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Kumar A, Fitoussi N, Sanadhya P, Sichov N, Bucki P, Bornstein M, Belausuv E, Brown Miyara S. Two Candidate Meloidogyne javanica Effector Genes, MjShKT and MjPUT3: A Functional Investigation of Their Roles in Regulating Nematode Parasitism. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:79-94. [PMID: 36324054 DOI: 10.1094/mpmi-10-22-0212-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
During parasitism, root-knot nematode Meloidogyne spp. inject molecules termed effectors that have multifunctional roles in construction and maintenance of nematode feeding sites. As an outcome of transcriptomic analysis of Meloidogyne javanica, we identified and characterized two differentially expressed genes encoding the predicted proteins MjShKT, carrying a Stichodactyla toxin (ShKT) domain, and MjPUT3, carrying a ground-like domain, both expressed during nematode parasitism of the tomato plant. Fluorescence in-situ hybridization revealed expression of MjShKT and MjPUT3 in the dorsal esophageal glands, suggesting their injection into host cells. MjShKT expression was upregulated during the parasitic life stages, to a maximum at the mature female stage, whereas MjPUT3 expression increased in third- to fourth-stage juveniles. Subcellular in-planta localization of MjShKT and MjPUT3 using a fused fluorescence marker indicated MjShKT co-occurrence with the endoplasmic reticulum, the perinuclear endoplasmatic reticulum, and the Golgi organelle markers, while MjPUT3 localized, to some extent, within the endoplasmatic reticulum and was clearly observed within the nucleoplasm. MjShKT inhibited programmed cell death induced by overexpression of MAPKKKα and Gpa2/RBP-1. Overexpression of MjShKT in tomato hairy roots allowed an increase in nematode reproduction, as indicated by the high number of eggs produced on roots overexpressing MjShKT. Roots overexpressing MjPUT3 were characterized by enhanced root growth, with no effect on nematode development on those roots. Investigation of the two candidate effectors suggested that MjShKT is mainly involved in manipulating the plant effector-triggered immune response toward establishment and maintenance of active feeding sites, whereas MjPUT3 might modulate roots morphology in favor of nematode fitness in the host roots. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Anil Kumar
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Nathalia Fitoussi
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
- Department of Plant Pathology and Microbiology, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Payal Sanadhya
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Natalia Sichov
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Patricia Bucki
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Menachem Bornstein
- Department of Plant Pathology and Weed Research, ARO, Volcani Center, Bet Dagan 50250, Israel
| | - Eduard Belausuv
- Department of Plant Sciences, ARO, Volcani Center, Bet Dagan 50250, Israel
| | - Sigal Brown Miyara
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
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Máthé C, Garda T, Freytag C, M-Hamvas M. The Role of Serine-Threonine Protein Phosphatase PP2A in Plant Oxidative Stress Signaling-Facts and Hypotheses. Int J Mol Sci 2019; 20:ijms20123028. [PMID: 31234298 PMCID: PMC6628354 DOI: 10.3390/ijms20123028] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 12/17/2022] Open
Abstract
Abiotic and biotic factors induce oxidative stress involving the production and scavenging of reactive oxygen species (ROS). This review is a survey of well-known and possible roles of serine-threonine protein phosphatases in plant oxidative stress signaling, with special emphasis on PP2A. ROS mediated signaling involves three interrelated pathways: (i) perception of extracellular ROS triggers signal transduction pathways, leading to DNA damage and/or the production of antioxidants; (ii) external signals induce intracellular ROS generation that triggers the relevant signaling pathways and (iii) external signals mediate protein phosphorylation dependent signaling pathway(s), leading to the expression of ROS producing enzymes like NADPH oxidases. All pathways involve inactivation of serine-threonine protein phosphatases. The metal dependent phosphatase PP2C has a negative regulatory function during ABA mediated ROS signaling. PP2A is the most abundant protein phosphatase in eukaryotic cells. Inhibitors of PP2A exert a ROS inducing activity as well and we suggest that there is a direct relationship between these two effects of drugs. We present current findings and hypotheses regarding PP2A-ROS signaling connections related to all three ROS signaling pathways and anticipate future research directions for this field. These mechanisms have implications in the understanding of stress tolerance of vascular plants, having applications regarding crop improvement.
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Affiliation(s)
- Csaba Máthé
- Department of Botany, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary.
| | - Tamás Garda
- Department of Botany, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary.
| | - Csongor Freytag
- Department of Botany, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary.
| | - Márta M-Hamvas
- Department of Botany, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary.
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3
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Nguyen HTH, Bouteau F, Mazars C, Kuse M, Kawano T. The involvement of calmodulin and protein kinases in the upstream of cytosolic and nucleic calcium signaling induced by hypoosmotic shock in tobacco cells. PLANT SIGNALING & BEHAVIOR 2018; 13:e1494467. [PMID: 30067454 PMCID: PMC6149468 DOI: 10.1080/15592324.2018.1494467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 06/19/2018] [Indexed: 05/21/2023]
Abstract
Changes in Ca2+ concentrations in cytosol ([Ca2+]C) or nucleus ([Ca2+]N) may play some vital roles in plants under hypoosmotic shock (Hypo-OS). Here, we observed that Hypo-OS induces biphasic increases in [Ca2+]C and [Ca2+]N in two tobacco cell lines (BY-2) expressing apoaequorin either in the cytosol or in the nucleus. Both [Ca2+]C and [Ca2+]N were sensitively modulated by the inhibitors of calmodulin and protein kinases, supporting the view that calmodulin suppresses the 1st peaks and and protein kinases enhance 2nd peaks in [Ca2+]C and [Ca2+]N. Data also suggested that the 1st and 2nd events depend on the internal and extracellular Ca2+ sources, respectively.
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Affiliation(s)
- H. T. H. Nguyen
- Laboratory of Chemical Biology and Bioengineering, Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Japan
| | - F. Bouteau
- Sorbonne Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, Paris, France
- University of Florence LINV Kitakyushu Research Center (LINV@Kitakyushu), Kitakyushu, Japan
- International Photosynthesis Industrialization Research Center, The University of Kitakyushu, Kitakyushu, Japan
| | - C. Mazars
- Laboratoire de Recherches en Sciences Végétales, Université de Toulouse UPS, CNRS UMR, Castanet-Tolosan, France
| | - M. Kuse
- Laboratory of Natural Products Chemistry, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - T. Kawano
- Laboratory of Chemical Biology and Bioengineering, Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Japan
- University of Florence LINV Kitakyushu Research Center (LINV@Kitakyushu), Kitakyushu, Japan
- International Photosynthesis Industrialization Research Center, The University of Kitakyushu, Kitakyushu, Japan
- Univ. Paris-Diderot, Sorbonne Paris Cité, Paris Interdisciplinary Energy Research Institute (PIERI), Paris, France
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Daneshkhah R, Grundler FMW, Wieczorek K. The Role of MPK6 as Mediator of Ethylene/Jasmonic Acid Signaling in Serendipita indica-Colonized Arabidopsis Roots. PLANT MOLECULAR BIOLOGY REPORTER 2018; 36:284-294. [PMID: 29875545 PMCID: PMC5966479 DOI: 10.1007/s11105-018-1077-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Serendipita indica is an axenically cultivable fungus, which colonizes a broad range of plant species including the model plant Arabidopsis thaliana. Root colonization by this endophyte leads to enhanced plant fitness and performance and promotes resistance against different biotic and abiotic stresses. The involvement of MPK6 in this mutualistic interaction had been previously shown with an mpk6 A. thaliana mutant, which failed to respond to S. indica colonization. Here, we demonstrate that mpk6 roots are significantly less colonized by S. indica compared to wild-type roots and the foliar application of plant hormones, ethylene, or jasmonic acid, restores the colonization rate at least to the wild-type level. Further, hormone-treated mpk6 plants show typical S. indica-induced growth promotion effects. Moreover, expression levels of several genes related to plant defense and hormone signaling are significantly changed at different colonization phases. Our results demonstrate that the successful root colonization by S. indica depends on efficient suppression of plant immune responses. In A. thaliana, this process relies on intact hormone signaling in which MPK6 seems to play a pivotal role.
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Affiliation(s)
- R. Daneshkhah
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, 3430 Tulln on the Danube, Austria
| | - F. M. W. Grundler
- Institute of Crop Science and Resource Conservation, Molecular Phytomedicine, University Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Germany
| | - Krzysztof Wieczorek
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, 3430 Tulln on the Danube, Austria
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Sidonskaya E, Schweighofer A, Shubchynskyy V, Kammerhofer N, Hofmann J, Wieczorek K, Meskiene I. Plant resistance against the parasitic nematode Heterodera schachtii is mediated by MPK3 and MPK6 kinases, which are controlled by the MAPK phosphatase AP2C1 in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:107-18. [PMID: 26438412 PMCID: PMC4682428 DOI: 10.1093/jxb/erv440] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plant-parasitic cyst nematodes infect plants and form highly sophisticated feeding sites in roots. It is not known which plant cell signalling mechanisms trigger plant defence during the early stages of nematode parasitism. Mitogen-activated protein kinases (MAPKs) are central components of protein phosphorylation cascades transducing extracellular signals to plant defence responses. MAPK phosphatases control kinase activities and the signalling outcome. The involvement and the role of MPK3 and MPK6, as well as the MAPK phosphatase AP2C1, is demonstrated during parasitism of the beet cyst nematode Heterodera schachtii in Arabidopsis. Our data reveal notable activation patterns of plant MAPKs and the induction of AP2C1 suggesting the attenuation of defence signalling in plant cells during early nematode infection. It is demonstrated that the ap2c1 mutant that is lacking AP2C1 is more attractive but less susceptible to nematodes compared with the AP2C1-overexpressing line. This implies that the function of AP2C1 is a negative regulator of nematode-induced defence. By contrast, the enhanced susceptibility of mpk3 and mpk6 plants indicates a positive role of stress-activated MAPKs in plant immunity against nematodes. Evidence is provided that phosphatase AP2C1, as well as AP2C1-targeted MPK3 and MPK6, are important regulators of plant-nematode interaction, where the co-ordinated action of these signalling components ensures the timely activation of plant defence.
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Affiliation(s)
- Ekaterina Sidonskaya
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, A-3430 Tulln on the Danube, Austria
| | - Alois Schweighofer
- Max F. Perutz Laboratories of the University and Medical University of Vienna, Dr Bohr-Gasse 9, A-1030 Vienna, Austria Institute of Biotechnology, University of Vilnius, Graiciuno 8, LT-02242 Vilnius, Lithuania
| | - Volodymyr Shubchynskyy
- Max F. Perutz Laboratories of the University and Medical University of Vienna, Dr Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Nina Kammerhofer
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, A-3430 Tulln on the Danube, Austria
| | - Julia Hofmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, A-3430 Tulln on the Danube, Austria
| | - Krzysztof Wieczorek
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz-Straße 24, A-3430 Tulln on the Danube, Austria
| | - Irute Meskiene
- Max F. Perutz Laboratories of the University and Medical University of Vienna, Dr Bohr-Gasse 9, A-1030 Vienna, Austria Institute of Biotechnology, University of Vilnius, Graiciuno 8, LT-02242 Vilnius, Lithuania Department of Ecogenomics and Systems Biology, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria
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6
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Haswell ES, Verslues PE. The ongoing search for the molecular basis of plant osmosensing. ACTA ACUST UNITED AC 2015; 145:389-94. [PMID: 25870206 PMCID: PMC4411250 DOI: 10.1085/jgp.201411295] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Elizabeth S Haswell
- Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130
| | - Paul E Verslues
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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Achuba FI. Petroleum Products in Soil Mediated Oxidative Stress in Cowpea (<i>Vigna unguiculata</i>) and Maize (<i>Zea mays</i>) Seedlings. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ojss.2014.412042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Process characterization of hCTLA4Ig production in transgenic rice cell cultures using a 3-L bioreactor. Appl Biochem Biotechnol 2013; 171:1276-88. [PMID: 23546868 DOI: 10.1007/s12010-013-0192-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 03/11/2013] [Indexed: 10/27/2022]
Abstract
Most of the technical know-how and experience of bioreactor engineering is applicable to plant cell cultures. In this study, transgenic rice cell cultures using RAmy3D promoter were used for the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig). In process aspect, the rice cells during production phase are strongly influenced by hydrodynamic stresses, such as shear stress and bubble burst. Therefore, the effects of agitation and aeration rates on cell growth and hCTLA4Ig production were investigated in a 3-L multi-bioreactor. By increasing over 240 rpm, the detrimental effects on cell growth and hCTLA4Ig production were observed. At an aeration rate of 0.3 vvm, relative cell viability sharply decreased 2 days earlier than those of lower aeration rates. In addition, it was confirmed that the specific yields and the specific productivity at 0.3 vvm were superior to those values at 0.05 vvm. Overall, higher aeration rate showed the improved hCTLA4Ig production in combination experiment. High aeration rates in general, however, have an undesired effect as excessive aeration was found to negatively affect the quality of hCTLA4Ig. Consequently, the hydrodynamic conditions must be tightly regulated during bioreactor operation in order to enhance hCTLA4Ig productivity and quality in transgenic rice cell cultures.
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Alvarez-Flórez F, Vidal D, Simón E. MAP-kinase activity in etiolated Cucumis sativus cotyledons: the effect of red and far-red light irradiation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 63:1-7. [PMID: 23228548 DOI: 10.1016/j.plaphy.2012.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 11/02/2012] [Indexed: 06/01/2023]
Abstract
Phytochrome (phy) signalling in plants may be transduced through protein phosphorylation. Mitogen-activated protein kinase (MAP-kinase, MAPK) activity and the effect of R (red) and FR (far-red) light irradiation on MAPK activity were studied in etiolated Cucumis sativus L. cotyledons. By in vitro protein phosphorylation and in-gel assays with myelin basic protein (MBP), a protein band (between 48 and 45 kDa) with MAPK-like activity was detected. The addition to the phosphorylation buffer of specific protein phosphatase (PTP) inhibitors (Na(3)VO(4) and NaF) and genistein, apigenin or PD98059 as MAPK inhibitors allowed us to confirm the MAPK activity of the protein band. Irradiation of etiolated cotyledons with FR light for 5, 10 or 60 min rapidly and transiently stimulated the MAPK activity of the protein band. This suggests that there was a very low fluence response (VLFR) of phys. In addition, 15 min of R light irradiation or a sequential treatment of 15 min of R plus 5 min of FR also increased MAPK activity. The stimulatory effect of R light was also attributed to the same photoreceptor, which suggests that MAPKs are involved in phytochrome signal transduction. Protein immunoprecipitation and immunoblotting analysis with the polyclonal antibody anti-pERK1/2 (Tyr 204) and the monoclonal antibody anti-phosphotyrosine PY20 allowed us to recognize the above mentioned protein band as two proteins with molecular masses (M(r)) of approximately 47 and 45 kDa, and MAPK activity. The biochemical and immunological properties showed by the proteins detected indicated that they were members of the MAPK family phosphorylated in tyrosine residues.
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Affiliation(s)
- Fagua Alvarez-Flórez
- Departamento de Biología Vegetal, Avda. Diagonal n° 643, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain.
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10
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Mishra NS, Tuteja R, Tuteja N. Signaling through MAP kinase networks in plants. Arch Biochem Biophys 2006; 452:55-68. [PMID: 16806044 DOI: 10.1016/j.abb.2006.05.001] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Revised: 05/04/2006] [Accepted: 05/05/2006] [Indexed: 01/01/2023]
Abstract
Protein phosphorylation is the most important mechanism for controlling many fundamental cellular processes in all living organisms including plants. A specific class of serine/threonine protein kinases, the mitogen-activated protein kinases (MAP kinases) play a central role in the transduction of various extra- and intracellular signals and are conserved throughout eukaryotes. These generally function via a cascade of networks, where MAP kinase (MAPK) is phosphorylated and activated by MAPK kinase (MAPKK), which itself is activated by MAPKK kinase (MAPKKK). Signaling through MAP kinase cascade can lead to cellular responses including cell division, differentiation as well as response to various stresses. In plants, MAP kinases are represented by multigene families and are organized into a complex network for efficient transmission of specific stimuli. Putative plant MAP kinase cascades have been postulated based on experimental analysis of in vitro interactions between specific MAP kinase components. These cascades have been tested in planta following expression of epitope-tagged kinases in protoplasts. It is known that signaling for cell division and stress responses in plants are mediated through MAP kinases and even auxin, ABA and possibly ethylene and cytokinin also utilize a MAP kinase pathway. Most of the biotic (pathogens and pathogen-derived elicitors) including wounding and abiotic stresses (salinity, cold, drought, and oxidative) can induce defense responses in plants through MAP kinase pathways. In this article we have covered the historical background, biochemical assay, activation/inactivation, and targets of MAP kinases with emphasis on plant MAP kinases and the responses regulated by them. The cross-talk between plant MAP kinases is also discussed to bring out the complexity within this three-component module.
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Affiliation(s)
- Neeti Sanan Mishra
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Zhang A, Jiang M, Zhang J, Tan M, Hu X. Mitogen-activated protein kinase is involved in abscisic acid-induced antioxidant defense and acts downstream of reactive oxygen species production in leaves of maize plants. PLANT PHYSIOLOGY 2006; 141:475-87. [PMID: 16531486 PMCID: PMC1475456 DOI: 10.1104/pp.105.075416] [Citation(s) in RCA: 196] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The role of mitogen-activated protein kinase (MAPK) in abscisic acid (ABA)-induced antioxidant defense was investigated in leaves of maize (Zea mays) plants. Treatments with ABA or H(2)O(2) induced the activation of a 46-kD MAPK and enhanced the expression of the antioxidant genes CAT1, cAPX, and GR1 and the total activities of the antioxidant enzymes catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Such enhancements were blocked by pretreatment with several MAPK kinase inhibitors and reactive oxygen species inhibitors or scavengers. Pretreatment with MAPK kinase inhibitors also substantially arrested the ABA-induced H(2)O(2) production after 2 h of ABA treatment, but did not affect the levels of H(2)O(2) within 1 h of ABA treatment. Pretreatment with several inhibitors of protein tyrosine phosphatase, which is believed to be a negative regulator of MAPK, only slightly prevented the ABA-induced H(2)O(2) production, but did not affect the ABA-induced MAPK activation and ABA-enhanced antioxidant defense systems. These results clearly suggest that MAPK but not protein tyrosine phosphatase is involved in the ABA-induced antioxidant defense, and a cross talk between H(2)O(2) production and MAPK activation plays a pivotal role in the ABA signaling. ABA-induced H(2)O(2) production activates MAPK, which in turn induces the expression and the activities of antioxidant enzymes. The activation of MAPK also enhances the H(2)O(2) production, forming a positive feedback loop.
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Affiliation(s)
- Aying Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
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12
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Rouet MA, Mathieu Y, Barbier-Brygoo H, Laurière C. Characterization of active oxygen-producing proteins in response to hypo-osmolarity in tobacco and Arabidopsis cell suspensions: identification of a cell wall peroxidase. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:1323-32. [PMID: 16551688 DOI: 10.1093/jxb/erj107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The oxidative response induced by hypo-osmolarity is characterized in tobacco and Arabidopsis cells in order to identify the corresponding active oxygen-producing proteins. The pharmacological profiles of the oxidative responses were clearly different in the two plant materials, leading to the identification of distinct active oxygen producers in tobacco and Arabidopsis cells. In tobacco cells, a 100 kDa protein, localized in the plasma membrane, was demonstrated to produce active oxygen in the presence of NADPH. This production can be activated by fatty acids and is strongly depressed by diphenylene iodonium, as measured by an in vivo response. In Arabidopsis, 30 kDa and 34 kDa proteins localized in the cell wall were shown to be able to produce active oxygen in the presence of cofactors and the production is prevented by peroxidase inhibitors, as is the in vivo response. The two purified proteins were identified by mass spectrometry and both correspond to the peroxidase gene At5g64120.
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Affiliation(s)
- M-A Rouet
- Institut des Sciences du Végétal, UPR 2355, CNRS, 1 av. de la terrasse, 91198 Gif s/Yvette Cedex, France
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13
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Hoffmann XK, Beck CF. Mating-induced shedding of cell walls, removal of walls from vegetative cells, and osmotic stress induce presumed cell wall genes in Chlamydomonas. PLANT PHYSIOLOGY 2005; 139:999-1014. [PMID: 16183845 PMCID: PMC1256013 DOI: 10.1104/pp.105.065037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 07/05/2005] [Accepted: 07/15/2005] [Indexed: 05/04/2023]
Abstract
The first step in sexual differentiation of the unicellular green alga Chlamydomonas reinhardtii is the formation of gametes. Three genes, GAS28, GAS30, and GAS31, encoding Hyp-rich glycoproteins that presumably are cell wall constituents, are expressed in the late phase of gametogenesis. These genes, in addition, are activated by zygote formation and cell wall removal and by the application of osmotic stress. The induction by zygote formation could be traced to cell wall shedding prior to gamete fusion since it was seen in mutants defective in cell fusion. However, it was absent in mutants defective in the initial steps of mating, i.e. in flagellar agglutination and in accumulation of adenosine 3',5'-cyclic monophosphate in response to this agglutination. Induction of the three GAS genes was also observed when cultures were exposed to hypoosmotic or hyperosmotic stress. To address the question whether the induction seen upon cell wall removal from both gametes and vegetative cells was elicited by osmotic stress, cell wall removal was performed under isosmotic conditions. Also under such conditions an activation of the genes was observed, suggesting that the signaling pathway(s) is (are) activated by wall removal itself.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Cell Wall/genetics
- Chlamydomonas reinhardtii/cytology
- Chlamydomonas reinhardtii/genetics
- Chlamydomonas reinhardtii/growth & development
- Chlamydomonas reinhardtii/metabolism
- DNA, Algal/genetics
- DNA, Protozoan/genetics
- Gene Expression Regulation, Developmental
- Genes, Protozoan
- Glycoproteins/genetics
- Models, Biological
- Molecular Sequence Data
- Mutation
- Osmotic Pressure
- Protozoan Proteins/biosynthesis
- Protozoan Proteins/genetics
- RNA, Algal/genetics
- RNA, Algal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- Sequence Homology, Amino Acid
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Ishikawa T, Morimoto Y, Madhusudhan R, Sawa Y, Shibata H, Yabuta Y, Nishizawa A, Shigeoka S. Acclimation to diverse environmental stresses caused by a suppression of cytosolic ascorbate peroxidase in tobacco BY-2 cells. PLANT & CELL PHYSIOLOGY 2005; 46:1264-71. [PMID: 15919670 DOI: 10.1093/pcp/pci135] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The active oxygen species (AOS) that arise from normal metabolic processes are kept under tight control by various antioxidant mechanisms. AOS are important signal molecules that regulate many physiological processes, including environmental stress responses. In this work, we have investigated the effect of lowered cytosolic ascorbate peroxidase (APX) activity in transgenic tobacco BY-2 cells, using two transformed BY-2 cell lines, cAPX-S2 and cAPX-S3, resulting from co-suppression by expression of Arabidopsis APX1 cDNA under the cauliflower mosaic virus (CaMV) 35S promoter. cAPX-S2 and cAPX-S3 possessed 50 and 75% lower cytosolic APX activity, respectively, compared with that in the untransformed cells. Chemical fluorescence analysis indicated that the AOS levels were markedly higher in the two APX-suppressed cell lines than in the wild-type cells. However, there were no substantial differences in the activity levels of the various other antioxidant enzymes. Interestingly, the APX-suppressed cells showed different responses and tolerances to environmental stresses, such as heat and salinity. Suppression subtractive hybridization revealed that several heat- and salt stress-inducible genes were up-regulated in cAPX-S3 cells. HSP70, DnaJ-like protein and purple acid phosphatase were among the constitutively induced genes. An in-gel kinase assay suggested that a mitogen-activated protein (MAP) kinase of approximately 46 kDa was predominantly active in the APX-suppressed cells, and transcript levels of both nicotiana protein kinase 1 (NPK1) and nucleoside diphosphate kinase 2 (NDPK2) were up-regulated. These data suggest the possibility that MAP kinase cascades are activated by subtle imbalances in the homeostasis of the cellular redox status caused by lowered cytosolic APX activity.
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Affiliation(s)
- Takahiro Ishikawa
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504 Japan.
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15
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Decreux A, Messiaen J. Wall-associated kinase WAK1 interacts with cell wall pectins in a calcium-induced conformation. PLANT & CELL PHYSIOLOGY 2005; 46:268-78. [PMID: 15769808 DOI: 10.1093/pcp/pci026] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Wall-associated kinase 1 (WAK1) is a transmembrane protein containing a cytoplasmic Ser/Thr kinase domain and an extracellular domain in contact with the pectin fraction of the plant cell walls. In order to characterize further the interaction of WAK1 with pectin, a 564 bp DNA sequence corresponding to amino acids 67-254 of the extracellular domain of WAK1 from Arabidopsis thaliana was cloned and expressed as a soluble recombinant peptide in yeast. Using enzyme-linked immunosorbent assays (ELISA), we show that peptide WAK(67-254) binds to polygalacturonic acid (PGA), oligogalacturonides, pectins extracted from A. thaliana cell walls and to structurally related alginates. Our results suggest that both ionic and steric interactions are required to match the relatively linear pectin backbone. Binding of WAK(67-254) to PGA, oligogalacturonides and alginates occurred only in the presence of calcium and in ionic conditions promoting the formation of calcium bridges between oligo-and polymers (also known as 'egg-boxes'). The conditions inhibiting the formation of calcium bridges (EDTA treatment, calcium substitution, high NaCl concentrations, depolymerization and methylesterification of pectins) also inhibited the binding of WAK(67-254) to calcium-induced egg-boxes. The relevance of this non-covalent link between WAK(67-254) and cell wall pectins is discussed in terms of cell elongation, cell differentiation and host-pathogen interactions.
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Affiliation(s)
- Annabelle Decreux
- FUNDP, Unité de Recherche en Biologie Végétale, 61 rue de Bruxelles, 5000 Namur, Belgium
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16
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Lee J, Rudd JJ, Macioszek VK, Scheel D. Dynamic changes in the localization of MAPK cascade components controlling pathogenesis-related (PR) gene expression during innate immunity in parsley. J Biol Chem 2004; 279:22440-8. [PMID: 15001572 DOI: 10.1074/jbc.m401099200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The activation of mitogen-activated protein kinase (MAPK) cascades is an important mechanism for stress adaptation through the control of gene expression in mammals, yeast, and plants. MAPK activation has emerged as a common mechanism by which plants trigger pathogen defense responses following innate immune recognition of potential microbial pathogens. We are studying the non-host plant defense response of parsley to attempted infection by Phytophthora species using an experimental system of cultured parsley cells and the Phytophthora-derived Pep-13 peptide elicitor. Following receptor-mediated recognition of this peptide, parsley cells trigger a multifaceted innate immune response, involving the activation of three MAPKs that have been shown to function in the oxidative burst-independent activation of defense gene expression. Using this same experimental model we now report the identification of a MAPK kinase (MAPKK) that functions upstream in this pathway. This kinase, referred to as PcMKK5 based on sequence similarity to Arabidopsis thaliana AtMKK5, is activated in parsley cells following Pep-13 treatment and functions as an in vivo activator of all three MAPKs previously shown to be involved in this response. Gain- and loss-of-function mutant versions of PcMKK5, when used in protoplast co-transfection assays, demonstrated that kinase activity of PcMKK5 is required for PR gene promoter activation following Pep-13 treatment. Furthermore, using specific antibodies and immunofluorescent labeling, we demonstrate that activation of MAPKs in parsley cells correlates with an increase in their nuclear localization, which is not detectable for activated PcMKK5. These results suggest that activation of gene expression through MAPK cascades during innate immune responses in plants involves dynamic changes in the localization of the proteins involved, which may reflect the distribution of key protein substrates for the activated MAPKs.
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Affiliation(s)
- Justin Lee
- Department of Stress and Developmental Biology, Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
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17
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Zonia L, Munnik T. Osmotically induced cell swelling versus cell shrinking elicits specific changes in phospholipid signals in tobacco pollen tubes. PLANT PHYSIOLOGY 2004; 134:813-23. [PMID: 14739344 PMCID: PMC344556 DOI: 10.1104/pp.103.029454] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2003] [Revised: 08/21/2003] [Accepted: 11/15/2003] [Indexed: 05/18/2023]
Abstract
Pollen tube cell volume changes rapidly in response to perturbation of the extracellular osmotic potential. This report shows that specific phospholipid signals are differentially stimulated or attenuated during osmotic perturbations. Hypo-osmotic stress induces rapid increases in phosphatidic acid (PA). This response occurs starting at the addition of 25% (v/v) water to the pollen tube cultures and peaks at 100% (v/v) water. Increased levels of PA were detected within 30 s and reached maximum by 15 to 30 min after treatment. The pollen tube apical region undergoes a 46% increase in cell volume after addition of 100% water (v/v), and there is an average 7-fold increase in PA. This PA increase appears to be generated by phospholipase D because concurrent transphosphatidylation of n-butanol results in an average 8-fold increase in phosphatidylbutanol. Hypo-osmotic stress also induces an average 2-fold decrease in phosphatidylinositol phosphate; however, there are no detectable changes in the levels of phosphatidylinositol bisphosphates. In contrast, salt-induced hyperosmotic stress from 50 to 400 mm NaCl inhibits phospholipase D activity, reduces the levels of PA, and induces increases in the levels of phosphatidylinositol bisphosphate isomers. The pollen tube apical region undergoes a 41% decrease in cell volume at 400 mm NaCl, and there is an average 2-fold increase in phosphatidylinositol 3,5-bisphosphate and 1.4-fold increase in phosphatidylinositol 4,5-bisphosphate. The phosphatidylinositol 3,5-bisphosphate increase is detected within 30 s and reaches maximum by 15 to 30 min after treatment. In summary, these results demonstrate that hypo-osmotic versus hyperosmotic perturbation and the resultant cell swelling or shrinking differentially activate specific phospholipid signaling pathways in tobacco (Nicotiana tabacum) pollen tubes.
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Affiliation(s)
- Laura Zonia
- Institute of Experimental Botany, Na Pernikarce 15, 160 00 Prague 6, Czech Republic.
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18
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Islas-Flores I, Zúñiga-Aguilar JJ, Rodríguez-Zapata LC, Carrillo-Pech M, Baízabal-Aguirre VM, Minero-García Y, Hernández-Sotomayor SM. MAP kinase-like activity in transformed Catharanthus roseus hairy roots varies with culture conditions such as temperature and hypo-osmotic shock. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2004; 42:65-72. [PMID: 15061086 DOI: 10.1016/j.plaphy.2003.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mitogen activated protein (MAP) kinase-like activity was determined in extracts obtained from transformed Catharanthus roseus hairy roots by the ability to phosphorylate myelin basic protein (MBP). Both in solution and in gel kinase assays showed variation in activity, depending on root developmental stage. In gel kinase assays, using the extract soluble fraction, revealed a 56 kDa polypeptide with phosphorylation activity on MBP. In addition, another 75 kDa polypeptide was observed in the particulate fraction. Immunodetection with monoclonal antibodies against ERK-1, a mammalian MAP kinase, and with anti-phosphotyrosine antibodies cross-reacted with the 56 kDa polypeptide, named SMK56, from the soluble fraction, suggesting that this polypeptide could be related with members of the MAP kinase family. Antibodies against the dually phosphorylated threonine-tyrosine motif, characteristic of active forms of MAP kinases, also cross-reacted with this 56 kDa polypeptide. Changes in the levels of SMK56 were detected within the first 30 min of root exposure to low temperatures or hypo-osmotic shock, suggesting that this protein may be involved in the perception of environmental changes.
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Affiliation(s)
- Ignacio Islas-Flores
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 #130, Col. Chuburná de Hidalgo, Mérida, Yucatán 97200, Mexico.
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19
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Rudd JJ, Osman K, Franklin FCH, Franklin-Tong VE. Activation of a putative MAP kinase in pollen is stimulated by the self-incompatibility (SI) response. FEBS Lett 2003; 547:223-7. [PMID: 12860418 DOI: 10.1016/s0014-5793(03)00710-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) operate downstream of receptor-ligand interactions, playing a pivotal role in responses to extracellular signals. The self-incompatibility (SI) response in Papaver rhoeas L. triggers a Ca2+-dependent signalling cascade resulting in inhibition of incompatible pollen. We have investigated the possible involvement of MAPKs in SI. We report the enhanced activation of a 56 kDa protein kinase (p56) in SI-induced pollen and provide evidence that p56 has MAPK activity. This provides an important advance in our understanding of the SI response. We believe this is the first direct biochemical demonstration of activation of a MAPK during SI.
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Affiliation(s)
- Jason J Rudd
- School of Biosciences, The University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
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20
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Pnueli L, Liang H, Rozenberg M, Mittler R. Growth suppression, altered stomatal responses, and augmented induction of heat shock proteins in cytosolic ascorbate peroxidase (Apx1)-deficient Arabidopsis plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 34:187-203. [PMID: 12694594 DOI: 10.1046/j.1365-313x.2003.01715.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The accumulation of hydrogen peroxide (H2O2) in plants is typically associated with biotic or abiotic stresses. However, H2O2 is continuously produced in cells during normal metabolism. Yet, little is known about how H2O2 accumulation will affect plant metabolism in the absence of pathogens or abiotic stress. Here, we report that a deficiency in the H2O2-scavenging enzyme, cytosolic ascorbate peroxidase (APX1), results in the accumulation of H2O2 in Arabidopsis plants grown under optimal conditions. Knockout-Apx1 plants were characterized by suppressed growth and development, altered stomatal responses, and augmented induction of heat shock proteins during light stress. The inactivation of Apx1 resulted in the induction of several transcripts encoding signal transduction proteins. These were not previously linked to H2O2 signaling during stress and may belong to a signal transduction pathway specifically involved in H2O2 sensing during normal metabolism. Surprisingly, the expression of transcripts encoding H2O2 scavenging enzymes, such as catalase or glutathione peroxidase, was not elevated in knockout-Apx1 plants. The expression of catalase, two typical plant peroxidases, and several different heat shock proteins was however elevated in knockout-Apx1 plants during light stress. Our results demonstrate that in planta accumulation of H2O2 can suppress plant growth and development, interfere with different physiological processes, and enhance the response of plants to abiotic stress conditions. Our findings also suggest that at least part of the induction of heat shock proteins during light stress in Arabidopsis is mediated by H2O2 that is scavenged by APX1.
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Affiliation(s)
- Lilach Pnueli
- Department of Biology, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
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21
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Liu Y, Jin H, Yang KY, Kim CY, Baker B, Zhang S. Interaction between two mitogen-activated protein kinases during tobacco defense signaling. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 34:149-60. [PMID: 12694591 DOI: 10.1046/j.1365-313x.2003.01709.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plant mitogen-activated protein kinases (MAPKs) represented by tobacco wounding-induced protein kinase (WIPK) have unique regulation at the level of transcription in response to stresses. By using transcriptional and translational inhibitors, it has been shown previously that WIPK gene expression and de novo protein synthesis are required for the high-level activity of WIPK in cells treated with elicitins from Phytophthora spp. However, regulation of WIPK expression and the role(s) of WIPK in plant disease resistance are unknown. In this report, we demonstrate that WIPK gene transcription is regulated by phosphorylation and de-phosphorylation events. Interestingly, salicylic acid-induced protein kinase (SIPK) was identified as the kinase involved in regulating WIPK gene expression based on both gain-of-function and loss-of-function analyses. This finding revealed an additional level of interaction between SIPK and WIPK, which share an upstream MAPKK, NtMEK2. Depending on whether WIPK shares its downstream targets with SIPK, it could either function as a positive feed-forward regulator of SIPK or initiate a new pathway. Consistent with the first scenario, co-expression of WIPK with the active mutant of NtMEK2 leads to accelerated hypersensitive response (HR)-like cell death in which SIPK also plays a role. Mutagenesis analysis revealed that the conserved common docking domain in WIPK is required for its function. Together with prior reports that (i) WIPK is activated in NN tobacco infected with tobacco mosaic virus, and (ii) PVX virus-induced gene silencing of WIPK attenuated N gene-mediated resistance, we concluded that WIPK plays a positive role in plant disease resistance, possibly through accelerating the pathogen-induced HR cell death.
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Affiliation(s)
- Yidong Liu
- Department of Biochemistry, University of Missouri-Columbia, 117 Schweitzer Hall, 65211, USA
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22
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Johnson SM, Doherty SJ, Croy RRD. Biphasic superoxide generation in potato tubers. A self-amplifying response to stress. PLANT PHYSIOLOGY 2003; 131:1440-9. [PMID: 12644693 PMCID: PMC166903 DOI: 10.1104/pp.013300] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2002] [Revised: 10/09/2002] [Accepted: 11/25/2002] [Indexed: 05/20/2023]
Abstract
Potato (Solanum tuberosum) cultivars differ quantitatively in their responses to mechanical stress including the ability to synthesize melanin pigments in tuber tissues. Investigations into the cellular events induced by mechanical stress on tuber tissues have shown that an early cellular response is a significant and rapid synthesis of superoxide radicals. This burst of radical production distinctively displays a reproducible biphasic pattern over time with peaks of generation at 2 and 5 h. A concomitant consequence of the generation of these free radicals is elevated levels of oxidatively modified tuber proteins. Both radical generation and protein modification vary between cultivars but both are directly proportional to the amount of melanin pigments produced. Cell-free extracts of mechanically stressed tissues, pectic fragments, and scission products generated from cell walls are able to induce superoxide generation in non-stressed tissues, indicating the participation of a biologically active factor that induces a further a phase of radical synthesis.
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Affiliation(s)
- S M Johnson
- Crop Protection Group, School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, United Kingdom
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23
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Dat JF, Pellinen R, Beeckman T, Van De Cotte B, Langebartels C, Kangasjärvi J, Inzé D, Van Breusegem F. Changes in hydrogen peroxide homeostasis trigger an active cell death process in tobacco. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 33:621-32. [PMID: 12609037 DOI: 10.1046/j.1365-313x.2003.01655.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In transgenic tobacco plants with reduced catalase activity, high levels of hydrogen peroxide (H2O2) can accumulate under photorespiratory conditions. Such a perturbation in H2O2 homeostasis induced cell death in clusters of palisade parenchyma cells, primarily along the veins. Ultrastructural alterations, such as chromatin condensation and disruption of mitochondrial integrity, took place before cell death. Furthermore, enhanced transcript levels of mitochondrial defense genes accompanied these mitochondrial changes. Pharmacological data indicated that the initiation and execution of cell death require de novo protein synthesis and that the signal transduction pathway leading to cell death involved changes in ion homeostasis, (de)phosphorylation events and an oxidative burst, as observed during hypersensitive responses. This oxidase-dependent oxidative burst is essential for cell death, but it is not required for the accumulation of defense proteins, suggesting a more prominent role for the oxidative burst in abiotic stress-induced cell death.
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Affiliation(s)
- James F Dat
- Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium
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24
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Kroj T, Rudd JJ, Nürnberger T, Gäbler Y, Lee J, Scheel D. Mitogen-activated protein kinases play an essential role in oxidative burst-independent expression of pathogenesis-related genes in parsley. J Biol Chem 2003; 278:2256-64. [PMID: 12426314 DOI: 10.1074/jbc.m208200200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plants are continuously exposed to attack by potential phytopathogens. Disease prevention requires pathogen recognition and the induction of a multifaceted defense response. We are studying the non-host disease resistance response of parsley to the oomycete, Phytophthora sojae using a cell culture-based system. Receptor-mediated recognition of P. sojae may be achieved through a thirteen amino acid peptide sequence (Pep-13) present within an abundant cell wall transglutaminase. Following recognition of this elicitor molecule, parsley cells mount a defense response, which includes the generation of reactive oxygen species (ROS) and transcriptional activation of genes encoding pathogenesis-related (PR) proteins or enzymes involved in the synthesis of antimicrobial phytoalexins. Treatment of parsley cells with the NADPH oxidase inhibitor, diphenylene iodonium (DPI), blocked both Pep-13-induced phytoalexin production and the accumulation of transcripts encoding enzymes involved in their synthesis. In contrast, DPI treatment had no effect upon Pep-13-induced PR gene expression, suggesting the existence of an oxidative burst-independent mechanism for the transcriptional activation of PR genes. The use of specific antibodies enabled the identification of three parsley mitogen-activated protein kinases (MAPKs) that are activated within the signal transduction pathway(s) triggered following recognition of Pep-13. Other environmental challenges failed to activate these kinases in parsley cells, suggesting that their activation plays a key role in defense signal transduction. Moreover, by making use of a protoplast co-transfection system overexpressing wild-type and loss-of-function MAPK mutants, we show an essential role for post-translational phosphorylation and activation of MAPKs for oxidative burst-independent PR promoter activation.
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Affiliation(s)
- Thomas Kroj
- Department of Stress and Developmental Biology, Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
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25
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Droillard M, Boudsocq M, Barbier-Brygoo H, Laurière C. Different protein kinase families are activated by osmotic stresses in Arabidopsis thaliana cell suspensions. Involvement of the MAP kinases AtMPK3 and AtMPK6. FEBS Lett 2002; 527:43-50. [PMID: 12220631 DOI: 10.1016/s0014-5793(02)03162-9] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Five Ca(2+)-independent protein kinases were rapidly activated by hypoosmotic stress, moderate or high hyperosmolarity induced by several osmolytes, sucrose, mannitol or NaCl. Three of these kinases, transiently activated by hypoosmolarity, recognised by anti-phosphorylated mitogen-activated protein (MAP) kinase antibodies, sensitive to a MAP kinase inhibitor and inactivated by the action of a tyrosine phosphatase, corresponded to MAP kinases. Using specific antibodies, two of the MAP kinases were identified as AtMPK6 and AtMPK3. The two other protein kinases, durably activated by high hyperosmolarity, did not belong to the MAP kinase family. Activation of AtMPK6 and AtMPK3 by hypoosmolarity depended on upstream protein kinases sensitive to staurosporine and on calcium influx. In contrast, these two transduction steps were not involved in the activation of the two protein kinases activated by high hyperosmolarity.
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Affiliation(s)
- Marie Droillard
- Institut des Sciences du Végétal, UPR 2355, CNRS, 1 av. de la terrasse, 91198 Cedex, Gif s/Yvette, France
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26
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Abstract
Traditionally, reactive oxygen intermediates (ROIs) were considered to be toxic by-products of aerobic metabolism, which were disposed of using antioxidants. However, in recent years, it has become apparent that plants actively produce ROIs as signaling molecules to control processes such as programmed cell death, abiotic stress responses, pathogen defense and systemic signaling. Recent advances including microarray studies and the development of mutants with altered ROI-scavenging mechanisms provide new insights into how the steady-state level of ROIs are controlled in cells. In addition, key steps of the signal transduction pathway that senses ROIs in plants have been identified. These raise several intriguing questions about the relationships between ROI signaling, ROI stress and the production and scavenging of ROIs in the different cellular compartments.
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Affiliation(s)
- Ron Mittler
- Dept of Botany, Plant Sciences Institute, 353 Bessey Hall, Iowa State University, Ames, IA 50011, USA.
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27
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Sangwan V, Orvar BL, Beyerly J, Hirt H, Dhindsa RS. Opposite changes in membrane fluidity mimic cold and heat stress activation of distinct plant MAP kinase pathways. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 31:629-38. [PMID: 12207652 DOI: 10.1046/j.1365-313x.2002.01384.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mitogen-activated protein kinases (MAPKs) appear to be ubiquitously involved in signal transduction during eukaryotic responses to extracellular stimuli. In plants, no heat shock-activated MAPK has so far been reported. Also, whereas cold activates specific plant MAPKs such as alfalfa SAMK, mechanisms of such activation are unknown. Here, we report a heat shock-activated MAPK (HAMK) immunologically related to ERK (Extracellular signal-Regulated Kinase) superfamily of protein kinases. Molecular mechanisms of heat-activation of HAMK and cold-activation of SAMK were investigated. We show that cold-activation of SAMK requires membrane rigidification, whereas heat-activation of HAMK occurs through membrane fluidization. The temperature stress- and membrane structure-dependent activation of both SAMK and HAMK is mimicked at 25 degrees C by destabilizers of microfilaments and microtubules, latrunculin B and oryzalin, respectively; but is blocked by jasplakinolide, a stabilizer of actin microfilaments. Activation of SAMK or HAMK by temperature, chemically modulated membrane fluidity, or by cytoskeleton destabilizers is inhibited by blocking the influx of extracellular calcium. Activation of SAMK or HAMK is also prevented by an antagonist of calcium-dependent protein kinases (CDPKs). In summary, our data indicate that cold and heat are sensed by structural changes in the plasma membrane that translates the signal via cytoskeleton, Ca2+ fluxes and CDPKs into the activation of distinct MAPK cascades.
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Affiliation(s)
- Veena Sangwan
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, Quebec, H3A 1B1, Canada
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28
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Vranová E, Inzé D, Van Breusegem F. Signal transduction during oxidative stress. JOURNAL OF EXPERIMENTAL BOTANY 2002. [PMID: 11997371 DOI: 10.1093/jxb/53.372.1227] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
As an unfortunate consequence of aerobic life, active oxygen species (AOS) are formed by partial reduction of molecular oxygen. Plants possess a complex battery of enzymatic and non-enzymatic antioxidants that can protect cells from oxidative damage by scavenging AOS. It is becoming evident that AOS, which are generated during pathogen attack and abiotic stress situations, are recognized by plants as a signal for triggering defence responses. An overview of the literature is presented on the signalling role of AOS in plant defence responses, cell death, and development. Special attention is given to AOS and redox-regulated gene expression and the role of kinases and phosphatases in redox signal transduction.
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Affiliation(s)
- Eva Vranová
- Vakgroep Moleculaire Genetica, Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Universiteit Gent, KL Ledeganckstraat 35, B-9000 Gent, Belgium
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29
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Yuasa T. Identification of a 40 kDa Protein Kinase Activated by Stress in a Halotolerant Green Alga Dunaliella tertiolecta. Microbes Environ 2002. [DOI: 10.1264/jsme2.2002.39] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Takashi Yuasa
- Laboratory of Life and Cognitive Sciences, Department of Biosciences, Graduate School of Arts and Sciences, University of Tokyo
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30
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Abstract
The Arabidopsis genome encodes approximately 20 different mitogen-activated protein kinases (MAPKs) that are likely to be involved in growth, development and responses to endogenous and environmental cues. Several plant MAPKs are activated by a variety of stress stimuli, including pathogen infection, wounding, temperature, drought, salinity, osmolarity, UV irradiation, ozone and reactive oxygen species. Recent gain-of-function studies show that two tobacco MAPKs induce the expression of defense genes and cause cell death. By contrast, loss-of-function studies of other MAPK pathways revealed negative regulation of disease resistance. This 'push-and-pull' regulation by different MAPK pathways might provide a more precise control of plant defense responses.
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Affiliation(s)
- S Zhang
- Dept Biochemistry, University of Missouri-Columbia, 117 Schweitzer Hall, Columbia, MO 65211, USA.
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31
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Yuasa T, Ichimura K, Mizoguchi T, Shinozaki K. Oxidative stress activates ATMPK6, an Arabidopsis homologue of MAP kinase. PLANT & CELL PHYSIOLOGY 2001; 42:1012-1016. [PMID: 11577197 DOI: 10.1093/pcp/pce123] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades function in biotic and abiotic stress responses in plants. We analysed effect of oxidative stress on the activation of ATMPK6, an Arabidopsis thaliana MAPK, in Arabidopsis T87 cultured cells and rosette leaves using anti-ATMPK6 specific antibody. ATMPK6 in T87 cells was strongly activated by reactive oxygen species (ROS) such as H(2)O(2) and KO(2). In leaves, ATMPK6 was activated by paraquat and 3-amino-1,2,4-triazole (a catalase inhibitor). These results indicate that ATMPK6 is one of the candidates for signal mediators in response to abiotic or biotic sources for ROS in Arabidopsis.
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Affiliation(s)
- T Yuasa
- Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074 Japan
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Abstract
Mitogen activated protein kinases (MAPK) are important mediators in signal transmission, connecting the perception of external stimuli to cellular responses. MAPK cascades are involved in signalling various biotic and abiotic stresses, like wounding and pathogen infection, temperature stress or drought, but are also involved in mediating the action of some plant hormones, such as ethylene and auxin. Moreover, MAPKs have been implicated in cell cycle and developmental processes. In Arabidopsis mutant screens and in vivo assays several components of plant MAPK cascades have been identified. This review gives an update of recent advances in plant MAPK signalling and discusses the emerging mechanisms of some selected MAPK pathways.
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Affiliation(s)
- K Zwerger
- Institute of Microbiology and Genetics, Vienna Biocenter, Austria
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Bindschedler LV, Minibayeva F, Gardner SL, Gerrish C, Davies DR, Bolwell GP. Early signalling events in the apoplastic oxidative burst in suspension cultured French bean cells involve cAMP and Ca 2. THE NEW PHYTOLOGIST 2001; 151:185-194. [PMID: 33873377 DOI: 10.1046/j.1469-8137.2001.00170.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
• Modulators of cAMP, calcium and G proteins were used to treat bean (Phaseolus vulgaris) cells before addition of an elicitor from Colletotrichum lindemuthianum in order to elucidate the early steps of signal transduction leading to the production of the apoplastic oxidative burst. • Hydrogen peroxide production by elicited bean cells was monitored with luminol-or xylenol-orange-based assays. • Pretreatment with forskolin, dibutyryl cAMP or the Ca2+ ionophore A23187 enhanced the production of reactive oxygen species (ROS). The Ca2+ channel blocker, verapamil, and the calmodulin antagonist W7 led to a decreased oxidative burst and cancelled the dibutyryl cAMP effect. The production of ROS was increased by cholera toxin (CTX), an activator of G proteins. • Thus, an increase of cytosolic calcium ([Ca2+ ]cyt ) mediated through an increased level of cAMP is required for ROS production. The data support a role for G proteins and cAMP in extracellular alkalinization and Ca2+ influx, possibly in the provision of a reductant, which with the extracellular peroxidase, are required for the apoplastic oxidative burst.
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Affiliation(s)
- Laurence V Bindschedler
- Division of Biochemistry, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK; Present address
| | - Farida Minibayeva
- Institute of Biochemistry and Biophysics, PO Box 30, Kazan 420503, Russia
| | - Sarah L Gardner
- School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Chris Gerrish
- Division of Biochemistry, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK; Present address
| | - Dewi R Davies
- Division of Biochemistry, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK; Present address
| | - G Paul Bolwell
- Division of Biochemistry, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK; Present address
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Abstract
Reversible protein phosphorylation is the most common mechanism for cellular regulation in eukaryotic systems. Indeed, approximately 5% of the Arabidopsis genome encodes protein kinases and phosphatases. Among the thousands of such enzymes, only a small fraction has been examined experimentally. Studies have demonstrated that Ser/Thr phosphorylation and dephosphorylation play a key role in the regulation of plant physiology and development. However, function of tyrosine phosphorylation, despite the overwhelming importance in animals, has not been systematically studied in higher plants. As a result, it is still controversial whether tyrosine phosphorylation is important in plant signal transduction. Recently, the first two protein tyrosine phosphatases (PTPs) from a higher plant were characterized. A diverse group of genes encoding putative PTPs have been identified from the Arabidopsis genome sequence databases. Genetic analyses of various PTPs are underway and preliminary results have provided evidence that these PTPs serve critical functions in plant responses to stress signals and in plant development.
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Affiliation(s)
- Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Julie Ting
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Rajeev Gupta
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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Abstract
The mitogen-activated protein kinase (MAP kinase) signal transduction cascades are routes through which eukaryotic cells deliver extracellular messages to the cytosol and nucleus. These signalling pathways direct cell division, cellular differentiation, metabolism, and both biotic and abiotic stress responses. In plants, MAP kinases and the upstream components of the cascades are represented by multigene families, organized into different pathways which are stimulated and interact in complex ways. Experimental strategies for the analysis of MAP kinase cascades include the yeast two-hybrid system; using this approach in vitro interactions between specific MAP kinase cascade components have been analysed and putative plant cascades postulated. Transient transformation of protoplasts with epitope-tagged kinases has allowed cascades to be tested in planta. There is clear evidence for the involvement of MAP kinases in plant cell division and in the regulation of auxin signalling. Biotic (pathogens and pathogen-derived elicitors from fungi, bacteria and viruses) and abiotic stresses including wounding, mechanical stimulation, cold, drought and ozone can elicit defence responses in plants through MAP kinase pathways. There are data suggesting that ABA signalling utilizes a MAP kinase pathway, and probably ethylene and perhaps cytokinins do so also. The objective of this paper is to review this rapidly advancing field. Contents Summary 67 I. Introduction 68 II. Background 68 III. MAP kinase targets and targeting specificity 69 IV. Assays and inhibitors 70 V. Two well characterized MAP kinase pathways, Hog1 and Sevenless 71 VI. MAP kinases in plants 73 VII. MAP kinases and cell division 76 VIII. MAP kinases and plant hormones 76 IX. MAP kinase and abiotic stress 78 X. MAP kinase and biotic stress 80 XI. Future perspectives for MAP kinase research in plants 83 Acknowledgements 84 References 84.
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Affiliation(s)
- Peter C Morris
- Heriot-Watt University, Department of Biological Sciences, Riccarton, Edinburgh, EH14 4AS
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Taylor AT, Kim J, Low PS. Involvement of mitogen-activated protein kinase activation in the signal-transduction pathways of the soya bean oxidative burst. Biochem J 2001; 355:795-803. [PMID: 11311144 PMCID: PMC1221797 DOI: 10.1042/bj3550795] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The oxidative burst constitutes one of the most rapid defence responses characterized in the Plant Kingdom. We have observed that four distinct elicitors of the soya bean oxidative burst activate kinases of masses approximately 44 kDa and approximately 47 kDa. Evidence that these kinases regulate production of reactive oxygen species include: (i) their rapid activation by oxidative burst elicitors, (ii) their tight temporal correlation between activation/deactivation of the kinases and activation/deactivation of the oxidative burst, (iii) the identical pharmacological profile of kinase activation and oxidant production for 13 commonly used inhibitors, and (iv) the autologous activation of both kinases and oxidant production by calyculin A and cantharidin, two phosphatase inhibitors. Immunological and biochemical studies reveal that the activated 44 kDa and 47 kDa kinases are mitogen-activated protein (MAP) kinase family members. The kinases prefer myelin basic protein as a substrate, and they phosphorylate primarily on threonine residues. The kinases are themselves phosphorylated on tyrosine residues, and this phosphorylation is required for activity. Finally, both kinases are recognized by an antibody against activated MAP kinase immediately after (but not before) cell stimulation by elicitors. Based on these and other observations, a preliminary sequence of signalling steps linking elicitor stimulation, kinase activation and Ca(2+) entry, to initiation of oxidant production, is proposed.
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Affiliation(s)
- A T Taylor
- Department of Chemistry, Purdue University, 1393 Brown Building, West Lafayette, IN 47907-1393, USA
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Mockaitis K, Howell SH. Auxin induces mitogenic activated protein kinase (MAPK) activation in roots of Arabidopsis seedlings. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:785-796. [PMID: 11135112 DOI: 10.1046/j.1365-313x.2000.00921.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Genome analyses have shown that plants contain gene families encoding various components of mitogen-activated protein kinase (MAPK) signaling pathways. Previous reports have described the involvement of MAPK pathways in stress and pathogen responses of leaves and suspension-cultured cells. Here we show that auxin treatment of Arabidopsis roots transiently induced increases in protein kinase activity with characteristics of mammalian ERK-like MAPKs. The MAPK response we monitored was the result of hormonal action of biologically active auxin, rather than a stress response provoked by auxin-like compounds. Auxin-induced MAPK pathway signaling was distinguished genetically in the Arabidopsis auxin response mutant axr4, in which MAPK activation by auxin, but not by salt stress, was significantly impaired. Perturbation of MAPK signaling in roots using inhibitors of a mammalian MAPKK blocked auxin-activated transgene expression in BA3-GUS seedlings, while potentiating higher than normal levels of MAPK activation in response to auxin. Data presented here indicate that MAPK pathway signaling is positively involved in auxin response, and further suggest that interactions among MAPK signaling pathways in plants influence plant responses to auxin.
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Affiliation(s)
- K Mockaitis
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
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38
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Mockaitis K, Howell SH. Auxin induces mitogenic activated protein kinase (MAPK) activation in roots of Arabidopsis seedlings. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:785-796. [PMID: 11135112 DOI: 10.1111/j.1365-313x.2000.00921.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Genome analyses have shown that plants contain gene families encoding various components of mitogen-activated protein kinase (MAPK) signaling pathways. Previous reports have described the involvement of MAPK pathways in stress and pathogen responses of leaves and suspension-cultured cells. Here we show that auxin treatment of Arabidopsis roots transiently induced increases in protein kinase activity with characteristics of mammalian ERK-like MAPKs. The MAPK response we monitored was the result of hormonal action of biologically active auxin, rather than a stress response provoked by auxin-like compounds. Auxin-induced MAPK pathway signaling was distinguished genetically in the Arabidopsis auxin response mutant axr4, in which MAPK activation by auxin, but not by salt stress, was significantly impaired. Perturbation of MAPK signaling in roots using inhibitors of a mammalian MAPKK blocked auxin-activated transgene expression in BA3-GUS seedlings, while potentiating higher than normal levels of MAPK activation in response to auxin. Data presented here indicate that MAPK pathway signaling is positively involved in auxin response, and further suggest that interactions among MAPK signaling pathways in plants influence plant responses to auxin.
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Affiliation(s)
- K Mockaitis
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
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Felix G, Regenass M, Boller T. Sensing of osmotic pressure changes in tomato cells. PLANT PHYSIOLOGY 2000; 124:1169-80. [PMID: 11080294 PMCID: PMC59216 DOI: 10.1104/pp.124.3.1169] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2000] [Accepted: 07/07/2000] [Indexed: 05/23/2023]
Abstract
Cells of tomato (Lycopersicon esculentum) growing in suspension gradually depleted their culture medium and caused a steady decrease in its osmolality. When confronted with a sudden change in medium osmolality (a hypo-osmotic or hyperosmotic shock), respectively, these cells responded with volume changes and stress symptoms such as rapid extracellular alkalinization, efflux of K(+)-ions, and induction of 1-aminocyclopropane-1-carboxylate synthase acid, the key enzyme of ethylene biosynthesis. This array of stress symptoms is well known from cultured plant cells treated with microbial elicitors. Compared with elicitor treatment, induction of responses by hyperosmotic shock was slow and occurred only after increases of approximately 200,000 Pa in osmotic pressure. In contrast, hypo-osmotic shock induced responses without measurable lag and faster than elicitor treatments. Measurable medium alkalinization was induced when medium osmolality was reduced by as little as approximately 10 mosmol, a change corresponding to only approximately 0.2 bar in osmotic pressure. Like treatment with elicitors, hypo-osmotic shock induced specific changes in protein phosphorylations as demonstrated by in vivo labeling with [(33)P]orthophosphate. Exposure of cells to consecutive up- and down-shifts in medium osmolality showed that sensing of osmotic changes occurred within seconds, whereas adaptation to new osmotic conditions proceeded over hours. In conclusion, suspension-cultured plant cells display rapid, easily measurable macroscopic responses to osmotic shock and provide an interesting model system to study osmoregulation, a key process in plant growth and development.
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Affiliation(s)
- G Felix
- Friedrich Miescher-Institute, P.O. Box 2543, CH-4002 Basel, Switzerland.
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Droillard MJ, Thibivilliers S, Cazalé AC, Barbier-Brygoo H, Laurière C. Protein kinases induced by osmotic stresses and elicitor molecules in tobacco cell suspensions: two crossroad MAP kinases and one osmoregulation-specific protein kinase. FEBS Lett 2000; 474:217-22. [PMID: 10838088 DOI: 10.1016/s0014-5793(00)01611-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two protein kinases displaying mitogen-activated protein kinase (MAPK) properties are activated both by an hypoosmotic stress and by oligogalacturonides in tobacco cell suspensions [Cazalé et al. (1999) Plant J. 19, 297-307]. Using specific antibodies, they were identified as the salicylic acid-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK). The SIPK was also activated by an hyperosmotic stress, indicating that the same kinase may play a role both in hypo- and hyperosmotic signalling pathways, in addition to its involvement in the transduction of elicitor signals. Using immunoprecipitation followed by two-dimensional in-gel kinase assay, three molecular forms of the SIPK were observed, suggesting that additional modifications of the activated kinase may occur. In contrast to WIPK and SIPK, which are located at the crossroad of several transduction pathways initiated by elicitor or osmotic stimuli, a 44 kDa kinase, that would not belong to the MAPK family, appeared more specific to osmotic stress.
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Affiliation(s)
- M J Droillard
- Institut des Sciences Végétales, UPR 40, CNRS, 1 Av. de la Terrasse, 91198 Cedex, Gif s/Yvette, France
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41
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Hoyos ME, Zhang S. Calcium-independent activation of salicylic acid-induced protein kinase and a 40-kilodalton protein kinase by hyperosmotic stress. PLANT PHYSIOLOGY 2000; 122:1355-63. [PMID: 10759532 PMCID: PMC58971 DOI: 10.1104/pp.122.4.1355] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/1999] [Accepted: 01/04/2000] [Indexed: 05/19/2023]
Abstract
Reversible protein phosphorylation/dephosphorylation plays important roles in signaling the plant adaptive responses to salinity/drought stresses. Two protein kinases with molecular masses of 48 and 40 kD are activated in tobacco cells exposed to NaCl. The 48-kD protein kinase was identified as SIPK (salicylic acid-induced protein kinase), a member of the tobacco MAPK (mitogen-activated protein kinase) family that is activated by various other stress stimuli. The activation of the 40-kD protein kinase is rapid and dose-dependent. Other osmolytes such as Pro and sorbitol activate these two kinases with similar kinetics. The activation of 40-kD protein kinase is specific for hyperosmotic stress, as hypotonic stress does not activate it. Therefore, this 40-kD kinase was named HOSAK (high osmotic stress-activated kinase). HOSAK is a Ca(2+)-independent kinase and uses myelin basic protein (MBP) and histone equally well as substrates. The kinase inhibitor K252a rapidly activates HOSAK in tobacco cells, implicating a dephosphorylation mechanism for HOSAK activation. Activation of both SIPK and HOSAK by high osmotic stress is Ca(2+) and abscisic acid (ABA) independent. Furthermore, mutation in SOS3 locus does not affect the activation of either kinase in Arabidopsis seedlings. These results suggest that SIPK and 40-kD HOSAK are two new components in a Ca(2+)- and ABA-independent pathway that may lead to plant adaptation to hyperosmotic stress.
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Affiliation(s)
- M E Hoyos
- Department of Biochemistry, University of Missouri-Columbia, 117 Schweitzer Hall, Columbia, Missouri 65211, USA
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