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Kandhol N, Srivastava A, Rai P, Sharma S, Pandey S, Singh VP, Tripathi DK. Cytokinin and indole-3-acetic acid crosstalk is indispensable for silicon mediated chromium stress tolerance in roots of wheat seedlings. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133134. [PMID: 38387171 DOI: 10.1016/j.jhazmat.2023.133134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/31/2023] [Accepted: 11/28/2023] [Indexed: 02/24/2024]
Abstract
The rising heavy metal contamination of soils imposes toxic impacts on plants as well as other life forms. One such highly toxic and carcinogenic heavy metal is hexavalent chromium [Cr(VI)] that has been reported to prominently retard the plant growth. The present study investigated the potential of silicon (Si, 10 µM) to alleviate the toxicity of Cr(VI) (25 µM) on roots of wheat (Triticum aestivum L.) seedlings. Application of Si to Cr(VI)-stressed wheat seedlings improved their overall growth parameters. This study also reveals the involvement of two phytohormones, namely auxin and cytokinin and their crosstalk in Si-mediated mitigation of the toxic impacts of Cr(VI) in wheat seedlings. The application of cytokinin alone to wheat seedlings under Cr(VI) stress reduced the intensity of toxic effects of Cr(VI). In combination with Si, cytokinin application to Cr(VI)-stressed wheat seedlings significantly minimized the decrease induced by Cr(VI) in different parameters such as root-shoot length (10.8% and 13%, respectively), root-shoot fresh mass (11.3% and 10.1%, respectively), and total chlorophyll and carotenoids content (13.4% and 6.8%, respectively) with respect to the control. This treatment also maintained the regulation of proline metabolism (proline content, and P5CS and PDH activities), ascorbate-glutathione (AsA-GSH) cycle and nutrient homeostasis. The protective effect of Si and cytokinin against Cr(VI) stress was minimized upon supplementation of an inhibitor of polar auxin transport- 2,3,5-triiodobenzoic acid (TIBA) which suggested a potential involvement of auxin in Si and cytokinin-mediated mitigation of Cr(VI) toxicity. The exogenous addition of a natural auxin - indole-3-acetic acid (IAA) confirmed auxin is an active member of a signaling cascade along with cytokinin that aids in Si-mediated Cr(VI) toxicity alleviation as IAA application reversed the negative impacts of TIBA on wheat roots treated with Cr(VI), cytokinin and Si. The results of this research are also confirmed by the gene expression analysis conducted for nutrient transporters (Lsi1, CCaMK, MHX, SULT1 and ZIP1) and enzymes involved in the AsA-GSH cycle (APX, GR, DHAR and MDHAR). The overall results of this research indicate towards possible induction of a crosstalk between cytokinin and IAA upon Si supplementation which in turn stimulates physiological, biochemical and molecular changes to exhibit protective effects against Cr(VI) stress. Further, the information obtained suggests probable employment of Si, cytokinin and IAA alone or combined in agriculture to maintain plant productivity under Cr(VI) stress and data regarding expression of key genes can be used to develop new crop varieties with enhanced resistance against Cr(VI) stress together with its reduced load in seedlings.
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Affiliation(s)
- Nidhi Kandhol
- Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida 201313, India
| | - Aakriti Srivastava
- Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida 201313, India
| | - Padmaja Rai
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, India
| | - Shivesh Sharma
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, India
| | - Sangeeta Pandey
- Plant Microbe Interaction Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida 201313, India
| | - Vijay Pratap Singh
- Plant Physiology Laboratory, Department of Botany, C.M.P. Degree College, University of Allahabad, Prayagraj 211002, India
| | - Durgesh Kumar Tripathi
- Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida 201313, India.
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Moing A, Berton T, Roch L, Diarrassouba S, Bernillon S, Arrivault S, Deborde C, Maucourt M, Cabasson C, Bénard C, Prigent S, Jacob D, Gibon Y, Lemaire-Chamley M. Multi-omics quantitative data of tomato fruit unveils regulation modes of least variable metabolites. BMC PLANT BIOLOGY 2023; 23:365. [PMID: 37479985 PMCID: PMC10362748 DOI: 10.1186/s12870-023-04370-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/11/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND The composition of ripe fruits depends on various metabolites which content evolves greatly throughout fruit development and may be influenced by the environment. The corresponding metabolism regulations have been widely described in tomato during fruit growth and ripening. However, the regulation of other metabolites that do not show large changes in content have scarcely been studied. RESULTS We analysed the metabolites of tomato fruits collected on different trusses during fruit development, using complementary analytical strategies. We identified the 22 least variable metabolites, based on their coefficients of variation. We first verified that they had a limited functional link with the least variable proteins and transcripts. We then posited that metabolite contents could be stabilized through complex regulations and combined their data with the quantitative proteome or transcriptome data, using sparse partial-least-square analyses. This showed shared regulations between several metabolites, which interestingly remained linked to early fruit development. We also examined regulations in specific metabolites using correlations with individual proteins and transcripts, which revealed that a stable metabolite does not always correlate with proteins and transcripts of its known related pathways. CONCLUSIONS The regulation of the least variable metabolites was then interpreted regarding their roles as hubs in metabolic pathways or as signalling molecules.
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Affiliation(s)
- Annick Moing
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Thierry Berton
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Léa Roch
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Salimata Diarrassouba
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Present Address: Laboratoire de Recherche en Sciences Végétales, UMR 5546 UPS/CNRS, Auzeville- Tolosane, F-31320 France
| | - Stéphane Bernillon
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Present Address: INRAE, Mycologie et Sécurité des Aliments, UR 1264, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Stéphanie Arrivault
- Max Planck Institute of Molecular Plant Physiology, am Muehlenberg 14476, Potsdam-Golm, Germany
| | - Catherine Deborde
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Present Address: INRAE, UR1268 BIA, Centre INRAE Pays de Loire – Nantes, Nantes, F-44000 France
- Present address: INRAE, BIBS Facility, Centre INRAE Pays de Loire – Nantes, Nantes, F-44000 France
| | - Mickaël Maucourt
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Cécile Cabasson
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Camille Bénard
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Sylvain Prigent
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Daniel Jacob
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Yves Gibon
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
- Bordeaux Metabolome, MetaboHUB, PHENOME-EMPHASIS, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
| | - Martine Lemaire-Chamley
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Centre INRAE de Nouvelle Aquitaine Bordeaux, Villenave d’Ornon, F-33140 France
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Jain S, Rai P, Singh J, Singh VP, Prasad R, Rana S, Deshmukh R, Tripathi DK, Sharma S. Exogenous addition of silicon alleviates metsulfuron methyl induced stress in wheat seedlings. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 167:705-712. [PMID: 34500195 DOI: 10.1016/j.plaphy.2021.07.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 07/03/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Uncontrolled application of herbicides in the agricultural field poses a severe risk to crops by affecting their yields. Therefore, methods are required to reduce the toxic effects of herbicides in plants. Studies indicate that silicon (Si) provides tolerance and enhances defence mechanism of the plant against abiotic stress. But its role in alleviating Metsulfuron methyl (Meth) herbicide induced toxicity in wheat seedlings is still not known. This study highlighted the potential of exogenous addition of Si in the alleviation of toxic effect of Meth herbicide in wheat seedlings. The exposure of wheat seedlings to Meth herbicide reduced the growth, photosynthetic pigments, antioxidant enzyme activity and nitric oxide (NO) content. Further, Meth herbicide also increased cell death and decreased cell viability in root tips. However, addition of Si reversed Meth-induced these alterations. Moreover, Si also activates antioxidant system which helps in scavenging of free radicals generated under Meth herbicide stress in wheat seedlings. Application of Si to Meth treated wheat seedlings also up-regulated silicon transporter gene Lsi1 (silicon influx transporter) and some of the antioxidant enzyme genes. All together, the data indicate that Si has capability of alleviating Meth herbicide stress in wheat seedlings but it appears that endogenous NO has a positive role in this endeavour of Si.
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Affiliation(s)
- Shruti Jain
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India
| | - Padmaja Rai
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India
| | - Jaspreet Singh
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India
| | - Vijay Pratap Singh
- Plant Physiology Laboratory, Department of Botany, C.M.P. Degree College, A Constituent Post Graduate College of University of Allahabad, Prayagraj, 211002, India
| | - Rajendra Prasad
- Department of Horticulture, Kulbhasker Ashram Post Graduate Collage, Prayagraj, Uttar Pradesh, India
| | - Shweta Rana
- Department of Physical and Natural Sciences, FLAME University, Pune, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, India
| | - Durgesh Kumar Tripathi
- Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida, 201313, India.
| | - Shivesh Sharma
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India.
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Furlan AL, Bianucci E, Giordano W, Castro S, Becker DF. Proline metabolic dynamics and implications in drought tolerance of peanut plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 151:566-578. [PMID: 32320942 DOI: 10.1016/j.plaphy.2020.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 05/25/2023]
Abstract
Proline accumulation and metabolism are associated with mechanisms of abiotic stress avoidance in plants. Proline accumulation generally improves osmotic stress tolerance whereas proline metabolism can have varying effects from ATP generation to the formation of reactive oxygen species. To further understand the roles of proline in stress protection, two peanut cultivars with contrasting tolerance to drought were examined by transcriptional and biochemical analyses during water stress. Plants exposed to polyethylene glycol had diminished relative water content and increased proline content; while, only the drought sensitive plants, cultivar Granoleico, showed lipid oxidative damage (measured as thiobarbituric acid reactive substances). The expression of proline biosynthesis genes (P5CS1, P5CS2a, P5CS2b, P5CR) was increased in both cultivars upon exposure to water stress. However, the relative expression of proline catabolism genes (ProDH1, ProDH2) was increased only in the sensitive cultivar during stress. Exogenous addition of proline and the proline analogue thiazolidine-4-carboxylic acid (T4C), both substrates of proline dehydrogenase, was also used to exacerbate and identify plant responses. Pretreatment of plants with T4C induced unique changes in the drought tolerant EC-98 cultivar such as higher mRNA levels of proline biosynthetic and catabolic ProDH genes, even in the absence of water stress. The increased levels of ProDH gene expression, potentially associated with higher T4C conversion to cysteine, may contribute to the tolerant phenotype.
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Affiliation(s)
- Ana Laura Furlan
- Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800, Río Cuarto, Córdoba, Argentina; Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
| | - Eliana Bianucci
- Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800, Río Cuarto, Córdoba, Argentina
| | - Walter Giordano
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800, Río Cuarto, Córdoba, Argentina
| | - Stella Castro
- Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800, Río Cuarto, Córdoba, Argentina
| | - Donald F Becker
- Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
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König K, Vaseghi MJ, Dreyer A, Dietz KJ. The significance of glutathione and ascorbate in modulating the retrograde high light response in Arabidopsis thaliana leaves. PHYSIOLOGIA PLANTARUM 2018; 162:262-273. [PMID: 28984358 DOI: 10.1111/ppl.12644] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/01/2017] [Accepted: 09/13/2017] [Indexed: 05/13/2023]
Abstract
Retrograde signals from the chloroplast control expression of nuclear genes. A large fraction of these genes is affected rapidly upon light intensity shifts. This study was designed to address the interdependence of signaling pathways involved in the rapid high light response and redox and reactive oxygen species signaling by exploiting the glutathione and ascorbate deficient mutants pad2 and vtc1. In the first set of experiments the transcriptional response of the two transcription factors ERF6 and ERF105 that had previously been shown to rapidly respond to light was shown to be deregulated in the pad2 mutant but not in the vtc1 background. The transcriptional response after combining the low-to-high light transfer with methylviologen pretreatment further demonstrated the significance of glutathione in strongly modulating the retrograde response. Transcripts encoding small heat shock proteins (HSP17.4, HSP176a, HSP20-like1 and HSP20-like2) and the lipid transfer protein LTP3 were taken as markers responding to the combinatorial treatment in wild type, and most strongly in pad2 in high light or upon methylviologen treatment. A correlation with H2 O2 accumulation was not observed. It is concluded that glutathione-dependent processes participate in light-triggered rapid gene regulation independent on cellular H2 O2 .
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Affiliation(s)
- Katharina König
- Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33501, Bielefeld, Germany
| | - Mohamad Javad Vaseghi
- Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33501, Bielefeld, Germany
| | - Anna Dreyer
- Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33501, Bielefeld, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33501, Bielefeld, Germany
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6
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Furlan AL, Bianucci E, Castro S, Dietz KJ. Metabolic features involved in drought stress tolerance mechanisms in peanut nodules and their contribution to biological nitrogen fixation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 263:12-22. [PMID: 28818367 DOI: 10.1016/j.plantsci.2017.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 05/04/2023]
Abstract
Legumes belong to the most important crops worldwide. They increase soil fertility due their ability to establish symbiotic associations with soil microorganisms, known as rhizobia, capable of fixing nitrogen from the atmosphere. However, they are frequently exposed to abiotic stress conditions in particular drought. Such adverse conditions impair the biological nitrogen fixation (BNF) and depend largely on the legume. Therefore, two peanut cultivars with contrasting tolerance to drought, namely the more tolerant EC-98 and the sensitive Granoleico, were investigated to elucidate the relative contribution of BNF to the tolerance to drought. The tolerant cultivar EC-98 sustained growth and BNF similar to the control condition despite the reduced water potential and photosynthesis, suggesting the functioning of distinct metabolic pathways that contributed to enhance the tolerance. The biochemical and metabolomics approaches revealed that nodules from the tolerant cultivar accumulated trehalose, proline and gamma-aminobutyric acid (GABA), metabolites with known function in protecting against drought stress. The amide metabolism was severely affected in nodules from the sensitive cultivar Granoleico as revealed by the low content of asparagine and glutamine in the drought stressed plants. The sensitive cultivar upon rehydration was unable to re-establish a metabolism similar to well-watered plants. This was evidenced by the low level of metabolites and, transcripts and specific activities of enzymes from the carbon (sucrose synthase) and nitrogen (glutamine synthetase) metabolism which decreased below the values of control plants. Therefore, the increased content of metabolites with protective functions under drought stress likely is crucial for the full restoration upon rehydration. Smaller changes of drought stress-related metabolites in nodule are another trait that contributes to the effective control of BNF in the tolerant peanut cultivar (EC-98).
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Affiliation(s)
- Ana Laura Furlan
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina; Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany.
| | - Eliana Bianucci
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Stella Castro
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
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He F, Sheng M, Tang M. Effects of Rhizophagus irregularis on Photosynthesis and Antioxidative Enzymatic System in Robinia pseudoacacia L. under Drought Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:183. [PMID: 28261240 PMCID: PMC5311038 DOI: 10.3389/fpls.2017.00183] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/30/2017] [Indexed: 05/06/2023]
Abstract
Arbuscular mycorrhizal (AM) fungi colonize roots improving plant water status and tolerance to drought. However, it is not clear whether the presence of AM would affect the photosynthesis and antioxidant gene-enzymes response, which help to alleviate drought stress of the host plant. Here, pot experiments were performed to investigate the effects of Rhizophagus irregularis, an AM fungus, on the tissue water content, photosynthesis, reactive oxygen species (ROS) production, antioxidant enzyme activity and gene expression in black locust (Robinia pseudoacacia L.) seedlings which were subjected to well-watered or moderate drought stress. Mycorrhizal symbiosis increased relative water content (RWC) of plant roots and leaves, promoted the accumulation of biomass and chlorophyll (Chl) content, and improved photochemistry efficiency, regardless of watering regimes. Mycorrhizal plants had higher SOD, POD, CAT, APX, and GR activities, and the transcript levels of Cu/Zn-SOD. APX and GR, but lower O2-, H2O2 and MDA concentrations in leaves and roots of black locust under drought and well-watered conditions. Results from the present study indicate that AM fungus (R. irregularis) symbiosis can enhance photosynthesis and ROS scavenging capabilities and increase RWC of leaves and roots to alleviate drought stress in black locust. Further research is needed to elucidate the relations among AM fungi and the metabolic pathways of antioxidant enzymes, and the function of antioxidant genes regulated by mycorrhizal symbiosis with the purpose of revealing the mechanisms of mycorrhizal-induced plant tolerance to drought stress.
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Affiliation(s)
- Fei He
- College of Forestry and Landscape Architecture, South China Agricultural UniversityGuangzhou, China
- College of Forestry, Northwest A&F UniversityYangling, China
- School of Modern Agriculture and Biotechnology, Ankang UniversityAnkang, China
| | - Min Sheng
- College of Forestry, Northwest A&F UniversityYangling, China
| | - Ming Tang
- College of Forestry and Landscape Architecture, South China Agricultural UniversityGuangzhou, China
- College of Forestry, Northwest A&F UniversityYangling, China
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Hossain MS, ElSayed AI, Moore M, Dietz KJ. Redox and Reactive Oxygen Species Network in Acclimation for Salinity Tolerance in Sugar Beet. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1283-1298. [PMID: 28338762 PMCID: PMC5441856 DOI: 10.1093/jxb/erx019] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Fine-tuned and coordinated regulation of transport, metabolism and redox homeostasis allows plants to acclimate to osmotic and ionic stress caused by high salinity. Sugar beet is a highly salt tolerant crop plant and is therefore an interesting model to study sodium chloride (NaCl) acclimation in crops. Sugar beet plants were subjected to a final level of 300 mM NaCl for up to 14 d in hydroponics. Plants acclimated to NaCl stress by maintaining its growth rate and adjusting its cellular redox and reactive oxygen species (ROS) network. In order to understand the unusual suppression of ROS accumulation under severe salinity, the regulation of elements of the redox and ROS network was investigated at the transcript level. First, the gene families of superoxide dismutase (SOD), peroxiredoxins (Prx), alternative oxidase (AOX), plastid terminal oxidase (PTOX) and NADPH oxidase (RBOH) were identified in the sugar beet genome. Salinity induced the accumulation of Cu-Zn-SOD, Mn-SOD, Fe-SOD3, all AOX isoforms, 2-Cys-PrxB, PrxQ, and PrxIIF. In contrast, Fe-SOD1, 1-Cys-Prx, PrxIIB and PrxIIE levels decreased in response to salinity. Most importantly, RBOH transcripts of all isoforms decreased. This pattern offers a straightforward explanation for the low ROS levels under salinity. Promoters of stress responsive antioxidant genes were analyzed in silico for the enrichment of cis-elements, in order to gain insights into gene regulation. The results indicate that special cis-elements in the promoters of the antioxidant genes in sugar beet participate in adjusting the redox and ROS network and are fundamental to high salinity tolerance of sugar beet.
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Affiliation(s)
- M Sazzad Hossain
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Abdelaleim Ismail ElSayed
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, D-33501 Bielefeld, Germany
- Biochemistry Department, Faculty of Agriculture, Zagazig University, 44519 Zagazig, Egypt
| | - Marten Moore
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Karl-Josef Dietz
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, D-33501 Bielefeld, Germany
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Farooq MA, Detterbeck A, Clemens S, Dietz KJ. Silicon-induced reversibility of cadmium toxicity in rice. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3573-85. [PMID: 27122572 PMCID: PMC4892736 DOI: 10.1093/jxb/erw175] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Silicon (Si) modulates tolerance to abiotic stresses, but little is known about the reversibility of stress effects by supplementing previously stressed plants with Si. This is surprising since recovery experiments might allow mechanisms of Si-mediated amelioration to be addressed. Rice was exposed to 10 µM CdCl2 for 4 d in hydroponics, followed by 0.6mM Si(OH)4 supplementation for 4 d. Si reversed the effects of Cd, as reflected in plant growth, photosynthesis, elemental composition, and some biochemical parameters. Cd-dependent deregulation of nutrient homeostasis was partially reversed by Si supply. Photosynthetic recovery within 48h following Si supply, coupled with strong stimulation of the ascorbate-glutathione system, indicates efficient activation of defense. The response was further verified by transcript analyses with emphasis on genes encoding members of the stress-associated protein (SAP) family. The transcriptional response to Cd was mostly reversed following Si supply. Reprogramming of the Cd response was obvious for Phytochelatin synthase 1, SAP1 , SAP14, and the transcription factor genes AP2/Erf020, Hsf31, and NAC6 whose transcript levels were strongly activated in roots of Cd-stressed rice, but down-regulated in the presence of Si. These findings, together with changes in biochemical parameters, highlight the significance of Si in growth recovery of Cd-stressed rice and indicate a decisive role for readjusting cell redox homeostasis.
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Affiliation(s)
- Muhammad Ansar Farooq
- Biochemistry and Physiology of Plants, Faculty of Biology, W5-134, Bielefeld University, University Street 25, D-33501 Bielefeld, Germany
| | - Amelie Detterbeck
- Department of Plant Physiology, University of Bayreuth, University Street 30, D-95440 Bayreuth, Germany
| | - Stephan Clemens
- Department of Plant Physiology, University of Bayreuth, University Street 30, D-95440 Bayreuth, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Faculty of Biology, W5-134, Bielefeld University, University Street 25, D-33501 Bielefeld, Germany
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10
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Furlan AL, Bianucci E, Tordable MADC, Castro S, Dietz KJ. Antioxidant enzyme activities and gene expression patterns in peanut nodules during a drought and rehydration cycle. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:704-713. [PMID: 32481025 DOI: 10.1071/fp13311] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/29/2014] [Indexed: 05/21/2023]
Abstract
Drought stress is one of the most important environmental factors that affect plant growth and limit biomass production. Most studies focus on drought stress development but the reversibility of the effects receives less attention. Therefore, the present work aims to explore the biological nitrogen fixation (BNF) of the symbiotic association between peanut (Arachis hypogaea L.) and Bradyrhizobium sp. during a drought-recovery cycle with a focus on the response of enzyme activity and gene expression of the antioxidant system. Peanuts exposed to drought stress had impaired BNF, as indicated by lower nitrogenase activity, and decreased leghaemoglobin content; the latter was reversed to control values upon rehydration. Previous results demonstrated that reactive oxygen species (O2·- and H2O2) were accumulated as a consequence of drought stress, suggesting that nodules experience oxidative stress. In addition, marker transcripts responsive to drought, abscisic acid and H2O2 were upregulated. Increased transcript levels of glutathione reductase were associated with an increased enzyme activity but superoxide dismutase and glutathione S-transferase activities were unchanged, despite upregulated gene transcription. In contrast, increased activity of ascorbate peroxidase (APX) was unrelated with changes in cytosolic APX transcript levels suggesting isogene specificity. In conclusion, the work exemplarily demonstrates the efficient and dynamic regulation of antioxidant enzymes and marker compounds during drought cycling, which is likely to be a prerequisite for functional optimisation of nodule metabolism.
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Affiliation(s)
- Ana Laura Furlan
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto. Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Eliana Bianucci
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto. Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Mar A Del Carmen Tordable
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto. Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Stella Castro
- Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto. Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
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11
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Alsharafa K, Vogel MO, Oelze ML, Moore M, Stingl N, König K, Friedman H, Mueller MJ, Dietz KJ. Kinetics of retrograde signalling initiation in the high light response of Arabidopsis thaliana. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130424. [PMID: 24591725 DOI: 10.1098/rstb.2013.0424] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
High light acclimation depends on retrograde control of nuclear gene expression. Retrograde regulation uses multiple signalling pathways and thus exploits signal patterns. To maximally challenge the acclimation system, Arabidopsis thaliana plants were either adapted to 8 (low light (L-light)) or 80 µmol quanta m(-2) s(-1) (normal light (N-light)) and subsequently exposed to a 100- and 10-fold light intensity increase, respectively, to high light (H-light, 800 µmol quanta m(-2) s(-1)), for up to 6 h. Both L → H- and N → H-light plants efficiently regulated CO2 assimilation to a constant level without apparent damage and inhibition. This experimental set-up was scrutinized for time-dependent regulation and efficiency of adjustment. Transcriptome profiles revealed that N-light and L-light plants differentially accumulated 2119 transcripts. After 6 h in H-light, only 205 remained differently regulated between the L → H- and N → H-light plants, indicating efficient regulation allowing the plants to reach a similar transcriptome state. Time-dependent analysis of transcripts as markers for signalling pathways, and of metabolites and hormones as possibly involved transmitters, suggests that oxylipins such as oxophytodienoic acid and jasmonic acid, metabolites and redox cues predominantly control the acclimation response, whereas abscisic acid, salicylic acid and auxins play an insignificant or minor role.
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Affiliation(s)
- Khalid Alsharafa
- Biochemistry and Physiology of Plants, Bielefeld University, , Bielefeld 33501, Germany
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12
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Vogel MO, Moore M, König K, Pecher P, Alsharafa K, Lee J, Dietz KJ. Fast retrograde signaling in response to high light involves metabolite export, MITOGEN-ACTIVATED PROTEIN KINASE6, and AP2/ERF transcription factors in Arabidopsis. THE PLANT CELL 2014; 26:1151-65. [PMID: 24668746 PMCID: PMC4001375 DOI: 10.1105/tpc.113.121061] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/31/2014] [Accepted: 02/28/2014] [Indexed: 05/18/2023]
Abstract
Regulation of the expression of nuclear genes encoding chloroplast proteins allows for metabolic adjustment in response to changing environmental conditions. This regulation is linked to retrograde signals that transmit information on the metabolic state of the chloroplast to the nucleus. Transcripts of several APETALA2/ETHYLENE RESPONSE FACTOR transcription factors (AP2/ERF-TFs) were found to respond within 10 min after transfer of low-light-acclimated Arabidopsis thaliana plants to high light. Initiation of this transcriptional response was completed within 1 min after transfer to high light. The fast responses of four AP2/ERF genes, ERF6, RRTF1, ERF104, and ERF105, were entirely deregulated in triose phosphate/phosphate translocator (tpt) mutants. Similarly, activation of MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) was upregulated after 1 min in the wild type but not in the tpt mutant. Based on this, together with altered transcript regulation in mpk6 and erf6 mutants, a retrograde signal transmission model is proposed starting with metabolite export through the triose phosphate/phosphate translocator with subsequent MPK6 activation leading to initiation of AP2/ERF-TF gene expression and other downstream gene targets. The results show that operational retrograde signaling in response to high light involves a metabolite-linked pathway in addition to previously described redox and hormonal pathways.
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Affiliation(s)
- Marc Oliver Vogel
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Marten Moore
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Katharina König
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Pascal Pecher
- Leibniz Institute of Plant Biochemistry, 06120 Halle, Germany
| | - Khalid Alsharafa
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Justin Lee
- Leibniz Institute of Plant Biochemistry, 06120 Halle, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
- Address correspondence to
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13
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Heiber I, Cai W, Baier M. Linking chloroplast antioxidant defense to carbohydrate availability: the transcript abundance of stromal ascorbate peroxidase is sugar-controlled via ascorbate biosynthesis. MOLECULAR PLANT 2014; 7:58-70. [PMID: 24203232 DOI: 10.1093/mp/sst154] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
All genes encoding chloroplast antioxidant enzymes are nuclear-encoded and posttranscriptionally targeted to chloroplasts. The transcript levels of most of them decreased upon sucrose feeding like the transcript levels of many genes encoding components of the photosynthetic electron transport chain. However, the transcript abundance of stromal ascorbate peroxidase (s-APX; At4g08390) increased. Due to mild sugar application conditions, the plants kept the phosphorylation status of the ADP+ATP pool and the redox states of the NADPH+NADP+ and the ascorbate pools under control, which excludes them as signals in s-APX regulation. Correlation with ascorbate pool size regulation and comparison of transcript abundance regulation in the starch-biosynthetic mutant adg1, the ascorbate biosynthesis mutant vtc1, and the abscisic acid (ABA) biosynthetic mutant aba2 showed a link between sugar induction of s-APX and ascorbate biosynthesis.
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Affiliation(s)
- Isabelle Heiber
- a Former address: Plant Physiology and Biochemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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Response of Mature, Developing and Senescing Chloroplasts to Environmental Stress. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_28] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Davey MP, Susanti NI, Wargent JJ, Findlay JE, Paul Quick W, Paul ND, Jenkins GI. The UV-B photoreceptor UVR8 promotes photosynthetic efficiency in Arabidopsis thaliana exposed to elevated levels of UV-B. PHOTOSYNTHESIS RESEARCH 2012; 114:121-31. [PMID: 23161229 DOI: 10.1007/s11120-012-9785-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/31/2012] [Indexed: 05/05/2023]
Abstract
The UV-B photoreceptor UVR8 regulates expression of genes in response to UV-B, some encoding chloroplast proteins, but the importance of UVR8 in maintaining photosynthetic competence is unknown. The maximum quantum yield of PSII (F (v)/F(m)) and the operating efficiency of PSII (Φ(PSII)) were measured in wild-type and uvr8 mutant Arabidopsis thaliana. The importance of specific UVR8-regulated genes in maintaining photosynthetic competence was examined using mutants. Both F (v)/F(m) and Φ(PSII) decreased when plants were exposed to elevated UV-B, in general more so in uvr8 mutant plants than wild-type. UV-B increased the level of psbD-BLRP (blue light responsive promoter) transcripts, encoding the PSII D2 protein. This increase was mediated by the UVR8-regulated chloroplast RNA polymerase sigma factor SIG5, but SIG5 was not required to maintain photosynthetic efficiency at elevated UV-B. Levels of the D1 protein of PSII decreased markedly when plants were exposed to elevated UV-B, but there was no significant difference between wild-type and uvr8 under conditions where the mutant showed increased photoinhibition. The results show that UVR8 promotes photosynthetic efficiency at elevated levels of UV-B. Loss of the DI polypeptide is probably important in causing photoinhibition, but does not entirely explain the reduced photosynthetic efficiency of the uvr8 mutant compared to wild-type.
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Affiliation(s)
- Matthew P Davey
- Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN, UK
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16
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Combinatorial signal integration by APETALA2/Ethylene Response Factor (ERF)-transcription factors and the involvement of AP2-2 in starvation response. Int J Mol Sci 2012; 13:5933-5951. [PMID: 22754341 PMCID: PMC3382747 DOI: 10.3390/ijms13055933] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/21/2012] [Accepted: 05/08/2012] [Indexed: 12/24/2022] Open
Abstract
Transcription factors of the APETALA 2/Ethylene Response Factor (AP2/ERF)- family have been implicated in diverse processes during development, stress acclimation and retrograde signaling. Fifty-three leaf-expressed AP2/ERFs were screened for their transcriptional response to abscisic acid (ABA), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), methylviologen (MV), sucrose and high or low light, respectively, and revealed high reactivity to these effectors. Six of them (AP2-2, ARF14, CEJ1, ERF8, ERF11, RAP2.5) were selected for combinatorial response analysis to ABA, DCMU and high light. Additive, synergistic and antagonistic effects demonstrated that these transcription factors are components of multiple signaling pathways. AP2-2 (At1g79700) was subjected to an in depth study. AP2-2 transcripts were high under conditions linked to limited carbohydrate availability and stress and down-regulated in extended light phase, high light or in the presence of sugar. ap2-2 knock out plants had unchanged metabolite profiles and transcript levels of co-expressed genes in extended darkness. However, ap2-2 revealed more efficient germination and faster early growth under high sugar, osmotic or salinity stress, but the difference was abolished in the absence of sugar or during subsequent growth. It is suggested that AP2-2 is involved in mediating starvation-related and hormonal signals.
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17
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Scheibe R, Dietz KJ. Reduction-oxidation network for flexible adjustment of cellular metabolism in photoautotrophic cells. PLANT, CELL & ENVIRONMENT 2012; 35:202-16. [PMID: 21410714 DOI: 10.1111/j.1365-3040.2011.02319.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Photosynthesis generates the energy carriers NADPH and ATP to be consumed in assimilatory processes. Continuous energy conversion and optimal use of the available light energy are only guaranteed when all reduction-oxidation (redox) processes are tightly controlled. A robust network links metabolism with regulation and signalling. Information on the redox situation is generated and transferred by various redox components that are parts of this network. Any imbalance in the network is sensed, and the information is transmitted in order to elicit a response at the various levels of regulation and in the different cellular compartments. Redox information within the chloroplast is derived from intersystem electron transport, the ferredoxin-NADP oxidoreductase (FNR)/NADPH branch of the redox network, the thioredoxin branch and from reactive oxygen species (ROS), resulting in a high diversity of responses that are able to adjust photosynthesis, as well as poising and antioxidant systems accordingly in each specific situation. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) represents a central step in CO(2) reduction and in carbohydrate oxidation involving both forms of energy, namely NAD(P)H and ATP, with its various isoforms that are located in plastids, cytosol and nucleus. GAPDH is used as an example to demonstrate complexity, flexibility and robustness of the regulatory redox network in plants.
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Affiliation(s)
- Renate Scheibe
- Plant Physiology, University of Osnabrueck, 49069 Osnabrueck, Germany
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18
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Oelze ML, Vogel MO, Alsharafa K, Kahmann U, Viehhauser A, Maurino VG, Dietz KJ. Efficient acclimation of the chloroplast antioxidant defence of Arabidopsis thaliana leaves in response to a 10- or 100-fold light increment and the possible involvement of retrograde signals. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1297-313. [PMID: 22131159 PMCID: PMC3276092 DOI: 10.1093/jxb/err356] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Chloroplasts are equipped with a nuclear-encoded antioxidant defence system the components of which are usually expressed at high transcript and activity levels. To significantly challenge the chloroplast antioxidant system, Arabidopsis thaliana plants, acclimated to extremely low light slightly above the light compensation point or to normal growth chamber light, were moved to high light corresponding to a 100- and 10-fold light jump, for 6 h and 24 h in order to observe the responses of the water-water cycle at the transcript, protein, enzyme activity, and metabolite levels. The plants coped efficiently with the high light regime and the photoinhibition was fully reversible. Reactive oxygen species (ROS), glutathione and ascorbate levels as well as redox states, respectively, revealed no particular oxidative stress in low-light-acclimated plants transferred to 100-fold excess light. Strong regulation of the water-water cycle enzymes at the transcript level was only partly reflected at the protein and activity levels. In general, low light plants had higher stromal (sAPX) and thylakoid ascorbate peroxidase (tAPX), dehydroascorbate reductase (DHAR), and CuZn superoxide dismutase (CuZnSOD) protein contents than normal light-grown plants. Mutants defective in components relevant for retrograde signalling, namely stn7, ex1, tpt1, and a mutant expressing E .coli catalase in the chloroplast showed unaltered transcriptional responses of water-water cycle enzymes. These findings, together with the response of marker transcripts, indicate that abscisic acid is not involved and that the plastoquinone redox state and reactive oxygen species do not play a major role in regulating the transcriptional response at t=6 h, while other marker transcripts suggest a major role for reductive power, metabolites, and lipids as signals for the response of the water-water cycle.
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Affiliation(s)
- Marie-Luise Oelze
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
| | - Marc Oliver Vogel
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
| | - Khalid Alsharafa
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
| | - Uwe Kahmann
- Zentrum für Ultrastrukturelle Diagnostik, Bielefeld University, D-33501 Bielefeld, Germany
| | - Andrea Viehhauser
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
| | - Veronica G. Maurino
- Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Bielefeld University, D-33501 Bielefeld, Germany
- To whom correspondence should be addressed. E-mail:
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Klein P, Seidel T, Stöcker B, Dietz KJ. The membrane-tethered transcription factor ANAC089 serves as redox-dependent suppressor of stromal ascorbate peroxidase gene expression. FRONTIERS IN PLANT SCIENCE 2012; 3:247. [PMID: 23162559 PMCID: PMC3493970 DOI: 10.3389/fpls.2012.00247] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/19/2012] [Indexed: 05/03/2023]
Abstract
The stromal ascorbate peroxidase (sAPX) functions as central element of the chloroplast antioxidant defense system. Its expression is under retrograde control of chloroplast signals including redox- and reactive oxygen species-linked cues. The sAPX promoter of Arabidopsis thaliana was dissected in transient reporter assays using mesophyll protoplasts. The study revealed regulatory elements up to -1868 upstream of the start codon. By yeast-one-hybrid screening, the transcription factor ANAC089 was identified to bind to the promoter fragment 2 (-1262 to -1646 bp upstream of translational initiation). Upon mutation of the cis-acting element CACG, binding of ANAC089 was abolished. Expression of a fused fluorescent protein version and comparison with known endomembrane markers localized ANAC089 to the trans-Golgi network and the ER. The transcription factor was released upon treatment with reducing agents and targeted to the nucleus. Transactivation assays using wild type and mutated versions of the promoter showed a partial suppression of reporter expression. The data indicate that ANAC089 functions in a negative retrograde loop, lowering sAPX expression if the cell encounters a highly reducing condition. This conclusion was supported by reciprocal transcript accumulation of ANAC089 and sAPX during acclimation to low, normal, and high light conditions.
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Affiliation(s)
| | | | | | - Karl-Josef Dietz
- *Correspondence: Karl-Josef Dietz, Biochemistry and Physiology of Plants, W5-134, Faculty of Biology and CeBiTec, Bielefeld University, 33501 Bielefeld, Germany. e-mail:
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Couturier J, Ströher E, Albetel AN, Roret T, Muthuramalingam M, Tarrago L, Seidel T, Tsan P, Jacquot JP, Johnson MK, Dietz KJ, Didierjean C, Rouhier N. Arabidopsis chloroplastic glutaredoxin C5 as a model to explore molecular determinants for iron-sulfur cluster binding into glutaredoxins. J Biol Chem 2011; 286:27515-27. [PMID: 21632542 DOI: 10.1074/jbc.m111.228726] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Unlike thioredoxins, glutaredoxins are involved in iron-sulfur cluster assembly and in reduction of specific disulfides (i.e. protein-glutathione adducts), and thus they are also important redox regulators of chloroplast metabolism. Using GFP fusion, AtGrxC5 isoform, present exclusively in Brassicaceae, was shown to be localized in chloroplasts. A comparison of the biochemical, structural, and spectroscopic properties of Arabidopsis GrxC5 (WCSYC active site) with poplar GrxS12 (WCSYS active site), a chloroplastic paralog, indicated that, contrary to the solely apomonomeric GrxS12 isoform, AtGrxC5 exists as two forms when expressed in Escherichia coli. The monomeric apoprotein possesses deglutathionylation activity mediating the recycling of plastidial methionine sulfoxide reductase B1 and peroxiredoxin IIE, whereas the dimeric holoprotein incorporates a [2Fe-2S] cluster. Site-directed mutagenesis experiments and resolution of the x-ray crystal structure of AtGrxC5 in its holoform revealed that, although not involved in its ligation, the presence of the second active site cysteine (Cys(32)) is required for cluster formation. In addition, thiol titrations, fluorescence measurements, and mass spectrometry analyses showed that, despite the presence of a dithiol active site, AtGrxC5 does not form any inter- or intramolecular disulfide bond and that its activity exclusively relies on a monothiol mechanism.
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Affiliation(s)
- Jérémy Couturier
- Unité Mixte de Recherches 1136, Institut National de la Recherche Agronomique-Nancy Université, Interactions Arbres Microorganismes, Institut Fédératif de Recherche 110 Ecosystèmes Forestiers, Agroressources, Biomolécule et Alimentation, 54506 Vandoeuvre-lès-Nancy Cedex, France
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Shaikhali J, Baier M. Ascorbate regulation of 2-Cys peroxiredoxin-A promoter activity is light-dependent. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:461-467. [PMID: 20022402 DOI: 10.1016/j.jplph.2009.10.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 10/17/2009] [Accepted: 10/18/2009] [Indexed: 05/28/2023]
Abstract
The 2-Cys peroxiredoxin-A (2CPA) promoter is a model promoter to study redox and ABA-dependent stress signaling. Here, an Arabidopsis reporter gene line expressing luciferase under control of the 2CPA promoter was used to study the impact of ascorbate on reporter gene transcription in a series of protoplast and leaf slice incubation experiments. It was shown that ascorbate has a dual function on gene expression regulation. First, a comparison of responses to ascorbate, dehydroascorbate and reduced and oxidized glutathione demonstrated that ascorbate feeding supports gene expression regulation by increasing the catalytic capacity in redox signaling, as defined by the concentration of low molecular weight antioxidants and their oxidized counterparts. Second, ascorbate had a specific and light-dependent effect on 2CPA transcription, which cannot be substituted by reduced glutathione. Based on the differences between ascorbate and glutathione in the subcellular redox-cycling capacities, it is concluded that ascorbate feeding modulates chloroplast-specific regulation of 2CPA expression.
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Bräutigam K, Dietzel L, Kleine T, Ströher E, Wormuth D, Dietz KJ, Radke D, Wirtz M, Hell R, Dörmann P, Nunes-Nesi A, Schauer N, Fernie AR, Oliver SN, Geigenberger P, Leister D, Pfannschmidt T. Dynamic plastid redox signals integrate gene expression and metabolism to induce distinct metabolic states in photosynthetic acclimation in Arabidopsis. THE PLANT CELL 2009; 21:2715-32. [PMID: 19737978 PMCID: PMC2768923 DOI: 10.1105/tpc.108.062018] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 07/22/2009] [Accepted: 08/20/2009] [Indexed: 05/18/2023]
Abstract
Plants possess acclimation responses in which structural reconfigurations adapt the photosynthetic apparatus to fluctuating illumination. Long-term acclimation involves changes in plastid and nuclear gene expression and is controlled by redox signals from photosynthesis. The kinetics of these signals and the adjustments of energetic and metabolic demands to the changes in the photosynthetic apparatus are currently poorly understood. Using a redox signaling system that preferentially excites either photosystem I or II, we measured the time-dependent impact of redox signals on the transcriptome and metabolome of Arabidopsis thaliana. We observed rapid and dynamic changes in nuclear transcript accumulation resulting in differential and specific expression patterns for genes associated with photosynthesis and metabolism. Metabolite pools also exhibited dynamic changes and indicate readjustments between distinct metabolic states depending on the respective illumination. These states reflect reallocation of energy resources in a defined and reversible manner, indicating that structural changes in the photosynthetic apparatus during long-term acclimation are additionally supported at the level of metabolism. We propose that photosynthesis can act as an environmental sensor, producing retrograde redox signals that trigger two parallel adjustment loops that coordinate photosynthesis and metabolism to adapt plant primary productivity to the environment.
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Affiliation(s)
- Katharina Bräutigam
- Nachwuchsgruppe Pflanzliche Anpassung an Umweltveränderungen: Proteinanalyse mittels MS, Lehrstuhl für Pflanzenphysiologie, Institut für Allgemeine Botanik und Pflanzenphysiologie, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
| | - Lars Dietzel
- Nachwuchsgruppe Pflanzliche Anpassung an Umweltveränderungen: Proteinanalyse mittels MS, Lehrstuhl für Pflanzenphysiologie, Institut für Allgemeine Botanik und Pflanzenphysiologie, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
| | - Tatjana Kleine
- Lehrstuhl für Botanik, Department Biologie I, Ludwig-Maximilians-Universität, 82152 Martinsried, Germany
| | - Elke Ströher
- Lehrstuhl für Biochemie und Pflanzenphysiologie, Universität Bielefeld, 33615 Bielefeld, Germany
| | - Dennis Wormuth
- Lehrstuhl für Biochemie und Pflanzenphysiologie, Universität Bielefeld, 33615 Bielefeld, Germany
| | - Karl-Josef Dietz
- Lehrstuhl für Biochemie und Pflanzenphysiologie, Universität Bielefeld, 33615 Bielefeld, Germany
| | - Dörte Radke
- Hans Knöll Institute, 07745 Jena, Germany
- Institute for Community Medicine, Ernst Moritz Arndt University of Greifswald, 17475 Greifswald, Germany
| | - Markus Wirtz
- Heidelberg Institute of Plant Sciences, University of Heidelberg, 69120 Heidelberg, Germany
| | - Rüdiger Hell
- Heidelberg Institute of Plant Sciences, University of Heidelberg, 69120 Heidelberg, Germany
| | - Peter Dörmann
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Adriano Nunes-Nesi
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Nicolas Schauer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Alisdair R. Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Sandra N. Oliver
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | - Peter Geigenberger
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
- Department Biologie I, Ludwig-Maximilians-Universität, 82152 Martinsried, Germany
| | - Dario Leister
- Lehrstuhl für Botanik, Department Biologie I, Ludwig-Maximilians-Universität, 82152 Martinsried, Germany
| | - Thomas Pfannschmidt
- Nachwuchsgruppe Pflanzliche Anpassung an Umweltveränderungen: Proteinanalyse mittels MS, Lehrstuhl für Pflanzenphysiologie, Institut für Allgemeine Botanik und Pflanzenphysiologie, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
- Address correspondence to
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Reinbothe C, Springer A, Samol I, Reinbothe S. Plant oxylipins: role of jasmonic acid during programmed cell death, defence and leaf senescence. FEBS J 2009; 276:4666-81. [PMID: 19663906 DOI: 10.1111/j.1742-4658.2009.07193.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Plants are continuously challenged by a variety of abiotic and biotic cues. To deter feeding insects, nematodes and fungal and bacterial pathogens, plants have evolved a plethora of defence strategies. A central player in many of these defence responses is jasmonic acid. It is the aim of this minireview to summarize recent findings that highlight the role of jasmonic acid during programmed cell death, plant defence and leaf senescence.
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24
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Ströher E, Wang XJ, Roloff N, Klein P, Husemann A, Dietz KJ. Redox-dependent regulation of the stress-induced zinc-finger protein SAP12 in Arabidopsis thaliana. MOLECULAR PLANT 2009; 2:357-67. [PMID: 19825620 DOI: 10.1093/mp/ssn084] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The stress-associated protein SAP12 belongs to the stress-associated protein (SAP) family with 14 members in Arabidopsis thaliana. SAP12 contains two AN1 zinc fingers and was identified in diagonal 2D redox SDS-PAGE as a protein undergoing major redox-dependent conformational changes. Its transcript was strongly induced under cold and salt stress in a time-dependent manner similar to SAP10, with high levels after 6 h and decreasing levels after 24 and 48 h. The transcript regulation resembled those of the stress marker peroxiredoxin PrxIID at 24 and 48 h. Recombinant SAP12 protein showed redox-dependent changes in quaternary structure as visualized by altered electrophoretic mobility in non-reducing SDS polyacrylamide gel electrophoresis. The oxidized oligomer was reduced by high dithiothreitol concentrations, and also by E. coli thioredoxin TrxA with low dithiothreitol (DTT) concentrations or NADPH plus NADPH-dependent thioredoxin reductase. From Western blots, the SAP12 protein amount was estimated to be in the range of 0.5 ng mug(-1) leaf protein. SAP12 protein decreased under salt and cold stress. These data suggest a redox state-linked function of SAP12 in plant cells particularly under cold and salt stress.
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Affiliation(s)
- Elke Ströher
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
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Kotchoni SO, Larrimore KE, Mukherjee M, Kempinski CF, Barth C. Alterations in the endogenous ascorbic acid content affect flowering time in Arabidopsis. PLANT PHYSIOLOGY 2009; 149:803-15. [PMID: 19028878 PMCID: PMC2633856 DOI: 10.1104/pp.108.132324] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 11/17/2008] [Indexed: 05/18/2023]
Abstract
Ascorbic acid (AA) protects plants against abiotic stress. Previous studies suggested that this antioxidant is also involved in the control of flowering. To decipher how AA influences flowering time, we studied the four AA-deficient Arabidopsis (Arabidopsis thaliana) mutants vtc1-1, vtc2-1, vtc3-1, and vtc4-1 when grown under short and long days. These mutants flowered and senesced before the wild type irrespective of the photoperiod, a response that cannot simply be attributed to slightly elevated oxidative stress in the mutants. Transcript profiling of various flowering pathway genes revealed a correlation of altered mRNA levels and flowering time. For example, circadian clock and photoperiodic pathway genes were significantly higher in the vtc mutants than in the wild type under both short and long days, a result that is consistent with the early-flowering phenotype of the mutants. In contrast, when the AA content was artificially increased, flowering was delayed, which correlated with lower mRNA levels of circadian clock and photoperiodic pathway genes compared with plants treated with water. Similar observations were made for the autonomous pathway. Genetic analyses demonstrated that various photoperiodic and autonomous pathway mutants are epistatic to the vtc1-1 mutant. In conclusion, our transcript and genetic analyses suggest that AA acts upstream of the photoperiodic and autonomous pathways.
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Affiliation(s)
- Simeon O Kotchoni
- Department of Biology, West Virginia University, Morgantown, West Virginia 26506, USA
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26
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Pfannschmidt T, Bräutigam K, Wagner R, Dietzel L, Schröter Y, Steiner S, Nykytenko A. Potential regulation of gene expression in photosynthetic cells by redox and energy state: approaches towards better understanding. ANNALS OF BOTANY 2009; 103:599-607. [PMID: 18492734 PMCID: PMC2707342 DOI: 10.1093/aob/mcn081] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 03/11/2008] [Accepted: 04/21/2008] [Indexed: 05/18/2023]
Abstract
BACKGROUND Photosynthetic electron transport is performed by a chain of redox components that are electrochemically connected in series. Its efficiency depends on the balanced action of the photosystems and on the interaction with the dark reaction. Plants are sessile and cannot escape from environmental conditions such as fluctuating illumination, limitation of CO(2) fixation by low temperatures, salinity, or low nutrient or water availability, which disturb the homeostasis of the photosynthetic process. Photosynthetic organisms, therefore, have developed various molecular acclimation mechanisms that maintain or restore photosynthetic efficiency under adverse conditions and counteract abiotic stresses. Recent studies indicate that redox signals from photosynthetic electron transport and reactive oxygen species (ROS) or ROS-scavenging molecules play a central role in the regulation of acclimation and stress responses. SCOPE The underlying signalling network of photosynthetic redox control is largely unknown, but it is already apparent that gene regulation by redox signals is of major importance for plants. Signalling cascades controlling the expression of chloroplast and nuclear genes have been identified and dissection of the different pathways is advancing. Because of the direction of information flow, photosynthetic redox signals can be defined as a distinct class of retrograde signals in addition to signals from organellar gene expression or pigment biosynthesis. They represent a vital signal of mature chloroplasts that report their present functional state to the nucleus. Here we describe possible problems in the elucidation of redox signalling networks and discuss some aspects of plant cell biology that are important for developing suitable experimental approaches. CONCLUSIONS The photosynthetic function of chloroplasts represents an important sensor that integrates various abiotic changes in the environment into corresponding molecular signals, which, in turn, regulate cellular activities to counterbalance the environmental changes or stresses.
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Lawlor DW, Tezara W. Causes of decreased photosynthetic rate and metabolic capacity in water-deficient leaf cells: a critical evaluation of mechanisms and integration of processes. ANNALS OF BOTANY 2009; 103:561-79. [PMID: 19155221 PMCID: PMC2707350 DOI: 10.1093/aob/mcn244] [Citation(s) in RCA: 293] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 08/27/2008] [Accepted: 11/10/2008] [Indexed: 05/18/2023]
Abstract
BACKGROUND Water deficit (WD) decreases photosynthetic rate (A) via decreased stomatal conductance to CO(2) (g(s)) and photosynthetic metabolic potential (A(pot)). The relative importance of g(s) and A(pot), and how they are affected by WD, are reviewed with respect to light intensity and to experimental approaches. SCOPE AND CONCLUSIONS With progressive WD, A decreases as g(s) falls. Under low light during growth and WD, A is stimulated by elevated CO(2), showing that metabolism (A(pot)) is not impaired, but at high light A is not stimulated, showing inhibition. At a given intercellular CO(2) concentration (C(i)) A decreases, showing impaired metabolism (A(pot)). The C(i) and probably chloroplast CO(2) concentration (C(c)), decreases and then increases, together with the equilibrium CO(2) concentration, with greater WD. Estimation of C(c) and internal (mesophyll) conductance (g(i)) is considered uncertain. Photosystem activity is unaffected until very severe WD, maintaining electron (e(-)) transport (ET) and reductant content. Low A, together with photorespiration (PR), which is maintained or decreased, provides a smaller sink for e(-)(,) causing over-energization of energy transduction. Despite increased non-photochemical quenching (NPQ), excess energy and e(-) result in generation of reactive oxygen species (ROS). Evidence is considered that ROS damages ATP synthase so that ATP content decreases progressively with WD. Decreased ATP limits RuBP production by the Calvin cycle and thus A(pot). Rubisco activity is unlikely to determine A(pot). Sucrose synthesis is limited by lack of substrate and impaired enzyme regulation. With WD, PR decreases relative to light respiration (R(L)), and mitochondria consume reductant and synthesise ATP. With progressing WD at low A, R(L) increases C(i) and C(c). This review emphasises the effects of light intensity, considers techniques, and develops a qualitative model of photosynthetic metabolism under WD that explains many observations: testable hypotheses are suggested.
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Affiliation(s)
- David W Lawlor
- Plant Sciences, Centre for Crop Improvement, Rothamsted Research, Harpenden, Herts, UK.
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Regulation of nif gene expression and the energetics of N2 fixation over the diel cycle in a hot spring microbial mat. ISME JOURNAL 2008; 2:364-78. [PMID: 18323780 DOI: 10.1038/ismej.2007.117] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Nitrogen fixation, a prokaryotic, O2-inhibited process that reduces N2 gas to biomass, is of paramount importance in biogeochemical cycling of nitrogen. We analyzed the levels of nif transcripts of Synechococcus ecotypes, NifH subunit and nitrogenase activity over the diel cycle in the microbial mat of an alkaline hot spring in Yellowstone National Park. The results showed a rise in nif transcripts in the evening, with a subsequent decline over the course of the night. In contrast, immunological data demonstrated that the level of the NifH polypeptide remained stable during the night, and only declined when the mat became oxic in the morning. Nitrogenase activity was low throughout the night; however, it exhibited two peaks, a small one in the evening and a large one in the early morning, when light began to stimulate cyanobacterial photosynthetic activity, but O2 consumption by respiration still exceeded the rate of O2 evolution. Once the irradiance increased to the point at which the mat became oxic, the nitrogenase activity was strongly inhibited. Transcripts for proteins associated with energy-producing metabolisms in the cell also followed diel patterns, with fermentation-related transcripts accumulating at night, photosynthesis- and respiration-related transcripts accumulating during the day and late afternoon, respectively. These results are discussed with respect to the energetics and regulation of N2 fixation in hot spring mats and factors that can markedly influence the extent of N2 fixation over the diel cycle.
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Wormuth D, Heiber I, Shaikali J, Kandlbinder A, Baier M, Dietz KJ. Redox regulation and antioxidative defence in Arabidopsis leaves viewed from a systems biology perspective. J Biotechnol 2007; 129:229-48. [PMID: 17207878 DOI: 10.1016/j.jbiotec.2006.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 11/11/2006] [Accepted: 12/04/2006] [Indexed: 12/18/2022]
Abstract
Redox regulation is a central control element in cell metabolism. It is employed to adjust photosynthesis and the antioxidant defence system of leaves to the prevailing environment. During recent years progress has been made in describing the redox-dependent alterations in metabolism, the thiol/disulfide proteome, the redox-dependent and cross-talking signalling pathways and the target genes of redox regulation. Some transcription factors have been identified as proteins that perform thiol/disulfide transitions linked to the redox-regulation of specific plant promoters. In addition first mathematical models have been designed to simulate antioxidant defence and predict its response. Taken together, a profound experimental data set has been generated which allows to approach a systems biology type of understanding of antioxidant defence in photosynthesising cells in the near future. Since oxidative stress is likely to limit plant growth under stress, such a systematic understanding of antioxidant defence will help to define novel targets for breeding stress-tolerant plants.
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Affiliation(s)
- Dennis Wormuth
- Biochemistry and Physiology of Plants, Faculty of Biology, W5, Bielefeld University, 33501 Bielefeld, Germany
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Heiber I, Ströher E, Raatz B, Busse I, Kahmann U, Bevan MW, Dietz KJ, Baier M. The redox imbalanced mutants of Arabidopsis differentiate signaling pathways for redox regulation of chloroplast antioxidant enzymes. PLANT PHYSIOLOGY 2007; 143:1774-88. [PMID: 17337533 PMCID: PMC1851819 DOI: 10.1104/pp.106.093328] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A network of enzymatic and nonenzymatic antioxidants protects chloroplasts from photooxidative damage. With all enzymatic components being nuclear encoded, the control of the antioxidant capacity depends on chloroplast-to-nucleus redox signaling. Using an Arabidopsis (Arabidopsis thaliana) reporter gene line expressing luciferase under control of the redox-sensitive 2-cysteine peroxiredoxin A (2CPA) promoter, six mutants with low 2CPA promoter activity were isolated, of which five mutants show limitations in redox-box regulation of the 2CPA promoter. In addition to 2CPA, the transcript levels for other chloroplast antioxidant enzymes were decreased, although a higher oxidation status of the ascorbate pool, a higher reduction state of the plastoquinone pool, and an increased oxidation status of the 2-Cys peroxiredoxin pool demonstrated photooxidative stress conditions. Greening of the mutants, chloroplast ultrastructure, steady-state photosynthesis, and the responses to the stress hormone abscisic acid were wild type like. In the rosette state, the mutants were more sensitive to low CO2 and to hydrogen peroxide. Comparison of gene expression patterns and stress sensitivity characterizes the mutants as redox imbalanced in the regulation of nuclear-encoded chloroplast antioxidant enzymes and differentiates redox signaling cascades.
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Affiliation(s)
- Isabelle Heiber
- Biochemistry and Physiology of Plants , Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
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