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Tang Q, Liu C, Zhong C, Ding J. Crystal Structures of Arabidopsis thaliana Nudix Hydrolase NUDT7 Reveal a Previously Unobserved Conformation. MOLECULAR PLANT 2015; 8:1557-1559. [PMID: 26253775 DOI: 10.1016/j.molp.2015.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 06/30/2015] [Accepted: 07/29/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Qingyu Tang
- National Center for Protein Sciences Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Caifeng Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Chen Zhong
- National Center for Protein Sciences Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Jianping Ding
- National Center for Protein Sciences Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; School of Life Science and Technology, Shanghai Tech University, 319 Yue-Yang Road, Shanghai 200031, China.
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52
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Camañes G, Scalschi L, Vicedo B, González-Bosch C, García-Agustín P. An untargeted global metabolomic analysis reveals the biochemical changes underlying basal resistance and priming in Solanum lycopersicum, and identifies 1-methyltryptophan as a metabolite involved in plant responses to Botrytis cinerea and Pseudomonas syringae. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:125-39. [PMID: 26270176 DOI: 10.1111/tpj.12964] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 07/12/2015] [Accepted: 07/24/2015] [Indexed: 05/03/2023]
Abstract
In this study, we have used untargeted global metabolomic analysis to determine and compare the chemical nature of the metabolites altered during the infection of tomato plants (cv. Ailsa Craig) with Botrytis cinerea (Bot) or Pseudomonas syringae pv. tomato DC3000 (Pst), pathogens that have different invasion mechanisms and lifestyles. We also obtained the metabolome of tomato plants primed using the natural resistance inducer hexanoic acid and then infected with these pathogens. By contrasting the metabolomic profiles of infected, primed, and primed + infected plants, we determined not only the processes or components related directly to plant defense responses, but also inferred the metabolic mechanisms by which pathogen resistance is primed. The data show that basal resistance and hexanoic acid-induced resistance to Bot and Pst are associated with a marked metabolic reprogramming. This includes significant changes in amino acids, sugars and free fatty acids, and in primary and secondary metabolism. Comparison of the metabolic profiles of the infections indicated clear differences, reflecting the fact that the plant's chemical responses are highly adapted to specific attackers. The data also indicate involvement of signaling molecules, including pipecolic and azelaic acids, in response to Pst and, interestingly, to Bot. The compound 1-methyltryptophan was shown to be associated with the tomato-Pst and tomato-Bot interactions as well as with hexanoic acid-induced resistance. Root application of this Trp-derived metabolite also demonstrated its ability to protect tomato plants against both pathogens.
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Affiliation(s)
- Gemma Camañes
- Grup de Bioquímica i Biotecnología, Àrea de Fisiologa Vegetal, Departament de Ciències Agràries y del Medi Natural, Escola Superior de Tecnología i Ciències Experimentals, Universitat Jaume I, Castelló, Spain
| | - Loredana Scalschi
- Grup de Bioquímica i Biotecnología, Àrea de Fisiologa Vegetal, Departament de Ciències Agràries y del Medi Natural, Escola Superior de Tecnología i Ciències Experimentals, Universitat Jaume I, Castelló, Spain
| | - Begonya Vicedo
- Grup de Bioquímica i Biotecnología, Àrea de Fisiologa Vegetal, Departament de Ciències Agràries y del Medi Natural, Escola Superior de Tecnología i Ciències Experimentals, Universitat Jaume I, Castelló, Spain
| | - Carmen González-Bosch
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Instituto de Agroquímica y Tecnología de los Alimentos-Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Pilar García-Agustín
- Grup de Bioquímica i Biotecnología, Àrea de Fisiologa Vegetal, Departament de Ciències Agràries y del Medi Natural, Escola Superior de Tecnología i Ciències Experimentals, Universitat Jaume I, Castelló, Spain
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53
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Kong G, Zhao Y, Jing M, Huang J, Yang J, Xia Y, Kong L, Ye W, Xiong Q, Qiao Y, Dong S, Ma W, Wang Y. The Activation of Phytophthora Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b. PLoS Pathog 2015; 11:e1005139. [PMID: 26317500 PMCID: PMC4552650 DOI: 10.1371/journal.ppat.1005139] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/10/2015] [Indexed: 11/25/2022] Open
Abstract
Plant pathogens secrete an arsenal of effector proteins to impair host immunity. Some effectors possess enzymatic activities that can modify their host targets. Previously, we demonstrated that a Phytophthora sojae RXLR effector Avr3b acts as a Nudix hydrolase when expressed in planta; and this enzymatic activity is required for full virulence of P. sojae strain P6497 in soybean (Glycine max). Interestingly, recombinant Avr3b produced by E. coli does not have the hydrolase activity unless it was incubated with plant protein extracts. Here, we report the activation of Avr3b by a prolyl-peptidyl isomerase (PPIase), cyclophilin, in plant cells. Avr3b directly interacts with soybean cyclophilin GmCYP1, which activates the hydrolase activity of Avr3b in a PPIase activity-dependent manner. Avr3b contains a putative Glycine-Proline (GP) motif; which is known to confer cyclophilin-binding in other protein substrates. Substitution of the Proline (P132) in the putative GP motif impaired the interaction of Avr3b with GmCYP1; as a result, the mutant Avr3bP132A can no longer be activated by GmCYP1, and is also unable to promote Phytophthora infection. Avr3b elicits hypersensitive response (HR) in soybean cultivars producing the resistance protein Rps3b, but Avr3bP132A lost its ability to trigger HR. Furthermore, silencing of GmCYP1 rendered reduced cell death triggered by Avr3b, suggesting that GmCYP1-mediated Avr3b maturation is also required for Rps3b recognition. Finally, cyclophilins of Nicotiana benthamiana can also interact with Avr3b and activate its enzymatic activity. Overall, our results demonstrate that cyclophilin is a "helper" that activates the enzymatic activity of Avr3b after it is delivered into plant cells; as such, cyclophilin is required for the avirulence and virulence functions of Avr3b.
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Affiliation(s)
- Guanghui Kong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yao Zhao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Maofeng Jing
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jie Huang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jin Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yeqiang Xia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Liang Kong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Wenwu Ye
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qin Xiong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yongli Qiao
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, California, United States of America
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Suomeng Dong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Wenbo Ma
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, California, United States of America
| | - Yuanchao Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Xu W, Meng Y, Surana P, Fuerst G, Nettleton D, Wise RP. The knottin-like Blufensin family regulates genes involved in nuclear import and the secretory pathway in barley-powdery mildew interactions. FRONTIERS IN PLANT SCIENCE 2015; 6:409. [PMID: 26089830 PMCID: PMC4454880 DOI: 10.3389/fpls.2015.00409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 05/21/2015] [Indexed: 05/24/2023]
Abstract
Plants have evolved complex regulatory mechanisms to control a multi-layered defense response to microbial attack. Both temporal and spatial gene expression are tightly regulated in response to pathogen ingress, modulating both positive and negative control of defense. BLUFENSINs, small knottin-like peptides in barley, wheat, and rice, are highly induced by attack from fungal pathogens, in particular, the obligate biotrophic fungus, Blumeria graminis f. sp. hordei (Bgh), causal agent of barley powdery mildew. Previous research indicated that Blufensin1 (Bln1) functions as a negative regulator of basal defense mechanisms. In the current report, we show that BLN1 and BLN2 can both be secreted to the apoplast and Barley stripe mosaic virus (BSMV)-mediated overexpression of Bln2 increases susceptibility of barley to Bgh. Bimolecular fluorescence complementation (BiFC) assays signify that BLN1 and BLN2 can interact with each other, and with calmodulin. We then used BSMV-induced gene silencing to knock down Bln1, followed by Barley1 GeneChip transcriptome analysis, to identify additional host genes influenced by Bln1. Analysis of differential expression revealed a gene set enriched for those encoding proteins annotated to nuclear import and the secretory pathway, particularly Importin α1-b and Sec61 γ subunits. Further functional analysis of these two affected genes showed that when silenced, they also reduced susceptibility to Bgh. Taken together, we postulate that Bln1 is co-opted by Bgh to facilitate transport of disease-related host proteins or effectors, influencing the establishment of Bgh compatibility on its barley host.
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Affiliation(s)
- Weihui Xu
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
| | - Yan Meng
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
| | - Priyanka Surana
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Bioinformatics and Computational Biology Graduate Program, Iowa State UniversityAmes, IA, USA
| | - Greg Fuerst
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Corn Insects and Crop Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Iowa State UniversityAmes, IA, USA
| | - Dan Nettleton
- Department of Statistics, Iowa State UniversityAmes, IA, USA
| | - Roger P. Wise
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Corn Insects and Crop Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Iowa State UniversityAmes, IA, USA
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55
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Song J, Keppler BD, Wise RR, Bent AF. PARP2 Is the Predominant Poly(ADP-Ribose) Polymerase in Arabidopsis DNA Damage and Immune Responses. PLoS Genet 2015; 11:e1005200. [PMID: 25950582 PMCID: PMC4423837 DOI: 10.1371/journal.pgen.1005200] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 04/08/2015] [Indexed: 01/09/2023] Open
Abstract
Poly (ADP-ribose) polymerases (PARPs) catalyze the transfer of multiple poly(ADP-ribose) units onto target proteins. Poly(ADP-ribosyl)ation plays a crucial role in a variety of cellular processes including, most prominently, auto-activation of PARP at sites of DNA breaks to activate DNA repair processes. In humans, PARP1 (the founding and most characterized member of the PARP family) accounts for more than 90% of overall cellular PARP activity in response to DNA damage. We have found that, in contrast with animals, in Arabidopsis thaliana PARP2 (At4g02390), rather than PARP1 (At2g31320), makes the greatest contribution to PARP activity and organismal viability in response to genotoxic stresses caused by bleomycin, mitomycin C or gamma-radiation. Plant PARP2 proteins carry SAP DNA binding motifs rather than the zinc finger domains common in plant and animal PARP1 proteins. PARP2 also makes stronger contributions than PARP1 to plant immune responses including restriction of pathogenic Pseudomonas syringae pv. tomato growth and reduction of infection-associated DNA double-strand break abundance. For poly(ADP-ribose) glycohydrolase (PARG) enzymes, we find that Arabidopsis PARG1 and not PARG2 is the major contributor to poly(ADP-ribose) removal from acceptor proteins. The activity or abundance of PARP2 is influenced by PARP1 and PARG1. PARP2 and PARP1 physically interact with each other, and with PARG1 and PARG2, suggesting relatively direct regulatory interactions among these mediators of the balance of poly(ADP-ribosyl)ation. As with plant PARP2, plant PARG proteins are also structurally distinct from their animal counterparts. Hence core aspects of plant poly(ADP-ribosyl)ation are mediated by substantially different enzymes than in animals, suggesting the likelihood of substantial differences in regulation.
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Affiliation(s)
- Junqi Song
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Brian D. Keppler
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Robert R. Wise
- Department of Biology, University of Wisconsin - Oshkosh, Oshkosh, Wisconsin, United States of America
| | - Andrew F. Bent
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
- * E-mail:
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56
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Jayakannan M, Bose J, Babourina O, Shabala S, Massart A, Poschenrieder C, Rengel Z. The NPR1-dependent salicylic acid signalling pathway is pivotal for enhanced salt and oxidative stress tolerance in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1865-75. [PMID: 25614660 PMCID: PMC4378626 DOI: 10.1093/jxb/eru528] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The role of endogenous salicylic acid (SA) signalling cascades in plant responses to salt and oxidative stresses is unclear. Arabidopsis SA signalling mutants, namely npr1-5 (non-expresser of pathogenesis related gene1), which lacks NPR1-dependent SA signalling, and nudt7 (nudix hydrolase7), which has both constitutively expressed NPR1-dependent and NPR1-independent SA signalling pathways, were compared with the wild type (Col-0) during salt or oxidative stresses. Growth and viability staining showed that, compared with wild type, the npr1-5 mutant was sensitive to either salt or oxidative stress, whereas the nudt7 mutant was tolerant. Acute salt stress caused the strongest membrane potential depolarization, highest sodium and proton influx, and potassium loss from npr1-5 roots in comparison with the wild type and nudt7 mutant. Though salt stress-induced hydrogen peroxide production was lowest in the npr1-5 mutant, the reactive oxygen species (ROS) stress (induced by 1mM of hydroxyl-radical-generating copper-ascorbate mix, or either 1 or 10mM hydrogen peroxide) caused a higher potassium loss from the roots of the npr1-5 mutant than the wild type and nudt7 mutant. Long-term salt exposure resulted in the highest sodium and the lowest potassium concentration in the shoots of npr1-5 mutant in comparison with the wild type and nudt7 mutant. The above results demonstrate that NPR1-dependent SA signalling is pivotal to (i) controlling Na(+) entry into the root tissue and its subsequent long-distance transport into the shoot, and (ii) preventing a potassium loss through depolarization-activated outward-rectifying potassium and ROS-activated non-selective cation channels. In conclusion, NPR1-dependent SA signalling is central to the salt and oxidative stress tolerance in Arabidopsis.
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Affiliation(s)
- Maheswari Jayakannan
- School of Earth and Environment, Faculty of Science, University of Western Australia, Crawley WA 6009, Australia School of Land and Food, University of Tasmania, Hobart TAS 7001, Australia School of Biological Sciences, University of Tasmania, Hobart TAS 7001, Australia
| | - Jayakumar Bose
- School of Land and Food, University of Tasmania, Hobart TAS 7001, Australia
| | - Olga Babourina
- School of Earth and Environment, Faculty of Science, University of Western Australia, Crawley WA 6009, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart TAS 7001, Australia
| | - Amandine Massart
- Fisiología Vegetal, Facultad de Biociencias, Universidad Autónoma de Barcelona, E-08193 Bellaterra, Spain Environmental Science and Engineering Section, Ecole Polytechnique Fédérale de Lausanne, CH 1015 Lausanne, Switzerland
| | | | - Zed Rengel
- School of Earth and Environment, Faculty of Science, University of Western Australia, Crawley WA 6009, Australia
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Transcriptome analysis of maize leaf systemic symptom infected by Bipolaris zeicola. PLoS One 2015; 10:e0119858. [PMID: 25781606 PMCID: PMC4363367 DOI: 10.1371/journal.pone.0119858] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 01/16/2015] [Indexed: 11/19/2022] Open
Abstract
Bipolaris zeicola is a fungal pathogen that causes Northern corn leaf spot (NCLS), which is a serious foliar disease in maize and one of the most significant pathogens affecting global food security. Here, we report a genome-wide transcriptional profile analysis using next-generation sequencing (NGS) of maize leaf development after inoculation with B. zeicola. We performed High-Throughput Digital Gene Expression analysis to identify differentially expressed genes (DEGs) in resistant inbred Mo17 lines after infection with B. zeicola at four successive disease development stages--CP (contact period), PP (penetration period), IP (incubation period), and DP (disease period); the expression of the genes was compared with those in a CK (mock-treatment) control. In addition, a sensitive maize line (Zheng58) was used for the comparisons with the Mo17. Among all tested genes, 466 differentially expressed genes were identified in all libraries, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of these genes suggested that they are involved in many biological processes related to systemic symptom development, such as plant hormone signal transduction, starch and sucrose metabolism, phenylpropanoid biosynthesis and photosynthesis. Our systematic analysis provides comprehensive transcriptomic information regarding systemic symptom development in fungal-infected plants. This information will help in furthering our understanding of the detailed mechanisms of plant responses to fungal infection.
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Muthuramalingam M, Zeng X, Iyer NJ, Klein P, Mahalingam R. A GCC-box motif in the promoter of nudix hydrolase 7 (AtNUDT7) gene plays a role in ozone response of Arabidopsis ecotypes. Genomics 2015; 105:31-8. [PMID: 25451743 DOI: 10.1016/j.ygeno.2014.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/15/2014] [Accepted: 10/29/2014] [Indexed: 01/01/2023]
Abstract
Arabidopsis nudix hydrolase 7 (AtNudt7) plays an important role in regulating redox homeostasis during stress/defense signaling and seed germination. The early responsiveness of AtNudt7 provides a useful marker especially during oxidative cell death in plants. Nuclear run-on assays demonstrate that AtNudt7 is transcriptionally regulated. AtNUDT7 promoter-GUS transgenic plants show rapid inducibility in response to ozone and pathogens. A 16-bp insertion containing a GCC-box motif was identified in the promoter of a Ws-2 ecotype and was absent in Col-0. The 16-bp sequence was identified in 5% of the Arabidopsis ecotypes used in the 1001 genome sequencing project. The kinetics of expression of Ethylene Response Factor 1 (ERF1), a GCC-box binding factor is in synchrony with expression of AtNudt7 in response to ozone stress. ERF1 protein binds to the GCC-box motif in the AtNUDT7 promoter. In silico analysis of erf1 mutant and overexpressor lines supports a role for this protein in regulating AtNUDT7 expression.
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Affiliation(s)
| | - Xin Zeng
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Niranjani J Iyer
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Peter Klein
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Ramamurthy Mahalingam
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
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Zeilmaker T, Ludwig NR, Elberse J, Seidl MF, Berke L, Van Doorn A, Schuurink RC, Snel B, Van den Ackerveken G. DOWNY MILDEW RESISTANT 6 and DMR6-LIKE OXYGENASE 1 are partially redundant but distinct suppressors of immunity in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:210-22. [PMID: 25376907 DOI: 10.1111/tpj.12719] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/04/2014] [Accepted: 10/27/2014] [Indexed: 05/19/2023]
Abstract
Arabidopsis downy mildew resistant 6 (dmr6) mutants have lost their susceptibility to the downy mildew Hyaloperonospora arabidopsidis. Here we show that dmr6 is also resistant to the bacterium Pseudomonas syringae and the oomycete Phytophthora capsici. Resistance is accompanied by enhanced defense gene expression and elevated salicylic acid levels. The suppressive effect of the DMR6 oxygenase was confirmed in transgenic Arabidopsis lines overexpressing DMR6 that show enhanced susceptibility to H. arabidopsidis, P. capsici, and P. syringae. Phylogenetic analysis of the superfamily of 2-oxoglutarate Fe(II)-dependent oxygenases revealed a subgroup of DMR6-LIKE OXYGENASEs (DLOs). Within Arabidopsis, DMR6 is most closely related to DLO1 and DLO2. Overexpression of DLO1 and DLO2 in the dmr6 mutant restored the susceptibility to downy mildew indicating that DLOs negatively affect defense, similar to DMR6. DLO1, but not DLO2, is co-expressed with DMR6, showing strong activation during pathogen attack and following salicylic acid treatment. DMR6 and DLO1 differ in their spatial expression pattern in downy mildew-infected Arabidopsis leaves; DMR6 is mostly expressed in cells that are in contact with hyphae and haustoria of H. arabidopsidis, while DLO1 is expressed mainly in the vascular tissues near infection sites. Strikingly, the dmr6-3_dlo1 double mutant, that is completely resistant to H. arabidopsidis, showed a strong growth reduction that was associated with high levels of salicylic acid. We conclude that DMR6 and DLO1 redundantly suppress plant immunity, but also have distinct activities based on their differential localization of expression.
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Affiliation(s)
- Tieme Zeilmaker
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
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60
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Chai T, Zhou J, Liu J, Xing D. LSD1 and HY5 antagonistically regulate red light induced-programmed cell death in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2015; 6:292. [PMID: 25999965 PMCID: PMC4419654 DOI: 10.3389/fpls.2015.00292] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/10/2015] [Indexed: 05/18/2023]
Abstract
Programmed cell death (PCD) in plant is triggered by abiotic and biotic stress. Light-dependent PCD is unique to plants. Light-induced PCD also requires reactive oxygen species (ROS) and salicylic acid (SA). In this study, lesion simulating disease1 (LSD1) and elongated hypocotyl 5 (HY5) perform opposite roles to regulate excess red light (RL)-triggered PCD associated with ROS and SA production. Under RL, the lsd1 mutant released more ROS and SA and displayed a stronger cell death rate than the hy5 mutant. It was shown that active LSD1 converted into inactive form by changing the redox status of the plastoquinone pool, and HY5 interacted with phytochrome B (phyB) to promote PCD in response to RL. LSD1 inhibited the enhanced disease susceptibility 1 (EDS1) expression by upregulating SR1, whereas HY5 enhanced the enhanced EDS1 expression by binding to the G-box of the EDS1 promoter. This study suggested that LSD1 and HY5 antagonistically modulated EDS1-dependent ROS and SA signaling; thus, PCD was mediated in response to RL.
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Affiliation(s)
| | | | | | - Da Xing
- *Correspondence: Da Xing, MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Shipai, Tianhe District, Guangzhou 510631, China
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61
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Yoshimura K, Shigeoka S. Versatile physiological functions of the Nudix hydrolase family in Arabidopsis. Biosci Biotechnol Biochem 2014; 79:354-66. [PMID: 25483172 DOI: 10.1080/09168451.2014.987207] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nudix hydrolases are widely distributed in all kingdoms of life and have the potential to hydrolyze a wide range of organic pyrophosphates, including nucleoside di- and triphosphates, nucleotide coenzymes, nucleotide sugars, and RNA caps. However, except for E. coli MutT and its orthologs in other organisms that sanitize oxidized nucleotides to prevent DNA and RNA mutations, the functions of Nudix hydrolases had largely remained unclear until recently, because many members of this enzyme family exhibited broad substrate specificities. There is now increasing evidence to show that their functions extend into many aspects of the regulation of cellular responses. This review summarizes current knowledge on the molecular and enzymatic properties as well as physiological functions of Arabidopsis Nudix hydrolases. The information presented here may provide novel insights into the physiological roles of these enzymes in not only plant species, but also other organisms.
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Affiliation(s)
- Kazuya Yoshimura
- a Department of Food and Nutritional Science , College of Bioscience and Biotechnology, Chubu University , Kasugai , Japan
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Gao D, Appiano M, Huibers RP, Chen X, Loonen AEHM, Visser RGF, Wolters AMA, Bai Y. Activation tagging of ATHB13 in Arabidopsis thaliana confers broad-spectrum disease resistance. PLANT MOLECULAR BIOLOGY 2014; 86:641-53. [PMID: 25293871 DOI: 10.1007/s11103-014-0253-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/30/2014] [Indexed: 05/21/2023]
Abstract
Powdery mildew species Oidium neolycopersici (On) can cause serious yield losses in tomato production worldwide. Besides on tomato, On is able to grow and reproduce on Arabidopsis. In this study we screened a collection of activation-tagged Arabidopsis mutants and identified one mutant, 3221, which displayed resistance to On, and in addition showed a reduced stature and serrated leaves. Additional disease tests demonstrated that the 3221 mutant exhibited resistance to downy mildew (Hyaloperonospora arabidopsidis) and green peach aphid (Myzus persicae), but retained susceptibility to bacterial pathogen Pseudomonas syringae pv tomato DC3000. The resistance trait and morphological alteration were mutually linked in 3221. Identification of the activation tag insertion site and microarray analysis revealed that ATHB13, a homeodomain-leucine zipper (HD-Zip) transcription factor, was constitutively overexpressed in 3221. Silencing of ATHB13 in 3221 resulted in the loss of both the morphological alteration and resistance, whereas overexpression of the cloned ATHB13 in Col-0 and Col-eds1-2 backgrounds resulted in morphological alteration and resistance. Microarray analysis further revealed that overexpression of ATHB13 influenced the expression of a large number of genes. Previously, it was reported that ATHB13-overexpressing lines conferred tolerance to abiotic stress. Together with our results, it appears that ATHB13 is involved in the crosstalk between abiotic and biotic stress resistance pathways.
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Affiliation(s)
- Dongli Gao
- Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
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63
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Abstract
SIGNIFICANCE Production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) occurs rapidly in response to attempted pathogen invasion of potential host plants. Such reduction-oxidation (redox) changes are sensed and transmitted to engage immune function, including the hypersensitive response, a programmed execution of challenged plant cells. RECENT ADVANCES Pathogen elicitors trigger changes in calcium that are sensed by calmodulin, calmodulin-like proteins, and calcium-dependent protein kinases, which activate ROS and RNS production. The ROS and RNS production is compartmentalized within the cell and occurs through multiple routes. Mitogen-activated protein kinase (MAPK) cascades are engaged upstream and downstream of ROS and nitric oxide (NO) production. NO is increasingly recognized as a key signaling molecule, regulating downstream protein function through S-nitrosylation, the addition of an NO moiety to a reactive cysteine thiol. CRITICAL ISSUES How multiple sources of ROS and RNS are coordinated is unclear. The putative protein sensors that detect and translate fluxes in ROS and RNS into differential gene expression are obscure. Protein tyrosine nitration following reaction of peroxynitrite with tyrosine residues has been proposed as another signaling mechanism or as a marker leading to protein degradation, but the reversibility remains to be established. FUTURE DIRECTIONS Research is needed to identify the full spectrum of NO-modified proteins with special emphasis on redox-activated transcription factors and their cognate target genes. A systems approach will be required to uncover the complexities integral to redox regulation of MAPK cascades, transcription factors, and defense genes through the combined effects of calcium, phosphorylation, S-nitrosylation, and protein tyrosine nitration.
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Affiliation(s)
- Debra E Frederickson Matika
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh , Edinburgh, United Kingdom
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64
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Zeng X, Li YF, Mahalingam R. Arabidopsis nudix hydrolase 7 plays a role in seed germination. PLANTA 2014; 239:1015-1025. [PMID: 24504697 DOI: 10.1007/s00425-014-2035-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/23/2014] [Indexed: 06/03/2023]
Abstract
Arabidopsis nudix hydrolase 7 (Atnudt7) mutants exhibit reduced seed germination phenotype following after-ripening. The role of AtNUDT7 in seeds and during early stages of imbibition was examined. Seeds of Atnudt7-1 and Col-0 following 3 days of imbibition were used to profile changes in NADH- and ADP-ribose pyrophosphohydrolase enzyme activities, expression of nudix family genes closely related to AtNudt7, and AtNUDT7 protein levels. Changes in pyridine nucleotides, phytohormones, reactive oxygen species and poly(ADP-ribose) levels in after-ripened seeds and 1 day after imbibition were also analyzed. Changes in AtNUDT7 gene expression, protein levels and enzyme activities in WT seeds and during early stages of imbibition were correlated. Atnudt7-1 seeds lacked NADH pyrophosphohydrolase activity that led to very high catabolic redox charge. Abscisic acid (ABA) levels were higher in Atnudt7-1 mutant while salicylic acid, gibberellic acid, and reactive oxygen species (ROS) levels were higher in WT seeds. In Atnudt7-1, there was excess ROS accumulation 1 day after imbibition. PAR levels were significantly higher in Atnudt7-1 mutant when compared to WT during imbibition. Based on these observations, we conclude NADH pyrophosphohydrolase activity conferred by AtNUDT7 is important for NAD:NADH homeostasis in seeds. Perturbations to this key redox couple alter ABA and ROS levels in the seeds that in turn lowers germination.
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Affiliation(s)
- Xin Zeng
- Department of Biochemistry and Molecular Biology, 246 Noble Research Center, Oklahoma State University, Stillwater, OK, 74078, USA
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65
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Brosché M, Blomster T, Salojärvi J, Cui F, Sipari N, Leppälä J, Lamminmäki A, Tomai G, Narayanasamy S, Reddy RA, Keinänen M, Overmyer K, Kangasjärvi J. Transcriptomics and functional genomics of ROS-induced cell death regulation by RADICAL-INDUCED CELL DEATH1. PLoS Genet 2014; 10:e1004112. [PMID: 24550736 PMCID: PMC3923667 DOI: 10.1371/journal.pgen.1004112] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 12/02/2013] [Indexed: 11/18/2022] Open
Abstract
Plant responses to changes in environmental conditions are mediated by a network of signaling events leading to downstream responses, including changes in gene expression and activation of cell death programs. Arabidopsis thaliana RADICAL-INDUCED CELL DEATH1 (RCD1) has been proposed to regulate plant stress responses by protein-protein interactions with transcription factors. Furthermore, the rcd1 mutant has defective control of cell death in response to apoplastic reactive oxygen species (ROS). Combining transcriptomic and functional genomics approaches we first used microarray analysis in a time series to study changes in gene expression after apoplastic ROS treatment in rcd1. To identify a core set of cell death regulated genes, RCD1-regulated genes were clustered together with other array experiments from plants undergoing cell death or treated with various pathogens, plant hormones or other chemicals. Subsequently, selected rcd1 double mutants were constructed to further define the genetic requirements for the execution of apoplastic ROS induced cell death. Through the genetic analysis we identified WRKY70 and SGT1b as cell death regulators functioning downstream of RCD1 and show that quantitative rather than qualitative differences in gene expression related to cell death appeared to better explain the outcome. Allocation of plant energy to defenses diverts resources from growth. Recently, a plant response termed stress-induced morphogenic response (SIMR) was proposed to regulate the balance between defense and growth. Using a rcd1 double mutant collection we show that SIMR is mostly independent of the classical plant defense signaling pathways and that the redox balance is involved in development of SIMR. Reactive oxygen species (ROS) are utilized in plants as signaling molecules to regulate development, stress responses and cell death. One extreme form of defense uses programmed cell death (PCD) in a scorched earth strategy to deliberately kill off cells invaded by a pathogen. Compared to animals, the regulation of plant PCD remains largely uncharacterized, particularly with regard to how ROS regulate changes in gene expression leading to PCD. Using comparative transcriptome analysis of mutants deficient in PCD regulation and publicly available cell death microarray data, we show that quantitative rather than qualitative differences in cell death gene expression appear to better explain the cell death response. In a genetic analysis with double mutants we also found the transcription factor WRKY70 and a component of ubiquitin mediated protein degradation, SGT1b, to be involved in regulation of ROS induced PCD.
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Affiliation(s)
- Mikael Brosché
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
- Institute of Technology, University of Tartu, Tartu, Estonia
- * E-mail:
| | - Tiina Blomster
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Jarkko Salojärvi
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Fuqiang Cui
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Nina Sipari
- Department of Biology, University of Eastern Finland, Joensuu, Finland
| | - Johanna Leppälä
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Airi Lamminmäki
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Gloria Tomai
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Shaman Narayanasamy
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Ramesha A. Reddy
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Markku Keinänen
- Department of Biology, University of Eastern Finland, Joensuu, Finland
| | - Kirk Overmyer
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Jaakko Kangasjärvi
- Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland
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66
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Zhang X, Han X, Shi R, Yang G, Qi L, Wang R, Li G. Arabidopsis cysteine-rich receptor-like kinase 45 positively regulates disease resistance to Pseudomonas syringae. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 73:383-91. [PMID: 24215930 DOI: 10.1016/j.plaphy.2013.10.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 10/18/2013] [Indexed: 05/10/2023]
Abstract
Arabidopsis cysteine-rich receptor-like protein kinase 45 (CRK45) was found to be involved in ABA signaling in Arabidopsis thaliana previously. Here, we reported that it also positively regulates disease resistance. The CRK45 overexpression plants increased expression of the defense genes, and enhanced resistance to Pseudomonas syringae whereas the crk45 mutant were more sensitive to P. syringae and weakened expression of the defense genes, compared to the wild type. We also found that treatment with P. syringae leads to a declined expression of CRK45 in the npr1 mutant and the NahG transgenic plants. At the same time, significantly decreased expression of CRK45 transcript in the wrky70 mutant than that in the wild type was also detected. Our results suggested that CRK45 acted as a positive regulator in Arabidopsis disease resistance, and was regulated downstream of NPR1 and WRKY70 at the transcriptional level.
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Affiliation(s)
- Xiujuan Zhang
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China; Inner Mongolia Institute of Biotechnology, Hohhot, Inner Mongolia 010070, PR China.
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67
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Zeier J. New insights into the regulation of plant immunity by amino acid metabolic pathways. PLANT, CELL & ENVIRONMENT 2013; 36:2085-103. [PMID: 23611692 DOI: 10.1111/pce.12122] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/09/2013] [Accepted: 04/14/2013] [Indexed: 05/20/2023]
Abstract
Besides defence pathways regulated by classical stress hormones, distinct amino acid metabolic pathways constitute integral parts of the plant immune system. Mutations in several genes involved in Asp-derived amino acid biosynthetic pathways can have profound impact on plant resistance to specific pathogen types. For instance, amino acid imbalances associated with homoserine or threonine accumulation elevate plant immunity to oomycete pathogens but not to pathogenic fungi or bacteria. The catabolism of Lys produces the immune signal pipecolic acid (Pip), a cyclic, non-protein amino acid. Pip amplifies plant defence responses and acts as a critical regulator of plant systemic acquired resistance, defence priming and local resistance to bacterial pathogens. Asp-derived pyridine nucleotides influence both pre- and post-invasion immunity, and the catabolism of branched chain amino acids appears to affect plant resistance to distinct pathogen classes by modulating crosstalk of salicylic acid- and jasmonic acid-regulated defence pathways. It also emerges that, besides polyamine oxidation and NADPH oxidase, Pro metabolism is involved in the oxidative burst and the hypersensitive response associated with avirulent pathogen recognition. Moreover, the acylation of amino acids can control plant resistance to pathogens and pests by the formation of protective plant metabolites or by the modulation of plant hormone activity.
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Affiliation(s)
- Jürgen Zeier
- Department of Biology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
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68
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Zhang X, Yang G, Shi R, Han X, Qi L, Wang R, Xiong L, Li G. Arabidopsis cysteine-rich receptor-like kinase 45 functions in the responses to abscisic acid and abiotic stresses. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 67:189-98. [PMID: 23583936 DOI: 10.1016/j.plaphy.2013.03.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 03/13/2013] [Indexed: 05/10/2023]
Abstract
The phytohormone abscisic acid (ABA) regulates seed germination, plant growth and development, and response to abiotic stresses such as drought and salt stresses. Receptor-like kinases are well known signaling components that mediate plant responses to developmental and environmental stimuli. Here, we characterized the biological function of an ABA and stress-inducible cysteine-rich receptor-like protein kinase, CRK45, in ABA signaling in Arabidopsis thaliana. The crk45 mutant was less sensitive to ABA than the wild type during seed germination and early seedling development, whereas CRK45 overexpression plants were more sensitive to ABA compared to the wild type. Furthermore, overexpression of CRK45 led to hypersensitivity to salt and glucose inhibition of seed germination, whereas the crk45 mutant showed the opposite phenotypes. In addition, CRK45 overexpression plants had enhanced tolerance to drought. Gene expression analyses revealed that the expression of representative stress-responsive genes was significantly enhanced in CRK45 overexpression plants in response to salt stress. ABA biosynthetic genes such as NCED3,(2)NCED5,(3)ABA2,(4) and AAO3(5) were also constitutively elevated in the CRK45 overexpression plants. We concluded that CRK45 plays an important role in ABA signaling that regulates Arabidopsis seeds germination, early seedling development and abiotic stresses response, by positively regulating ABA responses in these processes.
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Affiliation(s)
- Xiujuan Zhang
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
| | - Guanyu Yang
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
| | - Rui Shi
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
| | - Xiaomin Han
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
| | - Liwang Qi
- The Research Institute of Forestry, The Chinese Academy of Forestry, Beijing 100091, PR China.
| | - Ruigang Wang
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
| | - Liming Xiong
- Plant Stress Genomics Research Center, Division of Chemical and Life Sciences & Engineering, 4700 King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Guojing Li
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, PR China.
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69
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Zhang XC, Li MY, Ruan MB, Xia YJ, Wu KX, Peng M. Isolation of AtNUDT5 gene promoter and characterization of its activity in transgenic Arabidopsis thaliana. Appl Biochem Biotechnol 2013; 169:1557-65. [PMID: 23322251 DOI: 10.1007/s12010-012-0071-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 12/26/2012] [Indexed: 11/25/2022]
Abstract
AtNUDT5 is a cytosol Nudix that catalyzes the hydrolysis of a variety of substrates. In this report, a 1,387-bp 5'-flanking region of the AtNUDT5 gene was isolated from Arabidopsis thaliana. The tissue-specific activity of the 5'-flanking region was investigated by using the GUS gene as a reporter in transgenic A. thaliana plants. Weak GUS activity appeared in vascular tissues of young plants, strong GUS activity appeared in the axial roots, but no GUS activity was observed in the root cap, lateral roots, rosette leaf, mature silique and reproductive tissues such as stamen, pistil, and petal. Furthermore, by using these transgenic A. thaliana plants, results of the histochemical staining and fluorometric assays of GUS activity showed that the AtNUDT5 promoter can be activated by both avirulent Pst avrRpm1 and virulent Pst strains at 5 h post-infiltration and that the activity of AtNUDT5 promoter increased significantly at 24 h post-infiltration. Taken together, our results demonstrated that the AtNUDT5 promoter is pathogen-responsive. The promoter may be used to develop transgenic plants with an increased tolerance to pathogenic stresses.
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Affiliation(s)
- Xiu-Chun Zhang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, XueYuan Rd 4, Longhua District, Haikou, Hainan, People's Republic of China 571101
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70
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Pétriacq P, de Bont L, Tcherkez G, Gakière B. NAD: not just a pawn on the board of plant-pathogen interactions. PLANT SIGNALING & BEHAVIOR 2013; 8:e22477. [PMID: 23104110 PMCID: PMC3745554 DOI: 10.4161/psb.22477] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/06/2012] [Accepted: 10/08/2012] [Indexed: 05/18/2023]
Abstract
Many metabolic processes that occur in living cells involve oxido-reduction (redox) chemistry underpinned by redox compounds such as glutathione, ascorbate and/or pyridine nucleotides. Among these redox carriers, nicotinamide adenine dinucleotide (NAD) is the cornerstone of cellular oxidations along catabolism and is therefore essential for plant growth and development. In addition to its redox role, there is now compelling evidence that NAD is a signal molecule controlling crucial functions like primary and secondary carbon metabolism. Recent studies using integrative -omics approaches combined with molecular pathology have shown that manipulating NAD biosynthesis and recycling lead to an alteration of metabolites pools and developmental processes, and changes in the resistance to various pathogens. NAD levels should now be viewed as a potential target to improve tolerance to biotic stress and crop improvement. In this paper, we review the current knowledge on the key role of NAD (and its metabolism) in plant responses to pathogen infections.
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Affiliation(s)
- Pierre Pétriacq
- Institut de Biologie des Plantes; CNRS UMR 8618; Université Paris-Sud; Orsay, France
| | - Linda de Bont
- Institut de Biologie des Plantes; CNRS UMR 8618; Université Paris-Sud; Orsay, France
| | - Guillaume Tcherkez
- Institut de Biologie des Plantes; CNRS UMR 8618; Université Paris-Sud; Orsay, France
- Institut Universitaire de France; Paris, France
| | - Bertrand Gakière
- Institut de Biologie des Plantes; CNRS UMR 8618; Université Paris-Sud; Orsay, France
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71
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Bhadauria V, Banniza S, Vandenberg A, Selvaraj G, Wei Y. Overexpression of a novel biotrophy-specific Colletotrichum truncatum effector, CtNUDIX, in hemibiotrophic fungal phytopathogens causes incompatibility with their host plants. EUKARYOTIC CELL 2013; 12:2-11. [PMID: 22962277 PMCID: PMC3535838 DOI: 10.1128/ec.00192-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 09/01/2012] [Indexed: 11/20/2022]
Abstract
The hemibiotrophic fungus Colletotrichum truncatum causes anthracnose disease on lentils and a few other grain legumes. It shows initial symptomless intracellular growth, where colonized host cells remain viable (biotrophy), and then switches to necrotrophic growth, killing the colonized host plant tissues. Here, we report a novel effector gene, CtNUDIX, from C. truncatum that is exclusively expressed during the late biotrophic phase (before the switch to necrotrophy) and elicits a hypersensitive response (HR)-like cell death in tobacco leaves transiently expressing the effector. CtNUDIX homologs, which contain a signal peptide and a Nudix hydrolase domain, may be unique to hemibiotrophic fungal and fungus-like plant pathogens. CtNUDIX lacking a signal peptide or a Nudix motif failed to induce cell death in tobacco. Expression of CtNUDIX:eGFP in tobacco suggested that the fusion protein might act on the host cell plasma membrane. Overexpression of CtNUDIX in C. truncatum and the rice blast pathogen, Magnaporthe oryzae, resulted in incompatibility with the hosts lentil and barley, respectively, by causing an HR-like response in infected host cells associated with the biotrophic invasive hyphae. These results suggest that C. truncatum and possibly M. oryzae elicit cell death to signal the transition from biotrophy to necrotrophy.
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Affiliation(s)
- Vijai Bhadauria
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
- Crop Development Centre, University of Saskatchewan, Saskatoon, Canada
| | - Sabine Banniza
- Crop Development Centre, University of Saskatchewan, Saskatoon, Canada
| | - Albert Vandenberg
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Gopalan Selvaraj
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
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72
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Wang H, Lu Y, Liu P, Wen W, Zhang J, Ge X, Xia Y. The ammonium/nitrate ratio is an input signal in the temperature-modulated, SNC1-mediated and EDS1-dependent autoimmunity of nudt6-2 nudt7. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 73:262-75. [PMID: 23004358 DOI: 10.1111/tpj.12032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/03/2012] [Accepted: 09/12/2012] [Indexed: 05/27/2023]
Abstract
AtNUDT7 was reported to be a negative regulator of EDS1-mediated immunity in Arabidopsis. However, the underlying molecular and genetic mechanism of the AtNUDT7-regulated defense pathway remains elusive. Here we report that AtNUDT7 and its closest paralog AtNUDT6 function as novel negative regulators of SNC1, a TIR-NB-LRR-type R gene. SNC1 is upregulated at transcriptional and possibly post-transcriptional levels in nudt6-2 nudt7. The nudt6-2 nudt7 double mutant exhibits autoimmune phenotypes that are modulated by temperature and fully dependent on EDS1. The nudt6-2 nudt7 mutation causes EDS1 nuclear accumulation shortly after the establishment of autoimmunity caused by the temperature shift. We found that a low ammonium/nitrate ratio in growth media leads to a higher level of nitrite-dependent nitric oxide (NO) production in nudt6-2 nudt7, and NO acts in a positive feedback loop with EDS1 to promote the autoimmunity. The low ammonium/nitrate ratio also enhances autoimmunity in snc1-1 and cpr1, two other autoimmune mutants in Arabidopsis. Our study indicates that Arabidopsis senses the ammonium/nitrate ratio as an input signal to determine the amplitude of the EDS1-mediated defense response, probably through the modulation of NO production.
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Affiliation(s)
- Hai Wang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
- State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry and Molecular Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Yuqing Lu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Pei Liu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Wei Wen
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jianhua Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Xiaochun Ge
- State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry and Molecular Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
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73
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Xing JH, Weng QY, Hao CC, Jia J, Kou HM, Han JM, Dong JG. T1N6_22 gene is required for biotic and abiotic stress responses in Arabidopsis. RUSS J GENET+ 2012. [DOI: 10.1134/s1022795412120162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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74
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Sun A, Nie S, Xing D. Nitric oxide-mediated maintenance of redox homeostasis contributes to NPR1-dependent plant innate immunity triggered by lipopolysaccharides. PLANT PHYSIOLOGY 2012; 160:1081-96. [PMID: 22926319 PMCID: PMC3461531 DOI: 10.1104/pp.112.201798] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/26/2012] [Indexed: 05/19/2023]
Abstract
The perception of lipopolysaccharides (LPS) by plant cells can lead to nitric oxide (NO) production and defense gene induction. However, the signaling cascades underlying these cellular responses have not yet been resolved. This work investigated the biosynthetic origin of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) to gain insight into the mechanism involved in LPS-induced resistance of Arabidopsis (Arabidopsis thaliana). Analysis of inhibitors and mutants showed that LPS-induced NO synthesis was mainly mediated by an arginine-utilizing source of NO generation. Furthermore, LPS-induced NO caused transcript accumulation of alternative oxidase genes and increased antioxidant enzyme activity, which enhanced antioxidant capacity and modulated redox state. We also analyzed the subcellular localization of NPR1 to identify the mechanism for protein-modulated plant innate immunity triggered by LPS. LPS-activated defense responses, including callose deposition and defense-related gene expression, were found to be regulated through an NPR1-dependent pathway. In summary, a significant NO synthesis induced by LPS contributes to the LPS-induced defense responses by up-regulation of defense genes and modulation of cellular redox state. Moreover, NPR1 plays an important role in LPS-triggered plant innate immunity.
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Affiliation(s)
| | | | - Da Xing
- Corresponding author; e-mail
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75
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Macho AP, Boutrot F, Rathjen JP, Zipfel C. Aspartate oxidase plays an important role in Arabidopsis stomatal immunity. PLANT PHYSIOLOGY 2012; 159:1845-56. [PMID: 22730426 PMCID: PMC3425217 DOI: 10.1104/pp.112.199810] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 06/21/2012] [Indexed: 05/18/2023]
Abstract
Perception of pathogen-associated molecular patterns (PAMPs), such as bacterial flagellin (or the peptide flg22), by surface-localized receptors activates defense responses and subsequent immunity. In a previous forward-genetic screen aimed at the identification of Arabidopsis (Arabidopsis thaliana) flagellin-insensitive (fin) mutants, we isolated fin4, which is severely affected in flg22-triggered reactive oxygen species (ROS) bursts. Here, we report that FIN4 encodes the chloroplastic enzyme ASPARTATE OXIDASE (AO), which catalyzes the first irreversible step in the de novo biosynthesis of NAD. Genetic studies on the role of NAD have been hindered so far by the lethality of null mutants in NAD biosynthetic enzymes. Using newly identified knockdown fin alleles, we found that AO is required for the ROS burst mediated by the NADPH oxidase RBOHD triggered by the perception of several unrelated PAMPs. AO is also required for RBOHD-dependent stomatal closure. However, full AO activity is not required for flg22-induced responses that are RBOHD independent. Interestingly, although the fin4 mutation dramatically affects RBOHD function, it does not affect functions carried out by other members of the RBOH family, such as RBOHC and RBOHF. Finally, we determined that AO is required for stomatal immunity against the bacterium Pseudomonas syringae. Altogether, our work reveals a novel specific requirement for AO activity in PAMP-triggered RBOHD-dependent ROS burst and stomatal immunity. In addition, the availability of viable mutants for the chloroplastic enzyme AO will enable future detailed studies on the role of NAD metabolism in different cellular processes, including immunity, in Arabidopsis.
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76
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Wan D, Li R, Zou B, Zhang X, Cong J, Wang R, Xia Y, Li G. Calmodulin-binding protein CBP60g is a positive regulator of both disease resistance and drought tolerance in Arabidopsis. PLANT CELL REPORTS 2012; 31:1269-81. [PMID: 22466450 DOI: 10.1007/s00299-012-1247-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 03/10/2012] [Accepted: 03/15/2012] [Indexed: 05/19/2023]
Abstract
UNLABELLED Calmodulin-binding proteins (CBPs) have been known to be involved in both biotic and abiotic stress responses. Recently, two closely related CBPs, Arabidopsis SAR Deficient 1 and CBP60g, were found to belong to a new family of transcription factors that regulate salicylic acid (SA) biosynthesis triggered by microbe-associated molecular patterns. In this study, we found that overexpression of CBP60g in Arabidopsis caused elevated SA accumulation, increased expression of the defense genes, and enhanced resistance to Pseudomonas syringae. In addition to the enhanced defense response, the CBP60g overexpression lines showed hypersensitivity to abscisic acid (ABA) and enhanced tolerance to drought stress. We also found that treatment with ABA and drought stress leads to a higher expression level of the ICS1 gene, which encodes isochorismate synthase, in the CBP60g overexpression lines than in the wild-type control plants. Our results suggest that CBP60g serves as a molecular link that positively regulates ABA- and SA-mediated pathways in plants. KEY MESSAGE Overexpression of CBP60g in Arabidopsis enhanced the defense response, hypersensitivity to abscisic acid and tolerance to drought stress.
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Affiliation(s)
- Dongli Wan
- College of Life Sciences, Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China
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77
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Pétriacq P, de Bont L, Hager J, Didierlaurent L, Mauve C, Guérard F, Noctor G, Pelletier S, Renou JP, Tcherkez G, Gakière B. Inducible NAD overproduction in Arabidopsis alters metabolic pools and gene expression correlated with increased salicylate content and resistance to Pst-AvrRpm1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:650-65. [PMID: 22268572 DOI: 10.1111/j.1365-313x.2012.04920.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plant development and function are underpinned by redox reactions that depend on co-factors such as nicotinamide adenine dinucleotide (NAD). NAD has recently been shown to be involved in several signalling pathways that are associated with stress tolerance or defence responses. However, the mechanisms by which NAD influences plant gene regulation, metabolism and physiology still remain unclear. Here, we took advantage of Arabidopsis thaliana lines that overexpressed the nadC gene from E. coli, which encodes the NAD biosynthesis enzyme quinolinate phosphoribosyltransferase (QPT). Upon incubation with quinolinate, these lines accumulated NAD and were thus used as inducible systems to determine the consequences of an increased NAD content in leaves. Metabolic profiling showed clear changes in several metabolites such as aspartate-derived amino acids and NAD-derived nicotinic acid. Large-scale transcriptomic analyses indicated that NAD promoted the induction of various pathogen-related genes such as the salicylic acid (SA)-responsive defence marker PR1. Extensive comparison with transcriptomic databases further showed that gene expression under high NAD content was similar to that obtained under biotic stress, eliciting conditions or SA treatment. Upon inoculation with the avirulent strain of Pseudomonas syringae pv. tomato Pst-AvrRpm1, the nadC lines showed enhanced resistance to bacteria infection and exhibited an ICS1-dependent build-up of both conjugated and free SA pools. We therefore concluded that higher NAD contents are beneficial for plant immunity by stimulating SA-dependent signalling and pathogen resistance.
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Affiliation(s)
- Pierre Pétriacq
- Institut de Biologie des Plantes, CNRS UMR 8618, Bâtiment 630, Université Paris-Sud 11, Orsay Cedex, France.
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78
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Linka N, Esser C. Transport proteins regulate the flux of metabolites and cofactors across the membrane of plant peroxisomes. FRONTIERS IN PLANT SCIENCE 2012; 3:3. [PMID: 22645564 PMCID: PMC3355763 DOI: 10.3389/fpls.2012.00003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 01/03/2012] [Indexed: 05/18/2023]
Abstract
In land plants, peroxisomes play key roles in various metabolic pathways, including the most prominent examples, that is lipid mobilization and photorespiration. Given the large number of substrates that are exchanged across the peroxisomal membrane, a wide spectrum of metabolite and cofactor transporters is required and needs to be efficiently coordinated. These peroxisomal transport proteins are a prerequisite for metabolic reactions inside plant peroxisomes. The entire peroxisomal "permeome" is closely linked to the adaption of photosynthetic organisms during land plant evolution to fulfill and optimize their new metabolic demands in cells, tissues, and organs. This review assesses for the first time the distribution of these peroxisomal transporters within the algal and plant species underlining their evolutionary relevance. Despite the importance of peroxisomal transporters, the majority of these proteins, however, are still unknown at the molecular level in plants as well as in other eukaryotic organisms. Four transport proteins have been recently identified and functionally characterized in Arabidopsis so far: one transporter for the import of fatty acids and three carrier proteins for the uptake of the cofactors ATP and NAD into plant peroxisomes. The transport of the three substrates across the peroxisomal membrane is essential for the degradation of fatty acids and fatty acids-related compounds via β-oxidation. This metabolic pathway plays multiple functions for growth and development in plants that have been crucial in land plant evolution. In this review, we describe the current state of their physiological roles in Arabidopsis and discuss novel features in their putative transport mechanisms.
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Affiliation(s)
- Nicole Linka
- Department of Plant Biochemistry, Heinrich Heine UniversityDüsseldorf, Germany
| | - Christian Esser
- Department of Bioinformatics, Heinrich Heine UniversityDüsseldorf, Germany
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79
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Lamb RS, Citarelli M, Teotia S. Functions of the poly(ADP-ribose) polymerase superfamily in plants. Cell Mol Life Sci 2012; 69:175-89. [PMID: 21861184 PMCID: PMC11114847 DOI: 10.1007/s00018-011-0793-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 08/02/2011] [Accepted: 08/04/2011] [Indexed: 01/09/2023]
Abstract
Poly(ADP-ribosyl)ation is the covalent attachment of ADP-ribose subunits from NAD(+) to target proteins and was first described in plants in the 1970s. This post-translational modification is mediated by poly(ADP-ribose) polymerases (PARPs) and removed by poly(ADP-ribose) glycohydrolases (PARGs). PARPs have important functions in many biological processes including DNA repair, epigenetic regulation and transcription. However, these roles are not always associated with enzymatic activity. The PARP superfamily has been well studied in animals, but remains under-investigated in plants. Although plants lack the variety of PARP superfamily members found in mammals, they do encode three different types of PARP superfamily proteins, including a group of PARP-like proteins, the SRO family, that are plant specific. In plants, members of the PARP family and/or poly(ADP-ribosyl)ation have been linked to DNA repair, mitosis, innate immunity and stress responses. In addition, members of the SRO family have been shown to be necessary for normal sporophytic development. In this review, we summarize the current state of plant research into poly(ADP-ribosyl)ation and the PARP superfamily in plants.
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Affiliation(s)
- Rebecca S Lamb
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, 43210, USA.
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80
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Bernhardt K, Wilkinson S, Weber APM, Linka N. A peroxisomal carrier delivers NAD⁺ and contributes to optimal fatty acid degradation during storage oil mobilization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:1-13. [PMID: 21895810 DOI: 10.1111/j.1365-313x.2011.04775.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The existence of a transport protein that imports cytosolic NAD(+) into peroxisomes has been controversially discussed for decades. Nevertheless, the biosynthesis of NAD(+) in the cytosol necessitates the import of NAD(+) into peroxisomes for numerous reduction/oxidation (redox) reactions. However, a gene encoding such a transport system has not yet been identified in any eukaryotic organism. Here, we describe the peroxisomal NAD(+) carrier in Arabidopsis. Our candidate gene At2g39970 encodes for a member of the mitochondrial carrier family. We confirmed its peroxisomal localization using fluorescence microscopy. For a long time At2g39970 was assumed to represent the peroxisomal ATP transporter. In this study, we could show that the recombinant protein mediated the transport of NAD(+) . Hence, At2g39970 was named PXN for peroxisomal NAD(+) carrier. The loss of PXN in Arabidopsis causes defects in NAD(+) -dependent β-oxidation during seedling establishment. The breakdown of fatty acid released from storage oil was delayed, which led to the retention of oil bodies in pxn mutant seedlings. Based on our results, we propose that PXN delivers NAD(+) for optimal fatty acid degradation during storage oil mobilization.
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Affiliation(s)
- Kristin Bernhardt
- Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
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81
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Dong S, Yin W, Kong G, Yang X, Qutob D, Chen Q, Kale SD, Sui Y, Zhang Z, Dou D, Zheng X, Gijzen M, M. Tyler B, Wang Y. Phytophthora sojae avirulence effector Avr3b is a secreted NADH and ADP-ribose pyrophosphorylase that modulates plant immunity. PLoS Pathog 2011; 7:e1002353. [PMID: 22102810 PMCID: PMC3213090 DOI: 10.1371/journal.ppat.1002353] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 09/19/2011] [Indexed: 11/18/2022] Open
Abstract
Plants have evolved pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) to protect themselves from infection by diverse pathogens. Avirulence (Avr) effectors that trigger plant ETI as a result of recognition by plant resistance (R) gene products have been identified in many plant pathogenic oomycetes and fungi. However, the virulence functions of oomycete and fungal Avr effectors remain largely unknown. Here, we combined bioinformatics and genetics to identify Avr3b, a new Avr gene from Phytophthora sojae, an oomycete pathogen that causes soybean root rot. Avr3b encodes a secreted protein with the RXLR host-targeting motif and C-terminal W and Nudix hydrolase motifs. Some isolates of P. sojae evade perception by the soybean R gene Rps3b through sequence mutation in Avr3b and lowered transcript accumulation. Transient expression of Avr3b in Nicotiana benthamiana increased susceptibility to P. capsici and P. parasitica, with significantly reduced accumulation of reactive oxygen species (ROS) around invasion sites. Biochemical assays confirmed that Avr3b is an ADP-ribose/NADH pyrophosphorylase, as predicted from the Nudix motif. Deletion of the Nudix motif of Avr3b abolished enzyme activity. Mutation of key residues in Nudix motif significantly impaired Avr3b virulence function but not the avirulence activity. Some Nudix hydrolases act as negative regulators of plant immunity, and thus Avr3b might be delivered into host cells as a Nudix hydrolase to impair host immunity. Avr3b homologues are present in several sequenced Phytophthora genomes, suggesting that Phytophthora pathogens might share similar strategies to suppress plant immunity.
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Affiliation(s)
- Suomeng Dong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing, China
| | - Weixiao Yin
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guanghui Kong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Xinyu Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Dinah Qutob
- Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Qinghe Chen
- Virginia Bioinformatics Institute, Blacksburg, Virginia, United States of America
| | - Shiv D. Kale
- Virginia Bioinformatics Institute, Blacksburg, Virginia, United States of America
| | - Yangyang Sui
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhengguang Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing, China
| | - Daolong Dou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing, China
| | - Xiaobo Zheng
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing, China
| | - Mark Gijzen
- Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Brett M. Tyler
- Virginia Bioinformatics Institute, Blacksburg, Virginia, United States of America
| | - Yuanchao Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing, China
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82
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Prasath D, El-Sharkawy I, Sherif S, Tiwary KS, Jayasankar S. Cloning and characterization of PR5 gene from Curcuma amada and Zingiber officinale in response to Ralstonia solanacearum infection. PLANT CELL REPORTS 2011; 30:1799-809. [PMID: 21594675 DOI: 10.1007/s00299-011-1087-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 04/18/2011] [Accepted: 05/06/2011] [Indexed: 05/30/2023]
Abstract
Ginger (Zingiber officinale Roscoe), is an important spice crop that is badly affected by Ralstonia solanacearum wilt. Ginger does not set seed and sexual recombination has never been reported. In spite of extensive search in its habitats, no resistance source to Ralstonia induced bacterial wilt, could be located in ginger. Curcuma amada Roxb. is a potential donor for bacterial wilt resistance to Z. officinale, if the exact mechanism of resistance is understood. Pathogenesis-related (PR)-5 proteins are a family of proteins that are induced by different phytopathogens in many plants and share significant sequence similarity with thaumatin. Two putative PR5 genes, CaPR5 and ZoPR5, were amplified from C. amada and ginger, which encode precursor proteins of 227 and 224 amino acid residues, respectively, and share high homology with a number of other PR5 genes. The secondary and three-dimensional structure comparison did not reveal any striking differences between these two proteins. The expression of Ca and ZoPR5s under R. solanacearum inoculation was analyzed at different time points using quantitative real-time PCR (qRT-PCR). Our results reveal that CaPR5 is readily induced by the bacterium in C. amada, while ZoPR5 induction was very weak and slow in ginger. These results suggest that the CaPR5 could play a role in the molecular defense response of C. amada to pathogen attack. This is the first report of the isolation of PR5 gene from the C. amada and Z. officinale. Promoter analysis indicates the presence of a silencing element binding factor in ZoPR5-promoter, but not in CaPR5. Prospective promoter elements, such as GT-1 box and TGTCA, implicated as being positive regulatory elements for expression of PR proteins, occur in the 5'-flanking sequences of the CaPR5. Transient GUS expression study confirms its action with a weaker GUS expression in ginger, indicating that the PR5 expression may be controlled in the promoter.
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Affiliation(s)
- D Prasath
- Department of Plant Agriculture, University of Guelph, 4890 Victoria Ave. N., P.O. Box 7000, Vineland Station, ON, L0R 2E0, Canada
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83
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Briggs AG, Bent AF. Poly(ADP-ribosyl)ation in plants. TRENDS IN PLANT SCIENCE 2011; 16:372-80. [PMID: 21482174 DOI: 10.1016/j.tplants.2011.03.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Revised: 03/07/2011] [Accepted: 03/09/2011] [Indexed: 05/03/2023]
Abstract
Poly(ADP-ribose) polymerases (PARPs) and poly(ADP-ribose) glycohydrolases (PARGs) are the main enzymes responsible for the post-translational modification known as poly(ADP-ribosyl)ation. These enzymes play important roles in genotoxic stress tolerance and DNA repair, programmed cell death, transcription, and cell cycle control in animals. Similar impacts are being discovered in plants, as well as roles in plant-specific processes. In particular, we review recent work that has revealed significant roles for poly(ADP-ribosyl)ation in plant responses to biotic and abiotic stress, as well as roles for ADP-ribose pyrophosphatases (a subset of the nucleoside diphosphate linked to some moiety-X or NUDX hydrolases). Future challenges include identification of poly(ADP-ribosyl)ation targets and interacting proteins, improved use of inhibitors and plant mutants, and field-based studies with economically valuable plant species.
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Affiliation(s)
- Amy G Briggs
- Program in Cellular and Molecular Biology, University of Wisconsin - Madison, WI, USA
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84
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Liu G, Ji Y, Bhuiyan NH, Pilot G, Selvaraj G, Zou J, Wei Y. Amino acid homeostasis modulates salicylic acid-associated redox status and defense responses in Arabidopsis. THE PLANT CELL 2010; 22:3845-63. [PMID: 21097712 PMCID: PMC3015111 DOI: 10.1105/tpc.110.079392] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 09/13/2010] [Accepted: 10/28/2010] [Indexed: 05/17/2023]
Abstract
The tight association between nitrogen status and pathogenesis has been broadly documented in plant-pathogen interactions. However, the interface between primary metabolism and disease responses remains largely unclear. Here, we show that knockout of a single amino acid transporter, LYSINE HISTIDINE TRANSPORTER1 (LHT1), is sufficient for Arabidopsis thaliana plants to confer a broad spectrum of disease resistance in a salicylic acid-dependent manner. We found that redox fine-tuning in photosynthetic cells was causally linked to the lht1 mutant-associated phenotypes. Furthermore, the enhanced resistance in lht1 could be attributed to a specific deficiency of its main physiological substrate, Gln, and not to a general nitrogen deficiency. Thus, by enabling nitrogen metabolism to moderate the cellular redox status, a plant primary metabolite, Gln, plays a crucial role in plant disease resistance.
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Affiliation(s)
- Guosheng Liu
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Yuanyuan Ji
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Nazmul H. Bhuiyan
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Guillaume Pilot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Gopalan Selvaraj
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Jitao Zou
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
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85
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Han GW, Bakolitsa C, Miller MD, Kumar A, Carlton D, Najmanovich RJ, Abdubek P, Astakhova T, Axelrod HL, Chen C, Chiu HJ, Clayton T, Das D, Deller MC, Duan L, Ernst D, Feuerhelm J, Grant JC, Grzechnik A, Jaroszewski L, Jin KK, Johnson HA, Klock HE, Knuth MW, Kozbial P, Krishna SS, Marciano D, McMullan D, Morse AT, Nigoghossian E, Okach L, Reyes R, Rife CL, Sefcovic N, Tien HJ, Trame CB, van den Bedem H, Weekes D, Xu Q, Hodgson KO, Wooley J, Elsliger MA, Deacon AM, Godzik A, Lesley SA, Wilson IA. Structures of the first representatives of Pfam family PF06938 (DUF1285) reveal a new fold with repeated structural motifs and possible involvement in signal transduction. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:1218-25. [PMID: 20944214 PMCID: PMC2954208 DOI: 10.1107/s1744309109050416] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 11/23/2009] [Indexed: 11/14/2022]
Abstract
The crystal structures of SPO0140 and Sbal_2486 were determined using the semiautomated high-throughput pipeline of the Joint Center for Structural Genomics (JCSG) as part of the NIGMS Protein Structure Initiative (PSI). The structures revealed a conserved core with domain duplication and a superficial similarity of the C-terminal domain to pleckstrin homology-like folds. The conservation of the domain interface indicates a potential binding site that is likely to involve a nucleotide-based ligand, with genome-context and gene-fusion analyses additionally supporting a role for this family in signal transduction, possibly during oxidative stress.
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Affiliation(s)
- Gye Won Han
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Constantina Bakolitsa
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Mitchell D. Miller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Abhinav Kumar
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dennis Carlton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Rafael J. Najmanovich
- Département de Biochimie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke (Quebec), Canada
| | - Polat Abdubek
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Tamara Astakhova
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Herbert L. Axelrod
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Connie Chen
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Hsiu-Ju Chiu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Thomas Clayton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Debanu Das
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Marc C. Deller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lian Duan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Dustin Ernst
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Julie Feuerhelm
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Joanna C. Grant
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Anna Grzechnik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lukasz Jaroszewski
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Kevin K. Jin
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Hope A. Johnson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Heath E. Klock
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Mark W. Knuth
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Piotr Kozbial
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - S. Sri Krishna
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - David Marciano
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Daniel McMullan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Andrew T. Morse
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Edward Nigoghossian
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Linda Okach
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ron Reyes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Christopher L. Rife
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Natasha Sefcovic
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Henry J. Tien
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Christine B. Trame
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Henry van den Bedem
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dana Weekes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Qingping Xu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Keith O. Hodgson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - John Wooley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Marc-André Elsliger
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ashley M. Deacon
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Adam Godzik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Scott A. Lesley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ian A. Wilson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
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86
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Jambunathan N, Penaganti A, Tang Y, Mahalingam R. Modulation of redox homeostasis under suboptimal conditions by Arabidopsis nudix hydrolase 7. BMC PLANT BIOLOGY 2010; 10:173. [PMID: 20704736 PMCID: PMC3095304 DOI: 10.1186/1471-2229-10-173] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 08/12/2010] [Indexed: 05/06/2023]
Abstract
BACKGROUND Nudix hydrolases play a key role in maintaining cellular homeostasis by hydrolyzing various nuceloside diphosphate derivatives and capped mRNAs. Several independent studies have demonstrated that Arabidopsis nudix hydrolase 7 (AtNUDT7) hydrolyzes NADH and ADP-ribose. Loss of function Atnudt7-1 mutant plants (SALK_046441) exhibit stunted growth, higher levels of reactive oxygen species, enhanced resistance to pathogens. However, using the same T-DNA line, two other groups reported that mutant plants do not exhibit any visible phenotypes. In this study we analyze plausible factors that account for differences in the observed phenotypes in Atnudt7. Secondly, we evaluate the biochemical and molecular consequences of increased NADH levels due to loss of function of AtNUDT7 in Arabidopsis. RESULTS We identified a novel conditional phenotype of Atnudt7-1 knockout plants that was contingent upon nutrient composition of potting mix. In nutrient-rich Metro-Mix, there were no phenotypic differences between mutant and wild-type (WT) plants. In the nutrient-poor mix (12 parts vermiculite: 3 parts Redi-earth and 1 part sand), mutant plants showed the characteristic stunted phenotype. Compared with WT plants, levels of glutathione, NAD+, NADH, and in turn NADH:NAD+ ratio were higher in Atnudt7-1 plants growing in 12:3:1 potting mix. Infiltrating NADH and ADP-ribose into WT leaves was sufficient to induce AtNUDT7 protein. Constitutive over-expression of AtNudt7 did not alter NADH levels or resistance to pathogens. Transcriptome analysis identified nearly 700 genes differentially expressed in the Atnudt7-1 mutant compared to WT plants grown in 12:3:1 potting mix. In the Atnudt7-1 mutant, genes associated with defense response, proteolytic activities, and systemic acquired resistance were upregulated, while gene ontologies for transcription and phytohormone signaling were downregulated. CONCLUSIONS Based on these observations, we conclude that the differences observed in growth phenotypes of the Atnudt7-1 knockout mutants can be due to differences in the nutrient composition of potting mix. Our data suggests AtNUDT7 plays an important role in maintaining redox homeostasis, particularly for maintaining NADH:NAD+ balance for normal growth and development. During stress conditions, rapid induction of AtNUDT7 is important for regulating the activation of stress/defense signaling and cell death pathways.
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Affiliation(s)
- Niranjani Jambunathan
- 246 Noble Research Center, Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Anuradha Penaganti
- 246 Noble Research Center, Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Yuhong Tang
- The Samuel Roberts Noble Foundation Inc., Plant Biology Division, Ardmore, Oklahoma, USA
| | - Ramamurthy Mahalingam
- 246 Noble Research Center, Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, USA
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87
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Ishikawa K, Yoshimura K, Ogawa T, Shigeoka S. Distinct regulation of Arabidopsis ADP-ribose/NADH pyrophosphohydrolases, AtNUDX6 and 7, in biotic and abiotic stress responses. PLANT SIGNALING & BEHAVIOR 2010; 5:839-41. [PMID: 20448465 PMCID: PMC3014534 DOI: 10.4161/psb.5.7.11820] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Accepted: 03/12/2010] [Indexed: 05/21/2023]
Abstract
Among Arabidopsis Nudix hydrolases (AtNUDX1~27), AtNUDX6 and AtNUDX7 having ADP-ribose/NADH pyrophosphohydrolase activities have been found to contribute to keeping the energy and redox homeostasis, and/or modulating defense responses against biotic and abiotic stress. Interestingly, AtNUDX6 had an opposite effect to AtNUDX7 on the regulation of immune responses. A comparison of the activities of ADP-ribose/NADH pyrophosphohydrolase among wild-type, knockout (KO)-AtNUDX6, and KO-AtNUDX7 plants revealed AtNUDX7 to contribute more than AtNUDX6 to the total pyrophosphohydrolase activity toward both ADP-ribose and NADH under normal conditions and oxidative stress, while AtNUDX6 accounted for the majority of total NADH pyrophosphohydrolase activity under salicylic acid treatment. These results support the idea that the metabolism of ADP-ribose and/or NADH needs to be finely tuned for accurate regulation of cellular responses to biotic and abiotic stress.
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Affiliation(s)
- Kazuya Ishikawa
- Department of Advanced Bioscience; Faculty of Agriculture; Kinki University; Nakamachi, Nara Japan
| | - Kazuya Yoshimura
- Department of Food and Nutritional Science; College of Bioscience and Biotechnology; Chubu University; Kasugai, Aichi Japan
| | - Takahisa Ogawa
- Department of Advanced Bioscience; Faculty of Agriculture; Kinki University; Nakamachi, Nara Japan
| | - Shigeru Shigeoka
- Department of Advanced Bioscience; Faculty of Agriculture; Kinki University; Nakamachi, Nara Japan
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88
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Bartsch M, Bednarek P, Vivancos PD, Schneider B, von Roepenack-Lahaye E, Foyer CH, Kombrink E, Scheel D, Parker JE. Accumulation of isochorismate-derived 2,3-dihydroxybenzoic 3-O-beta-D-xyloside in arabidopsis resistance to pathogens and ageing of leaves. J Biol Chem 2010; 285:25654-65. [PMID: 20538606 DOI: 10.1074/jbc.m109.092569] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
An intricate network of hormone signals regulates plant development and responses to biotic and abiotic stress. Salicylic acid (SA), derived from the shikimate/isochorismate pathway, is a key hormone in resistance to biotrophic pathogens. Several SA derivatives and associated modifying enzymes have been identified and implicated in the storage and channeling of benzoic acid intermediates or as bioactive molecules. However, the range and modes of action of SA-related metabolites remain elusive. In Arabidopsis, Enhanced Disease Susceptibility 1 (EDS1) promotes SA-dependent and SA-independent responses in resistance against pathogens. Here, we used metabolite profiling of Arabidopsis wild type and eds1 mutant leaf extracts to identify molecules, other than SA, whose accumulation requires EDS1 signaling. Nuclear magnetic resonance and mass spectrometry of isolated and purified compounds revealed 2,3-dihydroxybenzoic acid (2,3-DHBA) as an isochorismate-derived secondary metabolite whose accumulation depends on EDS1 in resistance responses and during ageing of plants. 2,3-DHBA exists predominantly as a xylose-conjugated form (2-hydroxy-3-beta-O-D-xylopyranosyloxy benzoic acid) that is structurally distinct from known SA-glucose conjugates. Analysis of DHBA accumulation profiles in various Arabidopsis mutants suggests an enzymatic route to 2,3-DHBA synthesis that is under the control of EDS1. We propose that components of the EDS1 pathway direct the generation or stabilization of 2,3-DHBA, which as a potentially bioactive molecule is sequestered as a xylose conjugate.
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Affiliation(s)
- Michael Bartsch
- Department of Plant-Microbe Interactions, Max-Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829 Cologne, Germany
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89
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Straus MR, Rietz S, Ver Loren van Themaat E, Bartsch M, Parker JE. Salicylic acid antagonism of EDS1-driven cell death is important for immune and oxidative stress responses in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 62:628-40. [PMID: 20163553 DOI: 10.1111/j.1365-313x.2010.04178.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Reactive oxygen species (ROS) have emerged as signals in the responses of plants to stress. Arabidopsis Enhanced Disease Susceptibility1 (EDS1) regulates defense and cell death against biotrophic pathogens and controls cell death propagation in response to chloroplast-derived ROS. Arabidopsis Nudix hydrolase7 (nudt7) mutants are sensitized to photo-oxidative stress and display EDS1-dependent enhanced resistance, salicylic acid (SA) accumulation and initiation of cell death. Here we explored the relationship between EDS1, EDS1-regulated SA and ROS by examining gene expression profiles, photo-oxidative stress and resistance phenotypes of nudt7 mutants in combination with eds1 and the SA-biosynthetic mutant, sid2. We establish that EDS1 controls steps downstream of chloroplast-derived O(2)(*-) that lead to SA-assisted H(2)O(2) accumulation as part of a mechanism limiting cell death. A combination of EDS1-regulated SA-antagonized and SA-promoted processes is necessary for resistance to host-adapted pathogens and for a balanced response to photo-oxidative stress. In contrast to SA, the apoplastic ROS-producing enzyme NADPH oxidase RbohD promotes initiation of cell death during photo-oxidative stress. Thus, chloroplastic O(2)(*-) signals are processed by EDS1 to produce counter-balancing activities of SA and RbohD in the control of cell death. Our data strengthen the idea that EDS1 responds to the status of O(2)(*-) or O(2)(*-)-generated molecules to coordinate cell death and defense outputs. This activity may enable the plant to respond flexibly to different biotic and abiotic stresses in the environment.
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Affiliation(s)
- Marco R Straus
- Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829 Köln, Germany
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90
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Xie YD, Li W, Guo D, Dong J, Zhang Q, Fu Y, Ren D, Peng M, Xia Y. The Arabidopsis gene SIGMA FACTOR-BINDING PROTEIN 1 plays a role in the salicylate- and jasmonate-mediated defence responses. PLANT, CELL & ENVIRONMENT 2010; 33:828-39. [PMID: 20040062 PMCID: PMC3208021 DOI: 10.1111/j.1365-3040.2009.02109.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The chloroplast-localized SIB1 protein was previously identified by its interaction with SIGMA FACTOR 1 (SIG1), a component of the RNA polymerase machinery responsible for transcription of plastid genes. The physiological function of SIB1 is little known. We found that expression of SIB1 is induced by infection with Pseudomonas syringae, suggesting its possible involvement in the defence response. The sib1 loss-of-function mutation compromises induction of some defence-related genes triggered by pathogen infection and the treatments with salicylic acid (SA) and jasmonic acid (JA), two key signalling molecules in the defence response. Conversely, constitutive over-expression of SIB1 causes the plants to hyper-activate defence-related genes following pathogen infection or the SA and JA treatments, leading to enhanced resistance to infection by P. syringae. SIB1 is a member of the large plant-specific VQ motif-containing protein family, and might act as a link to connect defence signalling with chloroplast function.
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Affiliation(s)
- Y-D Xie
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China
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91
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Ishikawa K, Yoshimura K, Harada K, Fukusaki E, Ogawa T, Tamoi M, Shigeoka S. AtNUDX6, an ADP-ribose/NADH pyrophosphohydrolase in Arabidopsis, positively regulates NPR1-dependent salicylic acid signaling. PLANT PHYSIOLOGY 2010; 152:2000-12. [PMID: 20181750 PMCID: PMC2850003 DOI: 10.1104/pp.110.153569] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 02/21/2010] [Indexed: 05/19/2023]
Abstract
Here, we investigated the physiological role of Arabidopsis (Arabidopsis thaliana) AtNUDX6, the gene encoding ADP-ribose (Rib)/NADH pyrophosphohydrolase, using its overexpressor (Pro35S:AtNUDX6) or disruptant (KO-nudx6). The level of NADH in Pro35S:AtNUDX6 and KO-nudx6 plants was decreased and increased, respectively, compared with that of the control plants, while the level of ADP-Rib was not changed in either plant. The activity of pyrophosphohydrolase toward NADH was enhanced and reduced in the Pro35S:AtNUDX6 and KO-nudx6 plants, respectively. The decrease in the activity of NADH pyrophosphohydrolase and the increase in the level of NADH were observed in the rosette and cauline leaves, but not in the roots, of the KO-nudx6 plants. Notably, the expression level of AtNUDX6 and the activity of NADH pyrophosphohydrolase in the control plants, but not in the KO-nudx6 plants, were increased by the treatment with salicylic acid (SA). The expression of SA-induced genes (PR1, WRKY70, NIMIN1, and NIMIN2) depending on NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1), a key component required for pathogen resistance, was significantly suppressed and enhanced in the KO-nudx6 and Pro35S:AtNUDX6 plants, respectively, under the treatment with SA. Induction of thioredoxin h5 (TRX-h5) expression, which catalyzes a SA-induced NPR1 activation, was suppressed and accelerated in the KO-nudx6 and Pro35S:AtNUDX6 plants, respectively. The expression of isochorismate synthase1, required for the regulation of SA synthesis through the NPR1-mediated feedback loop, was decreased and increased in the KO-nudx6 and Pro35S:AtNUDX6 plants, respectively. Judging from seed germination rates, the KO-nudx6 plants had enhanced sensitivity to the toxicity of high-level SA. These results indicated that AtNUDX6 is a modulator of NADH rather than ADP-Rib metabolism and that, through induction of TRX-h5 expression, AtNUDX6 significantly impacts the plant immune response as a positive regulator of NPR1-dependent SA signaling pathways.
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Affiliation(s)
| | | | | | | | | | | | - Shigeru Shigeoka
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, Nara 631–8505, Japan (K.I., T.O., M.T., S.S.); Department of Food and Nutritional Science, College of Bioscience and Biotechnology, Chubu University, Aichi 487–8501, Japan (K.Y.); and Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka 565–0871, Japan (K.H., E.F.)
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92
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Adams-Phillips L, Briggs AG, Bent AF. Disruption of poly(ADP-ribosyl)ation mechanisms alters responses of Arabidopsis to biotic stress. PLANT PHYSIOLOGY 2010; 152:267-80. [PMID: 19889874 PMCID: PMC2799362 DOI: 10.1104/pp.109.148049] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 10/30/2009] [Indexed: 05/03/2023]
Abstract
Poly(ADP-ribosyl)ation is a posttranslational protein modification in which ADP-ribose (ADP-Rib) units derived from NAD(+) are attached to proteins by poly(ADP-Rib) polymerase (PARP) enzymes. ADP-Rib groups are removed from these polymer chains by the enzyme poly(ADP-Rib) glycohydrolase (PARG). In animals, poly(ADP-ribosyl)ation is associated with DNA damage responses and programmed cell death. Previously, we hypothesized a role for poly(ADP-ribosyl)ation in plant defense responses when we detected defense-associated expression of the poly(ADP-ribosyl)ation-related genes PARG2 and NUDT7 and observed altered callose deposition in the presence of a chemical PARP inhibitor. The role of poly(ADP-ribosyl)ation in plant defenses was more extensively investigated in this study, using Arabidopsis (Arabidopsis thaliana). Pharmacological inhibition of PARP using 3-aminobenzamide perturbs certain innate immune responses to microbe-associated molecular patterns (flg22 and elf18), including callose deposition, lignin deposition, pigment accumulation, and phenylalanine ammonia lyase activity, but does not disrupt other responses, such as the initial oxidative burst and expression of some early defense-associated genes. Mutant parg1 seedlings exhibit exaggerated seedling growth inhibition and pigment accumulation in response to elf18 and are hypersensitive to the DNA-damaging agent mitomycin C. Both parg1 and parg2 knockout plants show accelerated onset of disease symptoms when infected with Botrytis cinerea. Cellular levels of ADP-Rib polymer increase after infection with avirulent Pseudomonas syringae pv tomato DC3000 avrRpt2(+), and pathogen-dependent changes in the poly(ADP-ribosyl)ation of discrete proteins were also observed. We conclude that poly(ADP-ribosyl)ation is a functional component in plant responses to biotic stress.
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Affiliation(s)
| | | | - Andrew F. Bent
- Department of Plant Pathology (L.A.-P., A.G.B., A.F.B.) and Program in Cellular and Molecular Biology (A.G.B.), University of Wisconsin, Madison, Wisconsin 53706
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93
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Ishikawa K, Ogawa T, Hirosue E, Nakayama Y, Harada K, Fukusaki E, Yoshimura K, Shigeoka S. Modulation of the poly(ADP-ribosyl)ation reaction via the Arabidopsis ADP-ribose/NADH pyrophosphohydrolase, AtNUDX7, is involved in the response to oxidative stress. PLANT PHYSIOLOGY 2009; 151:741-54. [PMID: 19656905 PMCID: PMC2754630 DOI: 10.1104/pp.109.140442] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2009] [Accepted: 08/03/2009] [Indexed: 05/18/2023]
Abstract
Here, we assessed modulation of the poly(ADP-ribosyl)ation (PAR) reaction by an Arabidopsis (Arabidopsis thaliana) ADP-ribose (Rib)/NADH pyrophosphohydrolase, AtNUDX7 (for Arabidopsis Nudix hydrolase 7), in AtNUDX7-overexpressed (Pro(35S):AtNUDX7) or AtNUDX7-disrupted (KO-nudx7) plants under normal conditions and oxidative stress caused by paraquat treatment. Levels of NADH and ADP-Rib were decreased in the Pro(35S):AtNUDX7 plants but increased in the KO-nudx7 plants under normal conditions and oxidative stress compared with the control plants, indicating that AtNUDX7 hydrolyzes both ADP-Rib and NADH as physiological substrates. The Pro(35S):AtNUDX7 and KO-nudx7 plants showed increased and decreased tolerance, respectively, to oxidative stress compared with the control plants. Levels of poly(ADP-Rib) in the Pro(35S):AtNUDX7 and KO-nudx7 plants were markedly higher and lower, respectively, than those in the control plants. Depletion of NAD(+) and ATP resulting from the activation of the PAR reaction under oxidative stress was completely suppressed in the Pro(35S):AtNUDX7 plants. Accumulation of NAD(+) and ATP was observed in the KO-nudx7- and 3-aminobenzamide-treated plants, in which the PAR reaction was suppressed. The expression levels of DNA repair factors, AtXRCC1 and AtXRCC2 (for x-ray repair cross-complementing factors 1 and 2), paralleled that of AtNUDX7 under both normal conditions and oxidative stress, although an inverse correlation was observed between the levels of AtXRCC3, AtRAD51 (for Escherichia coli RecA homolog), AtDMC1 (for disrupted meiotic cDNA), and AtMND1 (for meiotic nuclear divisions) and AtNUDX7. These findings suggest that AtNUDX7 controls the balance between NADH and NAD(+) by NADH turnover under normal conditions. Under oxidative stress, AtNUDX7 serves to maintain NAD(+) levels by supplying ATP via nucleotide recycling from free ADP-Rib molecules and thus regulates the defense mechanisms against oxidative DNA damage via modulation of the PAR reaction.
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Affiliation(s)
- Kazuya Ishikawa
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, Nara 631-8505, Japan
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94
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Wang Y, Liu R, Chen L, Wang Y, Liang Y, Wu X, Li B, Wu J, Liang Y, Wang X, Zhang C, Wang Q, Hong X, Dong H. Nicotiana tabacum TTG1 contributes to ParA1-induced signalling and cell death in leaf trichomes. J Cell Sci 2009; 122:2673-85. [PMID: 19596794 DOI: 10.1242/jcs.049023] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Leaf trichomes serve as a physical barrier and can also secrete antimicrobial compounds to protect plants from attacks by insects and pathogens. Besides the use of the physical and chemical mechanisms, leaf trichomes might also support plant responses by communicating the extrinsic cues to plant intrinsic signalling pathways. Here we report a role of leaf trichomes in tobacco (Nicotiana tabacum) hypersensitive cell death (HCD) induced by ParA1, an elicitin protein from a plant-pathogenic oomycete. After localized treatment with ParA1, reactive oxygen species were produced first in the leaf trichomes and then in mesophylls. Reactive oxygen species are a group of intracellular signals that are crucial for HCD to develop and for cells to undergo cell death subsequent to chromatin condensation, a hallmark of HCD. These events were impaired when the production of hydrogen peroxide (H(2)O(2)) was inhibited by catalase or a NADPH-oxidase inhibitor applied to trichomes, suggesting the importance of H(2)O(2) in the pathway of HCD signal transduction from the trichomes to mesophylls. This pathway was no longer activated when leaf trichomes were treated with C51S, a ParA1 mutant protein defective in its interaction with N. tabacum TTG1 (NtTTG1), which is a trichome protein that binds ParA1, rather than C51S, in vitro and in trichome cells. The ParA1-NtTTG1 interaction and the HCD pathway were also abrogated when NtTTG1 was silenced in the trichomes. These observations suggest that NtTTG1 plays an essential role in HCD signal transduction from leaf trichomes to mesophylls.
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Affiliation(s)
- Yunpeng Wang
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of P.R. China, Nanjing Agricultural University, Nanjing 210095, China
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95
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Zhu H, Li GJ, Ding L, Cui X, Berg H, Assmann SM, Xia Y. Arabidopsis extra large G-protein 2 (XLG2) interacts with the Gbeta subunit of heterotrimeric G protein and functions in disease resistance. MOLECULAR PLANT 2009; 2:513-25. [PMID: 19825634 PMCID: PMC2902900 DOI: 10.1093/mp/ssp001] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 01/05/2009] [Indexed: 05/21/2023]
Abstract
Heterotrimeric GTP-binding proteins, which consist of Galpha, Gbeta, and Ggamma subunits, play important roles in transducing extracellular signals perceived by cell surface receptors into intracellular physiological responses. In addition to a single prototypical Galpha protein (GPA1), Arabidopsis has three unique Galpha-like proteins, known as XLG1, XLG2, and XLG3, that have been found to be localized in nuclei, although their functions and mode of action remain largely unknown. Through a transcriptomic analysis, we found that XLG2 and XLG3 were rapidly induced by infection with the bacterial pathogen Pseudomonas syringae, whereas the XLG1 transcript level was not affected by pathogen infection. A reverse genetic screen revealed that the xlg2 loss-of-function mutation causes enhanced susceptibility to P. syringae. Transcriptome profiling revealed that the xlg2 mutation affects pathogen-triggered induction of a small set of defense-related genes. However, xlg1 and xlg3 mutants showed no difference from wild-type plants in resistance to P. syringae. In addition, the xlg2 xlg3 double mutant and the xlg1 xlg2 xlg3 triple mutant were not significantly different from the xlg2 single mutant in the disease resistance phenotype, suggesting that the roles of XLG1 and XLG3 in defense, if any, are less significant than for XLG2. Constitutive overexpression of XLG2 leads to the accumulation of abnormal transcripts from multiple defense-related genes. Through co-immunoprecipitation assays, XLG2 was found to interact with AGB1, the sole Gbeta subunit in Arabidopsis, which has previously been found to be a positive regulator in resistance to necrotrophic fungal pathogens. However, no significant difference was found between three xlg single mutants, the xlg2 xlg3 double mutant, the xlg triple mutant, and wild-type plants in resistance to the necrotrophic fungal pathogens Botrytis cinerea or Alternaria brassicicola. These results suggest that XLG2 and AGB1 are components of a G-protein complex different from the prototypical heterotrimeric G-protein and may have distinct functions in modulating defense responses.
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Affiliation(s)
- Huifen Zhu
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA
| | - Guo-Jing Li
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA
- Present address: College of Bioengineering, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China
| | - Lei Ding
- Biology Department, Penn State University, University Park, PA 16802, USA
- Present address: Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Howard Berg
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA
| | - Sarah M. Assmann
- Biology Department, Penn State University, University Park, PA 16802, USA
| | - Yiji Xia
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA
- To whom correspondence should be addressed at the Danforth Center. E-mail , fax (314)587-1561, tel. (314)587-1461
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96
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Mukaihara T, Tamura N. Identification of novel Ralstonia solanacearum type III effector proteins through translocation analysis of hrpB-regulated gene products. MICROBIOLOGY-SGM 2009; 155:2235-2244. [PMID: 19406897 DOI: 10.1099/mic.0.027763-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Hrp type III secretion system (TTSS) is essential for the pathogenicity of Ralstonia solanacearum on host plants. Hrp TTSS is a specialized secretion system that injects virulence proteins, the so-called type III effector proteins, into plant cells. In R. solanacearum, the expression of Hrp TTSS-related genes is regulated by an AraC-type transcriptional activator, HrpB. We have identified 30 hrpB-regulated hpx (hrpB-dependent expression) genes and three well-known hrpB-regulated genes, popA, popB and popC, as candidate effector genes in R. solanacearum strain RS1000. In this study, we newly cloned 11 additional candidate effector genes that share homology with known hpx genes from R. solanacearum RS1000. Using a Cya reporter system, we investigated the translocation of these 44 gene products into plant cells via the Hrp TTSS and identified 34 effector proteins. These include three effector families composed of more than four members, namely the Hpx4, Hpx30 and GALA families. The Hpx30 family effectors are 2200-2500 aa in size and appear to be the largest class of effector proteins among animal- and plant-pathogenic bacteria. Members of this family contain 12-18 tandem repeats of a novel 42 aa motif, designated SKWP repeats.
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Affiliation(s)
- Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama 716-1241, Japan
| | - Naoyuki Tamura
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama 716-1241, Japan
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97
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Abstract
To investigate the proposed role for NAD metabolism in regulating seed dormancy, NAD metabolites and associated enzyme activities were analysed in seed of Arabidopsis thaliana ecotypes ranging from Col-0, which has low seed dormancy, to Cvi, which is highly dormant. Seed poly(ADP-ribosyl)ation levels did not correlate well with the depth of seed dormancy but did correlate with the sensitivity of germination to the DNA damaging agent MMS. Cvi seed had relatively high NAD and low NADP levels compared with the less dormant ecotypes and the NAD : NADP ratios correlated well with dormancy. The activity of NAD kinase was relatively low, and NADP phosphatase was relatively high in dormant Cvi seed, indicating that these enzymes may be involved in controlling the NAD : NADP ratio. Dormant fresh Cvi and nondormant after-ripened Cvi seeds were used to investigate further. Measurement of reduced and oxidised pyridine nucleotides indicated that breaking of dormancy was associated with a reduction in NAD levels but not with an increase in NADP levels. It is proposed that poly(ADP-ribose) polymerase is involved in protecting the seed from genotoxic stress, whereas the level of NAD affects the depth of dormancy, perhaps by enhancing abscisic acid (ABA) synthesis.
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Affiliation(s)
- Lee Hunt
- University of Sheffield, Department of Molecular Biology and Biotechnology, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Julie E Gray
- University of Sheffield, Department of Molecular Biology and Biotechnology, Firth Court, Western Bank, Sheffield S10 2TN, UK
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98
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Meng Y, Moscou MJ, Wise RP. Blufensin1 negatively impacts basal defense in response to barley powdery mildew. PLANT PHYSIOLOGY 2009; 149:271-85. [PMID: 19005086 PMCID: PMC2613711 DOI: 10.1104/pp.108.129031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plants have evolved complex regulatory mechanisms to control the defense response against microbial attack. Both temporal and spatial gene expression are tightly regulated in response to pathogen ingress, modulating both positive and negative control of defense. BLUFENSIN1 (BLN1), a small peptide belonging to a novel family of proteins in barley (Hordeum vulgare), is highly induced by attack from the obligate biotrophic fungus Blumeria graminis f. sp. hordei (Bgh), casual agent of powdery mildew disease. Computational interrogation of the Bln1 gene family determined that members reside solely in the BEP clade of the Poaceae family, specifically, barley, rice (Oryza sativa), and wheat (Triticum aestivum). Barley stripe mosaic virus-induced gene silencing of Bln1 enhanced plant resistance in compatible interactions, regardless of the presence or absence of functional Mla coiled-coil, nucleotide-binding site, Leu-rich repeat alleles, indicating that BLN1 can function in an R-gene-independent manner. Likewise, transient overexpression of Bln1 significantly increased accessibility toward virulent Bgh. Moreover, silencing in plants harboring the Mlo susceptibility factor decreased accessibility to Bgh, suggesting that BLN1 functions in parallel with or upstream of MLO to modulate penetration resistance. Collectively, these data suggest that the grass-specific Bln1 negatively impacts basal defense against Bgh.
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Affiliation(s)
- Yan Meng
- Department of Plant Pathology, Iowa State University, Ames, Iowa 50011-1020, USA
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99
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Ogawa T, Ishikawa K, Harada K, Fukusaki E, Yoshimura K, Shigeoka S. Overexpression of an ADP-ribose pyrophosphatase, AtNUDX2, confers enhanced tolerance to oxidative stress in Arabidopsis plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:289-301. [PMID: 18798872 DOI: 10.1111/j.1365-313x.2008.03686.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Mutant pqr-216 from an Arabidopsis activation-tagged line showed a phenotype of increased tolerance to oxidative stress after treatment with 3 mum paraquat (PQ). Based on the phenotype of transgenic plants overexpressing the genes flanking the T-DNA insert, it was clear that enhanced expression of a Nudix (nucleoside diphosphates linked to some moiety X) hydrolase gene, AtNUDX2 (At5g47650), was responsible for the tolerance. It has been reported that the AtNUDX2 protein has pyrophosphatase activities towards both ADP-ribose and NADH (Ogawa et al., 2005). Interestingly, the pyrophosphatase activity toward ADP-ribose, but not NADH, was increased in pqr-216 and Pro(35S):AtNUDX2 plants compared with control plants. The amount of free ADP-ribose was lower in the Pro(35S):AtNUDX2 plants, while the level of NADH was similar to those in control plants under both normal conditions and oxidative stress. Depletion of NAD(+) and ATP resulting from activation of poly(ADP-ribosyl)ation under oxidative stress was observed in the control Arabidopsis plants. Such alterations in the levels of these molecules were significantly suppressed in the Pro(35S):AtNUDX2 plants. The results indicate that overexpression of AtNUDX2, encoding ADP-ribose pyrophosphatase, confers enhanced tolerance of oxidative stress on Arabidopsis plants, resulting from maintenance of NAD(+) and ATP levels by nucleotide recycling from free ADP-ribose molecules under stress conditions.
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Affiliation(s)
- Takahisa Ogawa
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631 8505, Japan
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100
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Muñoz FJ, Baroja-Fernández E, Ovecka M, Li J, Mitsui T, Sesma MT, Montero M, Bahaji A, Ezquer I, Pozueta-Romero J. Plastidial localization of a potato 'Nudix' hydrolase of ADP-glucose linked to starch biosynthesis. PLANT & CELL PHYSIOLOGY 2008; 49:1734-46. [PMID: 18801762 DOI: 10.1093/pcp/pcn145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Escherichia coli and potato (Solanum tuberosum) ADP-sugar pyrophosphatases (EcASPP and StASPP, respectively) are 'Nudix' hydrolases of the bacterial glycogen and starch precursor molecule, ADP-glucose (ADPG). We have previously shown that potato leaves expressing EcASPP either in the cytosol or in the chloroplast exhibited large reductions in the levels of starch, suggesting the occurrence of cytosolic and plastidial pools of ADPG linked to starch biosynthesis. In this work, we produced and characterized potato and Arabidopsis plants expressing EcASPP and StASPP fused with green fluorescent protein (GFP). Confocal fluorescence microscopy analyses of these plants confirmed that EcASPP-GFP has a cytosolic localization, whereas StASPP-GFP occurs in the plastid stroma. Both source leaves and potato tubers from EcASPP-GFP-expressing plants showed a large reduction of the levels of both ADPG and starch. In contrast, StASPP-GFP-expressing leaves and tubers exhibited reduced starch and normal ADPG contents when compared with control plants. With the exception of starch synthase in StASPP-GFP-expressing plants, no pleiotropic changes in maximum catalytic activities of enzymes closely linked to starch metabolism could be detected in EcASPP-GFP- and StASPP-GFP-expressing plants. The overall data (i) show that potato plants possess a plastidial ASPP that has access to ADPG linked to starch biosynthesis and (ii) are consistent with the occurrence of plastidic and cytosolic pools of ADPG linked to starch biosynthesis.
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Affiliation(s)
- Francisco José Muñoz
- Instituto de Agrobiotecnología, Universidad Pública de Navarra/Consejo Superior de Investigaciones Científicas/Gobierno de Navarra, Mutiloako etorbidea zenbaki gabe, 31192 Mutiloabeti, Nafarroa, Spain
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