1
|
Roussin-Léveillée C, Mackey D, Ekanayake G, Gohmann R, Moffett P. Extracellular niche establishment by plant pathogens. Nat Rev Microbiol 2024:10.1038/s41579-023-00999-8. [PMID: 38191847 DOI: 10.1038/s41579-023-00999-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2023] [Indexed: 01/10/2024]
Abstract
The plant extracellular space, referred to as the apoplast, is inhabited by a variety of microorganisms. Reflecting the crucial nature of this compartment, both plants and microorganisms seek to control, exploit and respond to its composition. Upon sensing the apoplastic environment, pathogens activate virulence programmes, including the delivery of effectors with well-established roles in suppressing plant immunity. We posit that another key and foundational role of effectors is niche establishment - specifically, the manipulation of plant physiological processes to enrich the apoplast in water and nutritive metabolites. Facets of plant immunity counteract niche establishment by restricting water, nutrients and signals for virulence activation. The complex competition to control and, in the case of pathogens, exploit the apoplast provides remarkable insights into the nature of virulence, host susceptibility, host defence and, ultimately, the origin of phytopathogenesis. This novel framework focuses on the ecology of a microbial niche and highlights areas of future research on plant-microorganism interactions.
Collapse
Affiliation(s)
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, USA.
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA.
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, USA.
| | - Gayani Ekanayake
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, USA
| | - Reid Gohmann
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, USA
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| |
Collapse
|
2
|
Gohmann R, Mackey D. Protein phosphatase 2A: a high-value target of virulence factors. Trends Parasitol 2023; 39:803-805. [PMID: 37580205 DOI: 10.1016/j.pt.2023.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/16/2023]
Abstract
Pathogen-encoded virulence factors perturb host physiology and immune function to promote infection. Reinforcing the concept that protein phosphatase 2A (PP2A) is convergently targeted by virulence factors from diverse pathogens, Li et al. demonstrate that PP2A is coopted by members of a modular family of effector proteins from a plant-pathogenic oomycete.
Collapse
Affiliation(s)
- Reid Gohmann
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA; Molecular, Cellular, and Developmental Biology Program, Ohio State University, Columbus, OH 43210, USA
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA; Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA; Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
3
|
Kanawati B, Bertic M, Moritz F, Habermann F, Zimmer I, Mackey D, Schmitt‐Kopplin P, Schnitzler J, Durner J, Gaupels F. Blue-green fluorescence during hypersensitive cell death arises from phenylpropanoid deydrodimers. Plant Direct 2023; 7:e531. [PMID: 37705693 PMCID: PMC10496137 DOI: 10.1002/pld3.531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 08/12/2023] [Accepted: 08/25/2023] [Indexed: 09/15/2023]
Abstract
Infection of Arabidopsis with avirulent Pseudomonas syringae and exposure to nitrogen dioxide (NO2) both trigger hypersensitive cell death (HCD) that is characterized by the emission of bright blue-green (BG) autofluorescence under UV illumination. The aim of our current work was to identify the BG fluorescent molecules and scrutinize their biosynthesis, localization, and functions during the HCD. Compared with wild-type (WT) plants, the phenylpropanoid-deficient mutant fah1 developed normal HCD except for the absence of BG fluorescence. Ultrahigh resolution metabolomics combined with mass difference network analysis revealed that WT but not fah1 plants rapidly accumulate dehydrodimers of sinapic acid, sinapoylmalate, 5-hydroxyferulic acid, and 5-hydroxyferuloylmalate during the HCD. FAH1-dependent BG fluorescence appeared exclusively within dying cells of the upper epidermis as detected by microscopy. Saponification released dehydrodimers from cell wall polymers of WT but not fah1 plants. Collectively, our data suggest that HCD induction leads to the formation of free BG fluorescent dehydrodimers from monomeric sinapates and 5-hydroxyferulates. The formed dehydrodimers move from upper epidermis cells into the apoplast where they esterify cell wall polymers. Possible functions of phenylpropanoid dehydrodimers are discussed.
Collapse
Affiliation(s)
- Basem Kanawati
- Analytical BioGeoChemistryHelmholtz Zentrum MünchenNeuherbergGermany
| | - Marko Bertic
- Research Unit Environmental Simulation, Institute of Biochemical Plant PathologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - Franco Moritz
- Analytical BioGeoChemistryHelmholtz Zentrum MünchenNeuherbergGermany
| | - Felix Habermann
- Institute of Anatomy, Histology and Embryology, Department of Veterinary SciencesLudwig‐Maximilians‐University MunichMunichGermany
| | - Ina Zimmer
- Research Unit Environmental Simulation, Institute of Biochemical Plant PathologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - David Mackey
- Department of Horticulture and Crop Science and Department of Molecular GeneticsOhio State UniversityColumbusOhioUSA
| | | | - Jörg‐Peter Schnitzler
- Research Unit Environmental Simulation, Institute of Biochemical Plant PathologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - Jörg Durner
- Institute of Biochemical Plant PathologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - Frank Gaupels
- Institute of Biochemical Plant PathologyHelmholtz Zentrum MünchenNeuherbergGermany
| |
Collapse
|
4
|
Huang Z, Zhang D, Chen SC, Huang D, Mackey D, Chen FK, McLenachan S. Mitochondrial Dysfunction and Impaired Antioxidant Responses in Retinal Pigment Epithelial Cells Derived from a Patient with RCBTB1-Associated Retinopathy. Cells 2023; 12:1358. [PMID: 37408192 DOI: 10.3390/cells12101358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 07/07/2023] Open
Abstract
Mutations in the RCBTB1 gene cause inherited retinal disease; however, the pathogenic mechanisms associated with RCBTB1 deficiency remain poorly understood. Here, we investigated the effect of RCBTB1 deficiency on mitochondria and oxidative stress responses in induced pluripotent stem cell (iPSC)-derived retinal pigment epithelial (RPE) cells from control subjects and a patient with RCBTB1-associated retinopathy. Oxidative stress was induced with tert-butyl hydroperoxide (tBHP). RPE cells were characterized by immunostaining, transmission electron microscopy (TEM), CellROX assay, MitoTracker assay, quantitative PCR and immunoprecipitation assay. Patient-derived RPE cells displayed abnormal mitochondrial ultrastructure and reduced MitoTracker fluorescence compared with controls. Patient RPE cells displayed increased levels of reactive oxygen species (ROS) and were more sensitive to tBHP-induced ROS generation than control RPE. Control RPE upregulated RCBTB1 and NFE2L2 expression in response to tBHP treatment; however, this response was highly attenuated in patient RPE. RCBTB1 was co-immunoprecipitated from control RPE protein lysates by antibodies for either UBE2E3 or CUL3. Together, these results demonstrate that RCBTB1 deficiency in patient-derived RPE cells is associated with mitochondrial damage, increased oxidative stress and an attenuated oxidative stress response.
Collapse
Affiliation(s)
- Zhiqin Huang
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA 6009, Australia
- Lions Eye Institute, Nedlands, WA 6009, Australia
| | - Dan Zhang
- Lions Eye Institute, Nedlands, WA 6009, Australia
| | | | - Di Huang
- Lions Eye Institute, Nedlands, WA 6009, Australia
| | - David Mackey
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA 6009, Australia
- Lions Eye Institute, Nedlands, WA 6009, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA 6009, Australia
- Lions Eye Institute, Nedlands, WA 6009, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA 6000, Australia
- Ophthalmology, Department of Surgery, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Samuel McLenachan
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA 6009, Australia
- Lions Eye Institute, Nedlands, WA 6009, Australia
| |
Collapse
|
5
|
Ekanayake G, Gohmann R, Mackey D. A method for quantitation of apoplast hydration in Arabidopsis leaves reveals water-soaking activity of effectors of Pseudomonas syringae during biotrophy. Sci Rep 2022; 12:18363. [PMID: 36319664 PMCID: PMC9626588 DOI: 10.1038/s41598-022-22472-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 12/03/2022] Open
Abstract
The plant apoplast has a crucial role in photosynthesis and respiration due to its vital function in gas exchange and transpiration. The apoplast is also a dynamic environment that participates in many ion and nutrient transport processes via plasma membrane-localized proteins. Furthermore, diverse microbes colonize the plant apoplast, including the hemibiotrophic bacterial pathogen, Pseudomonas syringae pv. tomato (Pto) strain DC3000. Pto DC3000 initiates pathogenesis upon moving through stomata into the apoplast and then proliferating to high levels. Here we developed a centrifugation-based method to isolate and quantify the apoplast fluid in Arabidopsis leaves, without significantly damaging the tissue. We applied the simple apoplast extraction method to demonstrate that the Pto DC3000 type III bacterial effectors AvrE1 and HopM1 induce hydration of the Arabidopsis apoplast in advance of macroscopic water-soaking, disruption of host cell integrity, and disease progression. Finally, we demonstrate the utility of the apoplast extraction method for isolation of bacteria proliferating in the apoplast.
Collapse
Affiliation(s)
- Gayani Ekanayake
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA
| | - Reid Gohmann
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA
- Molecular, Cellular, and Developmental Biology Program, Ohio State University, Columbus, OH, 43210, USA
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA.
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, 43210, USA.
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA.
| |
Collapse
|
6
|
Zhao Z, Fan J, Yang P, Wang Z, Opiyo SO, Mackey D, Xia Y. Involvement of Arabidopsis Acyl Carrier Protein 1 in PAMP-Triggered Immunity. Mol Plant Microbe Interact 2022; 35:681-693. [PMID: 35343247 DOI: 10.1094/mpmi-02-22-0049-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plant fatty acids (FAs) and lipids are essential in storing energy and act as structural components for cell membranes and signaling molecules for plant growth and stress responses. Acyl carrier proteins (ACPs) are small acidic proteins that covalently bind the fatty acyl intermediates during the elongation of FAs. The Arabidopsis thaliana ACP family has eight members. Through reverse genetic, molecular, and biochemical approaches, we have discovered that ACP1 localizes to the chloroplast and limits the magnitude of pattern-triggered immunity (PTI) against the bacterial pathogen Pseudomonas syringae pv. tomato. Mutant acp1 plants have reduced levels of linolenic acid (18:3), which is the primary precursor for biosynthesis of the phytohormone jasmonic acid (JA), and a corresponding decrease in the abundance of JA. Consistent with the known antagonistic relationship between JA and salicylic acid (SA), acp1 mutant plants also accumulate a higher level of SA and display corresponding shifts in JA- and SA-regulated transcriptional outputs. Moreover, methyl JA and linolenic acid treatments cause an apparently enhanced decrease of resistance against P. syringae pv. tomato in acp1 mutants than that in WT plants. The ability of ACP1 to prevent this hormone imbalance likely underlies its negative impact on PTI in plant defense. Thus, ACP1 links FA metabolism to stress hormone homeostasis to be negatively involved in PTI in Arabidopsis plant defense. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Zhenzhen Zhao
- Department of Plant Pathology, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210, U.S.A
| | - Jiangbo Fan
- Department of Plant Pathology, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210, U.S.A
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai, 200240, China
| | - Piao Yang
- Department of Plant Pathology, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210, U.S.A
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Stephen Obol Opiyo
- Department of Plant Pathology, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210, U.S.A
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Ye Xia
- Department of Plant Pathology, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210, U.S.A
| |
Collapse
|
7
|
Macoy DMJ, Uddin S, Ahn G, Peseth S, Ryu GR, Cha JY, Lee JY, Bae D, Paek SM, Chung HJ, Mackey D, Lee SY, Kim WY, Kim MG. Effect of Hydroxycinnamic Acid Amides, Coumaroyl Tyramine and Coumaroyl Tryptamine on Biotic Stress Response in Arabidopsis. J Plant Biol 2022; 65:145-155. [DOI: 10.1007/s12374-021-09341-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 08/28/2023]
|
8
|
Bartholomew HP, Reynoso G, Thomas BJ, Mullins CM, Smith C, Gentzel IN, Giese LA, Mackey D, Stevens AM. The Transcription Factor Lrp of Pantoea stewartii subsp. stewartii Controls Capsule Production, Motility, and Virulence Important for in planta Growth. Front Microbiol 2022; 12:806504. [PMID: 35237242 PMCID: PMC8882988 DOI: 10.3389/fmicb.2021.806504] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
The bacterial phytopathogen Pantoea stewartii subsp. stewartii causes leaf blight and Stewart's wilt disease in susceptible corn varieties. A previous RNA-Seq study examined P. stewartii gene expression patterns during late-stage infection in the xylem, and a Tn-Seq study using a P. stewartii mutant library revealed genes essential for colonization of the xylem. Based on these findings, strains with in-frame chromosomal deletions in the genes encoding seven transcription factors (NsrR, IscR, Nac, Lrp, DSJ_00125, DSJ_03645, and DSJ_18135) and one hypothetical protein (DSJ_21690) were constructed to further evaluate the role of the encoded gene products during in vitro and in planta growth. Assays for capsule production and motility indicate that Lrp plays a role in regulating these two key physiological outputs in vitro. Single infections of each deletion strain into the xylem of corn seedlings determined that Lrp plays a significant role in P. stewartii virulence. In planta xylem competition assays between co-inoculated deletion and the corresponding complementation or wild-type strains as well as in vitro growth curves determined that Lrp controls functions important for P. stewartii colonization and growth in corn plants, whereas IscR may have a more generalized impact on growth. Defining the role of essential transcription factors, such as Lrp, during in planta growth will enable modeling of key components of the P. stewartii regulatory network utilized during growth in corn plants.
Collapse
Affiliation(s)
| | - Guadalupe Reynoso
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Brandi J. Thomas
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chase M. Mullins
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chastyn Smith
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Irene N. Gentzel
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
| | - Laura A. Giese
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
| | - David Mackey
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
- Department of Molecular Genetics and Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States
| | - Ann M. Stevens
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
- Center for Emerging, Zoonotic and Arthropod-Borne Pathogens, Virginia Tech, Blacksburg, VA, United States
| |
Collapse
|
9
|
Alam M, Tahir J, Siddiqui A, Magzoub M, Shahzad-Ul-Hussan S, Mackey D, Afzal AJ. RIN4 homologs from important crop species differentially regulate the Arabidopsis NB-LRR immune receptor, RPS2. Plant Cell Rep 2021; 40:2341-2356. [PMID: 34486076 DOI: 10.1007/s00299-021-02771-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
KEY MESSAGE RIN4 homologs from important crop species differ in their ability to prevent ectopic activity of the nucleotide binding-leucine rich repeat resistance protein, RPS2. Pathogens deploy virulence effectors to perturb host processes. Plants utilize intracellular resistance (R) proteins to recognize pathogen effectors either by direct interaction or indirectly via effector-mediated perturbations of host components. RPM1-INTERACTING PROTEIN4 (RIN4) is a plant immune regulator that mediates the indirect activation of multiple, independently evolved R-proteins by multiple, unrelated effector proteins. One of these, RPS2 (RESISTANT TO P. SYRINGAE2), is activated upon cleavage of Arabidopsis (At)RIN4 by the Pseudomonas syringae effector AvrRpt2. To gain insight into the AvrRpt2-RIN4-RPS2 defense-activation module, we compared the function of AtRIN4 with RIN4 homologs present in a diverse range of plant species. We selected seven homologs containing conserved features of AtRIN4, including two NOI (Nitrate induced) domains, each containing a predicted cleavage site for AvrRpt2, and a C-terminal palmitoylation site predicted to mediate membrane tethering of the proteins. Palmitoylation-mediated tethering of AtRIN4 to the plasma membrane and cleavage by AvrRpt2 are required for suppression and activation of RPS2, respectively. While all seven homologs are localized at the plasma membrane, only four suppress RPS2 when transiently expressed in Nicotiana benthamiana. All seven homologs are cleaved by AvrRpt2 and, for those homologs that are able to suppress RPS2, cleavage relieves suppression of RPS2. Further, we demonstrate that the membrane-tethered, C-terminal AvrRpt2-generated cleavage fragment is sufficient for the suppression of RPS2. Lastly, we show that the membrane localization of RPS2 is unaffected by its suppression or activation status.
Collapse
Affiliation(s)
- Maheen Alam
- Department of Biology, Lahore University of Management Sciences, Sector U, DHA, Lahore, Pakistan
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA
| | - Jibran Tahir
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 92-169, Auckland, 1025, New Zealand
| | - Anam Siddiqui
- Department of Plant Sciences, Rothamsted Research, West Common, Harpenden, AL52JQ, UK
| | - Mazin Magzoub
- Biology Program, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Syed Shahzad-Ul-Hussan
- Department of Biology, Lahore University of Management Sciences, Sector U, DHA, Lahore, Pakistan
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA
- Department of Molecular Genetics and Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA
| | - A J Afzal
- Biology Program, New York University Abu Dhabi, Abu Dhabi, UAE.
| |
Collapse
|
10
|
Chae HB, Kim MG, Kang CH, Park JH, Lee ES, Lee SU, Chi YH, Paeng SK, Bae SB, Wi SD, Yun BW, Kim WY, Yun DJ, Mackey D, Lee SY. Redox sensor QSOX1 regulates plant immunity by targeting GSNOR to modulate ROS generation. Mol Plant 2021; 14:1312-1327. [PMID: 33962063 DOI: 10.1016/j.molp.2021.05.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 02/25/2021] [Accepted: 05/03/2021] [Indexed: 05/22/2023]
Abstract
Reactive oxygen signaling regulates numerous biological processes, including stress responses in plants. Redox sensors transduce reactive oxygen signals into cellular responses. Here, we present biochemical evidence that a plant quiescin sulfhydryl oxidase homolog (QSOX1) is a redox sensor that negatively regulates plant immunity against a bacterial pathogen. The expression level of QSOX1 is inversely correlated with pathogen-induced reactive oxygen species (ROS) accumulation. Interestingly, QSOX1 both senses and regulates ROS levels by interactingn with and mediating redox regulation of S-nitrosoglutathione reductase, which, consistent with previous findings, influences reactive nitrogen-mediated regulation of ROS generation. Collectively, our data indicate that QSOX1 is a redox sensor that negatively regulates plant immunity by linking reactive oxygen and reactive nitrogen signaling to limit ROS production.
Collapse
Affiliation(s)
- Ho Byoung Chae
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Min Gab Kim
- College of Pharmacy, Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju 52828, Korea
| | - Chang Ho Kang
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Joung Hun Park
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Eun Seon Lee
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Sang-Uk Lee
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Yong Hun Chi
- Plant Propagation Team, Plant Production Division, Sejong National Arboretum, Sejong 30106, Korea
| | - Seol Ki Paeng
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Su Bin Bae
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Seong Dong Wi
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Byung-Wook Yun
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Woe-Yeon Kim
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea
| | - Dae-Jin Yun
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Korea
| | - David Mackey
- Department of Horticulture and Crop Science, Department of Molecular Genetics, and Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA.
| | - Sang Yeol Lee
- Division of Applied Life Sciences (BK21) and PMBBRC, Gyeongsang National University, Jinju 52828, Korea; College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, P.R. China.
| |
Collapse
|
11
|
Mackey D. "Eye genetics at the fork in the road" 2017 Franceschetti Lecture, Leeds UK. Ophthalmic Genet 2020; 41:201-207. [PMID: 32363976 DOI: 10.1080/13816810.2020.1755988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Inherited retinal diseases - a disparate group of eye disorders with over 200 known genetic causes - are now the leading cause of blindness in working-age adults in developed countries. Until recently there was no cure for genetic eye diseases. After over a century of defining inherited retinal diseases with their phenotypes, and then several decades of discovering associated genes and their mutations, we now have gene therapy, stem cell therapy, predictive DNA testing and a revolution in adaptive computer technology. With the explosion of expensive treatment options, we need to consider whether finite resources should go towards treatment, prevention or rehabilitation or an amalgamation of all three. In addition, although evidence-based medicine is the goal, how do we direct our desperate patients towards genuine clinical trials and away from quackery? How do we provide scientifically valid treatments for eye diseases too rare to run proper trials and then capture the results of "off label treatments"?
Collapse
Affiliation(s)
- David Mackey
- The University of Western Australia , Perth, Australia.,Lions Eye Institute , Nedlands, Australia
| |
Collapse
|
12
|
Castro-Moretti FR, Gentzel IN, Mackey D, Alonso AP. Metabolomics as an Emerging Tool for the Study of Plant-Pathogen Interactions. Metabolites 2020; 10:E52. [PMID: 32013104 PMCID: PMC7074241 DOI: 10.3390/metabo10020052] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/16/2020] [Accepted: 01/27/2020] [Indexed: 12/19/2022] Open
Abstract
Plants defend themselves from most microbial attacks via mechanisms including cell wall fortification, production of antimicrobial compounds, and generation of reactive oxygen species. Successful pathogens overcome these host defenses, as well as obtain nutrients from the host. Perturbations of plant metabolism play a central role in determining the outcome of attempted infections. Metabolomic analyses, for example between healthy, newly infected and diseased or resistant plants, have the potential to reveal perturbations to signaling or output pathways with key roles in determining the outcome of a plant-microbe interaction. However, application of this -omic and its tools in plant pathology studies is lagging relative to genomic and transcriptomic methods. Thus, it is imperative to bring the power of metabolomics to bear on the study of plant resistance/susceptibility. This review discusses metabolomics studies that link changes in primary or specialized metabolism to the defense responses of plants against bacterial, fungal, nematode, and viral pathogens. Also examined are cases where metabolomics unveils virulence mechanisms used by pathogens. Finally, how integrating metabolomics with other -omics can advance plant pathology research is discussed.
Collapse
Affiliation(s)
- Fernanda R. Castro-Moretti
- BioDiscovery Institute, University of North Texas, TX 76201, USA;
- Department of Biological Sciences, University of North Texas, TX 76201, USA
| | - Irene N. Gentzel
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA;
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA;
| | - Ana P. Alonso
- BioDiscovery Institute, University of North Texas, TX 76201, USA;
- Department of Biological Sciences, University of North Texas, TX 76201, USA
| |
Collapse
|
13
|
Doblas-Ibáñez P, Deng K, Vasquez MF, Giese L, Cobine PA, Kolkman JM, King H, Jamann TM, Balint-Kurti P, De La Fuente L, Nelson RJ, Mackey D, Smith LG. Dominant, Heritable Resistance to Stewart's Wilt in Maize Is Associated with an Enhanced Vascular Defense Response to Infection with Pantoea stewartii. Mol Plant Microbe Interact 2019; 32:1581-1597. [PMID: 31657672 DOI: 10.1094/mpmi-05-19-0129-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Vascular wilt bacteria such as Pantoea stewartii, the causal agent of Stewart's bacterial wilt of maize (SW), are destructive pathogens that are difficult to control. These bacteria colonize the xylem, where they form biofilms that block sap flow leading to characteristic wilting symptoms. Heritable forms of SW resistance exist and are used in maize breeding programs but the underlying genes and mechanisms are mostly unknown. Here, we show that seedlings of maize inbred lines with pan1 mutations are highly resistant to SW. However, current evidence suggests that other genes introgressed along with pan1 are responsible for resistance. Genomic analyses of pan1 lines were used to identify candidate resistance genes. In-depth comparison of P. stewartii interaction with susceptible and resistant maize lines revealed an enhanced vascular defense response in pan1 lines characterized by accumulation of electron-dense materials in xylem conduits visible by electron microscopy. We propose that this vascular defense response restricts P. stewartii spread through the vasculature, reducing both systemic bacterial colonization of the xylem network and consequent wilting. Though apparently unrelated to the resistance phenotype of pan1 lines, we also demonstrate that the effector WtsE is essential for P. stewartii xylem dissemination, show evidence for a nutritional immunity response to P. stewartii that alters xylem sap composition, and present the first analysis of maize transcriptional responses to P. stewartii infection.
Collapse
Affiliation(s)
- Paula Doblas-Ibáñez
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, U.S.A
| | - Kaiyue Deng
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, U.S.A
| | - Miguel F Vasquez
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, U.S.A
| | - Laura Giese
- Department of Horticulture and Crop Sciences, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, U.S.A
| | - Judith M Kolkman
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Helen King
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, U.S.A
| | - Tiffany M Jamann
- Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Peter Balint-Kurti
- United States Department of Agriculture-Agricultural Research Service, Plant Science Research Unit, Raleigh, NC 27695, U.S.A. and Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, U.S.A
| | | | - Rebecca J Nelson
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - David Mackey
- Department of Horticulture and Crop Sciences, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Laurie G Smith
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, U.S.A
| |
Collapse
|
14
|
Redditt TJ, Chung EH, Karimi HZ, Rodibaugh N, Zhang Y, Trinidad JC, Kim JH, Zhou Q, Shen M, Dangl JL, Mackey D, Innes RW. AvrRpm1 Functions as an ADP-Ribosyl Transferase to Modify NOI Domain-Containing Proteins, Including Arabidopsis and Soybean RPM1-Interacting Protein4. Plant Cell 2019; 31:2664-2681. [PMID: 31727786 PMCID: PMC6881136 DOI: 10.1105/tpc.19.00020r2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 08/26/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
The Pseudomonas syringae effector protein AvrRpm1 activates the Arabidopsis (Arabidopsis thaliana) intracellular innate immune receptor protein RESISTANCE TO PSEUDOMONAS MACULICOLA1 (RPM1) via modification of a second Arabidopsis protein, RPM1-INTERACTING PROTEIN4 (AtRIN4). Prior work has shown that AvrRpm1 induces phosphorylation of AtRIN4, but homology modeling indicated that AvrRpm1 may be an ADP-ribosyl transferase. Here, we show that AvrRpm1 induces ADP-ribosylation of RIN4 proteins from both Arabidopsis and soybean (Glycine max) within two highly conserved nitrate-induced (NOI) domains. It also ADP ribosylates at least 10 additional Arabidopsis NOI domain-containing proteins. The ADP-ribosylation activity of AvrRpm1 is required for subsequent phosphorylation on Thr-166 of AtRIN4, an event that is necessary and sufficient for RPM1 activation. We also show that the C-terminal NOI domain of AtRIN4 interacts with the exocyst subunits EXO70B1, EXO70E1, EXO70E2, and EXO70F1. Mutation of either EXO70B1 or EXO70E2 inhibited secretion of callose induced by the bacterial flagellin-derived peptide flg22. Substitution of RIN4 Thr-166 with Asp enhanced the association of AtRIN4 with EXO70E2, which we posit inhibits its callose deposition function. Collectively, these data indicate that AvrRpm1 ADP-ribosyl transferase activity contributes to virulence by promoting phosphorylation of RIN4 Thr-166, which inhibits the secretion of defense compounds by promoting the inhibitory association of RIN4 with EXO70 proteins.plantcell;31/11/2664/FX1F1fx1.
Collapse
Affiliation(s)
- Thomas J Redditt
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Eui-Hwan Chung
- Department of Biology, and Howard Hughes Medical Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Hana Zand Karimi
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Natalie Rodibaugh
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Yixiang Zhang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405
| | | | - Jin Hee Kim
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
| | - Qian Zhou
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
| | - Mingzhe Shen
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
| | - Jeffery L Dangl
- Department of Biology, and Howard Hughes Medical Institute, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Microbiology and Immunology, and Curriculum in Genetics and Molecular Biology, and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Roger W Innes
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| |
Collapse
|
15
|
Gentzel I, Giese L, Zhao W, Alonso AP, Mackey D. A Simple Method for Measuring Apoplast Hydration and Collecting Apoplast Contents. Plant Physiol 2019; 179:1265-1272. [PMID: 30824565 PMCID: PMC6446764 DOI: 10.1104/pp.18.01076] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/21/2019] [Indexed: 05/23/2023]
Abstract
The plant leaf apoplast is a dynamic environment subject to a variety of both internal and external stimuli. In addition to being a conduit for water vapor and gas exchange involved in transpiration and photosynthesis, the apoplast also accumulates many nutrients transported from the soil as well as those produced through photosynthesis. The internal leaf also provides a protective environment for endophytic and pathogenic microbes alike. Given the diverse array of physiological processes occurring in the apoplast, it is expedient to develop methods to study its contents. Many established methods rely on vacuum infiltration of an apoplast wash solution followed by centrifugation. In this study, we describe a refined method optimized for maize (Zea mays) seedling leaves, which not only provides a simple procedure for obtaining apoplast fluid, but also allows direct calculation of apoplast hydration at the time of harvest for every sample. In addition, we describe an abbreviated method for estimating apoplast hydration if the full apoplast extraction is not necessary. Finally, we show the applicability of this optimized apoplast extraction procedure for plants infected with the maize pathogen Pantoea stewartii ssp stewartii, including the efficient isolation of bacteria previously residing in the apoplast. The approaches to establishing this method should make it generally applicable to other types of plants.
Collapse
Affiliation(s)
- Irene Gentzel
- Translational Plant Sciences Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Laura Giese
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
| | - Wanying Zhao
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
| | - Ana Paula Alonso
- BioDiscovery Institute, University of North Texas, Denton, Texas 76201
- Department of Biological Sciences, University of North Texas, Denton, Texas 76201
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210
| |
Collapse
|
16
|
Toruño TY, Shen M, Coaker G, Mackey D. Regulated Disorder: Posttranslational Modifications Control the RIN4 Plant Immune Signaling Hub. Mol Plant Microbe Interact 2019; 32:56-64. [PMID: 30418084 PMCID: PMC6501815 DOI: 10.1094/mpmi-07-18-0212-fi] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
RIN4 is an intensively studied immune regulator in Arabidopsis and is involved in perception of microbial features outside and bacterial effectors inside plant cells. Furthermore, RIN4 is conserved in land plants and is targeted for posttranslational modifications by several virulence proteins from the bacterial pathogen Pseudomonas syringae. Despite the important roles of RIN4 in plant immune responses, its molecular function is not known. RIN4 is an intrinsically disordered protein (IDP), except at regions where pathogen-induced posttranslational modifications take place. IDP act as hubs for protein complex formation due to their ability to bind to multiple client proteins and, thus, are important players in signal transduction pathways. RIN4 is known to associate with multiple proteins involved in immunity, likely acting as an immune-signaling hub for the formation of distinct protein complexes. Genetically, RIN4 is a negative regulator of immunity, but diverse posttranslational modifications can either enhance its negative regulatory function or, on the contrary, render it a potent immune activator. In this review, we describe the structural domains of RIN4 proteins, their intrinsically disordered regions, posttranslational modifications, and highlight the implications that these features have on RIN4 function. In addition, we will discuss the potential role of plasma membrane subdomains in mediating RIN4 protein complex formations.
Collapse
Affiliation(s)
- Tania Y. Toruño
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | - Mingzhe Shen
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, U.S.A
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, U.S.A
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, U.S.A
- Corresponding author: D. Mackey;
| |
Collapse
|
17
|
Wang M, Rui L, Yan H, Shi H, Zhao W, Lin JE, Zhang K, Blakeslee JJ, Mackey D, Tang D, Wei Z, Wang G. The major leaf ferredoxin Fd2 regulates plant innate immunity in Arabidopsis. Mol Plant Pathol 2018; 19:1377-1390. [PMID: 28976113 PMCID: PMC6637997 DOI: 10.1111/mpp.12621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/30/2017] [Accepted: 09/29/2017] [Indexed: 05/06/2023]
Abstract
Ferredoxins, the major distributors for electrons to various acceptor systems in plastids, contribute to redox regulation and antioxidant defence in plants. However, their function in plant immunity is not fully understood. In this study, we show that the expression of the major leaf ferredoxin gene Fd2 is suppressed by Pseudomonas syringae pv. tomato (Pst) DC3000 infection, and that knockout of Fd2 (Fd2-KO) in Arabidopsis increases the plant's susceptibility to both Pst DC3000 and Golovinomyces cichoracearum. On Pst DC3000 infection, the Fd2-KO mutant accumulates increased levels of jasmonic acid and displays compromised salicylic acid-related immune responses. Fd2-KO also shows defects in the accumulation of reactive oxygen species induced by pathogen-associated molecular pattern-triggered immunity. However, Fd2-KO shows enhanced R-protein-mediated resistance to Pst DC3000/AvrRpt2 infection, suggesting that Fd2 plays a negative role in effector-triggered immunity. Furthermore, Fd2 interacts with FIBRILLIN4 (FIB4), a harpin-binding protein localized in chloroplasts. Interestingly, Fd2, but not FIB4, localizes to stromules that extend from chloroplasts. Taken together, our results demonstrate that Fd2 plays an important role in plant immunity.
Collapse
Affiliation(s)
- Mo Wang
- Department of Plant PathologyOhio State UniversityColumbusOH 43210USA
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of CropsPlant Immunity Center, Fujian Agriculture and Forestry UniversityFuzhou 350002China
- Fujian University Key Laboratory for Plant–Microbe InteractionFujian Agriculture and Forestry UniversityFuzhou 350002China
| | - Lu Rui
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of CropsPlant Immunity Center, Fujian Agriculture and Forestry UniversityFuzhou 350002China
- State Key Laboratory of Ecological Control of Fujian‐Taiwan Crop PestsFujian Agriculture and Forestry UniversityFuzhou 350002China
| | - Haojie Yan
- State Key Laboratory of Plant Cell and Chromosome EngineeringInstitute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing 100101China
| | - Hua Shi
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of CropsPlant Immunity Center, Fujian Agriculture and Forestry UniversityFuzhou 350002China
- State Key Laboratory of Ecological Control of Fujian‐Taiwan Crop PestsFujian Agriculture and Forestry UniversityFuzhou 350002China
| | - Wanying Zhao
- Department of Horticulture and Crop ScienceOhio State University, Columbus/WoosterOH 43210USA
| | - Jinshan Ella Lin
- Department of Horticulture and Crop ScienceOhio State University, Columbus/WoosterOH 43210USA
- Department of Horticulture and Crop SciencesOARDC Metabolite Analysis Cluster (OMAC)WoosterOH 44691USA
| | - Kai Zhang
- Department of Plant PathologyOhio State UniversityColumbusOH 43210USA
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing 100193China
| | - Joshua J. Blakeslee
- Department of Horticulture and Crop ScienceOhio State University, Columbus/WoosterOH 43210USA
- Department of Horticulture and Crop SciencesOARDC Metabolite Analysis Cluster (OMAC)WoosterOH 44691USA
| | - David Mackey
- Department of Horticulture and Crop ScienceOhio State University, Columbus/WoosterOH 43210USA
| | - Dingzhong Tang
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of CropsPlant Immunity Center, Fujian Agriculture and Forestry UniversityFuzhou 350002China
- State Key Laboratory of Ecological Control of Fujian‐Taiwan Crop PestsFujian Agriculture and Forestry UniversityFuzhou 350002China
| | | | - Guo‐Liang Wang
- Department of Plant PathologyOhio State UniversityColumbusOH 43210USA
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing 100193China
| |
Collapse
|
18
|
Deb D, Mackey D, Opiyo SO, McDowell JM. Application of alignment-free bioinformatics methods to identify an oomycete protein with structural and functional similarity to the bacterial AvrE effector protein. PLoS One 2018; 13:e0195559. [PMID: 29641586 PMCID: PMC5895030 DOI: 10.1371/journal.pone.0195559] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 03/23/2018] [Indexed: 11/23/2022] Open
Abstract
Diverse plant pathogens export effector proteins to reprogram host cells. One of the most challenging goals in the molecular plant-microbe field is to functionally characterize the complex repertoires of effectors secreted by these pathogens. For bacterial pathogens, the predominant class of effectors is delivered to host cells by Type III secretion. For oomycetes, the predominant class of effectors is defined by a signal peptide that mediates secretion from the oomycete and a conserved RxLR motif. Downy mildew pathogens and Phytophthora species maintain hundreds of candidate RxLR effector genes in their genomes. Although no primary sequence similarity is evident between bacterial Type III effectors (T3Es) and oomycete RXLR effectors, some bacterial and oomycete effectors have convergently evolved to target the same host proteins. Such effectors might have evolved domains that are functionally similar but sequence-unrelated. We reasoned that alignment-free bioinformatics approaches could be useful to identify structural similarities between bacterial and oomycete effectors. To test this approach, we used partial least squares regression, alignment-free bioinformatics methods to identify effector proteins from the genome of the oomycete Hyaloperonospora arabidopsidis that are similar to the well-studied AvrE1 effector from Pseudomonas syringae. This approach identified five RxLR proteins with putative structural similarity to AvrE1. We focused on one, HaRxL23, because it is an experimentally validated effector and it is conserved between distantly related oomycetes. Several experiments indicate that HaRxL23 is functionally similar to AvrE1, including the ability to partially rescue an AvrE1 loss-of-function mutant. This study provides an example of how an alignment-free bioinformatics approach can identify functionally similar effector proteins in the absence of primary sequence similarity. This approach could be useful to identify effectors that have convergently evolved regardless of whether the shared host target is known.
Collapse
Affiliation(s)
- Devdutta Deb
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - David Mackey
- Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Stephen O. Opiyo
- Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (SOO); (JMM)
| | - John M. McDowell
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail: (SOO); (JMM)
| |
Collapse
|
19
|
Yang X, Beres ZT, Jin L, Parrish JT, Zhao W, Mackey D, Snow AA. Effects of over-expressing a native gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) on glyphosate resistance in Arabidopsis thaliana. PLoS One 2017; 12:e0175820. [PMID: 28426703 PMCID: PMC5398549 DOI: 10.1371/journal.pone.0175820] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/13/2017] [Indexed: 11/18/2022] Open
Abstract
Widespread overuse of the herbicide glyphosate, the active ingredient in RoundUp®, has led to the evolution of glyphosate-resistant weed biotypes, some of which persist by overproducing the herbicide's target enzyme, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). EPSPS is a key enzyme in the shikimic acid pathway for biosynthesis of aromatic amino acids, lignin, and defensive compounds, but little is known about how overproducing EPSPS affects downstream metabolites, growth, or lifetime fitness in the absence of glyphosate. We are using Arabidopsis as a model system for investigating phenotypic effects of overproducing EPSPS, thereby avoiding confounding effects of genetic background or other mechanisms of herbicide resistance in agricultural weeds. Here, we report results from the first stage of this project. We designed a binary vector expressing a native EPSPS gene from Arabidopsis under control of the CaMV35S promoter (labelled OX, for over-expression). For both OX and the empty vector (labelled EV), we obtained nine independent T3 lines. Subsets of these lines were used to characterize glyphosate resistance in greenhouse experiments. Seven of the nine OX lines exhibited enhanced glyphosate resistance when compared to EV and wild-type control lines, and one of these was discarded due to severe deformities. The remaining six OX lines exhibited enhanced EPSPS gene expression and glyphosate resistance compared to controls. Glyphosate resistance was correlated with the degree of EPSPS over-expression for both vegetative and flowering plants, indicating that glyphosate resistance can be used as a surrogate for EPSPS expression levels in this system. These findings set the stage for examination of the effects of EPSPS over-expression on fitness-related traits in the absence of glyphosate. We invite other investigators to contact us if they wish to study gene expression, downstream metabolic effects, and other questions with these particular lines.
Collapse
Affiliation(s)
- Xiao Yang
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio, United States of America
| | - Zachery T. Beres
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio, United States of America
| | - Lin Jin
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio, United States of America
| | - Jason T. Parrish
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio, United States of America
| | - Wanying Zhao
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio, United States of America
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio, United States of America
| | - Allison A. Snow
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio, United States of America
| |
Collapse
|
20
|
Abstract
One of the primary considerations in immunoassay design is optimizing the concentration of capture antibody in order to achieve maximal antigen binding and, subsequently, improved sensitivity and limit of detection. Many immunoassay technologies involve immobilization of the antibody to solid surfaces. Antibodies are large molecules in which the position and accessibility of the antigen-binding site depend on their orientation and packing density. In this paper we propose a simple mathematical model, based on the theory known as random sequential adsorption (RSA), in order to calculate how the concentration of correctly oriented antibodies (active site exposed for subsequent reactions) evolves during the deposition process. It has been suggested by experimental studies that high concentrations will decrease assay performance, due to molecule denaturation and obstruction of active binding sites. However, crowding of antibodies can also have the opposite effect by favouring upright orientations. A specific aim of our model is to predict which of these competing effects prevails under different experimental conditions and study the existence of an optimal coverage, which yields the maximum expected concentration of active particles (and hence the highest signal).
Collapse
Affiliation(s)
- D Mackey
- School of Mathematical Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland.
| | | | | |
Collapse
|
21
|
Curtis JR, Xie F, Mackey D, Gerber N, Bharat A, Beukelman T, Saag KG, Chen L, Nowell B, Ginsberg S. Patient's experience with subcutaneous and oral methotrexate for the treatment of rheumatoid arthritis. BMC Musculoskelet Disord 2016; 17:405. [PMID: 27669978 PMCID: PMC5037591 DOI: 10.1186/s12891-016-1254-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 09/13/2016] [Indexed: 12/18/2022] Open
Abstract
Background Despite the prominent position of methotrexate (MTX) in Rheumatoid Arthiris (RA) therapeutics, its real-world effectiveness may be influenced by a relative lack of tolerability or other side effects that physicians may not be aware of but that are bothersome to patients. The aim of this study is to identify suboptimal patient experience with MTX and to raise awareness for clinicians to identify opportunities to mitigate bothersome symptoms and side effects and optimize response to MTX. Methods We conducted a prospective, cross-sectional, online survey among RA patients who were members of Creakyjoints, a large arthritis patient community. Eligible participants must have recently initiated a new biologic, subcutaneous (SQ) MTX, or oral MTX in the last 12 months and were uniquely assigned to one of these 3 groups. Descriptive statistics were used to compare patient-reported side effects and tolerability related to MTX use in the 3 medication groups (SQ MTX, oral MTX, and biologic). Results A total of 382 (85 %) of 448 eligible patients completed the survey and were grouped as: biologic (n = 218), SQ MTX (n = 49), and oral MTX (n = 115). Demographics were mean standard deviation (SD) age 48 (10) years, 92 % white, 91 % women. Symptoms significantly more prevalent in the SQ and oral MTX groups included diarrhea, fatigue, malaise, and hair loss. Injection related pain was lower with SQ MTX compared to SQ biologics. Out of a total of 8 potential symptoms and side effects examined, higher dose MTX (> = 20 mg/week) was associated with a 2.26 (1.25–4.09) greater likelihood of more side effects referent to < =10 mg/week. Conclusion Results from this real-world RA patient cohort suggest that MTX is accompanied by many patient-reported side effects and tolerability problems that may be under-recognized by physicians. These may impact both treatment satisfaction and medication adherence.
Collapse
Affiliation(s)
- J R Curtis
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA.
| | - F Xie
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - D Mackey
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - N Gerber
- Global Healthy Living Foundation, Upper Nyack, NY, 10960, USA
| | - A Bharat
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - T Beukelman
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - K G Saag
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - L Chen
- University of Alabama at Birmingham, 510 20th Street South, FOT 802, Birmingham, AL, 35294, USA
| | - B Nowell
- Global Healthy Living Foundation, Upper Nyack, NY, 10960, USA
| | - S Ginsberg
- Global Healthy Living Foundation, Upper Nyack, NY, 10960, USA
| |
Collapse
|
22
|
Pebay A, Gill K, Needham K, van Bergen N, Lim S, Hernandez D, Liang H, Kearns L, Hung S, Hewitt A, Mackey D, Trounce I, Wong R. Stem cells in reparing optic nerve damage. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
23
|
Eschen-Lippold L, Jiang X, Elmore JM, Mackey D, Shan L, Coaker G, Scheel D, Lee J. Bacterial AvrRpt2-Like Cysteine Proteases Block Activation of the Arabidopsis Mitogen-Activated Protein Kinases, MPK4 and MPK11. Plant Physiol 2016; 171:2223-38. [PMID: 27208280 PMCID: PMC4936563 DOI: 10.1104/pp.16.00336] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/18/2016] [Indexed: 05/08/2023]
Abstract
To establish infection, pathogens deliver effectors into host cells to target immune signaling components, including elements of mitogen-activated protein kinase (MPK) cascades. The virulence function of AvrRpt2, one of the first identified Pseudomonas syringae effectors, involves cleavage of the plant defense regulator, RPM1-INTERACTING PROTEIN4 (RIN4), and interference with plant auxin signaling. We show now that AvrRpt2 specifically suppresses the flagellin-induced phosphorylation of Arabidopsis (Arabidopsis thaliana) MPK4 and MPK11 but not MPK3 or MPK6. This inhibition requires the proteolytic activity of AvrRpt2, is associated with reduced expression of some plant defense genes, and correlates with enhanced pathogen infection in AvrRpt2-expressing transgenic plants. Diverse AvrRpt2-like homologs can be found in some phytopathogens, plant-associated and soil bacteria. Employing these putative bacterial AvrRpt2 homologs and inactive AvrRpt2 variants, we can uncouple the inhibition of MPK4/MPK11 activation from the cleavage of RIN4 and related members from the so-called nitrate-induced family as well as from auxin signaling. Thus, this selective suppression of specific mitogen-activated protein kinases is independent of the previously known AvrRpt2 targets and potentially represents a novel virulence function of AvrRpt2.
Collapse
Affiliation(s)
- Lennart Eschen-Lippold
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - Xiyuan Jiang
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - James Mitch Elmore
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - David Mackey
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - Libo Shan
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - Gitta Coaker
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - Dierk Scheel
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| | - Justin Lee
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120 Germany (L.E.-L., X.J., D.S., J.L.);Department of Plant Pathology, University of California, Davis, California 95616 (J.M.E., G.C.);Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 (D.M.); andDepartment of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843 (L.S.)
| |
Collapse
|
24
|
Jin L, Ham JH, Hage R, Zhao W, Soto-Hernández J, Lee SY, Paek SM, Kim MG, Boone C, Coplin DL, Mackey D. Direct and Indirect Targeting of PP2A by Conserved Bacterial Type-III Effector Proteins. PLoS Pathog 2016; 12:e1005609. [PMID: 27191168 PMCID: PMC4871590 DOI: 10.1371/journal.ppat.1005609] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 04/12/2016] [Indexed: 11/19/2022] Open
Abstract
Bacterial AvrE-family Type-III effector proteins (T3Es) contribute significantly to the virulence of plant-pathogenic species of Pseudomonas, Pantoea, Ralstonia, Erwinia, Dickeya and Pectobacterium, with hosts ranging from monocots to dicots. However, the mode of action of AvrE-family T3Es remains enigmatic, due in large part to their toxicity when expressed in plant or yeast cells. To search for targets of WtsE, an AvrE-family T3E from the maize pathogen Pantoea stewartii subsp. stewartii, we employed a yeast-two-hybrid screen with non-lethal fragments of WtsE and a synthetic genetic array with full-length WtsE. Together these screens indicate that WtsE targets maize protein phosphatase 2A (PP2A) heterotrimeric enzyme complexes via direct interaction with B' regulatory subunits. AvrE1, another AvrE-family T3E from Pseudomonas syringae pv. tomato strain DC3000 (Pto DC3000), associates with specific PP2A B' subunit proteins from its susceptible host Arabidopsis that are homologous to the maize B' subunits shown to interact with WtsE. Additionally, AvrE1 was observed to associate with the WtsE-interacting maize proteins, indicating that PP2A B' subunits are likely conserved targets of AvrE-family T3Es. Notably, the ability of AvrE1 to promote bacterial growth and/or suppress callose deposition was compromised in Arabidopsis plants with mutations of PP2A genes. Also, chemical inhibition of PP2A activity blocked the virulence activity of both WtsE and AvrE1 in planta. The function of HopM1, a Pto DC3000 T3E that is functionally redundant to AvrE1, was also impaired in specific PP2A mutant lines, although no direct interaction with B' subunits was observed. These results indicate that sub-component specific PP2A complexes are targeted by bacterial T3Es, including direct targeting by members of the widely conserved AvrE-family.
Collapse
Affiliation(s)
- Lin Jin
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Jong Hyun Ham
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
| | - Rosemary Hage
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Wanying Zhao
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Jaricelis Soto-Hernández
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Sang Yeol Lee
- Division of Applied Life Science (BK21Plus), PMBBRC, Gyeongsang National University, Jinju daero, Jinju, Republic of Korea
| | - Seung-Mann Paek
- College of Pharmacy, Research Institute of Pharmaceutical Science, PMBBRC, Gyeongsang National University, Jinju daero, Jinju, Republic of Korea
| | - Min Gab Kim
- College of Pharmacy, Research Institute of Pharmaceutical Science, PMBBRC, Gyeongsang National University, Jinju daero, Jinju, Republic of Korea
| | - Charles Boone
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - David L. Coplin
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio, United States of America
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| |
Collapse
|
25
|
Geng X, Shen M, Kim JH, Mackey D. The Pseudomonas syringae type III effectors AvrRpm1 and AvrRpt2 promote virulence dependent on the F-box protein COI1. Plant Cell Rep 2016; 35:921-32. [PMID: 26795143 DOI: 10.1007/s00299-016-1932-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/19/2015] [Accepted: 01/05/2016] [Indexed: 05/13/2023]
Abstract
Type III effectors AvrRpm1 and AvrRpt2 promote bacterial growth dependent on a COI1-mediated pathway in the absence of the RPM1 and RPS2 resistance proteins. The type III effectors, AvrRpm1 and AvrRpt2, promote bacterial virulence by suppressing host defense responses. The defense suppressing activities of AvrRpm1 and AvrRpt2 are best studied in the absence of the resistance proteins RPM1 and RPS2, which induce defense responses to them. We tested whether the type III effectors could modulate a CORONATINE INSENSITIVE1 (COI1)-mediated hormone signaling pathway to promote virulence. COI1 has been demonstrated to contribute in the induction of chlorosis during Pseudomonas syringae infection. By comparing the activity of inducibly expressed AvrRpm1-HA or AvrRpt2-HA in rpm1rps2 and rpm1rps2coi1 backgrounds, we demonstrate that both effectors promote bacterial growth dependent on a COI1-mediated pathway and additively with the action of coronatine (COR) and that AvrRpt2-HA induces COI1-dependent chlorosis. Further, PATHOGENESIS RELATED1 (PR-1) expression resulting from inducible expression of AvrRpm1-HA or AvrRpt2-HA is elevated in coi1 plants consistent with the effectors activating JA-signaling to antagonize SA-signaling. In addition, we found that AvrRpm1-HA or AvrRpt2-HA requires COI1 to promote bacterial growth through suppression of both SA-dependent and SA-independent defense responses. Collectively, these results indicate that type III effectors AvrRpm1 and AvrRpt2 promote bacterial virulence by targeting a COI1-dependent signaling pathway.
Collapse
Affiliation(s)
- Xueqing Geng
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
- Department of Horticulture and Crop Science, The Ohio State Univerity, Rm. 306C Kottman Hall, 2021 Coffey Rd, Columbus, OH, 43210, USA.
| | - Mingzhe Shen
- Department of Horticulture and Crop Science, The Ohio State Univerity, Rm. 306C Kottman Hall, 2021 Coffey Rd, Columbus, OH, 43210, USA
| | - Jin Hee Kim
- Department of Horticulture and Crop Science, The Ohio State Univerity, Rm. 306C Kottman Hall, 2021 Coffey Rd, Columbus, OH, 43210, USA
- Academy of New Biology for Plant Senescence and Life History/New Biology, DGIST, 50-1 Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun, Daegu, 711-873, Korea
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State Univerity, Rm. 306C Kottman Hall, 2021 Coffey Rd, Columbus, OH, 43210, USA.
- Department of Molecular and Genetics, The Ohio State Univerity, Columbus, USA.
| |
Collapse
|
26
|
Sanchez IL, Van Bergen N, Kearns L, Hewitt A, Mackey D, Crowston J, Trounce I. Complex IV compensation in Leber Hereditary Optic Neuropathy unaffected carriers. Mitochondrion 2015. [DOI: 10.1016/j.mito.2015.07.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
27
|
Asselin JAE, Lin J, Perez-Quintero AL, Gentzel I, Majerczak D, Opiyo SO, Zhao W, Paek SM, Kim MG, Coplin DL, Blakeslee JJ, Mackey D. Perturbation of maize phenylpropanoid metabolism by an AvrE family type III effector from Pantoea stewartii. Plant Physiol 2015; 167:1117-35. [PMID: 25635112 PMCID: PMC4348765 DOI: 10.1104/pp.114.253120] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/24/2015] [Indexed: 05/20/2023]
Abstract
AvrE family type III effector proteins share the ability to suppress host defenses, induce disease-associated cell death, and promote bacterial growth. However, despite widespread contributions to numerous bacterial diseases in agriculturally important plants, the mode of action of these effectors remains largely unknown. WtsE is an AvrE family member required for the ability of Pantoea stewartii ssp. stewartii (Pnss) to proliferate efficiently and cause wilt and leaf blight symptoms in maize (Zea mays) plants. Notably, when WtsE is delivered by a heterologous system into the leaf cells of susceptible maize seedlings, it alone produces water-soaked disease symptoms reminiscent of those produced by Pnss. Thus, WtsE is a pathogenicity and virulence factor in maize, and an Escherichia coli heterologous delivery system can be used to study the activity of WtsE in isolation from other factors produced by Pnss. Transcriptional profiling of maize revealed the effects of WtsE, including induction of genes involved in secondary metabolism and suppression of genes involved in photosynthesis. Targeted metabolite quantification revealed that WtsE perturbs maize metabolism, including the induction of coumaroyl tyramine. The ability of mutant WtsE derivatives to elicit transcriptional and metabolic changes in susceptible maize seedlings correlated with their ability to promote disease. Furthermore, chemical inhibitors that block metabolic flux into the phenylpropanoid pathways targeted by WtsE also disrupted the pathogenicity and virulence activity of WtsE. While numerous metabolites produced downstream of the shikimate pathway are known to promote plant defense, our results indicate that misregulated induction of phenylpropanoid metabolism also can be used to promote pathogen virulence.
Collapse
Affiliation(s)
- Jo Ann E Asselin
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Jinshan Lin
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Alvaro L Perez-Quintero
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Irene Gentzel
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Doris Majerczak
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Stephen O Opiyo
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Wanying Zhao
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Seung-Mann Paek
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Min Gab Kim
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - David L Coplin
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - Joshua J Blakeslee
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| | - David Mackey
- Department of Horticulture and Crop Science (J.E.A., J.L., A.L.P.-Q., Do.M., W.Z., J.J.B., Da.M.), Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center (J.L., S.O.O., J.J.B.), Translational Plant Sciences Graduate Program (I.G.), Center for Applied Plant Sciences (I.G., Da.M.), Department of Plant Pathology (D.L.C.), and Department of Molecular Genetics (Da.M.), Ohio State University, Columbus, Ohio 43210; andCollege of Pharmacy, Research Institute of Pharmaceutical Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-751, Republic of Korea (S.-M.P., M.G.K.)
| |
Collapse
|
28
|
Andersson MX, Nilsson AK, Johansson ON, Boztaş G, Adolfsson LE, Pinosa F, Petit CG, Aronsson H, Mackey D, Tör M, Hamberg M, Ellerström M. Involvement of the electrophilic isothiocyanate sulforaphane in Arabidopsis local defense responses. Plant Physiol 2015; 167:251-61. [PMID: 25371552 PMCID: PMC4281013 DOI: 10.1104/pp.114.251892] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 11/03/2014] [Indexed: 05/18/2023]
Abstract
Plants defend themselves against microbial pathogens through a range of highly sophisticated and integrated molecular systems. Recognition of pathogen-secreted effector proteins often triggers the hypersensitive response (HR), a complex multicellular defense reaction where programmed cell death of cells surrounding the primary site of infection is a prominent feature. Even though the HR was described almost a century ago, cell-to-cell factors acting at the local level generating the full defense reaction have remained obscure. In this study, we sought to identify diffusible molecules produced during the HR that could induce cell death in naive tissue. We found that 4-methylsulfinylbutyl isothiocyanate (sulforaphane) is released by Arabidopsis (Arabidopsis thaliana) leaf tissue undergoing the HR and that this compound induces cell death as well as primes defense in naive tissue. Two different mutants impaired in the pathogen-induced accumulation of sulforaphane displayed attenuated programmed cell death upon bacterial and oomycete effector recognition as well as decreased resistance to several isolates of the plant pathogen Hyaloperonospora arabidopsidis. Treatment with sulforaphane provided protection against a virulent H. arabidopsidis isolate. Glucosinolate breakdown products are recognized as antifeeding compounds toward insects and recently also as intracellular signaling and bacteriostatic molecules in Arabidopsis. The data presented here indicate that these compounds also trigger local defense responses in Arabidopsis tissue.
Collapse
Affiliation(s)
- Mats X Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Anders K Nilsson
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Oskar N Johansson
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Gülin Boztaş
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Lisa E Adolfsson
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Francesco Pinosa
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Christel Garcia Petit
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Henrik Aronsson
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - David Mackey
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Mahmut Tör
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Mats Hamberg
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| | - Mats Ellerström
- Department of Biological and Environmental Sciences, University of Gothenburg, SE-405 30 Gothenburg, Sweden (M.X.A., A.K.N., O.N.J., L.E.A., F.P., C.G.P., H.A., M.E.);National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester WR2 6AJ, United Kingdom (G.B., M.T.);Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio 43210 (D.M.); andDivision of Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden (M.H.)
| |
Collapse
|
29
|
Geng X, Jin L, Shimada M, Kim MG, Mackey D. The phytotoxin coronatine is a multifunctional component of the virulence armament of Pseudomonas syringae. Planta 2014; 240:1149-65. [PMID: 25156488 PMCID: PMC4228168 DOI: 10.1007/s00425-014-2151-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 08/08/2014] [Indexed: 05/20/2023]
Abstract
Plant pathogens deploy an array of virulence factors to suppress host defense and promote pathogenicity. Numerous strains of Pseudomonas syringae produce the phytotoxin coronatine (COR). A major aspect of COR function is its ability to mimic a bioactive jasmonic acid (JA) conjugate and thus target the JA-receptor COR-insensitive 1 (COI1). Biological activities of COR include stimulation of JA-signaling and consequent suppression of SA-dependent defense through antagonistic crosstalk, antagonism of stomatal closure to allow bacterial entry into the interior of plant leaves, contribution to chlorotic symptoms in infected plants, and suppression of plant cell wall defense through perturbation of secondary metabolism. Here, we review the virulence function of COR, including updates on these established activities as well as more recent findings revealing COI1-independent activity of COR and shedding light on cooperative or redundant defense suppression between COR and type III effector proteins.
Collapse
Affiliation(s)
- Xueqing Geng
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240 People’s Republic of China
| | - Lin Jin
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
| | - Mikiko Shimada
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
| | - Min Gab Kim
- College of Pharmacy, Research Institute of Pharmaceutical Science, PMBBRC Gyeongsang National University, Jinju daero, Jinju, 660-751 Republic of Korea
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210 USA
| |
Collapse
|
30
|
Breitenbach HH, Wenig M, Wittek F, Jordá L, Maldonado-Alconada AM, Sarioglu H, Colby T, Knappe C, Bichlmeier M, Pabst E, Mackey D, Parker JE, Vlot AC. Contrasting Roles of the Apoplastic Aspartyl Protease APOPLASTIC, ENHANCED DISEASE SUSCEPTIBILITY1-DEPENDENT1 and LEGUME LECTIN-LIKE PROTEIN1 in Arabidopsis Systemic Acquired Resistance. Plant Physiol 2014; 165:791-809. [PMID: 24755512 PMCID: PMC4044859 DOI: 10.1104/pp.114.239665] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 04/22/2014] [Indexed: 05/19/2023]
Abstract
Systemic acquired resistance (SAR) is an inducible immune response that depends on ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1). Here, we show that Arabidopsis (Arabidopsis thaliana) EDS1 is required for both SAR signal generation in primary infected leaves and SAR signal perception in systemic uninfected tissues. In contrast to SAR signal generation, local resistance remains intact in eds1 mutant plants in response to Pseudomonas syringae delivering the effector protein AvrRpm1. We utilized the SAR-specific phenotype of the eds1 mutant to identify new SAR regulatory proteins in plants conditionally expressing AvrRpm1. Comparative proteomic analysis of apoplast-enriched extracts from AvrRpm1-expressing wild-type and eds1 mutant plants led to the identification of 12 APOPLASTIC, EDS1-DEPENDENT (AED) proteins. The genes encoding AED1, a predicted aspartyl protease, and another AED, LEGUME LECTIN-LIKE PROTEIN1 (LLP1), were induced locally and systemically during SAR signaling and locally by salicylic acid (SA) or its functional analog, benzo 1,2,3-thiadiazole-7-carbothioic acid S-methyl ester. Because conditional overaccumulation of AED1-hemagglutinin inhibited SA-induced resistance and SAR but not local resistance, the data suggest that AED1 is part of a homeostatic feedback mechanism regulating systemic immunity. In llp1 mutant plants, SAR was compromised, whereas the local resistance that is normally associated with EDS1 and SA as well as responses to exogenous SA appeared largely unaffected. Together, these data indicate that LLP1 promotes systemic rather than local immunity, possibly in parallel with SA. Our analysis reveals new positive and negative components of SAR and reinforces the notion that SAR represents a distinct phase of plant immunity beyond local resistance.
Collapse
Affiliation(s)
- Heiko H Breitenbach
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Marion Wenig
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Finni Wittek
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Lucia Jordá
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Ana M Maldonado-Alconada
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Hakan Sarioglu
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Thomas Colby
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Claudia Knappe
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Marlies Bichlmeier
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Elisabeth Pabst
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - David Mackey
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - Jane E Parker
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| | - A Corina Vlot
- Helmholtz Zentrum Muenchen, Department of Environmental Sciences, Institute of Biochemical Plant Pathology (H.H.B., M.W., F.W., C.K., M.B., E.P., A.C.V.), and Research Unit Protein Science (H.S.), 85764 Neuherberg, Germany;Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions (L.J., J.E.P., A.C.V.) and Mass Spectrometry Unit (T.C.), 50829 Cologne, Germany;John Innes Centre, Norwich NR4 7UH, United Kingdom (A.M.M.-A.); andOhio State University, Department of Horticulture and Crop Science and Department of Molecular Genetics, Columbus, Ohio 43210 (D.M.)
| |
Collapse
|
31
|
Leal LG, Perez Á, Quintero A, Bayona Á, Ortiz JF, Gangadharan A, Mackey D, López C, López-Kleine L. Identification of immunity-related genes in Arabidopsis and cassava using genomic data. Genomics Proteomics Bioinformatics 2013; 11:345-53. [PMID: 24316329 PMCID: PMC4357831 DOI: 10.1016/j.gpb.2013.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/19/2013] [Accepted: 09/22/2013] [Indexed: 11/01/2022]
Abstract
Recent advances in genomic and post-genomic technologies have provided the opportunity to generate a previously unimaginable amount of information. However, biological knowledge is still needed to improve the understanding of complex mechanisms such as plant immune responses. Better knowledge of this process could improve crop production and management. Here, we used holistic analysis to combine our own microarray and RNA-seq data with public genomic data from Arabidopsis and cassava in order to acquire biological knowledge about the relationships between proteins encoded by immunity-related genes (IRGs) and other genes. This approach was based on a kernel method adapted for the construction of gene networks. The obtained results allowed us to propose a list of new IRGs. A putative function in the immunity pathway was predicted for the new IRGs. The analysis of networks revealed that our predicted IRGs are either well documented or recognized in previous co-expression studies. In addition to robust relationships between IRGs, there is evidence suggesting that other cellular processes may be also strongly related to immunity.
Collapse
Affiliation(s)
- Luis Guillermo Leal
- Department of Statistics, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Álvaro Perez
- Department of Biology, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Andrés Quintero
- Department of Biology, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Ángela Bayona
- Department of Biology, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Juan Felipe Ortiz
- Department of Biology, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Anju Gangadharan
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
| | - David Mackey
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
| | - Camilo López
- Department of Biology, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Liliana López-Kleine
- Department of Statistics, Universidad Nacional de Colombia, Bogotá 111321, Colombia.
| |
Collapse
|
32
|
Gangadharan A, Sreerekha MV, Whitehill J, Ham JH, Mackey D. The Pseudomonas syringae pv. tomato type III effector HopM1 suppresses Arabidopsis defenses independent of suppressing salicylic acid signaling and of targeting AtMIN7. PLoS One 2013; 8:e82032. [PMID: 24324742 PMCID: PMC3855835 DOI: 10.1371/journal.pone.0082032] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/21/2013] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas syringae pv tomato strain DC3000 (Pto) delivers several effector proteins promoting virulence, including HopM1, into plant cells via type III secretion. HopM1 contributes to full virulence of Pto by inducing degradation of Arabidopsis proteins, including AtMIN7, an ADP ribosylation factor-guanine nucleotide exchange factor. Pseudomonas syringae pv phaseolicola strain NPS3121 (Pph) lacks a functional HopM1 and elicits robust defenses in Arabidopsis thaliana, including accumulation of pathogenesis related 1 (PR-1) protein and deposition of callose-containing cell wall fortifications. We have examined the effects of heterologously expressed HopM1Pto on Pph-induced defenses. HopM1 suppresses Pph-induced PR-1 expression, a widely used marker for salicylic acid (SA) signaling and systemic acquired resistance. Surprisingly, HopM1 reduces PR-1 expression without affecting SA accumulation and also suppresses the low levels of PR-1 expression apparent in SA-signaling deficient plants. Further, HopM1 enhances the growth of Pto in SA-signaling deficient plants. AtMIN7 contributes to Pph-induced PR-1 expression. However, HopM1 fails to degrade AtMIN7 during Pph infection and suppresses Pph-induced PR-1 expression and callose deposition in wild-type and atmin7 plants. We also show that the HopM1-mediated suppression of PR-1 expression is not observed in plants lacking the TGA transcription factor, TGA3. Our data indicate that HopM1 promotes bacterial virulence independent of suppressing SA-signaling and links TGA3, AtMIN7, and other HopM1 targets to pathways distinct from the canonical SA-signaling pathway contributing to PR-1 expression and callose deposition. Thus, efforts to understand this key effector must consider multiple targets and unexpected outputs of its action.
Collapse
Affiliation(s)
- Anju Gangadharan
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Mysore-Venkatarau Sreerekha
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Justin Whitehill
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio, United States of America
| | - Jong Hyun Ham
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
| |
Collapse
|
33
|
Lim SH, St Germain E, Tran-Viet KN, Staffieri S, Marino M, Dollfus PH, Nading EB, Crowe S, Gole G, Perdomo-Trujillo Y, Haybittel M, Elder J, Pelletier V, Traboulsi E, Mackey D, Young TL. Sequencing analysis of the ATOH7 gene in individuals with optic nerve hypoplasia. Ophthalmic Genet 2013; 35:1-6. [PMID: 23802135 DOI: 10.3109/13816810.2012.752017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The Atonal Homolog 7 (ATOH7) gene has been implicated in association studies with optic nerve head diameter size. Hence, we screened optic nerve hypoplasia (ONH) patient DNA samples from Australia, France, and the United States for sequence variants in theATOH7 gene using Sanger sequencing. METHODS Sanger sequencing of theATOH7 gene was performed on 34 affected individual DNA samples. Sequencing was also carried out in three unaffected family members to confirm segregation of identified single nucleotide variations. RESULTS Seven sequence variations were identified in ATOH7. No disease-causing sequence changes in the ATOH7 gene was discovered in the ONH patient samples. CONCLUSIONS Mutations within the ATOH7 gene are not implicated in the pathogenesis of optic nerve hypoplasia in our patient cohort.
Collapse
Affiliation(s)
- Sing-Hui Lim
- The Center for Human Genetics, Duke University Medical Center , Durham, NC , USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
Here we present an overview of our existing knowledge on the function of RIN4 as a regulator of plant defense and as a guardee of multiple plant R-proteins. Domain analysis of RIN4 reveals two NOI domains. The NOI domain was originally identified in a screen for nitrate induced genes. The domain is comprised of approximately 30 amino acids and contains 2 conserved motifs (PXFGXW and Y/FTXXF). The NOI gene family contains members exclusively from the plant lineage as far back as moss. In addition to the conserved NOI domain, members within the family also contain conserved C-terminal cysteine residue(s) which are sites for acylation and membrane tethering. Other than these two characteristic features, the sequence of the family of NOI-containing proteins is diverse and, with the exception of RIN4, their functions are not known. Recently published interactome data showing interactions between RIN4 and components of the exocyst complex prompt us to raise the hypothesis that RIN4 might be involved in defense associated vesicle trafficking.
Collapse
Affiliation(s)
- Ahmed J Afzal
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, USA.
| | | | | |
Collapse
|
35
|
Venkatakrishnan S, Mackey D, Meier I. Functional investigation of the plant-specific long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL) in Arabidopsis thaliana. PLoS One 2013; 8:e57283. [PMID: 23451199 PMCID: PMC3581476 DOI: 10.1371/journal.pone.0057283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 01/23/2013] [Indexed: 12/20/2022] Open
Abstract
We have identified and characterized two Arabidopsis long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL). PICC (147 kDa) and PICL (87 kDa) are paralogs that consist predominantly of a long coiled-coil domain (expanded in PICC), with a predicted transmembrane domain at the immediate C-terminus. Orthologs of PICC and PICL were found exclusively in vascular plants. PICC and PICL GFP fusion proteins are anchored to the cytoplasmic surface of the endoplasmic reticulum (ER) membrane by a C-terminal transmembrane domain and a short tail domain, via a tail-anchoring mechanism. T-DNA-insertion mutants of PICC and PICL as well as the double mutant show an increased sensitivity to the plant abiotic stress hormone abscisic acid (ABA) in a post-germination growth response. PICC, but not PICL gene expression is induced by the bacterial pathogen-associated molecular pattern (PAMP) flg22. T-DNA insertion alleles of PICC, but not PICL, show increased susceptibility to the non-virulent strain P. syringae pv. tomato DC3000 hrcC, but not to the virulent strain P. syringae pv. tomato DC3000. This suggests that PICC mutants are compromised in PAMP-triggered immunity (PTI). The data presented here provide first evidence for the involvement of a plant long coiled-coil protein in a plant defense response.
Collapse
Affiliation(s)
- Sowmya Venkatakrishnan
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - David Mackey
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
| | - Iris Meier
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| |
Collapse
|
36
|
Geng X, Cheng J, Gangadharan A, Mackey D. The coronatine toxin of Pseudomonas syringae is a multifunctional suppressor of Arabidopsis defense. Plant Cell 2012; 24:4763-4774. [PMID: 23204405 PMCID: PMC3531865 DOI: 10.1105/tpc.112.105312] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/24/2012] [Accepted: 11/09/2012] [Indexed: 05/20/2023]
Abstract
The phytotoxin coronatine (COR) promotes various aspects of Pseudomonas syringae virulence, including invasion through stomata, growth in the apoplast, and induction of disease symptoms. COR is a structural mimic of active jasmonic acid (JA) conjugates. Known activities of COR are mediated through its binding to the F-box-containing JA coreceptor CORONATINE INSENSITIVE1. By analyzing the interaction of P. syringae mutants with Arabidopsis thaliana mutants, we demonstrate that, in the apoplastic space of Arabidopsis, COR is a multifunctional defense suppressor. COR and the critical P. syringae type III effector HopM1 target distinct signaling steps to suppress callose deposition. In addition to its well-documented ability to suppress salicylic acid (SA) signaling, COR suppresses an SA-independent pathway contributing to callose deposition by reducing accumulation of an indole glucosinolate upstream of the activity of the PEN2 myrosinase. COR also suppresses callose deposition and promotes bacterial growth in coi1 mutant plants, indicating that COR may have multiple targets inside plant cells.
Collapse
Affiliation(s)
- Xueqing Geng
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Jiye Cheng
- Department of Plant Pathology, Ohio State University, Columbus, Ohio 43210
| | - Anju Gangadharan
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
- Address correspondence to
| |
Collapse
|
37
|
McConnachie A, Richardson J, Mackey D. Andromeda and the Milky Way: Twin sisters, distant relations, or strangers in the night? EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20121901003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
38
|
Afzal AJ, da Cunha L, Mackey D. Separable fragments and membrane tethering of Arabidopsis RIN4 regulate its suppression of PAMP-triggered immunity. Plant Cell 2011; 23:3798-811. [PMID: 21984695 PMCID: PMC3229150 DOI: 10.1105/tpc.111.088708] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
RPM1-interacting protein 4 (RIN4) is a multifunctional Arabidopsis thaliana protein that regulates plant immune responses to pathogen-associated molecular patterns (PAMPs) and bacterial type III effector proteins (T3Es). RIN4, which is targeted by multiple defense-suppressing T3Es, provides a mechanistic link between PAMP-triggered immunity (PTI) and effector-triggered immunity and effector suppression of plant defense. Here we report on a structure-function analysis of RIN4-mediated suppression of PTI. Separable fragments of RIN4, including those produced when the T3E AvrRpt2 cleaves RIN4 and each containing a plant-specific nitrate-induced (NOI) domain, suppress PTI. The N-terminal and C-terminal NOIs each contribute to PTI suppression and are evolutionarily conserved. Native RIN4 is anchored to the plasma membrane by C-terminal acylation. Nonmembrane-tethered derivatives of RIN4 activate a cell death response in wild-type Arabidopsis and are hyperactive PTI suppressors in a mutant background that lacks the cell death response. Our results indicate that RIN4 is a multifunctional suppressor of PTI and that a virulence function of AvrRpt2 may include cleaving RIN4 into active defense-suppressing fragments.
Collapse
Affiliation(s)
- Ahmed J. Afzal
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
| | - Luis da Cunha
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
- Address correspondence to
| |
Collapse
|
39
|
Chung EH, da Cunha L, Wu AJ, Gao Z, Cherkis K, Afzal AJ, Mackey D, Dangl JL. Specific threonine phosphorylation of a host target by two unrelated type III effectors activates a host innate immune receptor in plants. Cell Host Microbe 2011; 9:125-36. [PMID: 21320695 DOI: 10.1016/j.chom.2011.01.009] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/13/2010] [Accepted: 01/13/2011] [Indexed: 11/26/2022]
Abstract
The Arabidopsis NB-LRR immune receptor RPM1 recognizes the Pseudomonas syringae type III effectors AvrB or AvrRpm1 to mount an immune response. Although neither effector is itself a kinase, AvrRpm1 and AvrB are known to target Arabidopsis RIN4, a negative regulator of basal plant defense, for phosphorylation. We show that RIN4 phosphorylation activates RPM1. RIN4(142-176) is necessary and, with appropriate localization sequences, sufficient to support effector-triggered RPM1 activation, with the threonine residue at position 166 being critical. Phosphomimic substitutions at T166 cause effector-independent RPM1 activation. RIN4 T166 is phosphorylated in vivo in the presence of AvrB or AvrRpm1. RIN4 mutants that lose interaction with AvrB cannot be coimmunoprecipitated with RPM1. This defines a common interaction platform required for RPM1 activation by phosphorylated RIN4 in response to pathogenic effectors. Conservation of an analogous threonine across all RIN4-like proteins suggests a key function for this residue beyond the regulation of RPM1.
Collapse
Affiliation(s)
- Eui-Hwan Chung
- Department of Biology, University of North Carolina, Chapel Hill, 27599, USA
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
Construction of transgenic plants is central to modern plant molecular genetics. Inducible systems permit spatial and temporal control of transgene expression. One commonly used inducible system relies on the use of dexamethasone to activate an endogenously expressed hybrid transcription factor, which positively regulates the expression of the gene of interest (Aoyama and Chua, Plant J 11:605-612, 1997). We have developed Arabidopsis plants using this inducible system to drive expression of a bacterial type III effector protein. The effector, AvrRpm1, elicits either strong cell death or weak cell death and chlorosis depending on the genetic background of the plant. Using these reagents, we examine several properties of the inducible system in Arabidopsis, including the timing of induction, the ability to tune the level of transgene expression by altering the concentration of applied dexamethasone, and the movement of dexamethasone within the plant.
Collapse
Affiliation(s)
- Xueqing Geng
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, USA
| | | |
Collapse
|
41
|
Aitelli C, Aitelli C, Saad R, Mackey D, Asmar L, Jones S, Jones S, Jones S, Pippen J, Pippen J, Pippen J. Analysis of Topoisomerase IIa and HER2 Status in 126 Patients from the US Oncology 9735 Trial of Adjuvant Chemotherapy with Docetaxel/Cyclophosphamide (TC) vs Doxorubicin/Cyclophosphamide (AC) in Early Breast Cancer. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-09-2134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: HER2/neu (HER2) positive breast cancers are associated with worse survival, resistance to cyclophosphamide/methotrexate/fluorouracil, and hypothesized to be sensitive to anthracyclines. It has been postulated that only a subset of HER2 positive breast cancers are sensitive to anthracyclines. Investigators have been working on how to identify this subset of patients, thus sparing patients from anthracyclines that have potential cardiac and bone marrow toxicities. Overexpression of the topoisomerase IIa gene (TOP2A) is the putative biomarker for sensitivity to anthracyclines. Testing tumors for overexpression of this gene may help identify patients who will not benefit from anthracylines. TOP2A is located in the same amplicon as the HER2 gene and can be assessed for overexpression by a FISH assay.Materials and Methods: Paraffin tissue blocks were obtained in 126 patients entered on US Oncology trial 9735 which recruited patients between 1997 and 2000. Data on HER2 status and outcome was previously reported (JCO 27:1177-1183, 2009). TOP2A status was then assessed by fluorescent in situ hybridization (FISH) using the LSI TOP2A Spectrum Orange Probe (Vysis). A total of 20 cells were counted and a gene ratio of greater than 2.0 was considered positive. Clinical data and outcome were available for statistical analysis.Results: We found that none of the 97 HER2 negative cases demonstrated overexpression of TOP2A by FISH analysis. TOP2A was overexpressed in 43% of the 29 HER2 positive cases. An analysis of outcome will be presented at the meeting, although the number of cases limits this observation.Discussion: Our study supports the observation that TOP2A is not overexpressed in HER2 negative disease and is only observed in a subset of cancers overexpressing HER2. Clinical correlation of outcome will be necessary to confirm whether or not TOP2A is a reliable biomarker of sensitivity to anthracyclines. The ongoing US Oncology trial of TC vs. TAC in HER2 negative breast cancer (USOR Trial 06-090) should provide that evidence.Supported in part by a grant from sanofi-aventis.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2134.
Collapse
Affiliation(s)
| | | | - R. Saad
- 4Baylor University Medical Center, TX,
| | | | | | - S. Jones
- 1Baylor Sammons Cancer Center, TX,
| | | | | | | | | | | |
Collapse
|
42
|
Ham JH, Majerczak DR, Nomura K, Mecey C, Uribe F, He SY, Mackey D, Coplin DL. Multiple activities of the plant pathogen type III effector proteins WtsE and AvrE require WxxxE motifs. Mol Plant Microbe Interact 2009; 22:703-12. [PMID: 19445595 PMCID: PMC2748107 DOI: 10.1094/mpmi-22-6-0703] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The broadly conserved AvrE-family of type III effectors from gram-negative plant-pathogenic bacteria includes important virulence factors, yet little is known about the mechanisms by which these effectors function inside plant cells to promote disease. We have identified two conserved motifs in AvrE-family effectors: a WxxxE motif and a putative C-terminal endoplasmic reticulum membrane retention/retrieval signal (ERMRS). The WxxxE and ERMRS motifs are both required for the virulence activities of WtsE and AvrE, which are major virulence factors of the corn pathogen Pantoea stewartii subsp. stewartii and the tomato or Arabidopsis pathogen Pseudomonas syringae pv. tomato, respectively. The WxxxE and the predicted ERMRS motifs are also required for other biological activities of WtsE, including elicitation of the hypersensitive response in nonhost plants and suppression of defense responses in Arabidopsis. A family of type III effectors from mammalian bacterial pathogens requires WxxxE and subcellular targeting motifs for virulence functions that involve their ability to mimic activated G-proteins. The conservation of related motifs and their necessity for the function of type III effectors from plant pathogens indicates that disturbing host pathways by mimicking activated host G-proteins may be a virulence mechanism employed by plant pathogens as well.
Collapse
Affiliation(s)
- Jong Hyun Ham
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210
| | - Doris R. Majerczak
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210
| | - Kinya Nomura
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824
| | - Christy Mecey
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824
| | - Francisco Uribe
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824
| | - Sheng-Yang He
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210
| | - David L. Coplin
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210
| |
Collapse
|
43
|
Metlapally R, Li YJ, Tran-Viet KN, Abbott D, Czaja GR, Malecaze F, Calvas P, Mackey D, Rosenberg T, Paget S, Zayats T, Owen MJ, Guggenheim JA, Young TL. COL1A1 and COL2A1 genes and myopia susceptibility: evidence of association and suggestive linkage to the COL2A1 locus. Invest Ophthalmol Vis Sci 2009; 50:4080-6. [PMID: 19387081 DOI: 10.1167/iovs.08-3346] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Collagen involvement in myopia development via scleral remodeling is well-known. Recently, COL1A1 and COL2A1 gene polymorphisms were reported to be associated with high-grade and common myopia, respectively. This study was conducted to investigate whether these collagen genes are associated and/or genetically linked with myopia in large Caucasian family datasets. METHODS High-grade myopia was defined as <or=-5.00 D. Two independent datasets comprising 146 (Duke) and 130 (Cardiff) families with high-grade myopia participated in the association study. Allelic discrimination assays were performed on tagging SNPs for COL1A1 and COL2A1. The pedigree disequilibrium test (PDT) and the association test in the presence of linkage (APL) were used for association analyses. Linkage analyses for COL2A1 locus markers were performed with the Fastlink and Merlin programs in conjunction with data obtained from our collaborative whole-genome linkage study (254 families). RESULTS Significant association was identified between five SNPs (rs1034762, rs1635529, rs1793933, rs3803183, and rs17122571) of the COL2A1 locus and high-grade myopia (P < 0.045, minimum (min) P = 0.008) and with myopia status set at <or=-0.50 or -0.75 D (min P = 0.004) in the Duke dataset. The SNP rs1635529 also showed significant association in the Cardiff dataset (<or=-5.00 D, min P = 0.004; <or=-0.50 D, min P = 0.007). Linkage analyses showed suggestive linkage to the COL2A1 locus on 12q. No association was found between COL1A1 SNPs and any degree of myopia. CONCLUSIONS The COL2A1 gene was associated with high-grade myopia in two independent Caucasian family datasets. COL1A1 gene polymorphisms were not associated with myopia in our dataset, indicating possible heterogeneity across different ethnicities.
Collapse
|
44
|
Kim MG, Geng X, Lee SY, Mackey D. The Pseudomonas syringae type III effector AvrRpm1 induces significant defenses by activating the Arabidopsis nucleotide-binding leucine-rich repeat protein RPS2. Plant J 2009; 57:645-653. [PMID: 18980653 DOI: 10.1111/j.1365-313x.2008.03716.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Plant disease resistance (R) proteins recognize potential pathogens expressing corresponding avirulence (Avr) proteins through 'gene-for-gene' interactions. RPM1 is an Arabidopsis R-protein that triggers a robust defense response upon recognizing the Pseudomonas syringae effector AvrRpm1. Avr-proteins of phytopathogenic bacteria include type III effector proteins that are often capable of enhancing virulence when not recognized by an R-protein. In rpm1 plants, AvrRpm1 suppresses basal defenses induced by microbe-associated molecular patterns. Here, we show that expression of AvrRpm1 in rpm1 plants induced PR-1, a classical defense marker, and symptoms including chlorosis and necrosis. PR-1 expression and symptoms were reduced in plants with mutations in defense signaling genes (pad4, sid2, npr1, rar1, and ndr1) and were strongly reduced in rpm1 rps2 plants, indicating that AvrRpm1 elicits defense signaling through the Arabidopsis R-protein, RPS2. Bacteria expressing AvrRpm1 grew more on rpm1 rps2 than on rpm1 plants. Thus, independent of its classical 'gene-for-gene' activation of RPM1, AvrRpm1 also induces functionally relevant defenses that are dependent on RPS2. Finally, AvrRpm1 suppressed host defenses and promoted the growth of type III secretion mutant bacteria equally well in rps2 and RPS2 plants, indicating that virulence activity of over-expressed AvrRpm1 predominates over defenses induced by weak activation of RPS2.
Collapse
Affiliation(s)
- Min Gab Kim
- Department of Horticulture and Crop Science, Rm. 306C Kottman Hall, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | |
Collapse
|
45
|
Widjaja I, Naumann K, Roth U, Wolf N, Mackey D, Dangl JL, Scheel D, Lee J. Combining subproteome enrichment and Rubisco depletion enables identification of low abundance proteins differentially regulated during plant defense. Proteomics 2009; 9:138-47. [DOI: 10.1002/pmic.200800293] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
46
|
Devaney N, Dalimier E, Farrell T, Coburn D, Mackey R, Mackey D, Laurent F, Daly E, Dainty C. Correction of ocular and atmospheric wavefronts: a comparison of the performance of various deformable mirrors. Appl Opt 2008; 47:6550-6562. [PMID: 19079464 DOI: 10.1364/ao.47.006550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The main applications of adaptive optics are the correction of the effects of atmospheric turbulence on ground-based telescopes and the correction of ocular aberrations in retinal imaging and visual simulation. The requirements for the wavefront corrector, usually a deformable mirror, will depend on the statistics of the aberrations to be corrected; here we compare the spatial statistics of wavefront aberrations expected in these two applications. We also use measured influence functions and numerical simulations to compare the performance of eight commercially available deformable mirrors for these tasks. The performance is studied as a function of the size of the optical pupil relative to the actuated area of the mirrors and as a function of the number of modes corrected. In the ocular case it is found that, with the exception of segmented mirrors, the performance is greatly enhanced by having a ring of actuators outside the optical pupil, as this improves the correction of the pupil edge. The effect is much smaller in the case of Kolmogorov wavefronts. It is also found that a high Strehl ratio can be obtained in the ocular case with a relatively low number of actuators if the stroke is sufficient. Increasing the number of actuators has more importance in the Kolmogorov case, even for the relatively weak turbulence considered here.
Collapse
Affiliation(s)
- Nicholas Devaney
- School of Experimental Physics, National University of Ireland, Galway, Ireland.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Ham JH, Majerczak D, Ewert S, Sreerekha MV, Mackey D, Coplin D. WtsE, an AvrE-family type III effector protein of Pantoea stewartii subsp. stewartii, causes cell death in non-host plants. Mol Plant Pathol 2008; 9:633-43. [PMID: 19018993 PMCID: PMC6640224 DOI: 10.1111/j.1364-3703.2008.00489.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Pantoea stewartii subsp. stewartii (Pnss) causes Stewart's bacterial wilt of sweet corn and leaf blight of maize. The pathogenicity of Pnss depends on synthesis of extracellular polysaccharide and an Hrp type III secretion system. WtsE, a type III secreted effector protein, is essential for the virulence of Pnss on corn. It belongs to the AvrE family of effectors, which includes DspA/E from Erwinia amylovora and AvrE1 from Pseudomonas syringae. Previously, WtsE was shown to cause disease-associated cell death in its host plant, sweet corn. Here, we examine the biological activity of WtsE in several non-host plants. WtsE induced cell death in Nicotiana benthamiana, tobacco, beet and Arabidopsis thaliana when it was transiently produced in plant cells following agroinfiltration or translocated into plant cells from Pnss, Escherichia coli or Pseudomonas syringae pv. phaseolicola (Pph). WtsE-induced cell death in N. benthamiana, tobacco and beet resembled a hypersensitive response and in N. benthamiana it was delayed by cycloheximide. Interestingly, WtsE strongly promoted the growth of Pnss in N. benthamiana prior to the onset of cell death. Deletion derivatives of WtsE that failed to induce cell death in N. benthamiana and tobacco also did not complement wtsE mutants of Pnss for virulence in sweet corn, indicating a correlation between the two activities. WtsE also induced cell death in A. thaliana, where it suppressed basal defences induced by Pph. Thus, WtsE has growth-promoting, defence-suppressing and cell death-inducing activities in non-host plants. Expression of WtsE also prevented the growth of yeast, possibly due to an innate toxicity to eukaryotic cells.
Collapse
Affiliation(s)
- Jong Hyun Ham
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | | | | | |
Collapse
|
48
|
Kim MG, Kim SY, Kim WY, Mackey D, Lee SY. Responses of Arabidopsis thaliana to challenge by Pseudomonas syringae. Mol Cells 2008; 25:323-31. [PMID: 18483469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
Plants are continually exposed to a variety of potentially pathogenic microbes, and the interactions between plants and pathogenic invaders determine the outcome, disease or disease resistance. To defend themselves, plants have developed a sophisticated immune system. Unlike animals, however, they do not have specialized immune cells and, thus all plant cells appear to have the innate ability to recognize pathogens and turn on an appropriate defense response. Using genetic, genomic and biochemical methods, tremendous advances have been made in understanding how plants recognize pathogens and mount effective defenses. The primary immune response is induced by microbe-associated molecular patterns (MAMPs). MAMP receptors recognize the presence of probable pathogens and evoke defense. In the co-evolution of plant-microbe interactions, pathogens gained the ability to make and deliver effector proteins to suppress MAMP-induced defense responses. In response to effector proteins, plants acquired R-proteins to directly or indirectly monitor the presence of effector proteins and activate an effective defense response. In this review we will describe and discuss the plant immune responses induced by two types of elicitors, PAMPs and effector proteins.
Collapse
Affiliation(s)
- Min Gab Kim
- National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon, Korea
| | | | | | | | | |
Collapse
|
49
|
Abstract
Plants are resistant to most potentially pathogenic microbes. Frequently, resistance results from defenses activated upon recognition of "non-self." Invasion of a variety of pathogens, including Gram-negative bacteria, into plants is betrayed by the presence of pathogen-associated molecular patterns (PAMPs). Plants challenged by a non-pathogenic bacterial strain or a purified PAMP often form cell wall modifications called papillae. These cell wall thickenings, which can be observed in the electron microscope, can more easily be visualized by staining for the component molecule callose and using fluorescent microscopy. We describe a method to measure callose following infiltration of leaves of Arabidopsis thaliana, a model organism for basic and applied research on plant biology, with pathogenic and non-pathogenic strains of Pseudomonas syringae pv. tomato or a purified bacterial PAMP. We also detail a method to measure the growth of bacteria infiltrated into leaves of Arabidopsis. These methods can be used to understand the interactions between pathogen and host plant.
Collapse
Affiliation(s)
- Min Gab Kim
- Department of Plant Cellular and Molecular Biology, Program in Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, USA
| | | |
Collapse
|
50
|
Cronin K, Mackey D, Cregan V, O’Brien S, Gleeson J, Abodayeh K. Selection of Processing Temperature to Minimize Product Temperature Variability in Food Heating Processes. Food and Bioproducts Processing 2007. [DOI: 10.1205/fbp07080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|