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Stael S, Kmiecik P, Willems P, Van Der Kelen K, Coll NS, Teige M, Van Breusegem F. Plant innate immunity--sunny side up? TRENDS IN PLANT SCIENCE 2015; 20:3-11. [PMID: 25457110 PMCID: PMC4817832 DOI: 10.1016/j.tplants.2014.10.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 09/17/2014] [Accepted: 10/02/2014] [Indexed: 05/03/2023]
Abstract
Reactive oxygen species (ROS)- and calcium- dependent signaling pathways play well-established roles during plant innate immunity. Chloroplasts host major biosynthetic pathways and have central roles in energy production, redox homeostasis, and retrograde signaling. However, the organelle's importance in immunity has been somehow overlooked. Recent findings suggest that the chloroplast also has an unanticipated function as a hub for ROS- and calcium-signaling that affects immunity responses at an early stage after pathogen attack. In this opinion article, we discuss a chloroplastic calcium-ROS signaling branch of plant innate immunity. We propose that this chloroplastic branch acts as a light-dependent rheostat that, through the production of ROS, influences the severity of the immune response.
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Affiliation(s)
- Simon Stael
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Department of Medical Protein Research, VIB, 9000 Ghent, Belgium; Department of Biochemistry, Ghent University, 9000 Ghent, Belgium
| | - Przemyslaw Kmiecik
- Department of Ecogenomics and Systems Biology, Vienna University, Vienna, Austria
| | - Patrick Willems
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Department of Medical Protein Research, VIB, 9000 Ghent, Belgium; Department of Biochemistry, Ghent University, 9000 Ghent, Belgium
| | - Katrien Van Der Kelen
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Nuria S Coll
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics, CSIC-IRTA-UAB-UB Consortium, 08193 Barcelona, Spain
| | - Markus Teige
- Department of Ecogenomics and Systems Biology, Vienna University, Vienna, Austria; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Frank Van Breusegem
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
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Ambastha V, Tripathy BC, Tiwari BS. Programmed cell death in plants: A chloroplastic connection. PLANT SIGNALING & BEHAVIOR 2015; 10:e989752. [PMID: 25760871 PMCID: PMC4622501 DOI: 10.4161/15592324.2014.989752] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 11/12/2014] [Accepted: 11/13/2014] [Indexed: 05/18/2023]
Abstract
Programmed cell death (PCD) is an integral cellular program by which targeted cells culminate to demise under certain developmental and pathological conditions. It is essential for controlling cell number, removing unwanted diseased or damaged cells and maintaining the cellular homeostasis. The details of PCD process has been very well elucidated and characterized in animals but similar understanding of the process in plants has not been achieved rather the field is still in its infancy that sees some sporadic reports every now and then. The plants have 2 energy generating sub-cellular organelles- mitochondria and chloroplasts unlike animals that just have mitochondria. The presence of chloroplast as an additional energy transducing and ROS generating compartment in a plant cell inclines to advocate the involvement of chloroplasts in PCD execution process. As chloroplasts are supposed to be progenies of unicellular photosynthetic organisms that evolved as a result of endosymbiosis, the possibility of retaining some of the components involved in bacterial PCD by chloroplasts cannot be ruled out. Despite several excellent reviews on PCD in plants, there is a void on an update of information at a place on the regulation of PCD by chloroplast. This review has been written to provide an update on the information supporting the involvement of chloroplast in PCD process and the possible future course of the field.
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Affiliation(s)
- Vivek Ambastha
- School of Life Sciences; Jawaharlal Nehru University; New Delhi, India
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53
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Geng X, Jin L, Shimada M, Kim MG, Mackey D. The phytotoxin coronatine is a multifunctional component of the virulence armament of Pseudomonas syringae. PLANTA 2014; 240:1149-65. [PMID: 25156488 PMCID: PMC4228168 DOI: 10.1007/s00425-014-2151-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 08/08/2014] [Indexed: 05/20/2023]
Abstract
Plant pathogens deploy an array of virulence factors to suppress host defense and promote pathogenicity. Numerous strains of Pseudomonas syringae produce the phytotoxin coronatine (COR). A major aspect of COR function is its ability to mimic a bioactive jasmonic acid (JA) conjugate and thus target the JA-receptor COR-insensitive 1 (COI1). Biological activities of COR include stimulation of JA-signaling and consequent suppression of SA-dependent defense through antagonistic crosstalk, antagonism of stomatal closure to allow bacterial entry into the interior of plant leaves, contribution to chlorotic symptoms in infected plants, and suppression of plant cell wall defense through perturbation of secondary metabolism. Here, we review the virulence function of COR, including updates on these established activities as well as more recent findings revealing COI1-independent activity of COR and shedding light on cooperative or redundant defense suppression between COR and type III effector proteins.
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Affiliation(s)
- Xueqing Geng
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240 People’s Republic of China
| | - Lin Jin
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
| | - Mikiko Shimada
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
| | - Min Gab Kim
- College of Pharmacy, Research Institute of Pharmaceutical Science, PMBBRC Gyeongsang National University, Jinju daero, Jinju, 660-751 Republic of Korea
| | - David Mackey
- Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210 USA
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210 USA
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54
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Sakuraba Y, Park SY, Kim YS, Wang SH, Yoo SC, Hörtensteiner S, Paek NC. Arabidopsis STAY-GREEN2 is a negative regulator of chlorophyll degradation during leaf senescence. MOLECULAR PLANT 2014; 7:1288-1302. [PMID: 24719469 DOI: 10.1093/mp/ssu045] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Chlorophyll (Chl) degradation causes leaf yellowing during senescence or under stress conditions. For Chl breakdown, STAY-GREEN1 (SGR1) interacts with Chl catabolic enzymes (CCEs) and light-harvesting complex II (LHCII) at the thylakoid membrane, possibly to allow metabolic channeling of potentially phototoxic Chl breakdown intermediates. Among these Chl catabolic components, SGR1 acts as a key regulator of leaf yellowing. In addition to SGR1 (At4g22920), the Arabidopsis thaliana genome contains an additional homolog, SGR2 (At4g11910), whose biological function remains elusive. Under senescence-inducing conditions, SGR2 expression is highly up-regulated, similarly to SGR1 expression. Here we show that SGR2 function counteracts SGR1 activity in leaf Chl degradation; SGR2-overexpressing plants stayed green and the sgr2-1 knockout mutant exhibited early leaf yellowing under age-, dark-, and stress-induced senescence conditions. Like SGR1, SGR2 interacted with LHCII but, in contrast to SGR1, SGR2 interactions with CCEs were very limited. Furthermore, SGR1 and SGR2 formed homo- or heterodimers, strongly suggesting a role for SGR2 in negatively regulating Chl degradation by possibly interfering with the proposed CCE-recruiting function of SGR1. Our data indicate an antagonistic evolution of the functions of SGR1 and SGR2 in Arabidopsis to balance Chl catabolism in chloroplasts with the dismantling and remobilizing of other cellular components in senescing leaf cells.
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Affiliation(s)
- Yasuhito Sakuraba
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - So-Yon Park
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea; Present address: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ye-Sol Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea; Present address: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185, Korea
| | - Seung-Hyun Wang
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Soo-Cheul Yoo
- Department of Plant & Environmental Science, Hankyong National University, Ansung 456-749, Korea
| | | | - Nam-Chon Paek
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
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55
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Abstract
Stay-green (sometimes staygreen) refers to the heritable delayed foliar senescence character in model and crop plant species. In a cosmetic stay-green, a lesion interferes with an early step in chlorophyll catabolism. The possible contribution of synthesis to chlorophyll turnover in cosmetic stay-greens is considered. In functional stay-greens, the transition from the carbon capture period to the nitrogen mobilization (senescence) phase of canopy development is delayed, and/or the senescence syndrome proceeds slowly. Yield and composition in high-carbon (C) crops such as cereals, and in high-nitrogen (N) species such as legumes, reflect the source-sink relationship with canopy C capture and N remobilization. Quantitative trait loci studies show that functional stay-green is a valuable trait for improving crop stress tolerance, and is associated with the domestication syndrome in cereals. Stay-green variants reveal how autumnal senescence and dormancy are coordinated in trees. The stay-green phenotype can be the result of alterations in hormone metabolism and signalling, particularly affecting networks involving cytokinins and ethylene. Members of the WRKY and NAC families, and an ever-expanding cast of additional senescence-associated transcription factors, are identifiable by mutations that result in stay-green. Empirical selection for functional stay-green has contributed to increasing crop yields, particularly where it is part of a strategy that also targets other traits such as sink capacity and environmental sensitivity and is associated with appropriate crop management methodology. The onset and progress of senescence are phenological metrics that show climate change sensitivity, indicating that understanding stay-green can contribute to the design of appropriate crop types for future environments.
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Affiliation(s)
- Howard Thomas
- IBERS, Edward Llwyd Building, Aberystwyth University, Ceredigion SY23 3FG, UK
| | - Helen Ougham
- IBERS, Edward Llwyd Building, Aberystwyth University, Ceredigion SY23 3FG, UK
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Hoeberichts FA, Davoine C, Vandorpe M, Morsa S, Ksas B, Stassen C, Triantaphylidès C, Van Breusegem F. Cryptogein-induced transcriptional reprogramming in tobacco is light dependent. PLANT PHYSIOLOGY 2013; 163:263-75. [PMID: 23878079 PMCID: PMC3762647 DOI: 10.1104/pp.113.217240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 07/02/2013] [Indexed: 05/15/2023]
Abstract
The fungal elicitor cryptogein triggers a light-dependent hypersensitive response in tobacco (Nicotiana tabacum). To assess the effect of light on this nonhost resistance in more detail, we studied various aspects of the response under dark and light conditions using the tobacco-cryptogein experimental system. Here, we show that light drastically alters the plant's transcriptional response to cryptogein, notably by dampening the induction of genes involved in multiple processes, such as ethylene biosynthesis, secondary metabolism, and glutathione turnover. Furthermore, chlorophyll fluorescence measurements demonstrated that quantum yield and functioning of the light-harvesting antennae decreased simultaneously, indicating that photoinhibition underlies the observed decreased photosynthesis and that photooxidative damage might be involved in the establishment of the altered response. Analysis of the isomer distribution of hydroxy fatty acids illustrated that, in the light, lipid peroxidation was predominantly due to the production of singlet oxygen. Differences in (reduced) glutathione concentrations and the rapid development of symptoms in the light when cryptogein was coinfiltrated with glutathione biosynthesis inhibitors suggest that glutathione might become a limiting factor during the cryptogein-induced hypersensitive response in the dark and that this response might be modified by an increased antioxidant availability in the light.
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Affiliation(s)
| | | | - Michaël Vandorpe
- Department of Plant Systems Biology, VIB, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Commissariat à l’Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Biologie Végétale et Microbiologie Environnementale, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.); and
- Université d’Aix Marseille, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
| | | | - Brigitte Ksas
- Department of Plant Systems Biology, VIB, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Commissariat à l’Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Biologie Végétale et Microbiologie Environnementale, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.); and
- Université d’Aix Marseille, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
| | | | - Christian Triantaphylidès
- Department of Plant Systems Biology, VIB, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B–9052 Ghent, Belgium (F.A.H., M.V., S.M., C.S., F.V.B.)
- Commissariat à l’Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Biologie Végétale et Microbiologie Environnementale, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.); and
- Université d’Aix Marseille, F–13108 Saint Paul lez Durance, France (C.D., B.K., C.T.)
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57
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Hörtensteiner S. Update on the biochemistry of chlorophyll breakdown. PLANT MOLECULAR BIOLOGY 2013; 82:505-17. [PMID: 22790503 DOI: 10.1007/s11103-012-9940-z] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 06/28/2012] [Indexed: 05/18/2023]
Abstract
In land plants, chlorophyll is broken down to colorless linear tetrapyrroles in a highly conserved multi-step pathway. The pathway is termed the 'PAO pathway', because the opening of the chlorine macrocycle present in chlorophyll catalyzed by pheophorbide a oxygenase (PAO), the key enzyme of the pathway, provides the characteristic structural basis found in all further downstream chlorophyll breakdown products. To date, most of the biochemical steps of the PAO pathway have been elucidated and genes encoding many of the chlorophyll catabolic enzymes been identified. This review summarizes the current knowledge on the biochemistry of the PAO pathway and provides insight into recent progress made in the field that indicates that the pathway is more complex than thought in the past.
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Affiliation(s)
- Stefan Hörtensteiner
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
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58
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Hu X, Tanaka A, Tanaka R. Simple extraction methods that prevent the artifactual conversion of chlorophyll to chlorophyllide during pigment isolation from leaf samples. PLANT METHODS 2013; 9:19. [PMID: 23783080 PMCID: PMC3698059 DOI: 10.1186/1746-4811-9-19] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/18/2013] [Indexed: 05/24/2023]
Abstract
BACKGROUND When conducting plant research, the measurement of photosynthetic pigments can provide basic information on the physiological status of a plant. High-pressure liquid chromatography (HPLC) is becoming widely used for this purpose because it provides an accurate determination of a variety of photosynthetic pigments simultaneously. This technique has a drawback compared with conventional spectroscopic techniques, however, in that it is more prone to structural modification of pigments during extraction, thus potentially generating erroneous results. During pigment extraction procedures with acetone or alcohol, the phytol side chain of chlorophyll is sometimes removed, forming chlorophyllide, which affects chlorophyll measurement using HPLC. RESULTS We evaluated the artifactual chlorophyllide production during chlorophyll extraction by comparing different extraction methods with wild-type and mutant Arabidopsis leaves that lack the major isoform of chlorophyllase. Several extraction methods were compared to provide alternatives to researchers who utilize HPLC for the analysis of chlorophyll levels. As a result, the following three methods are recommended. In the first method, leaves are briefly boiled prior to extraction. In the second method, grinding and homogenization of leaves are performed at sub-zero temperatures. In the third method, N, N'-dimethylformamide (DMF) is used for the extraction of pigments. When compared, the first two methods eliminated almost all chlorophyllide-forming activity in Arabidopsis thaliana, Glebionis coronaria, Pisum sativum L. and Prunus sargentii Rehd. However, DMF effectively suppressed the activity of chlorophyllase only in Arabidopsis leaves. CONCLUSION Chlorophyllide production in leaf extracts is predominantly an artifact. All three methods evaluated in this study reduce the artifactual production of chlorophyllide and are thus suitable for pigment extraction for HPLC analysis. The boiling method would be a practical choice when leaves are not too thick. However, it may convert a small fraction of chlorophyll a into pheophytin a. Although extraction at sub-zero temperatures is suitable for all plant species examined in this study, this method might be complicated for a large number of samples and it requires liquid nitrogen and equipment for leaf grinding. Using DMF as an extractant is simple and suitable with Arabidopsis samples. However, this solvent cannot completely block the formation of chlorophyllide in thicker leaves.
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Affiliation(s)
- Xueyun Hu
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
- CREST/JST, Hokkaido University, Sapporo, 060-0819, Japan
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
- CREST/JST, Hokkaido University, Sapporo, 060-0819, Japan
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59
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Fischer BB, Hideg É, Krieger-Liszkay A. Production, detection, and signaling of singlet oxygen in photosynthetic organisms. Antioxid Redox Signal 2013; 18:2145-62. [PMID: 23320833 DOI: 10.1089/ars.2012.5124] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
SIGNIFICANCE In photosynthetic organisms, excited chlorophylls (Chl) can stimulate the formation of singlet oxygen ((1)O(2)), a highly toxic molecule that acts in addition to its damaging nature as an important signaling molecule. Thus, due to this dual role of (1)O(2), its production and detoxification have to be strictly controlled. RECENT ADVANCES Regulation of pigment synthesis is essential to control (1)O(2) production, and several components of the Chl synthesis and pigment insertion machineries to assemble and disassemble protein/pigment complexes have recently been identified. Once produced, (1)O(2) activates a signaling cascade from the chloroplast to the nucleus that can involve multiple mechanisms and stimulate a specific gene expression response. Further, (1)O(2) signaling was shown to interact with signal cascades of other reactive oxygen species, oxidized carotenoids, and lipid hydroperoxide-derived reactive electrophile species. CRITICAL ISSUES Despite recent progresses, hardly anything is known about how and where the (1)O(2) signal is sensed and transmitted to the cytoplasm. One reason for that is the limitation of available detection methods challenging the reliable quantification and localization of (1)O(2) in plant cells. In addition, the process of Chl insertion into the reaction centers and antenna complexes is still unclear. FUTURE DIRECTIONS Unraveling the mechanisms controlling (1)O(2) production and signaling would help clarifying the specific role of (1)O(2) in cellular stress responses. It would further enable to investigate the interaction and sensitivity to other abiotic and biotic stress signals and thus allow to better understand why some stressors activate an acclimation, while others provoke a programmed cell death response.
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Affiliation(s)
- Beat B Fischer
- Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
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60
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Zhang YJ, Yang QY, Lee DW, Goldstein G, Cao KF. Extended leaf senescence promotes carbon gain and nutrient resorption: importance of maintaining winter photosynthesis in subtropical forests. Oecologia 2013; 173:721-30. [PMID: 23636462 DOI: 10.1007/s00442-013-2672-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 04/17/2013] [Indexed: 11/26/2022]
Abstract
The relative advantages of being deciduous or evergreen in subtropical forests and the relationship between leaf phenology and nutrient resorption efficiency are not well understood. The most successful deciduous species (Lyonia ovalifolia) in an evergreen-dominated subtropical montane cloud forest in southwest (SW) China maintains red senescing leaves throughout much of the winter. The aim of this study was to investigate whether red senescing leaves of this species were able to assimilate carbon in winter, to infer the importance of maintaining a positive winter carbon balance in subtropical forests, and to test whether an extended leaf life span is associated with enhanced nutrient resorption and yearly carbon gain. The red senescing leaves of L. ovalifolia assimilated considerable carbon during part of the winter, resulting in a higher yearly carbon gain than co-occurring deciduous species. Its leaf N and P resorption efficiency was higher than for co-occurring non-anthocyanic deciduous species that dropped leaves in autumn, supporting the hypothesis that anthocyanin accumulation and/or extended leaf senescence help in nutrient resorption. Substantial winter carbon gain and efficient nutrient resorption may partially explain the success of L. ovalifolia versus that of the other deciduous species in this subtropical forest. The importance of maintaining a positive carbon balance for ecological success in this forest also provides indirect evidence for the dominance of evergreen species in the subtropical forests of SW China.
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Affiliation(s)
- Yong-Jiang Zhang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 666303, Mengla, Yunnan, China
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Ramel F, Ksas B, Akkari E, Mialoundama AS, Monnet F, Krieger-Liszkay A, Ravanat JL, Mueller MJ, Bouvier F, Havaux M. Light-induced acclimation of the Arabidopsis chlorina1 mutant to singlet oxygen. THE PLANT CELL 2013; 25:1445-62. [PMID: 23590883 PMCID: PMC3663279 DOI: 10.1105/tpc.113.109827] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/11/2013] [Accepted: 03/24/2013] [Indexed: 05/18/2023]
Abstract
Singlet oxygen (¹O₂) is a reactive oxygen species that can function as a stress signal in plant leaves leading to programmed cell death. In microalgae, ¹O₂-induced transcriptomic changes result in acclimation to ¹O₂. Here, using a chlorophyll b-less Arabidopsis thaliana mutant (chlorina1 [ch1]), we show that this phenomenon can also occur in vascular plants. The ch1 mutant is highly photosensitive due to a selective increase in the release of ¹O₂ by photosystem II. Under photooxidative stress conditions, the gene expression profile of ch1 mutant leaves very much resembled the gene responses to ¹O₂ reported in the Arabidopsis mutant flu. Preexposure of ch1 plants to moderately elevated light intensities eliminated photooxidative damage without suppressing ¹O₂ formation, indicating acclimation to ¹O₂. Substantial differences in gene expression were observed between acclimation and high-light stress: A number of transcription factors were selectively induced by acclimation, and contrasting effects were observed for the jasmonate pathway. Jasmonate biosynthesis was strongly induced in ch1 mutant plants under high-light stress and was noticeably repressed under acclimation conditions, suggesting the involvement of this hormone in ¹O₂-induced cell death. This was confirmed by the decreased tolerance to photooxidative damage of jasmonate-treated ch1 plants and by the increased tolerance of the jasmonate-deficient mutant delayed-dehiscence2.
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Affiliation(s)
- Fanny Ramel
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Brigitte Ksas
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Elsy Akkari
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Alexis S. Mialoundama
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg cedex, France
| | - Fabien Monnet
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
- Université d’Avignon et des Pays de Vaucluse, 84000 Avignon, France
| | - Anja Krieger-Liszkay
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Institut de Biologie et de Technologies de Saclay, Centre National de la Recherche Scientifique, Unité de Recherche Associée 2096, Service de Bioénergétique, Biologie Structurale et Mécanisme, F-91191 Gif-sur-Yvette cedex, France
| | - Jean-Luc Ravanat
- Laboratoire Lésions des Acides Nucléiques, Institut Nanosciences et Cryogénie, Service de Chimie Inorganique et Biologique, Unité Mixte de Recherche E3 Commissariat à l’Energie Atomique et aux Energies Alternatives–Université Joseph Fourier, F-38054 Grenoble cedex 9, France
| | - Martin J. Mueller
- Julius-von-Sachs-Institute for Biosciences, Pharmaceutical Biology, Biocenter, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Florence Bouvier
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg cedex, France
| | - Michel Havaux
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
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Luo Z, Zhang J, Li J, Yang C, Wang T, Ouyang B, Li H, Giovannoni J, Ye Z. A STAY-GREEN protein SlSGR1 regulates lycopene and β-carotene accumulation by interacting directly with SlPSY1 during ripening processes in tomato. THE NEW PHYTOLOGIST 2013; 198:442-452. [PMID: 23406468 DOI: 10.1111/nph.12175] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 01/06/2013] [Indexed: 05/17/2023]
Abstract
As a primary source of lycopene in the human diet, fleshy fruits synthesize this compound both de novo and via chlorophyll metabolism during ripening. SlSGR1 encodes a STAY-GREEN protein that plays a critical role in the regulation of chlorophyll degradation in tomato leaves and fruits. We report that SlSGR1 can regulate tomato (Solanum lycopersicum) lycopene accumulation through direct interaction with a key carotenoid synthetic enzyme SlPSY1, and can inhibit its activity. This interaction with SlSGR1 mediates lycopene accumulation during tomato fruit maturation. We confirmed this inhibitory activity in bacteria engineered to produce lycopene, where the introduction of SlSGR1 reduced dramatically lycopene biosynthesis. The repression of SlSGR1 in transgenic tomato fruits resulted in altered accumulation patterns of phytoene and lycopene, whilst simultaneously elevating SlPSY1 mRNA accumulation and plastid conversion at the early stages of fruit ripening, resulting in increased lycopene and β-carotene (four- and nine-fold, respectively) in red ripe fruits. SlSGR1 influences ethylene signal transduction via the altered expression of ethylene receptor genes and ethylene-induced genes. Fruit shelf-life is extended significantly in SlSGR1-repressed tomatoes. Our results indicate that SlSGR1 plays a pivotal regulatory role in color formation and fruit ripening regulation in tomato, and further suggest that SlSGR1 activity is mediated through direct interaction with PSY1.
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Affiliation(s)
- Zhidan Luo
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Junhong Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinhua Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Changxian Yang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Taotao Wang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Bo Ouyang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hanxia Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - James Giovannoni
- United States Department of Agriculture and Boyce Thompson Institute for Plant Research, Cornell University, Tower Road, Ithaca, NY, 14853, USA
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
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63
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Wang J, Bayles KW. Programmed cell death in plants: lessons from bacteria? TRENDS IN PLANT SCIENCE 2013; 18:133-139. [PMID: 23083702 PMCID: PMC3556228 DOI: 10.1016/j.tplants.2012.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 09/10/2012] [Accepted: 09/13/2012] [Indexed: 05/29/2023]
Abstract
Programmed cell death (PCD) has well-established roles in the development and physiology of animals, plants, and fungi. Although aspects of PCD control appear evolutionarily conserved between these organisms, the extent of conservation remains controversial. Recently, a putative bacterial PCD protein homolog in plants was found to play a significant role in cell death control, indicating a conservation of function between these highly divergent organisms. Interestingly, these bacterial proteins are thought to be evolutionarily linked to the Bcl-2 family of proteins. In this opinion article, we propose a new unifying model to describe the relationship between bacterial and plant PCD systems and propose that the underlying control of PCD is conserved across at least three Kingdoms of life.
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Affiliation(s)
- Junhui Wang
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
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64
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Plastid Signaling During the Plant Life Cycle. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_22] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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65
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Hörtensteiner S. The Pathway of Chlorophyll Degradation: Catabolites, Enzymes and Pathway Regulation. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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66
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Grassl J, Pružinská A, Hörtensteiner S, Taylor NL, Millar AH. Early events in plastid protein degradation in stay-green Arabidopsis reveal differential regulation beyond the retention of LHCII and chlorophyll. J Proteome Res 2012; 11:5443-52. [PMID: 23025280 DOI: 10.1021/pr300691k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An individually darkened leaf model was used to study protein changes in the Arabidopsis mutant stay-green1 (sgr1) to partially mimic the process of leaf covering senescence that occurs naturally in the shaded rosettes of Arabidopsis plants. Utilizing this controlled and predictable induced senescence model has allowed the direct comparison of sgr1 with Col-0 during the developmental period preceding the retention of chlorophyll and light harvesting complex II (LHCII) in sgr1 and the induction of senescence in Col-0. Quantitative proteomic analysis of soluble leaf proteins from sgr1 and Col-0 before the initiation of senescence has revealed a range of differences in plastid soluble protein abundance in sgr1 when compared to Col-0. Changes were also observed in membrane located machinery for photosystem II (PSII), in Calvin cycle components, proteins involved in redox control of the stromal compartment and ammonia assimilation that differentiated sgr1 during the early stages of the senescence process. The changes in PSII abundance were accompanied with a lower capacity of photosynthetic CO(2) assimilation in sgr1 than Col-0 after return of plants to lighted conditions following 3 and 5 days of darkness. A light-harvesting chlorophyll-a/b binding protein (LHCB2) was retained during the later stages of senescence in sgr1 but this was accompanied by an enhanced loss of oxygen evolving complex (OEC) subunits from PSII, which was confirmed by Western blotting, and an enhanced stability of PSII repair proteins in sgr1, compared to Col-0. Together these data provide insights into the significant differences in the steady-state proteome in sgr1 and its response to senescence, showing this cosmetic stay-green mutant is in fact significantly different to wild-type plants both before and during leaf senescence.
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Affiliation(s)
- Julia Grassl
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Western Australia, Australia
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67
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Liao HL, Burns JK. Gene expression in Citrus sinensis fruit tissues harvested from huanglongbing-infected trees: comparison with girdled fruit. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3307-19. [PMID: 22407645 PMCID: PMC3350938 DOI: 10.1093/jxb/ers070] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/08/2012] [Accepted: 02/13/2012] [Indexed: 05/19/2023]
Abstract
Distribution of viable Candidatus Liberibacter asiaticus (CaLas) in sweet orange fruit and leaves ('Hamlin' and 'Valencia') and transcriptomic changes associated with huanglongbing (HLB) infection in fruit tissues are reported. Viable CaLas was present in most fruit tissues tested in HLB trees, with the highest titre detected in vascular tissue near the calyx abscission zone. Transcriptomic changes associated with HLB infection were analysed in flavedo (FF), vascular tissue (VT), and juice vesicles (JV) from symptomatic (SY), asymptomatic (AS), and healthy (H) fruit. In SY 'Hamlin', HLB altered the expression of more genes in FF and VT than in JV, whereas in SY 'Valencia', the number of genes whose expression was changed by HLB was similar in these tissues. The expression of more genes was altered in SY 'Valencia' JV than in SY 'Hamlin' JV. More genes were also affected in AS 'Valencia' FF and VT than in AS 'Valencia' JV. Most genes whose expression was changed by HLB were classified as transporters or involved in carbohydrate metabolism. Physiological characteristics of HLB-infected and girdled fruit were compared to differentiate between HLB-specific and carbohydrate metabolism-related symptoms. SY and girdled fruit were smaller than H and ungirdled fruit, respectively, with poor juice quality. However, girdling did not cause misshapen fruit or differential peel coloration. Quantitative PCR analysis indicated that many selected genes changed their expression significantly in SY flavedo but not in girdled flavedo. Mechanisms regulating development of HLB symptoms may lie in the host disease response rather than being a direct consequence of carbohydrate starvation.
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Affiliation(s)
| | - Jacqueline K. Burns
- University of Florida, IFAS, Horticultural Sciences Department, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred, FL 33850-2299, USA
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68
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Pattanayak GK, Venkataramani S, Hortensteiner S, Kunz L, Christ B, Moulin M, Smith AG, Okamoto Y, Tamiaki H, Sugishima M, Greenberg JT. Accelerated cell death 2 suppresses mitochondrial oxidative bursts and modulates cell death in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:589-600. [PMID: 21988537 PMCID: PMC3274588 DOI: 10.1111/j.1365-313x.2011.04814.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The Arabidopsis ACCELERATED CELL DEATH 2 (ACD2) protein protects cells from programmed cell death (PCD) caused by endogenous porphyrin-related molecules like red chlorophyll catabolite or exogenous protoporphyrin IX. We previously found that during bacterial infection, ACD2, a chlorophyll breakdown enzyme, localizes to both chloroplasts and mitochondria in leaves. Additionally, acd2 cells show mitochondrial dysfunction. In plants with acd2 and ACD2 (+) sectors, ACD2 functions cell autonomously, implicating a pro-death ACD2 substrate as being cell non-autonomous in promoting the spread of PCD. ACD2 targeted solely to mitochondria can reduce the accumulation of an ACD2 substrate that originates in chloroplasts, indicating that ACD2 substrate molecules are likely to be mobile within cells. Two different light-dependent reactive oxygen bursts in mitochondria play prominent and causal roles in the acd2 PCD phenotype. Finally, ACD2 can complement acd2 when targeted to mitochondria or chloroplasts, respectively, as long as it is catalytically active: the ability to bind substrate is not sufficient for ACD2 to function in vitro or in vivo. Together, the data suggest that ACD2 localizes dynamically during infection to protect cells from pro-death mobile substrate molecules, some of which may originate in chloroplasts, but have major effects on mitochondria.
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Affiliation(s)
- Gopal K. Pattanayak
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Sujatha Venkataramani
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
| | | | - Lukas Kunz
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Bastien Christ
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Michael Moulin
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB23EA, United Kingdom
| | - Alison G. Smith
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB23EA, United Kingdom
| | - Yukihiro Okamoto
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hitoshi Tamiaki
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Masakazu Sugishima
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Jean T. Greenberg
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
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69
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Mecey C, Hauck P, Trapp M, Pumplin N, Plovanich A, Yao J, He SY. A critical role of STAYGREEN/Mendel's I locus in controlling disease symptom development during Pseudomonas syringae pv tomato infection of Arabidopsis. PLANT PHYSIOLOGY 2011; 157:1965-74. [PMID: 21994350 PMCID: PMC3327183 DOI: 10.1104/pp.111.181826] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 09/29/2011] [Indexed: 05/18/2023]
Abstract
Production of disease symptoms represents the final phase of infectious diseases and is a main cause of crop loss and/or marketability. However, little is known about the molecular basis of disease symptom development. In this study, a genetic screening was conducted to identify Arabidopsis (Arabidopsis thaliana) mutants that are impaired specifically in the development of disease symptoms (leaf chlorosis and/or necrosis) after infection with the bacterial pathogen Pseudomonas syringae pv tomato (Pst) DC3000. An ethyl methanesulfonate-induced Arabidopsis mutant (no chlorosis1 [noc1]) was identified. In wild-type plants, the abundance of chlorophylls decreased markedly after Pst DC3000 infection, whereas the total amount of chlorophylls remained relatively unchanged in the noc1 mutant. Interestingly, noc1 mutant plants also exhibited reduced disease symptoms in response to the fungal pathogen Alternaria brassicicola. Genetic and molecular analyses showed that the nuclear gene STAYGREEN (SGR; or Mendel's I locus) is mutated (resulting in the aspartic acid to tyrosine substitution at amino acid position 88) in noc1 plants. Transforming wild-type SGR cDNA into the noc1 mutant rescued the chlorosis phenotype in response to Pst DC3000 infection. The SGR transcript was highly induced by Pst DC3000, A. brassicicola, or coronatine (COR), a bacterial phytotoxin that promotes chlorosis. The induction of SGR expression by COR is dependent on COI1, a principal component of the jasmonate receptor complex. These results suggest that pathogen/COR-induced expression of SGR is a critical step underlying the development of plant disease chlorosis.
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70
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Tang Y, Li M, Chen Y, Wu P, Wu G, Jiang H. Knockdown of OsPAO and OsRCCR1 cause different plant death phenotypes in rice. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1952-9. [PMID: 21807436 DOI: 10.1016/j.jplph.2011.05.026] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 05/07/2011] [Accepted: 05/09/2011] [Indexed: 05/21/2023]
Abstract
Pheophorbide a oxygenase (PAO) and red chlorophyll catabolite reductase (RCCR) catalyze key steps in chlorophyll degradation by opening the porphyrin macrocycle of pheophorbide a and forming the primary non-photoreactive fluorescent chlorophyll catabolite. These genes strongly participate in senescence and reportedly involved in plants' responses to physical wounding and pathogens. In this report, a single PAO gene (OsPAO) and two RCCR genes (OsRCCR1 and OsRCCR2) have been isolated from rice. Expression analysis by semi-quantitative PCR or quantitative real-time PCR showed that OsRCCR1 transcripts were much more abundant than OsRCCR2, and all of these genes were upregulated during senescence and following wound treatment. RNA interference knockdown of OsPAO led to pheophorbide a accumulation in leaves (especially dark-induced senescent leaves) and leaf death from regeneration stage onwards, even transgenic plants inviability after transplantation. While, knockdown of OsRCCR1 resulted in lesion-mimic spots generation in older leaves which died off early in the transgenic plants. These results suggest that OsPAO and OsRCCR1 play key roles in senescence and are involved in wound responses.
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Affiliation(s)
- Yongyan Tang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China
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71
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Saucedo-García M, González-Solís A, Rodríguez-Mejía P, de Jesús Olivera-Flores T, Vázquez-Santana S, Cahoon EB, Gavilanes-Ruiz M. Reactive oxygen species as transducers of sphinganine-mediated cell death pathway. PLANT SIGNALING & BEHAVIOR 2011; 6:1616-9. [PMID: 21921699 PMCID: PMC3256400 DOI: 10.4161/psb.6.10.16981] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Long chain bases or sphingoid bases are building blocks of complex sphingolipids that display a signaling role in programmed cell death in plants. So far, the type of programmed cell death in which these signaling lipids have been demonstrated to participate is the cell death that occurs in plant immunity, known as the hypersensitive response. The few links that have been described in this pathway are: MPK6 activation, increased calcium concentrations, and reactive oxygen species (ROS) generation. The latter constitute one of the more elusive loops because of the chemical nature of ROS the multiple possible cell sites where they can be formed and the ways in which they influence cell structure and function.
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Affiliation(s)
- Mariana Saucedo-García
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
| | - Ariadna González-Solís
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
| | - Priscila Rodríguez-Mejía
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
| | - Teresa de Jesús Olivera-Flores
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
| | - Sonia Vázquez-Santana
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
| | - Edgar B Cahoon
- Center for Plant Science Innovation & Department of Biochemistry; University of Nebraska-Lincoln; Lincoln, NE USA
| | - Marina Gavilanes-Ruiz
- Departamento de Bioquímica; Fac. de Química; Universidad Nacional Autónoma de México. Cd. Universitaria, México, D.F. 04510 México
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72
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Araújo WL, Ishizaki K, Nunes-Nesi A, Tohge T, Larson TR, Krahnert I, Balbo I, Witt S, Dörmann P, Graham IA, Leaver CJ, Fernie AR. Analysis of a range of catabolic mutants provides evidence that phytanoyl-coenzyme A does not act as a substrate of the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase complex in Arabidopsis during dark-induced senescence. PLANT PHYSIOLOGY 2011; 157:55-69. [PMID: 21788362 PMCID: PMC3221279 DOI: 10.1104/pp.111.182188] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The process of dark-induced senescence in plants is not fully understood, however, the functional involvement of an electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO), has been demonstrated. Recent studies have revealed that the enzymes isovaleryl-coenzyme A (CoA) dehydrogenase and 2-hydroxyglutarate dehydrogenase act as important electron donors to this complex. In addition both enzymes play a role in the breakdown of cellular carbon storage reserves with isovaleryl-CoA dehydrogenase being involved in degradation of the branched-chain amino acids, phytol, and lysine while 2-hydroxyglutarate dehydrogenase is exclusively involved in lysine degradation. Given that the chlorophyll breakdown intermediate phytanoyl-CoA accumulates dramatically both in knockout mutants of the ETF/ETFQO complex and of isovaleryl-CoA dehydrogenase following growth in extended dark periods we have investigated the direct importance of chlorophyll breakdown for the supply of carbon and electrons during this process. For this purpose we isolated three independent Arabidopsis (Arabidopsis thaliana) knockout mutants of phytanoyl-CoA 2-hydroxylase and grew them under the same extended darkness regime as previously used. Despite the fact that these mutants accumulated phytanoyl-CoA and also 2-hydroxyglutarate they exhibited no morphological changes in comparison to the other mutants previously characterized. These results are consistent with a single entry point of phytol breakdown into the ETF/ETFQO system and furthermore suggest that phytol is not primarily metabolized by this pathway. Furthermore analysis of isovaleryl-CoA dehydrogenase/2-hydroxyglutarate dehydrogenase double mutants generated here suggest that these two enzymes essentially account for the entire electron input via the ETF complex.
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73
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Saucedo-García M, Guevara-García A, González-Solís A, Cruz-García F, Vázquez-Santana S, Markham JE, Lozano-Rosas MG, Dietrich CR, Ramos-Vega M, Cahoon EB, Gavilanes-Ruíz M. MPK6, sphinganine and the LCB2a gene from serine palmitoyltransferase are required in the signaling pathway that mediates cell death induced by long chain bases in Arabidopsis. THE NEW PHYTOLOGIST 2011; 191:943-957. [PMID: 21534970 DOI: 10.1111/j.1469-8137.2011.03727.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Long chain bases (LCBs) are sphingolipid intermediates acting as second messengers in programmed cell death (PCD) in plants. Most of the molecular and cellular features of this signaling function remain unknown. We induced PCD conditions in Arabidopsis thaliana seedlings and analyzed LCB accumulation kinetics, cell ultrastructure and phenotypes in serine palmitoyltransferase (spt), mitogen-activated protein kinase (mpk), mitogen-activated protein phosphatase (mkp1) and lcb-hydroxylase (sbh) mutants. The lcb2a-1 mutant was unable to mount an effective PCD in response to fumonisin B1 (FB1), revealing that the LCB2a gene is essential for the induction of PCD. The accumulation kinetics of LCBs in wild-type (WT) and lcb2a-1 plants and reconstitution experiments with sphinganine indicated that this LCB was primarily responsible for PCD elicitation. The resistance of the null mpk6 mutant to manifest PCD on FB1 and sphinganine addition and the failure to show resistance on pathogen infection and MPK6 activation by FB1 and LCBs indicated that MPK6 mediates PCD downstream of LCBs. This work describes MPK6 as a novel transducer in the pathway leading to LCB-induced PCD in Arabidopsis, and reveals that sphinganine and the LCB2a gene are required in a PCD process that operates as one of the more effective strategies used as defense against pathogens in plants.
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Affiliation(s)
- Mariana Saucedo-García
- Dpto. de Bioquímica, Fac. de Química, Universidad Nacional Autónoma de México, México D.F., 04510 México
| | - Arturo Guevara-García
- Dpto. de Biología Molecular de Plantas, Inst. de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62271, Morelos, México
| | - Ariadna González-Solís
- Dpto. de Bioquímica, Fac. de Química, Universidad Nacional Autónoma de México, México D.F., 04510 México
| | - Felipe Cruz-García
- Dpto. de Bioquímica, Fac. de Química, Universidad Nacional Autónoma de México, México D.F., 04510 México
| | - Sonia Vázquez-Santana
- Dpto. de Biología Comparada, Fac. de Ciencias, Universidad Nacional Autónoma de México, México D.F., 04510 México
| | | | - M Guadalupe Lozano-Rosas
- Dpto. de Bioquímica, Fac. de Química, Universidad Nacional Autónoma de México, México D.F., 04510 México
| | | | - Maricela Ramos-Vega
- Dpto. de Biología Molecular de Plantas, Inst. de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62271, Morelos, México
| | - Edgar B Cahoon
- Center for Plant Science Innovation & Department of Biochemistry, University of Nebraska-Lincoln, E318 Beadle Center, 1901 Vine St., Lincoln, NE 68588, USA
| | - Marina Gavilanes-Ruíz
- Dpto. de Bioquímica, Fac. de Química, Universidad Nacional Autónoma de México, México D.F., 04510 México
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75
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Jiang H, Chen Y, Li M, Xu X, Wu G. Overexpression of SGR results in oxidative stress and lesion-mimic cell death in rice seedlings. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2011; 53:375-87. [PMID: 21375689 DOI: 10.1111/j.1744-7909.2011.01037.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
It is thought that the Stay Green Rice (SGR) gene is involved in the disaggregation of the light harvesting complex and in the subsequent breakdown of chlorophyll and apo-protein during senescence. In this study, we found that overexpression of SGR (Ov-SGR) resulted in the generation of singlet oxygen and other reactive oxygen species and produced a chlorophyll-dependent regional cell death phenotype on leaves of rice seedlings. Transcriptome analyses using Affymetrix Rice GeneChips revealed that Ov-SGR rice seedlings exhibited a number of signs of singlet oxygen response. The genes and their associated biochemical pathways identified provide an insight into how rice plants respond to singlet oxygen at the molecular and physiologic level.
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Affiliation(s)
- Huawu Jiang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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Hörtensteiner S, Kräutler B. Chlorophyll breakdown in higher plants. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1807:977-88. [PMID: 21167811 DOI: 10.1016/j.bbabio.2010.12.007] [Citation(s) in RCA: 372] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 12/07/2010] [Accepted: 12/08/2010] [Indexed: 01/05/2023]
Abstract
Chlorophyll breakdown is an important catabolic process of leaf senescence and fruit ripening. Structure elucidation of colorless linear tetrapyrroles as (final) breakdown products of chlorophyll was crucial for the recent delineation of a chlorophyll breakdown pathway which is highly conserved in land plants. Pheophorbide a oxygenase is the key enzyme responsible for opening of the chlorin macrocycle of pheophorbide a characteristic to all further breakdown products. Degradation of chlorophyll was rationalized by the need of a senescing cell to detoxify the potentially phototoxic pigment, yet recent investigations in leaves and fruits indicate that chlorophyll catabolites could have physiological roles. This review updates structural information of chlorophyll catabolites and the biochemical reactions involved in their formation, and discusses the significance of chlorophyll breakdown. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts.
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Affiliation(s)
- Stefan Hörtensteiner
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland.
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Rogers H. New light shed on life and death: the role of staygreen in the hypersensitive response. THE NEW PHYTOLOGIST 2010; 188:4-6. [PMID: 20840145 DOI: 10.1111/j.1469-8137.2010.03434.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Hilary Rogers
- School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3TL, UK.
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