after secretion. Effectors can remain in the extracellular space, i.e. the plant apoplast (apoplastic effectors), or can cross the plant plasma membrane and exert their function inside the host cell (cytoplasmic effectors). The U. maydis effectors lack conserved motifs in their primary sequences that could allow a classification of the effectome into apoplastic/cytoplasmic effectors. This represents a significant obstacle in functional effector characterization. Here we describe our attempts to establish a system for effector classification into apoplastic and cytoplasmic members, using U. maydis for effector delivery.
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32
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Tyler BM, Kale SD, Wang Q, Tao K, Clark HR, Drews K, Antignani V, Rumore A, Hayes T, Plett JM, Fudal I, Gu B, Chen Q, Affeldt KJ, Berthier E, Fischer GJ, Dou D, Shan W, Keller NP, Martin F, Rouxel T, Lawrence CB. Microbe-Independent Entry of Oomycete RxLR Effectors and Fungal RxLR-Like Effectors Into Plant and Animal Cells Is Specific and Reproducible. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 2015:51-56. [PMID: 27839069 DOI: 10.1094/mpmi-99-99-0002.testissue] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Brett M Tyler
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Shiv D Kale
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Qunqing Wang
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Kai Tao
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Helen R Clark
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Kelly Drews
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Vincenzo Antignani
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Amanda Rumore
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Tristan Hayes
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Jonathan M Plett
- 3 Lab of Excellence ARBRE, UMR INRA/UHP 1136, Interactions Arbres/Micro-organismes, Centre INRA de Nancy, 54280 Champenoux, France
| | - Isabelle Fudal
- 4 INRA-Bioger, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - Biao Gu
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
- 5 College of Plant Protection and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qinghe Chen
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Katharyn J Affeldt
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Erwin Berthier
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Gregory J Fischer
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Daolong Dou
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
- 7 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Weixing Shan
- 5 College of Plant Protection and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Nancy P Keller
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Francis Martin
- 3 Lab of Excellence ARBRE, UMR INRA/UHP 1136, Interactions Arbres/Micro-organismes, Centre INRA de Nancy, 54280 Champenoux, France
| | - Thierry Rouxel
- 4 INRA-Bioger, Campus AgroParisTech, 78850 Thiverval-Grignon, France
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Fletcher J, Leach JE, Eversole K, Tauxe R. Human Pathogens on Plants: Designing a Multidisciplinary Strategy for Research. PHYTOPATHOLOGY 2014:PHYTO09120236RVWtest. [PMID: 27454683 PMCID: PMC10962904 DOI: 10.1094/phyto-09-12-0236-rvw.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define cross-over issues that pertain also to HPOP research, and can suggest logical strategies for minimizing the risk of microbial contamination. Continued interactions and communication among these two disciplinary communities is essential and can be achieved by the creation of an interdisciplinary research coordination network. We hope that this article, an introduction to the multidisciplinary HPOP arena, will be useful to researchers in many related fields.
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Affiliation(s)
- Jacqueline Fletcher
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Jan E Leach
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Kellye Eversole
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Robert Tauxe
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
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Fletcher J, Leach JE, Eversole K, Tauxe R. Human Pathogens on Plants: Designing a Multidisciplinary Strategy for Research. PHYTOPATHOLOGY 2014:PHYTO09120236IAtest. [PMID: 27454682 DOI: 10.1094/phyto-09-12-0236-ia.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define cross-over issues that pertain also to HPOP research, and can suggest logical strategies for minimizing the risk of microbial contamination. Continued interactions and communication among these two disciplinary communities is essential and can be achieved by the creation of an interdisciplinary research coordination network. We hope that this article, an introduction to the multidisciplinary HPOP arena, will be useful to researchers in many related fields.
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Affiliation(s)
- Jacqueline Fletcher
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Jan E Leach
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Kellye Eversole
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Robert Tauxe
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
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35
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Nunney L, Elfekih S, Stouthamer R. The Importance of Multilocus Sequence Typing: Cautionary Tales from the Bacterium Xylella fastidiosa. PHYTOPATHOLOGY 2014:PHYTO10110298Rtest. [PMID: 27454684 DOI: 10.1094/phyto-10-11-0298-r.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Microbial identification methods have evolved rapidly over the last few decades. One such method is multilocus sequence typing (MLST). MLST is a powerful tool for understanding the evolutionary dynamics of pathogens and to gain insight into their genetic diversity. We illustrate the importance of accurate typing by reporting on three problems that have arisen in the study of a single bacterial species, the plant pathogen Xylella fastidiosa. Two of these were particularly serious since they concerned contamination of important research material that has had detrimental consequences for Xylella research: the contamination of DNA used in the sequencing of an X. fastidiosa genome (Ann-1) with DNA from another X. fastidiosa strain, and the unrecognized mislabeling of a strain (Temecula1) distributed from a culture collection (ATCC). We advocate the routine use of MLST to define strains maintained in culture collections and emphasize the importance of confirming the purity of DNA submitted for sequencing. We also present a third example that illustrates the value of MLST in guiding the choice of taxonomic types. Beyond these situations, there is a strong case for MLST whenever an isolate is used experimentally, especially where genotypic differences are suspected to influence the outcome.
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Affiliation(s)
- L Nunney
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
| | - S Elfekih
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
| | - R Stouthamer
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
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Abstract
Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens.
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Affiliation(s)
- Benjamin Petre
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
- INRA, Interactions Arbres/Microorganismes, UMR 1136, Champenoux, France
| | - Sophien Kamoun
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
- * E-mail:
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37
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Clark HR, Hayes TA, Kale SD. Characterizing and measuring endocytosis of lipid-binding effectors in mammalian cells. Methods Enzymol 2014; 535:103-19. [PMID: 24377920 DOI: 10.1016/b978-0-12-397925-4.00007-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Pathogen-host interactions are mediated in part by secreted microbial proteins capable of exploiting host cells for their survival. Several of these manipulations involve, but are not limited to, suppression of defense responses, alterations in host vesicular trafficking, and manipulation of gene expression. The delivery of such molecules from microbe to host has been of intense interest in several microbe-host systems. Several well-studied bacterial effectors are delivered directly into host cells through a needle injection apparatus. Conversely, there have been several examples of secreted effectors and protein toxins from bacteria and eukaryotic microbes, such as fungi and oomycetes, being internalized into host cells by receptor-mediated endocytosis. In the following chapter, we discuss various techniques utilized to measure these endocytosed lipid-binding effectors that can be delivered in the absence of the pathogen.
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Affiliation(s)
- Helen R Clark
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA; Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, USA
| | - Tristan A Hayes
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Shiv D Kale
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA.
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38
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Structural and functional studies of a phosphatidic acid-binding antifungal plant defensin MtDef4: identification of an RGFRRR motif governing fungal cell entry. PLoS One 2013; 8:e82485. [PMID: 24324798 PMCID: PMC3853197 DOI: 10.1371/journal.pone.0082485] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 10/25/2013] [Indexed: 01/27/2023] Open
Abstract
MtDef4 is a 47-amino acid cysteine-rich evolutionary conserved defensin from a model legume Medicago truncatula. It is an apoplast-localized plant defense protein that inhibits the growth of the ascomycetous fungal pathogen Fusarium graminearum in vitro at micromolar concentrations. Little is known about the mechanisms by which MtDef4 mediates its antifungal activity. In this study, we show that MtDef4 rapidly permeabilizes fungal plasma membrane and is internalized by the fungal cells where it accumulates in the cytoplasm. Furthermore, analysis of the structure of MtDef4 reveals the presence of a positively charged γ-core motif composed of β2 and β3 strands connected by a positively charged RGFRRR loop. Replacement of the RGFRRR sequence with AAAARR or RGFRAA abolishes the ability of MtDef4 to enter fungal cells, suggesting that the RGFRRR loop is a translocation signal required for the internalization of the protein. MtDef4 binds to phosphatidic acid (PA), a precursor for the biosynthesis of membrane phospholipids and a signaling lipid known to recruit cytosolic proteins to membranes. Amino acid substitutions in the RGFRRR sequence which abolish the ability of MtDef4 to enter fungal cells also impair its ability to bind PA. These findings suggest that MtDef4 is a novel antifungal plant defensin capable of entering into fungal cells and affecting intracellular targets and that these processes are mediated by the highly conserved cationic RGFRRR loop via its interaction with PA.
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39
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Abstract
Over the past decade, considerable advances have been made in understanding the molecular mechanisms that underpin the arms race between plant pathogens and their hosts. Alongside genomic, bioinformatic, proteomic, biochemical and cell biological analyses of plant-pathogen interactions, three-dimensional structural studies of virulence proteins deployed by pathogens to promote infection, in some cases complexed with their plant cell targets, have uncovered key insights into the functions of these molecules. Structural information on plant immune receptors, which regulate the response to pathogen attack, is also starting to emerge. Structural studies of bacterial plant pathogen-host systems have been leading the way, but studies of filamentous plant pathogens are gathering pace. In this Review, we summarize the key developments in the structural biology of plant pathogen-host interactions.
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Lapin D, Van den Ackerveken G. Susceptibility to plant disease: more than a failure of host immunity. TRENDS IN PLANT SCIENCE 2013; 18:546-54. [PMID: 23790254 DOI: 10.1016/j.tplants.2013.05.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 05/15/2013] [Accepted: 05/21/2013] [Indexed: 05/23/2023]
Abstract
Susceptibility to infectious diseases caused by pathogens affects most plants in their natural habitat and leads to yield losses in agriculture. However, plants are not helpless because their immune system can deal with the vast majority of attackers. Nevertheless, adapted pathogens are able to circumvent or avert host immunity making plants susceptible to these uninvited guests. In addition to the failure of the plant immune system, there are other host processes that contribute to plant disease susceptibility. In this review, we discuss recent studies that show the active role played by the host in supporting disease, focusing mainly on biotrophic stages of infection. Plants attract pathogens, enable their entry and accommodation, and facilitate nutrient provision.
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Affiliation(s)
- Dmitry Lapin
- Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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41
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Lu S, Chen L, Tao K, Sun N, Wu Y, Lu X, Wang Y, Dou D. Intracellular and extracellular phosphatidylinositol 3-phosphate produced by Phytophthora species is important for infection. MOLECULAR PLANT 2013; 6:1592-604. [PMID: 23475996 DOI: 10.1093/mp/sst047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
RxLR effectors produced by Phytophthora pathogens have been proposed to bind to phosphatidylinositol 3-phosphate (PtdIns(3)P) to mediate their translocation into host cells and/or to increase their stability in planta. Since the levels of PtdIns(3)P in plants are low, we examined whether Phytophthora species may produce PtdIns(3)P to promote infection. We observed that PtdIns(3)P-specific GFP biosensors could bind to P. parasitica and P. sojae hyphae during infection of Nicotiana benthamiana leaves transiently secreting the biosensors, suggesting that the hyphae exposed PtdIns(3)P on their plasma membrane and/or secreted PtdIns(3)P. Silencing of the phosphatidylinositol 3-kinases (PI3K) genes, treatment with LY294002, or expression of PtdIns(3)P-binding proteins by P. sojae reduced the virulence of the pathogen on soybean, indicating that pathogen-synthesized PtdIns(3)P was required for full virulence. Secretion of PtdIns(3)P-binding proteins or of a PI3P-5-kinase by N. benthamiana leaves significantly increased the level of resistance to infection by P. parasitica and P. capsici. Together, our results support the hypothesis that Phytophthora species produce external PtdIns(3)P to aid in infection, such as to promote entry of RxLR effectors into host cells. Our results derived from P. sojae RxLR effector Avr1b confirm that both the N-terminus and the C-terminus of this effector can bind PtdIns(3)P.
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Affiliation(s)
- Shan Lu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
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42
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Rodewald J, Trognitz B. Solanum resistance genes against Phytophthora infestans and their corresponding avirulence genes. MOLECULAR PLANT PATHOLOGY 2013; 14:740-57. [PMID: 23710878 PMCID: PMC6638693 DOI: 10.1111/mpp.12036] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Resistance genes against Phytophthora infestans (Rpi genes), the most important potato pathogen, are still highly valued in the breeding of Solanum spp. for enhanced resistance. The Rpi genes hitherto explored are localized most often in clusters, which are similar between the diverse Solanum genomes. Their distribution is not independent of late maturity traits. This review provides a summary of the most recent important revelations on the genomic position and cloning of Rpi genes, and the structure, associations, mode of action and activity spectrum of Rpi and corresponding avirulence (Avr) proteins. Practical implications for research into and application of Rpi genes are deduced and combined with an outlook on approaches to address remaining issues and interesting questions. It is evident that the potential of Rpi genes has not been exploited fully.
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Affiliation(s)
- Jan Rodewald
- Department of Health and Environment, Austrian Institute of Technology, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria.
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43
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Na R, Yu D, Qutob D, Zhao J, Gijzen M. Deletion of the Phytophthora sojae avirulence gene Avr1d causes gain of virulence on Rps1d. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:969-76. [PMID: 23550527 DOI: 10.1094/mpmi-02-13-0036-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Phytophthora sojae is an oomycete and a pathogen of soybean that causes root rot. During infection P. sojae delivers effector proteins into host cells to foster disease. However, effector-triggered immunity (ETI) results when pathogen factors are recognized by host resistance (R) proteins. We have now identified the P. sojae Avr1d gene, which encodes a predicted effector protein with the amino acid motif Arg-X-Leu-Arg (RXLR). Genetic mapping of 16 different P. sojae isolates and of a segregating F2 population of 40 individuals shows that the predicted RXLR effector gene Avh6 precisely cosegregates with the Avr1d phenotype. Transient expression assays confirm that Avr1d triggers cell death specifically in Rps1d soybean plants. The Avr1d gene is present in P. sojae strains that are avirulent on Rps1d, whereas the gene is deleted from the genome of virulent strains. Two sequence variants of the Avr1d gene encoding different protein products occur in P. sojae strains, but both are recognized by Rps1d and cause ETI. Liposome binding assays show that Avr1d has affinity for phosphatidylinositol 4-phosphate and that binding can be disrupted by mutation of lysine residues in the carboxy-terminal effector domain of the protein. The identification of Avr1d aids pathogen diagnostics and soybean cultivar development.
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Affiliation(s)
- Ren Na
- Agriculture and Agri-Food, Canada
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44
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Song T, Kale SD, Arredondo FD, Shen D, Su L, Liu L, Wu Y, Wang Y, Dou D, Tyler BM. Two RxLR avirulence genes in Phytophthora sojae determine soybean Rps1k-mediated disease resistance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:711-20. [PMID: 23530601 DOI: 10.1094/mpmi-12-12-0289-r] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Resistance to Phytophthora sojae (Rps) genes have been widely used in soybean against root and stem rot diseases caused by this oomycete. Among 15 known soybean Rps genes, Rps1k has been the most widely used in the past four decades. Here, we show that the products of two distinct but closely linked RxLR effector genes are detected by Rps1k-containing plants, resulting in disease resistance. One of the genes is Avr1b-1, that confers avirulence in the presence of Rps1b. Three lines of evidence, including overexpression and gene silencing of Avr1b-1 in stable P. sojae transformants, as well as transient expression of this gene in soybean, indicated that Avr1b could trigger an Rps1k-mediated defense response. Some isolates of P. sojae that do not express Avr1b are nevertheless unable to infect Rps1k plants. In those isolates, we identified a second RxLR effector gene (designated Avr1k), located 5 kb away from Avr1b-1. Silencing or overexpression of Avr1k in P. sojae stable transformants resulted in the loss or gain, respectively, of the avirulence phenotype in the presence of Rps1k. Only isolates of P. sojae with mutant alleles of both Avr1b-1 and Avr1k could evade perception by the soybean plants carrying Rps1k.
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Affiliation(s)
- Tianqiao Song
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
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45
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Tyler BM, Kale SD, Wang Q, Tao K, Clark HR, Drews K, Antignani V, Rumore A, Hayes T, Plett JM, Fudal I, Gu B, Chen Q, Affeldt KJ, Berthier E, Fischer GJ, Dou D, Shan W, Keller NP, Martin F, Rouxel T, Lawrence CB. Microbe-independent entry of oomycete RxLR effectors and fungal RxLR-like effectors into plant and animal cells is specific and reproducible. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:611-6. [PMID: 23550528 PMCID: PMC3994703 DOI: 10.1094/mpmi-02-13-0051-ia] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A wide diversity of pathogens and mutualists of plant and animal hosts, including oomycetes and fungi, produce effector proteins that enter the cytoplasm of host cells. A major question has been whether or not entry by these effectors can occur independently of the microbe or requires machinery provided by the microbe. Numerous publications have documented that oomycete RxLR effectors and fungal RxLR-like effectors can enter plant and animal cells independent of the microbe. A recent reexamination of whether the RxLR domain of oomycete RxLR effectors is sufficient for microbe-independent entry into host cells concluded that the RxLR domains of Phytophthora infestans Avr3a and of P. sojae Avr1b alone are NOT sufficient to enable microbe-independent entry of proteins into host and nonhost plant and animal cells. Here, we present new, more detailed data that unambiguously demonstrate that the RxLR domain of Avr1b does show efficient and specific entry into soybean root cells and also into wheat leaf cells, at levels well above background nonspecific entry. We also summarize host cell entry experiments with a wide diversity of oomycete and fungal effectors with RxLR or RxLR-like motifs that have been independently carried out by the seven different labs that coauthored this letter. Finally we discuss possible technical reasons why specific cell entry may have been not detected by Wawra et al. (2013).
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Affiliation(s)
- Brett M Tyler
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA.
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46
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Yaeno T, Shirasu K. The RXLR motif of oomycete effectors is not a sufficient element for binding to phosphatidylinositol monophosphates. PLANT SIGNALING & BEHAVIOR 2013; 8:e23865. [PMID: 23425855 PMCID: PMC7030308 DOI: 10.4161/psb.23865] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The translocation of effector proteins into the host plant cells is essential for pathogens to suppress plant immune responses. The oomycete pathogen Phytophthora infestans secretes AVR3a, a crucial virulence effector protein with an N-terminal RXLR motif that is required for this translocation. It has been reported that the RXLR motif of P. sojae Avr1b, which is a close homolog of AVR3a, is required for binding to phosphatidylinositol monophosphates (PIPs). However, in our previous report, AVR3a as well as Avr1b bind to PIPs not via RXLR but via lysine residues forming a positively-charged area in the effector domain. In this report, we examined whether other RXLR effectors whose structures have been determined bind to PIPs. Both P. capsici AVR3a11 and Hyaloperonospora arabidopsidis ATR1 have an RXLR motif in their N-terminal regions but did not bind to any PIPs. These results suggest that the RXLR motif is not sufficient for PIP binding.
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Affiliation(s)
- Takashi Yaeno
- Plant Science Center; RIKEN; Tsurumi, Yokohama, Kanagawa, Japan
- * Correspondence to: Takashi Yaeno;
| | - Ken Shirasu
- Plant Science Center; RIKEN; Tsurumi, Yokohama, Kanagawa, Japan
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Jiang RHY, Stahelin RV, Bhattacharjee S, Haldar K. Eukaryotic virulence determinants utilize phosphoinositides at the ER and host cell surface. Trends Microbiol 2013; 21:145-56. [PMID: 23375057 DOI: 10.1016/j.tim.2012.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 12/12/2012] [Accepted: 12/18/2012] [Indexed: 01/03/2023]
Abstract
Similar to bacteria, eukaryotic pathogens may utilize common strategies of pathogenic secretion, because effector proteins from the oomycete Phytophthora infestans and virulence determinants from the human malaria parasite Plasmodium falciparum share a functionally equivalent host-cell-targeting motif (RxLR-dEER in P. infestans and RxLxE/D/Q in P. falciparum). Here we summarize recent studies that reveal that the malarial motif may function differently than previously envisioned. Binding of the lipid phosphatidylinositol 3-phosphate [PI(3)P] is a critical step in accessing the host for both pathogens, but occurs in different locations. Nanomolar affinity for PI(3)P by these short amino acid motifs suggests that a newly identified mechanism of phosphoinositide binding that unexpectedly occurs in secretory locations has been exploited for virulence by diverse eukaryotic pathogens.
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Affiliation(s)
- Rays H Y Jiang
- Department of Infectious Diseases and Immunology, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA
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Gillaspy GE. The Role of Phosphoinositides and Inositol Phosphates in Plant Cell Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 991:141-57. [DOI: 10.1007/978-94-007-6331-9_8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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