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Doll NM, Nowack MK. Endosperm cell death: roles and regulation in angiosperms. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4346-4359. [PMID: 38364847 PMCID: PMC7616292 DOI: 10.1093/jxb/erae052] [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: 12/11/2023] [Accepted: 02/08/2024] [Indexed: 02/18/2024]
Abstract
Double fertilization in angiosperms results in the formation of a second zygote, the fertilized endosperm. Unlike its embryo sibling, the endosperm is a transient structure that eventually undergoes developmentally controlled programmed cell death (PCD) at specific time points of seed development or germination. The nature of endosperm PCD exhibits a considerable diversity, both across different angiosperm taxa and within distinct endosperm tissues. In endosperm-less species, PCD might cause central cell degeneration as a mechanism preventing the formation of a fertilized endosperm. In most other angiosperms, embryo growth necessitates the elimination of surrounding endosperm cells. Nevertheless, complete elimination of the endosperm is rare and, in most cases, specific endosperm tissues persist. In mature seeds, these persisting cells may be dead, such as the starchy endosperm in cereals, or remain alive to die only during germination, like the cereal aleurone or the endosperm of castor beans. In this review, we explore current knowledge surrounding the cellular, molecular, and genetic aspects of endosperm PCD, and the influence environmental stresses have on PCD processes. Overall, this review provides an exhaustive overview of endosperm PCD processes in angiosperms, shedding light on its diverse mechanisms and its significance in seed development and seedling establishment.
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Affiliation(s)
- Nicolas M. Doll
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center of Plant Systems Biology, Ghent 9052, Belgium
| | - Moritz K. Nowack
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center of Plant Systems Biology, Ghent 9052, Belgium
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2
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Guan L, Yin L, Liu Y, Yan J, Wang B, Luan M, Lan W. A plasma membrane-localized transporter remobilizes aleurone layer magnesium for seed germination in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 38837713 DOI: 10.1111/tpj.16867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/21/2024] [Accepted: 05/25/2024] [Indexed: 06/07/2024]
Abstract
The aleurone layer in cereal grains acts as a major reservoir of essential mineral nutrients, significantly influencing seed germination. However, the molecular mechanism underlying the redistribution of nutrients from the aleurone layer in the germinating seed is still not well understood. Here, in rice, we identified a plasma membrane (PM) localized magnesium transporter, MAGNESIUM RELEASE TRANSPORTER 3 (MGR3), is critical for seed germination. OsMGR3 is predominantly expressed in the aleurone layer cells of endosperm, facilitating magnesium remobilization during germination. Non-invasive Micro-test Technology assay data demonstrated that the loss-of-function of OsMGR3 restrained magnesium efflux from the aleurone layer. In the embryo/endosperm grafting experiment, we observed that the mutation of OsMGR3 in the aleurone layer suppressed the growth and differentiation of the embryo during germination. Furthermore, magnesium fluorescence imaging revealed the osmgr3 mutant seeds showed impaired exportation of aleurone layer-stored magnesium to the embryo, consequently delaying germination. Importantly, we discovered that disrupting OsMGR3 could inhibit pre-harvest sprouting without affecting rice yield and quality. Therefore, the magnesium efflux transporter OsMGR3 in the aleurone layer represents a promising genetic target for future agronomic trait improvement.
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Affiliation(s)
- Liurong Guan
- School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Li Yin
- Institute of Future Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yingna Liu
- Institute of Future Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jun Yan
- Institute of Future Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Bin Wang
- School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Mingda Luan
- Institute of Future Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Wenzhi Lan
- Institute of Future Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
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Sun Y, Zhang F, Wei J, Song K, Sun L, Yang Y, Qin Q, Yang S, Li Z, Xu G, Sun S, Xue Y. Phosphate Transporter OsPT4, Ubiquitinated by E3 Ligase OsAIRP2, Plays a Crucial Role in Phosphorus and Nitrogen Translocation and Consumption in Germinating Seed. RICE (NEW YORK, N.Y.) 2023; 16:54. [PMID: 38052756 PMCID: PMC10697913 DOI: 10.1186/s12284-023-00666-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/18/2023] [Indexed: 12/07/2023]
Abstract
Phosphorus (P) and nitrogen (N) are essential macronutrients necessary for plant growth and development. OsPT4 is a high-affinity phosphate (Pi) transporter that has a positive impact on nutrient uptake and seed development. In this study, the expression patterns of different Pi transporter genes in germinating seeds were determined, and the relative expression of OsPT4 was induced in Pi-deficient seeds and gradually increased with the passage of germination time. The analysis of P, N, Pi, and amino acid concentrations in germinating seeds of OsPT4 mutants showed that the OsPT4 mutation caused P and N retention and a continuous reduction in multiple amino acid concentrations in germinating seeds. Transcriptome analysis and qRT-PCR results also indicated that the OsPT4 mutation inhibits the expression of genes related to P and N transportation and amino acid synthesis in germinating seeds. In addition, the paraffin section and TUNEL assay of OsPT4 mutant germinating seeds suggests that OsPT4 mutation causes programmed cell death (PCD) delayed in the aleurone layer and inhibition of leaf outgrowth. Moreover, we also found that OsPT4 was ubiquitinated by OsAIRP2, which is a C3HC4-type RING E3 Ub ligase. Our studies illustrate that OsPT4 plays a crucial role in P and N collaborative translocation and consumption in germinating seeds. It also provides a theoretical basis for the molecules and physiological mechanisms of P and N cross-talk under suppressed Pi uptake conditions.
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Affiliation(s)
- Yafei Sun
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Fang Zhang
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Jia Wei
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Ke Song
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Lijuan Sun
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Yang Yang
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Qin Qin
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Shiyan Yang
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Zhouwen Li
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shubin Sun
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yong Xue
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China.
- Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China.
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Kaźmierczak A, Tarkowská D, Plačková L, Doniak M, Doležal K. Hormonal crosstalk controls cell death induced by kinetin in roots of Vicia faba ssp. minor seedlings. Sci Rep 2023; 13:11661. [PMID: 37468550 DOI: 10.1038/s41598-023-38641-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023] Open
Abstract
Studies of vitality/mortality of cortex cells, as well as of the concentrations of ethylene (ETH), gibberellins (GAs), indolic compounds/auxins (ICs/AUXs) and cytokinins (CKs), were undertaken to explain the hormonal background of kinetin (Kin)-regulated cell death (RCD), which is induced in the cortex of the apical parts of roots of faba bean (Vicia faba ssp. minor) seedlings. Quantification was carried out with fluorescence microscopy, ETH sensors, spectrophotometry and ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS). The results indicated that Kin was metabolized to the transport form, i.e., kinetin-9-glucoside (Kin9G) and kinetin riboside (KinR). KinR was then converted to cis-zeatin (cZ) in apical parts of roots with meristems, to cis-zeatin riboside (cZR) in apical parts of roots without meristems and finally to cis-zeatin riboside 5'-monophosphate (cZR5'MP), which is indicated to be a ligand of cytokinin-dependent receptors inducing CD. The process may be enhanced by an increase in the amount of dihydrozeatin riboside (DHZR) as a byproduct of the pathway of zeatin metabolism. It seems that crosstalk of ETH, ICs/AUXs, GAs and CKs with the cZR5'MP, the cis-zeatin-dependent pathway, but not the trans-zeatin-dependent pathway, is responsible for Kin-RCD, indicating that the process is very specific and offers a useful model for studies of CD hallmarks in plants.
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Affiliation(s)
- Andrzej Kaźmierczak
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland.
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany Academy of Sciences of the Czech Republic and Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Lenka Plačková
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences, and Faculty of Science Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Magdalena Doniak
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland
| | - Karel Doležal
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences, and Faculty of Science Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
- Department of Chemical Biology and Genetics, Center of Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
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5
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Doronina TV, Sheval EV, Lazareva EM. Programmed Cell Death during Formation of the Embryo Sac and Seed. Russ J Dev Biol 2020. [DOI: 10.1134/s1062360420030029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Markers of Developmentally Regulated Programmed Cell Death and Their Analysis in Cereal Seeds. Methods Mol Biol 2018; 1743:21-37. [PMID: 29332283 DOI: 10.1007/978-1-4939-7668-3_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Programmed cell death (PCD) is a key process for the development and differentiation of multicellular organisms, which is characterized by well-defined morphological and biochemical features. These include chromatin condensation, DNA degradation and nuclear fragmentation, with nucleases and proteases playing a relevant function in these processes. In this chapter we describe methods routinely used for the analysis of hallmarks of developmentally regulated PCD in cereal seed tissues, which are based on agarose and polyacrylamide gel electrophoresis, in situ staining of DNA fragmentation, and cell-free assays of relevant enzymatic activities.
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Gerna D, Roach T, Stöggl W, Wagner J, Vaccino P, Limonta M, Kranner I. Changes in low-molecular-weight thiol-disulphide redox couples are part of bread wheat seed germination and early seedling growth. Free Radic Res 2017; 51:568-581. [PMID: 28580817 DOI: 10.1080/10715762.2017.1338344] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The tripeptide antioxidant glutathione (γ-l-glutamyl-l-cysteinyl-glycine; GSH) essentially contributes to thiol-disulphide conversions, which are involved in the control of seed development, germination, and seedling establishment. However, the relative contribution of GSH metabolism in different seed structures is not fully understood. We studied the GSH/glutathione disulphide (GSSG) redox couple and associated low-molecular-weight (LMW) thiols and disulphides related to GSH metabolism in bread wheat (Triticum aestivum L.) seeds, focussing on redox changes in the embryo and endosperm during germination. In dry seeds, GSH was the predominant LMW thiol and, 15 h after the onset of imbibition, embryos of non-germinated seeds contained 12 times more LMW thiols than the endosperm. In germinated seeds, the embryo contained 17 and 11 times more LMW thiols than the endosperm after 15 and 48 h, respectively. This resulted in the embryo having significantly more reducing half-cell reduction potentials of GSH/GSSG and cysteine (Cys)/cystine (CySS) redox couples (EGSSG/2GSH and ECySS/2Cys, respectively). Upon seed germination and early seedling growth, Cys and CySS concentrations significantly increased in both embryo and endosperm, progressively contributing to the cellular LMW thiol-disulphide redox environment (Ethiol-disulphide). The changes in ECySS/2Cys could be related to the mobilisation of storage proteins in the endosperm during early seedling growth. We suggest that EGSSG/2GSH and ECySS/2Cys can be used as markers of the physiological and developmental stage of embryo and endosperm. We also present a model of interaction between LMW thiols and disulphides with hydrogen peroxide (H2O2) in redox regulation of bread wheat germination and early seedling growth.
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Affiliation(s)
- Davide Gerna
- a Department of Botany , Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innsbruck , Austria
| | - Thomas Roach
- a Department of Botany , Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innsbruck , Austria
| | - Wolfgang Stöggl
- a Department of Botany , Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innsbruck , Austria
| | - Johanna Wagner
- a Department of Botany , Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innsbruck , Austria
| | - Patrizia Vaccino
- b Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria , Research Unit for Cereal Selection in Continental Areas, S . Angelo Lodigiano , Italy
| | - Margherita Limonta
- b Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria , Research Unit for Cereal Selection in Continental Areas, S . Angelo Lodigiano , Italy
| | - Ilse Kranner
- a Department of Botany , Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innsbruck , Austria
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8
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Escamez S, Tuominen H. Contribution of cellular autolysis to tissular functions during plant development. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:124-130. [PMID: 27936412 DOI: 10.1016/j.pbi.2016.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/23/2016] [Accepted: 11/25/2016] [Indexed: 05/26/2023]
Abstract
Plant development requires specific cells to be eliminated in a predictable and genetically regulated manner referred to as programmed cell death (PCD). However, the target cells do not merely die but they also undergo autolysis to degrade their cellular corpses. Recent progress in understanding developmental cell elimination suggests that distinct proteins execute PCD sensu stricto and autolysis. In addition, cell death alone and cell dismantlement can fulfill different functions. Hence, it appears biologically meaningful to distinguish between the modules of PCD and autolysis during plant development.
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Affiliation(s)
- Sacha Escamez
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90187 Umeå, Sweden
| | - Hannele Tuominen
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90187 Umeå, Sweden.
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9
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The relationship between vacuolation and initiation of PCD in rice (Oryza sativa) aleurone cells. Sci Rep 2017; 7:41245. [PMID: 28117452 PMCID: PMC5259747 DOI: 10.1038/srep41245] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 12/19/2016] [Indexed: 02/05/2023] Open
Abstract
Vacuole fusion is a necessary process for the establishment of a large central vacuole, which is the central location of various hydrolytic enzymes and other factors involved in death at the beginning of plant programmed cell death (PCD). In our report, the fusion of vacuoles has been presented in two ways: i) small vacuoles coalesce to form larger vacuoles through membrane fusion, and ii) larger vacuoles combine with small vacuoles when small vacuoles embed into larger vacuoles. Regardless of how fusion occurs, a large central vacuole is formed in rice (Oryza sativa) aleurone cells. Along with the development of vacuolation, the rupture of the large central vacuole leads to the loss of the intact plasma membrane and the degradation of the nucleus, resulting in cell death. Stabilizing or disrupting the structure of actin filaments (AFs) inhibits or promotes the fusion of vacuoles, which delays or induces PCD. In addition, the inhibitors of the vacuolar processing enzyme (VPE) and cathepsin B (CathB) block the occurrence of the large central vacuole and delay the progression of PCD in rice aleurone layers. Overall, our findings provide further evidence for the rupture of the large central vacuole triggering the PCD in aleruone layers.
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Wu H, Zheng Y, Liu J, Zhang H, Chen H. Heme Oxygenase-1 Delays Gibberellin-Induced Programmed Cell Death of Rice Aleurone Layers Subjected to Drought Stress by Interacting with Nitric Oxide. FRONTIERS IN PLANT SCIENCE 2016; 6:1267. [PMID: 26834769 PMCID: PMC4717306 DOI: 10.3389/fpls.2015.01267] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/28/2015] [Indexed: 05/25/2023]
Abstract
Cereal aleurone layers undergo a gibberellin (GA)-regulated process of programmed cell death (PCD) following germination. Heme oxygenase-1 (HO-1) is known as a rate-liming enzyme in the degradation of heme to biliverdin IXα, carbon monoxide (CO), and free iron ions (Fe(2+)). It is a critical component in plant development and adaptation to environment stresses. Our previous studies confirmed that HO-1 inducer hematin (Ht) promotes the germination of rice seeds in drought (20% polyethylene glycol-6000, PEG) conditions, but the corresponding effects of HO-1 on the alleviation of germination-triggered PCD in GA-treated rice aleurone layers remain unknown. The present study has determined that GA co-treated with PEG results in lower HO-1 transcript levels and HO activity, which in turn results in the development of vacuoles in aleurone cells, followed by PCD. The pharmacology approach illustrated that up- or down-regulated HO-1 gene expression and HO activity delayed or accelerated GA-induced PCD. Furthermore, the application of the HO-1 inducer Ht and nitric oxide (NO) donor sodium nitroprusside (SNP) not only activated HO-1 gene expression, HO activity, and endogenous NO content, but also blocked GA-induced rapid vacuolation and accelerated aleurone layers PCD under drought stress. However, both HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) and NO scavenger 2-(4-carboxyphenyl0-4, 4,5,5-tetramethylimidazoline-l-oxyl-3-oxide potassium salt (cPTIO) reserved the effects of Ht and SNP on rice aleurone layer PCD under drought stress by down-regulating endogenous HO-1 and NO, respectively. The inducible effects of Ht and SNP on HO-1 gene expression, HO activity, and NO content were blocked by cPTIO. Together, these results clearly suggest that HO-1 is involved in the alleviation of GA-induced PCD of drought-triggered rice aleurone layers by associating with NO.
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López-Fernández MP, Maldonado S. Programmed cell death in seeds of angiosperms. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:996-1002. [PMID: 25953251 DOI: 10.1111/jipb.12367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/06/2015] [Indexed: 06/04/2023]
Abstract
During the diversification of angiosperms, seeds have evolved structural, chemical, molecular and physiologically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed cell death (PCD) has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.
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Affiliation(s)
- María Paula López-Fernández
- Laboratory of Plant Development, Department of Biodiversity and Experimental Biology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina
- National Research Council of Argentine (CONICET)
| | - Sara Maldonado
- Laboratory of Plant Development, Department of Biodiversity and Experimental Biology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina
- National Research Council of Argentine (CONICET)
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12
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Rybaczek D, Musiałek MW, Balcerczyk A. Caffeine-Induced Premature Chromosome Condensation Results in the Apoptosis-Like Programmed Cell Death in Root Meristems of Vicia faba. PLoS One 2015; 10:e0142307. [PMID: 26545248 PMCID: PMC4636323 DOI: 10.1371/journal.pone.0142307] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/19/2015] [Indexed: 12/27/2022] Open
Abstract
We have demonstrated that the activation of apoptosis-like programmed cell death (AL-PCD) was a secondary result of caffeine (CF) induced premature chromosome condensation (PCC) in hydroxyurea-synchronized Vicia faba root meristem cells. Initiation of the apoptotic-like cell degradation pathway seemed to be the result of DNA damage generated by treatment with hydroxyurea (HU) [double-stranded breaks (DSBs) mostly] and co-treatment with HU/CF [single-stranded breaks (SSBs) mainly]. A single chromosome comet assay was successfully used to study different types of DNA damage (neutral variant–DSBs versus alkaline–DSBs or SSBs). The immunocytochemical detection of H2AXS139Ph and PARP-2 were used as markers for DSBs and SSBs, respectively. Acridine orange and ethidium bromide (AO/EB) were applied for quantitative immunofluorescence measurements of dead, dying and living cells. Apoptotic-type DNA fragmentation and positive TUNEL reaction finally proved that CF triggers AL-PCD in stressed V. faba root meristem cells. In addition, the results obtained under transmission electron microscopy (TEM) further revealed apoptotic-like features at the ultrastructural level of PCC-type cells: (i) extensive vacuolization; (ii) abnormal chromatin condensation, its marginalization and concomitant degradation; (iii) formation of autophagy-like vesicles (iv) protoplast shrinkage (v) fragmentation of cell nuclei and (vi) extensive degeneration of the cells. The results obtained have been discussed with respect to the vacuolar/autolytic type of plant-specific AL-PCD.
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Affiliation(s)
- Dorota Rybaczek
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
- * E-mail:
| | - Marcelina Weronika Musiałek
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Aneta Balcerczyk
- Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
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Cai J, Zhang Z, Zhou Z, Yang W, Liu Y, Mei F, Zhou G, Wang L. Localization of BEN1-LIKE protein and nuclear degradation during development of metaphloem sieve elements in Triticum aestivum L. ACTA BIOLOGICA HUNGARICA 2015; 66:66-79. [PMID: 25740439 DOI: 10.1556/abiol.66.2015.1.6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Metaphloem sieve elements (MSEs) in the developing caryopsis of Triticum aestivum L. undergo a unique type of programmed cell death (PCD); cell organelles gradually degrade with the MSE differentiation while mature sieve elements keep active. This study focuses on locating BEN1-LIKE protein and nuclear degradation in differentiating MSEs of wheat. Transmission electron microscopy (TEM) showed that nuclei degraded in MSE development. First, the degradation started at 2-3 days after flowering (DAF). The degraded fragments were then swallowed by phagocytic vacuoles at 4 DAF. Finally, nuclei almost completely degraded at 5 DAF. We measured the BEN1-LIKE protein expression in differentiating MSEs. In situ hybridization showed that BEN1-LIKE mRNA was a more obvious hybridization signal at 3-4 DAF at the microscopic level. Immuno-electron microscopy further revealed that BEN1-LIKE protein was mainly localized in MSE nuclei. Furthermore, MSE differentiation was tested using a TSQ Zn2+ fluorescence probe which showed that the dynamic change of Zn2+ accumulation was similar to BEN1-LIKE protein expression. These results suggest that nucleus degradation in wheat MSEs is associated with BEN1-LIKE protein and that the expression of this protein may be regulated by Zn2+ accumulation variation.
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Affiliation(s)
- Jingtong Cai
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
| | - Zhihui Zhang
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
| | - Zhuqing Zhou
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
| | - Wenli Yang
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
| | - Yang Liu
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
| | - Fangzhu Mei
- Huazhong Agricultural University College of Plant Sciences & Technology Wuhan, Hubei 430070 China
| | - Guangsheng Zhou
- Huazhong Agricultural University College of Plant Sciences & Technology Wuhan, Hubei 430070 China
| | - Likai Wang
- Huazhong Agricultural University Laboratory of Cell Biology, College of Life Science and Technology Wuhan, Hubei 430070 China
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Granot G, Morgenstern Y, Khan A, Rapp YG, Pesok A, Nevo E, Grafi G. Internucleosomal DNA fragmentation in wild emmer wheat is catalyzed by S1-type endonucleases translocated to the nucleus upon induction of cell death. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1849:239-46. [PMID: 25497371 DOI: 10.1016/j.bbagrm.2014.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 11/17/2022]
Abstract
Leaves of cereal plants display nucleosomal fragmentation of DNA attributed to the action of nucleases induced during program cell death (PCD). Yet, the specific nuclease activity responsible for generating double strand DNA breaks (DSBs) that lead to DNA fragmentation has not been fully described. Here, we characterized a Ca2+/Mg2+-dependent S1-type endonuclease activity in leaves of wild emmer wheat (Triticum dicoccoides Köern.) capable of introducing DSBs as demonstrated by the conversion of supercoiled plasmid DNA into a linear duplex DNA. In-gel nuclease assay revealed a nuclease of about 35 kDa capable of degrading both single stranded DNA and RNA. We further showed that the endonuclease activity can be purified on Concanavalin A and treatment with peptide-N-glycosidase F (PNGase F) did not abolish its activity. Furthermore, ConA-associated endonuclease was capable of generating nucleosomal DNA fragmentation in tobacco nuclei. Since S1-type endonucleases lack canonical nuclear localization signal it was necessary to determine their subcellular localization. To this end, a cDNA encoding for a putative 34 kDa S1-type nuclease, designated TaS1-like (TaS1L) was synthesized based on available sequence data of Triticum aestivum and fused with RFP. Introduction into protoplasts showed that TaS1L-RFP is cytoplasmic 24h post transformation but gradually turn nuclear at 48 h concomitantly with induction of cell death. Our results suggest that DNA fragmentation occurring in leaves of wild emmer wheat may be attributed to S1-type endonuclease(s) that reside in the cytoplasm but translocate to the nucleus upon induction of cell death.
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Affiliation(s)
- Gila Granot
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Yaakov Morgenstern
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Asif Khan
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Yemima Givaty Rapp
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Anat Pesok
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, 199 Aba-Hushi Avenue Mount Carmel, Haifa 3498838, Israel
| | - Gideon Grafi
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel.
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Wu J, Zhu C, Pang J, Zhang X, Yang C, Xia G, Tian Y, He C. OsLOL1, a C2C2-type zinc finger protein, interacts with OsbZIP58 to promote seed germination through the modulation of gibberellin biosynthesis in Oryza sativa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:1118-30. [PMID: 25353370 DOI: 10.1111/tpj.12714] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 08/25/2014] [Accepted: 10/20/2014] [Indexed: 05/05/2023]
Abstract
Seed germination is a key developmental process in the plant life cycle that is influenced by various environmental cues and phytohormones through gene expression and a series of metabolism pathways. In the present study, we investigated a C2C2-type finger protein, OsLOL1, which promotes gibberellin (GA) biosynthesis and affects seed germination in Oryza sativa (rice). We used OsLOL1 antisense and sense transgenic lines to explore OsLOL1 functions. Seed germination timing in antisense plants was restored to wild type when exogenous GA3 was applied. The reduced expression of the GA biosynthesis gene OsKO2 and the accumulation of ent-kaurene were observed during germination in antisense plants. Based on yeast two-hybrid and firefly luciferase complementation analyses, OsLOL1 interacted with the basic leucine zipper protein OsbZIP58. The results from electrophoretic mobility shift and dual-luciferase reporter assays showed that OsbZIP58 binds the G-box cis-element of the OsKO2 promoter and activates LUC reporter gene expression, and that interaction between OsLOL1 and OsbZIP58 activates OsKO2 gene expression. In addition, OsLOL1 decreased SOD1 gene expression and accelerated programmed cell death (PCD) in the aleurone layer of rice grains. These findings demonstrate that the interaction between OsLOL1 and OsbZIP58 influences GA biosynthesis through the activation of OsKO2 via OsbZIP58, thereby stimulating aleurone PCD and seed germination.
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Affiliation(s)
- Jiahe Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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16
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Lambert R, Quiles FA, Cabello-Díaz JM, Piedras P. Purification and identification of a nuclease activity in embryo axes from French bean. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 224:137-143. [PMID: 24908514 DOI: 10.1016/j.plantsci.2014.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/02/2014] [Accepted: 04/28/2014] [Indexed: 06/03/2023]
Abstract
Plant nucleases are involved in nucleic acid degradation associated to programmed cell death processes as well as in DNA restriction, repair and recombination processes. However, the knowledge about the function of plant nucleases is limited. A major nuclease activity was detected by in-gel assay with whole embryonic axes of common bean by using ssDNA or RNA as substrate, whereas this activity was minimal in cotyledons. The enzyme has been purified to electrophoretic homogeneity from embryonic axes. The main biochemical properties of the purified enzyme indicate that it belongs to the S1/P1 family of nucleases. This was corroborated when this protein, after SDS-electrophoresis, was excised from the gel and further analysis by MALDI TOF/TOF allowed identification of the gene (PVN1) that codes this protein. The gene that codes the purified protein was identified. The expression of PVN1 gene was induced at the specific moment of radicle protrusion. The inclusion of inorganic phosphate to the imbibition media reduced the level of expression of this gene and the nuclease activity suggesting a relationship with the phosphorous status in French bean seedlings.
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Affiliation(s)
- Rocío Lambert
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif. Severo Ochoa, 1ª Planta, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Francisco Antonio Quiles
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif. Severo Ochoa, 1ª Planta, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Juan Miguel Cabello-Díaz
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif. Severo Ochoa, 1ª Planta, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Pedro Piedras
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif. Severo Ochoa, 1ª Planta, Universidad de Córdoba, 14071 Córdoba, Spain.
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17
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Xie Y, Zhang C, Lai D, Sun Y, Samma MK, Zhang J, Shen W. Hydrogen sulfide delays GA-triggered programmed cell death in wheat aleurone layers by the modulation of glutathione homeostasis and heme oxygenase-1 expression. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:53-62. [PMID: 24331419 DOI: 10.1016/j.jplph.2013.09.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 09/01/2013] [Accepted: 09/02/2013] [Indexed: 05/21/2023]
Abstract
Hydrogen sulfide (H2S) is considered as a cellular signaling intermediate in higher plants, but corresponding molecular mechanisms and signal transduction pathways in plant biology are still limited. In the present study, a combination of pharmacological and biochemical approaches was used to study the effect of H2S on the alleviation of GA-induced programmed cell death (PCD) in wheat aleurone cells. The results showed that in contrast with the responses of ABA, GA brought about a gradual decrease of l-cysteine desulfhydrase (LCD) activity and H2S production, and thereafter PCD occurred. Exogenous H2S donor sodium hydrosulfide (NaHS) not only effectively blocked the decrease of endogenous H2S release, but also alleviated GA-triggered PCD in wheat aleurone cells. These responses were sensitive to hypotaurine (HT), a H2S scavenger, suggesting that this effect of NaHS was in an H2S-dependent fashion. Further experiment confirmed that H2S, rather than other sodium- or sulphur-containing compounds derived from the decomposing of NaHS, was attributed to the rescuing response. Importantly, the reversing effect was associated with glutathione (GSH) because the NaHS triggered increases of endogenous GSH content and the ratio of GSH/oxidized GSH (GSSG) in GA-treated layers, and the NaHS-mediated alleviation of PCD was markedly eliminated by l-buthionine-sulfoximine (BSO, a selective inhibitor of GSH biosynthesis). The inducible effect of NaHS was also ascribed to the modulation of heme oxygenase-1 (HO-1), because the specific inhibitor of HO-1 zinc protoporphyrin IX (ZnPP) significantly suppressed the NaHS-related responses. By contrast, the above inhibitory effects were reversed partially when carbon monoxide (CO) aqueous solution or bilirubin (BR), two of the by-products of HO-1, was added, respectively. NaHS-triggered HO-1 gene expression in GA-treated layers was also confirmed. Together, the above results clearly suggested that the H2S-delayed PCD in GA-treated wheat aleurone cells was associated with the modulation of GSH homeostasis and HO-1 gene expression.
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Affiliation(s)
- Yanjie Xie
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Chen Zhang
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Diwen Lai
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Ya Sun
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Muhammad Kaleem Samma
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Jing Zhang
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Wenbiao Shen
- College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
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18
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Domínguez F, Cejudo FJ. Programmed cell death (PCD): an essential process of cereal seed development and germination. FRONTIERS IN PLANT SCIENCE 2014; 5:366. [PMID: 25120551 PMCID: PMC4112785 DOI: 10.3389/fpls.2014.00366] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/09/2014] [Indexed: 05/18/2023]
Abstract
The life cycle of cereal seeds can be divided into two phases, development and germination, separated by a quiescent period. Seed development and germination require the growth and differentiation of new tissues, but also the ordered disappearance of cells, which takes place by a process of programmed cell death (PCD). For this reason, cereal seeds have become excellent model systems for the study of developmental PCD in plants. At early stages of seed development, maternal tissues such as the nucellus, the pericarp, and the nucellar projections undergo a progressive degeneration by PCD, which allows the remobilization of their cellular contents for nourishing new filial tissues such as the embryo and the endosperm. At a later stage, during seed maturation, the endosperm undergoes PCD, but these cells remain intact in the mature grain and their contents will not be remobilized until germination. Thus, the only tissues that remain alive when seed development is completed are the embryo axis, the scutellum and the aleurone layer. In germinating seeds, both the scutellum and the aleurone layer play essential roles in producing the hydrolytic enzymes for the mobilization of the storage compounds of the starchy endosperm, which serve to support early seedling growth. Once this function is completed, scutellum and aleurone cells undergo PCD; their contents being used to support the growth of the germinated embryo. PCD occurs with tightly controlled spatial-temporal patterns allowing coordinated fluxes of nutrients between the different seed tissues. In this review, we will summarize the current knowledge of the tissues undergoing PCD in developing and germinating cereal seeds, focussing on the biochemical features of the process. The effect of hormones and redox regulation on PCD control will be discussed.
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Affiliation(s)
| | - Francisco J. Cejudo
- *Correspondence: Francisco J. Cejudo, Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Avda Américo Vespucio 49, Sevilla 41092, Spain e-mail:
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19
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Sánchez-Pons N, Vicient CM. Identification of a type I Ca2+/Mg2+-dependent endonuclease induced in maize cells exposed to camptothecin. BMC PLANT BIOLOGY 2013; 13:186. [PMID: 24256432 PMCID: PMC4225560 DOI: 10.1186/1471-2229-13-186] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 11/16/2013] [Indexed: 05/24/2023]
Abstract
BACKGROUND Camptothecin is a plant alkaloid that specifically binds topoisomerase I, inhibiting its activity and inducing double stranded breaks in DNA and activating the cell responses to DNA damage. RESULTS Maize cultured cells were incubated in the presence of different concentrations of camptothecin. Camptothecin inhibits cultured cell growth, induces genomic DNA degradation, and induces a 32 kDa Ca2+/Mg2+-dependent nuclease activity. This nuclease, we called CaMNUC32, is inhibited by Zn2+ and by acid pH, it is mainly localized in the nucleus and it cleaves single- and double-stranded DNA, with a higher activity against single-stranded DNA. Two-dimensional electrophoresis combined with mass spectrometry suggests that CaMNUC32 is a member of the type I S1/P1 nuclease family. This type of nucleases are usually Zn2+-dependent but our results support previous indications that S1-type nucleases have a wide variety of enzyme activities, including Ca2+/Mg2+-dependent. CONCLUSIONS We have identified and characterized CaMNUC32, a 32 kDa Ca2+/Mg2+-dependent nuclease of the S1/P1 family induced by the topoisomerase I inhibitor camptothecin in maize cultured cells.
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Affiliation(s)
- Núria Sánchez-Pons
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain
| | - Carlos M Vicient
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain
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20
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Carrillo-Barral N, Matilla AJ, Iglesias-Fernández R, Del Carmen Rodríguez-Gacio M. Nitrate-induced early transcriptional changes during imbibition in non-after-ripened Sisymbrium officinale seeds. PHYSIOLOGIA PLANTARUM 2013; 148:560-573. [PMID: 23106241 DOI: 10.1111/j.1399-3054.2012.01720.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 10/10/2012] [Accepted: 10/11/2012] [Indexed: 06/01/2023]
Abstract
We have here demonstrated for the first time that nitrate not only accelerates testa rupture of non- AR seeds but also modifies expression pattern of the cell-wall remodeling proteins (mannanases; SoMAN6 and SoMAN7) and key genes belonging to metabolism and signaling of ABA (SoNCED6, SoNCED9, SoCYP707A2 and SoABI5) and GAs (SoGA3ox, SoGA20ox, SoGA2ox and SoRGL2). These results were obtained during Sisymbrium officinale seed imbibition in the absence of endosperm rupture. Exogenous ABA induced a notable inhibition of testa rupture in both absence and presence of nitrate being this effect sharply reversed by GA(4+7). However, nitrate was capable to provoke testa rupture in absence of ABA synthesis. The expression of SoMAN6 and SoMAN7 were positively altered by nitrate. Although ABA synthesis seems apparent at the start of non-AR seed imbibition, taken together the results of SoNCED6, SoNCED9 and SoCYP707A2 expression seem to suggest that nitrate leads to a strong net ABA decrease. Likewise, nitrate positively affected the SoABI5 expression when the SoNCED9 expression was also stimulated. By contrast, at the early and final of imbibition, nitrate clearly inhibited the SoABI5 expression. The expression of SoGA2ox6 and SoGA3ox2 are strongly inhibited by nitrate whereas of SoGA20ox6 was stimulated. On the other hand, SoRGL2 transcript level decreased in the presence of nitrate. Taken together, the results presented here suggest that the nitrate signaling is already operative during the non-AR S. officinale seeds imbibition. The nitrate, in cross-talk with the AR network likely increases the favorable molecular conditions that trigger germination.
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Affiliation(s)
- Nestor Carrillo-Barral
- Departamento de Fisiología Vegetal, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, 15782, Spain
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21
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López-Fernández MP, Maldonado S. Programmed cell death during quinoa perisperm development. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:3313-25. [PMID: 23833197 PMCID: PMC3733152 DOI: 10.1093/jxb/ert170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.
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22
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Donà M, Macovei A, Faè M, Carbonera D, Balestrazzi A. Plant hormone signaling and modulation of DNA repair under stressful conditions. PLANT CELL REPORTS 2013; 32:1043-52. [PMID: 23508254 DOI: 10.1007/s00299-013-1410-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 05/08/2023]
Abstract
The role played by phytohormone signaling in the modulation of DNA repair gene and the resulting effects on plant adaptation to genotoxic stress are poorly investigated. Information has been gathered using the Arabidopsis ABA (abscisic acid) overly sensitive mutant abo4-1, defective in the DNA polymerase ε function that is required for DNA repair and recombination. Similarly, phytohormone-mediated regulation of the Ku genes, encoding the Ku heterodimer protein involved in DNA repair, cell cycle control and telomere homeostasis has been demonstrated, highlighting a scenario in which hormones might affect genome stability by modulating the frequency of homologous recombination, favoring plant adaptation to genotoxic stress. Within this context, the characterisation of Arabidopsis AtKu mutants allowed disclosing novel connections between DNA repair and phytohormone networks. Another intriguing aspect deals with the emerging correlation between plant defense response and the mechanisms responsible for genome stability. There is increasing evidence that systemic acquired resistance (SAR) and homologous recombination share common elements represented by proteins involved in DNA repair and chromatin remodeling. This hypothesis is supported by the finding that volatile compounds, such as methyl salicylate (MeSA) and methyl jasmonate (MeJA), participating in the plant-to-plant communication can trigger genome instability in response to genotoxic stress agents. Phytohormone-mediated control of genome stability involves also chromatin remodeling, thus expanding the range of molecular targets. The present review describes the most significant advances in this specific research field, in the attempt to provide a better comprehension of how plant hormones modulate DNA repair proteins as a function of stress.
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Affiliation(s)
- Mattia Donà
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, via Ferrata 1, 27100 Pavia, Italy
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23
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Trobacher CP, Senatore A, Holley C, Greenwood JS. Induction of a ricinosomal-protease and programmed cell death in tomato endosperm by gibberellic acid. PLANTA 2013; 237:665-79. [PMID: 23086343 DOI: 10.1007/s00425-012-1780-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 10/01/2012] [Indexed: 05/08/2023]
Abstract
Several examples of programmed cell death (PCD) in plants utilize ricinosomes, organelles that appear prior to cell death and store inactive KDEL-tailed cysteine proteinases. Upon cell death, the contents of ricinosomes are released into the cell corpse where the proteinases are activated and proceed to degrade any remaining protein for use in adjacent cells or, in the case of nutritive seed tissues, by the growing seedling. Ricinosomes containing pro-SlCysEP have been observed in anther tissues prior to PCD and ricinosome-like structures have been observed in imbibed seeds within endosperm cells of tomato. The present study confirms that the structures in tomato endosperm cells contain pro-SlCysEP making them bona fide ricinosomes. The relative abundance of pro- versus mature SlCysEP is suggested to be a useful indicator of the degree of PCD that has occurred in tomato endosperm, and is supported by biochemical and structural data. This diagnostic tool is used to demonstrate that a sub-region of the micropylar endosperm surrounding the emerged radical is relatively long-lived and may serve to prevent loss of mobilized reserves from the lateral endosperm. We also demonstrate that GA-induced reserve mobilization, SlCysEP accumulation and processing, and PCD in tomato endosperm are antagonized by ABA.
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24
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Sarwat M, Naqvi AR, Ahmad P, Ashraf M, Akram NA. Phytohormones and microRNAs as sensors and regulators of leaf senescence: assigning macro roles to small molecules. Biotechnol Adv 2013; 31:1153-71. [PMID: 23453916 DOI: 10.1016/j.biotechadv.2013.02.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 01/26/2013] [Accepted: 02/02/2013] [Indexed: 10/27/2022]
Abstract
Ageing or senescence is an intricate and highly synchronized developmental phase in the life of plant parts including leaf. Senescence not only means death of a plant part, but during this process, different macromolecules undergo degradation and the resulting components are transported to other parts of the plant. During the period from when a leaf is young and green to the stage when it senesces, a multitude of factors such as hormones, environmental factors and senescence associated genes (SAGs) are involved. Plant hormones including salicylic acid, abscisic acid, jasmonic acid and ethylene advance leaf senescence, whereas others like cytokinins, gibberellins, and auxins delay this process. The environmental factors which generally affect plant development and growth, can hasten senescence, the examples being nutrient dearth, water stress, pathogen attack, radiations, high temperature and light intensity, waterlogging, and air, water or soil contamination. Other important influences include carbohydrate accumulation and high carbon/nitrogen level. To date, although several genes involved in this complex process have been identified, still not much information exists in the literature on the signalling mechanism of leaf senescence. Now, the Arabidopsis mutants have paved our way and opened new vistas to elucidate the signalling mechanism of leaf senescence for which various mutants are being utilized. Recent studies demonstrating the role of microRNAs in leaf senescence have reinforced our knowledge of this intricate process. This review provides a comprehensive and critical analysis of the information gained particularly on the roles of several plant growth regulators and microRNAs in regulation of leaf senescence.
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Affiliation(s)
- Maryam Sarwat
- Pharmaceutical Biotechnology, Amity Institute of Pharmacy, Amity University, Uttar Pradesh (AUUP), NOIDA, India.
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25
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Domínguez F, Cejudo FJ. A comparison between nuclear dismantling during plant and animal programmed cell death. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 197:114-121. [PMID: 23116678 DOI: 10.1016/j.plantsci.2012.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 09/14/2012] [Accepted: 09/25/2012] [Indexed: 06/01/2023]
Abstract
Programmed cell death (PCD) is a process of organized destruction of cells, essential for the development and maintenance of cellular homeostasis of multicellular organisms. Cells undergoing PCD begin a degenerative process in response to internal or external signals, whereby the nucleus becomes one of the targets. The process of nuclear dismantling includes events affecting the nuclear envelope, such as formation of lobes at the nuclear surface, selective proteolysis of nucleoporins and nuclear pore complex clustering. In addition, chromatin condensation increases in coordination with DNA fragmentation. These processes have been largely studied in animals, but remain poorly understood in plants. The overall process of cell death has different morphological and biochemical features in plants and animals. However, recent advances suggest that nuclear dismantling in plant cells progresses with morphological and biochemical characteristics similar to those in apoptotic animal cells. In this review, we summarize nuclear dismantling in plant PCD, focusing on the similarities and differences with their animal counterparts.
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Affiliation(s)
- Fernando Domínguez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Avda Américo Vespucio 49, 41092 Sevilla, Spain
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26
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Domínguez F, Moreno J, Cejudo FJ. The scutellum of germinated wheat grains undergoes programmed cell death: identification of an acidic nuclease involved in nucleus dismantling. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:5475-85. [PMID: 22888125 PMCID: PMC3444264 DOI: 10.1093/jxb/ers199] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Programmed cell death (PCD) is a crucial phenomenon in the life cycle of cereal grains. In germinating grains, the scutellum allows the transport of nutrients from the starchy endosperm to the growing embryo, and therefore it may be the last grain tissue to undergo PCD. Thus, the aim of this work was to analyse whether the scutellum of wheat grains undergoes PCD and to perform a morphological and biochemical analysis of this process. Scutellum cells of grains following germination showed a progressive increase of DNA fragmentation, and the TUNEL assay showed that PCD extended in an apical-to-basal gradient along the scutellum affecting epidermal and parenchymal cells. Electron-transmission microscopy revealed high cytoplasm vacuolation, altered mitochondria, and the presence of double-membrane structures, which might constitute symptoms of vacuolar cell death, whereas the nucleus appeared lobed and had an increased heterochromatin content as the most distinctive features. An acid- and Zn(2+)-dependent nucleolytic activity was identified in nuclear extracts of scutellum cells undergoing PCD. This nuclease was not detected in grains imbibed in the presence of abscisic acid, which inhibited germination. This nucleolytic activity promoted DNA fragmentation in vitro on nuclei isolated from healthy cells, thus suggesting a main role in nucleus dismantling during PCD.
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Affiliation(s)
- Fernando Domínguez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSICAvda Américo Vespucio, 49, 41092-SevillaSpain
| | - Javier Moreno
- Departamento de Biología Celular, Facultad de Biología, Universidad de SevillaAvda Reina Mercedes s/n, 41012 -SevillaSpain
| | - Francisco Javier Cejudo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSICAvda Américo Vespucio, 49, 41092-SevillaSpain
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de Almeida M, de Almeida CV, Mendes Graner E, Ebling Brondani G, Fiori de Abreu-Tarazi M. Pre-procambial cells are niches for pluripotent and totipotent stem-like cells for organogenesis and somatic embryogenesis in the peach palm: a histological study. PLANT CELL REPORTS 2012; 31:1495-515. [PMID: 22534682 DOI: 10.1007/s00299-012-1264-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/26/2012] [Accepted: 04/10/2012] [Indexed: 05/18/2023]
Abstract
UNLABELLED The direct induction of adventitious buds and somatic embryos from explants is a morphogenetic process that is under the influence of exogenous plant growth regulators and its interactions with endogenous phytohormones. We performed an in vitro histological analysis in peach palm (Bactris gasipaes Kunth) shoot apexes and determined that the positioning of competent cells and their interaction with neighboring cells, under the influence of combinations of exogenously applied growth regulators (NAA/BAP and NAA/TDZ), allows the pre-procambial cells (PPCs) to act in different morphogenic pathways to establish niche competent cells. It is likely that there has been a habituation phenomenon during the regeneration and development of the microplants. This includes promoting the tillering of primary or secondary buds due to culturing in the absence of NAA/BAP or NAA/TDZ after a period in the presence of these growth regulators. Histological analyses determined that the adventitious roots were derived from the dedifferentiation of the parenchymal cells located in the basal region of the adventitious buds, with the establishment of rooting pole, due to an auxin gradient. Furthermore, histological and histochemical analyses allowed us to characterize how the PPCs provide niches for multipotent, pluripotent and totipotent stem-like cells for vascular differentiation, organogenesis and somatic embryogenesis in the peach palm. The histological and histochemical analyses also allowed us to detect the unicellular or multicellular origin of somatic embryogenesis. Therefore, our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. KEY MESSAGE Our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells.
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Affiliation(s)
- Marcilio de Almeida
- Departamento de Ciências Biológicas PPG em Fisiologia e Bioquímica de Plantas e PPG em Recursos Florestais, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba, São Paulo 13.418-900, Brazil.
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Chen HM, Pang Y, Zeng J, Ding Q, Yin SY, Liu C, Lu MZ, Cui KM, He XQ. The Ca2+ -dependent DNases are involved in secondary xylem development in Eucommia ulmoides. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012; 54:456-70. [PMID: 22694768 DOI: 10.1111/j.1744-7909.2012.01134.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Secondary xylem development has long been recognized as a typical case of programmed cell death (PCD) in plants. During PCD, the degradation of genomic DNA is catalyzed by endonucleases. However, to date, no endonuclease has been shown to participate in secondary xylem development. Two novel Ca(2+) -dependent DNase genes, EuCaN1 and EuCaN2, were identified from the differentiating secondary xylem of the tree Eucommia ulmoides Oliv., their functions were studied by DNase activity assay, in situ hybridization, protein immunolocalization and virus-induced gene silencing experiments. Full-length cDNAs of EuCaN1 and EuCaN2 contained an open reading frame of 987 bp, encoding two proteins of 328 amino acids with SNase-like functional domains. The genomic DNA sequence for EuCaN1 had no introns, while EuCaN2 had 8 introns. EuCaN1 and EuCaN2 digested ssDNA and dsDNA with Ca(2+) -dependence at neutral pH. Their expression was confined to differentiating secondary xylem cells and the proteins were localized in the nucleus. Their activity dynamics was closely correlated with secondary xylem development. Secondary xylem cell differentiation is influenced by RNAi of endonuclease genes. The results provide evidence that the Ca(2+) -dependent DNases are involved in secondary xylem development.
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Affiliation(s)
- Hui-Min Chen
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
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29
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Sabelli PA. Replicate and die for your own good: Endoreduplication and cell death in the cereal endosperm. J Cereal Sci 2012. [DOI: 10.1016/j.jcs.2011.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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30
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Ko CY, Lai YL, Liu WY, Lin CH, Chen YT, Chen LFO, Lin TY, Shaw JF. Arabidopsis ENDO2: its catalytic role and requirement of N-glycosylation for function. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:5169-5179. [PMID: 22506810 DOI: 10.1021/jf300945c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Arabidopsis thaliana At1g68290 gene encoding an endonuclease was isolated and designated ENDO2, which was cloned into a binary vector to overexpress ENDO2 with a C-terminal 6 × His-tag in A. thaliana. Our Arabidopsis transgenic lines harboring 35SP::ENDO2 produced stable active enzyme with high yield. The protein was affinity purified from transgenic plants, and its identity was confirmed by liquid chromatography-mass spectrometry and automatic Edman degradation. ENDO2 enzyme digests RNA, ssDNA, and dsDNA, with a substrate preference for ssDNA and RNA. The activity toward ssDNA (361.7 U/mg) is greater than its dsDNase activity (14.1 U/mg) at neutral pH. ENDO2 effectively cleaves mismatch regions in heteroduplex DNA containing single base pair mismatches or insertion/deletion bases and can be applied to high-throughput detection of single base mutation. Our data also validated that the removal of sugar groups from ENDO2 strongly affects its enzymatic stability and activity.
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Affiliation(s)
- Chia-Yun Ko
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University , Hsinchu, 30013, Taiwan
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31
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Control of Programmed Cell Death During Plant Reproductive Development. BIOCOMMUNICATION OF PLANTS 2012. [DOI: 10.1007/978-3-642-23524-5_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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32
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Farage-Barhom S, Burd S, Sonego L, Mett A, Belausov E, Gidoni D, Lers A. Localization of the Arabidopsis senescence- and cell death-associated BFN1 nuclease: from the ER to fragmented nuclei. MOLECULAR PLANT 2011; 4:1062-73. [PMID: 21665915 DOI: 10.1093/mp/ssr045] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Plant senescence- or PCD-associated nucleases share significant homology with nucleases from different organisms. However, knowledge of their function is limited. Intracellular localization of the Arabidopsis senescence- and PCD-associated nuclease BFN1 was investigated. Analysis of BFN1-GFP localization in transiently transformed tobacco protoplasts revealed initial localization in filamentous structures spread throughout the cytoplasm, which then clustered around the nuclei as the protoplasts senesced. These filamentous structures were identified as being of ER origin. In BFN1-GFP-transgenic Arabidopsis plants, similar localization of BFN1-GFP was observed in young leaves, that is, in filamentous structures that reorganized around the nuclei only in senescing cells. In late senescence, BFN1-GFP was localized with fragmented nuclei in membrane-wrapped vesicles. BFN1's postulated function as a nucleic acid-degrading enzyme in senescence and PCD is supported by its localization pattern. Our results suggest the existence of a dedicated compartment mediating nucleic acid degradation in senescence and PCD processes.
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Affiliation(s)
- Sarit Farage-Barhom
- Department of Postharvest Science of Fresh Produce, Volcani Center, Agricultural Research Organization, Bet Dagan, 50250, Israel
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Gu HT, Wang DH, Li X, He CX, Xu ZH, Bai SN. Characterization of an ethylene-inducible, calcium-dependent nuclease that is differentially expressed in cucumber flower development. THE NEW PHYTOLOGIST 2011; 192:590-600. [PMID: 21801181 DOI: 10.1111/j.1469-8137.2011.03825.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
• Production of unisexual flowers is an important mechanism that promotes cross-pollination in angiosperms. We previously identified primordial anther-specific DNA damage and organ-specific ethylene perception responsible for the arrest of stamen development in female flowers, but little is known about how the two processes are linked. • To identify potential links between the two processes, we performed suppression subtractive hybridization (SSH) on cucumber (Cucumis sativus L.) stamens of male and female flowers at stage 6, with stamens at stage 5 of bisexual flowers as a control. • Among the differentially expressed genes, we identified an expressed sequence tag (EST) encoding a cucumber homolog to an Arabidopsis calcium-dependent nuclease (CAN), designated CsCaN. Full-length CsCaN cDNA and the respective genomic DNA sequence were cloned and characterized. The CsCaN protein exhibited calcium-dependent nuclease activity. CsCaN showed ubiquitous expression; however, increased gene expression was detected in the stamens of stage 6 female flowers compared with male flowers. As expected, CsCaN expression was ethylene inducible. It was of great interest that CsCaN was post-translationally modified. • This study demonstrated that CsCaN is a novel cucumber nuclease gene, whose DNase activity is regulated at multiple levels, and which could be involved in the primordial anther-specific DNA damage of developing female cucumber flowers.
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Affiliation(s)
- Hai-Tao Gu
- PKU-Yale Joint Research Center of Agricultural and Plant Molecular Biology, National Key Laboratory of Protein Engineering and Plant Gene Engineering, College of Life Sciences, Peking University, Beijing, China
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Bissenbaev AK, Ishchenko AA, Taipakova SM, Saparbaev MK. Presence of base excision repair enzymes in the wheat aleurone and their activation in cells undergoing programmed cell death. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2011; 49:1155-1164. [PMID: 21856164 DOI: 10.1016/j.plaphy.2011.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 07/28/2011] [Indexed: 05/31/2023]
Abstract
Cereal aleurone cells are specialized endosperm cells that produce enzymes to hydrolyze the starchy endosperm during germination. Aleurone cells can undergo programmed cell death (PCD) when incubated in the presence of gibberellic acid (GA) in contrast to abscisic acid (ABA) which inhibits the process. The progression of PCD in aleurone layer cells of wheat grain is accompanied by an increase in deoxyribonuclease (DNase) activities and the internucleosomal degradation of nuclear DNA. Reactive oxygen species (ROS) are increased during PCD in the aleurone cells owing to the β-oxidation of triglycerides and inhibition of the antioxidant enzymes possibly leading to extensive oxidative damage to DNA. ROS generate mainly non-bulky DNA base lesions which are removed in the base excision repair (BER) pathway, initiated by the DNA glycosylases. At present, very little is known about oxidative DNA damage repair in cereals. Here, we study DNA repair in the cell-free extracts of wheat aleurone layer incubated or not with phytohormones. We show, for the first time, the presence of 8-oxoguanine-DNA and ethenoadenine-DNA glycosylase activities in wheat aleurone cells. Interestingly, the DNA glycosylase and AP endonuclease activities are strongly induced in the presence of GA. Based on these data we propose that GA in addition to activation of nuclear DNases also induces the DNA repair activities which remove oxidized DNA bases in the BER pathway. Potential roles of the wheat DNA glycosylases in GA-induced oligonucleosomal fragmentation of DNA and metabolic activation of aleurone layer cells via repair of transcribed regions are discussed.
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Affiliation(s)
- Amangeldy K Bissenbaev
- Department of Molecular Biology and Genetics, Faculty of Biology, al-Farabi Kazakh National University, 530038 Almaty, Kazakhstan.
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De Backer E, Gebruers K, Van den Ende W, Courtin CM, Delcour JA. Post-translational processing of beta-d-xylanases and changes in extractability of arabinoxylans during wheat germination. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2010; 48:90-97. [PMID: 20031435 DOI: 10.1016/j.plaphy.2009.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 10/29/2009] [Accepted: 10/31/2009] [Indexed: 05/28/2023]
Abstract
Endo-1,4-beta-d-xylanase (EC 3.2.1.8, beta-d-xylanase) activity, and arabinoxylan (AX) level and extractability were monitored for the first time simultaneously in wheat kernels (Triticum aestivum cv. Glasgow) up to 24 days post-imbibition (DPI), both in the absence and presence of added gibberellic acid (GA). Roughly three different stages (early, intermediate and late) can be discriminated. Addition of GA resulted in a faster increase of water extractable arabinoxylan (WEAX) level in the early stage (up to 3-4 DPI). This increase was not accompanied by the discernible presence of homologues of the barley X-I beta-d-xylanase as established by immunodetection. This suggests that other, yet unidentified beta-d-xylanases operate in this early time window. The intermediate stage (up to 13 DPI) was characterized by the presence of unprocessed 67 kDa X-I like beta-d-xylanase, which was much more abundant in the presence of GA. The occurrence of higher levels of the unprocessed enzyme was related with higher beta-d-xylanase activities and a further increase in WEAX level, pointing to in vivo activity of the unprocessed 67 kDa beta-d-xylanase. During the late stage (up to 24 DPI) gradual processing of the 67 kDa beta-d-xylanase occurred and was associated with a drastic increase in beta-d-xylanase activity. Up to 120-fold higher activity was recorded at 24 DPI, with approx. 85% thereof originating from the kernel remnants. The WEAX level decreased during the late stage, suggesting that the beta-d-xylanase is processed into more active forms to achieve extensive AX breakdown.
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Affiliation(s)
- Evelien De Backer
- Laboratory of Food Chemistry and Biochemistry, and Leuven Food Science and Nutrition Research Centre (LFoRCe), Katholieke Universiteit Leuven, Kasteelpark Arenberg 20 bus 2463, B-3001 Leuven, Belgium
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Pulido P, Cazalis R, Cejudo FJ. An antioxidant redox system in the nucleus of wheat seed cells suffering oxidative stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:132-45. [PMID: 18786001 DOI: 10.1111/j.1365-313x.2008.03675.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Cereal seed cells contain different mechanisms for protection against the oxidative stress that occurs during maturation and germination. One such mechanism is based on the antioxidant activity of a 1-Cys peroxiredoxin (1-Cys Prx) localized in the nuclei of aleurone and scutellum cells. However, nothing is known about the mechanism of activation of this enzyme. Here, we describe the pattern of localization of NADPH thioredoxin reductase (NTR) in developing and germinating wheat seeds using an immunocytochemical analysis. The presence of NTR in transfer cells, vascular tissue, developing embryo and root meristematic cells, agrees with the localization of thioredoxin h (Trx h), and supports the important function of the NTR/Trx system in cell proliferation and communication. Interestingly, NTR is found in the nuclei of seed cells suffering oxidative stress, thus showing co-localization with Trx h and 1-Cys Prx. To test whether the NTR/Trx system serves as a reductant of the 1-Cys Prx, we cloned a full-length cDNA encoding 1-Cys Prx from wheat, and expressed the recombinant protein in Escherichia coli. Using the purified components, we show NTR-dependent activity of the 1-Cys Prx. Mutants of the 1-Cys Prx allowed us to demonstrate that the peroxidatic residue of the wheat enzyme is Cys46, which is overoxidized in vitro under oxidant conditions. Analysis of extracts from developing and germinating seeds confirmed 1-Cys Prx overoxidation in vivo. Based on these results, we propose that NADPH is the source of the reducing power to regenerate 1-Cys Prx in the nuclei of seed cells suffering oxidative stress, in a process that is catalyzed by NTR.
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Affiliation(s)
- Pablo Pulido
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y CSIC, Avda Américo Vespucio 49, Seville, Spain
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Pulido P, Domínguez F, Cejudo FJ. A hydrogen peroxide detoxification system in the nucleus of wheat seed cells: protection or signaling role? PLANT SIGNALING & BEHAVIOR 2009; 4:23-5. [PMID: 19704698 PMCID: PMC2634063 DOI: 10.4161/psb.4.1.7221] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 10/15/2008] [Indexed: 05/21/2023]
Abstract
Aerobic metabolism inevitably produces reactive oxygen species (ROS), including hydrogen peroxide, which may cause damage to the cell. Besides this toxic effect, hydrogen peroxide has an important signaling function in plant development and response to environmental stimuli. So, the balance of toxic and signaling effects of hydrogen peroxide is highly dependent on mechanisms to adjust its level in the different cell compartments. We recently described a redox system, formed by NADPH thioredoxin reductase (NTR) and 1-Cys peroxiredoxin (1-Cys Prx), able to use the reducing power of NADPH to reduce hydrogen peroxide. This system is localized in the nucleus of wheat seed cells and probably has an important antioxidant function in aleurone and scutellum cells, which suffer oxidative stress during seed development and germination. We discuss here the possibility that the control of the level of hydrogen peroxide in the nucleus may be important to balance redox regulation of gene expression and cell death in cereal seed cells.
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Affiliation(s)
- Pablo Pulido
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y CSIC, Sevilla, Spain
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Fedoreyeva LI, Sobolev DE, Vanyushin BF. Wheat coleoptile endonuclease Wen2 is dependent on S-adenosyl-L-methionine and sensitive to DNA methylation status. BIOCHEMISTRY (MOSCOW) 2008; 73:1000-6. [DOI: 10.1134/s0006297908090071] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Jiang AL, Cheng Y, Li J, Zhang W. A zinc-dependent nuclear endonuclease is responsible for DNA laddering during salt-induced programmed cell death in root tip cells of rice. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:1134-41. [PMID: 18295371 DOI: 10.1016/j.jplph.2007.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 12/21/2007] [Accepted: 12/21/2007] [Indexed: 05/10/2023]
Abstract
DNA laddering is one of the biochemical processes characteristic of programmed cell death (PCD) both in animals and plants. However, the mechanism of DNA laddering varies in different species, even in different tissues of one organism. In the present study, we used root tip cells of rice, which have been induced by NaCl stress to undergo PCD, to analyze the endonuclease activities of cytoplasmic and nuclear extracts. Two endonucleases, a cytoplasmic of 20kDa (OsCyt20) and a nuclear of 37kDa (OsNuc37), were identified as PCD related. Our results indicated that OsCyt20 is a Ca(2+)/Mg(2+)-dependent nuclease, which is most active at neutral pH, and that OsNuc37 is Zn(2+)-dependent, with a pH optimum of 4.5-6. Both nucleases were induced at the early stage of PCD (2h salt treatment) and exhibited the highest activity approximately 4h after exposure to NaCl, paralleling with the occurrence of DNA laddering. In vitro assays of endonuclease activities further revealed that OsNuc37, a glycoprotein localized in the nucleus, is the executor for DNA laddering. The different effects of both endonucleases on DNA degradation during salt-induced PCD are discussed.
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Affiliation(s)
- Ai-Liang Jiang
- Department of Biochemistry & Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, PR China
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40
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Farage-Barhom S, Burd S, Sonego L, Perl-Treves R, Lers A. Expression analysis of the BFN1 nuclease gene promoter during senescence, abscission, and programmed cell death-related processes. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:3247-58. [PMID: 18603613 PMCID: PMC2529240 DOI: 10.1093/jxb/ern176] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 05/19/2008] [Accepted: 06/03/2008] [Indexed: 05/18/2023]
Abstract
Little is known about the biological role of nucleases induced during plant senescence and programmed cell death (PCD). Arabidopsis BFN1 has been identified as a senescence-associated type I nuclease, whose protein sequence shares high homology with some other senescence- or PCD-associated plant nucleases. To learn about BFN1 regulation, its expression pattern was analysed. A 2.3 kb portion of the 5' promoter sequence of BFN1 was cloned and its ability to activate the GUS reporter gene was examined. Transgenic Arabidopsis and tomato plants harbouring this chimeric construct were analysed for GUS expression. In both, the BFN1 promoter was able specifically to direct GUS expression in senescent leaves, differentiating xylem and the abscission zone of flowers. Thus, at least part of the regulation of BFN1 is mediated at the transcriptional level, and the regulatory elements are recognized in the two different plants. In tomato, specific expression was observed in the leaf and the fruit abscission zones. The BFN1 promoter was also active in other tissues, including developing anthers and seeds, and in floral organs after fertilization. PCD has been implicated in all of these processes, suggesting that in addition to senescence, BFN1 is involved in PCD associated with different development processes in Arabidopsis.
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Affiliation(s)
- Sarit Farage-Barhom
- Department of Postharvest Science of Fresh Produce, Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel
- Faculty of Life Science, Bar Ilan University, Ramat Gan, Israel
| | - Shaul Burd
- Department of Postharvest Science of Fresh Produce, Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel
| | - Lilian Sonego
- Department of Postharvest Science of Fresh Produce, Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel
| | | | - Amnon Lers
- Department of Postharvest Science of Fresh Produce, Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel
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Abstract
Programmed cell death (PCD) is now accepted as a fundamental cellular process in plants. It is involved in defence, development and response to stress, and our understanding of these processes would be greatly improved through a greater knowledge of the regulation of plant PCD. However, there may be several types of PCD that operate in plants, and PCD research findings can be confusing if they are not assigned to a specific type of PCD. The various cell-death mechanisms need therefore to be carefully described and defined. This review describes one of these plant cell death processes, namely the apoptotic-like PCD (AL-PCD). We begin by examining the hallmark 'apoptotic-like' features (protoplast condensation, DNA degradation) of the cell's destruction that are characteristic of AL-PCD, and include examples of AL-PCD during the plant life cycle. The review explores the possible cellular 'executioners' (caspase-like molecules; mitochondria; de novo protein synthesis) that are responsible for the hallmark features of the cellular destruction. Finally, senescence is used as a case study to show that a rigorous definition of cell-death processes in plant cells can help to resolve arguments that occur in the scientific literature regarding the timing and control of plant cell death.
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Affiliation(s)
- Theresa J Reape
- School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
| | - Paul F McCabe
- School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
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Gadjev I, Stone JM, Gechev TS. Programmed cell death in plants: new insights into redox regulation and the role of hydrogen peroxide. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 270:87-144. [PMID: 19081535 DOI: 10.1016/s1937-6448(08)01403-2] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Programmed cell death (PCD), the highly regulated dismantling of cells, is essential for plant growth and survival. PCD plays key roles in embryo development, formation and maturation of many cell types and tissues, and plant reaction/adaptation to environmental conditions. Reactive oxygen species (ROS) are not only toxic by products of aerobic metabolism with strictly controlled cellular levels, but they also function as signaling agents regulating many biological processes and producing pleiotropic effects. Over the last decade, ROS have become recognized as important modulators of plant PCD. Molecular genetic approaches using plant mutants and transcriptome studies related to ROS-mediated PCD have revealed a wide array of plant-specific cell death regulators and have contributed to unraveling the elaborate redox signaling network. This review summarizes the biological processes, in which plant PCD participates and discusses the signaling functions of ROS with emphasis on hydrogen peroxide.
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Affiliation(s)
- Ilya Gadjev
- Department of Plant Physiology and Plant Molecular Biology, University of Plovdiv, Plovdiv 4000, Bulgaria
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Mylona PV, Polidoros AN, Scandalios JG. Antioxidant gene responses to ROS-generating xenobiotics in developing and germinated scutella of maize. JOURNAL OF EXPERIMENTAL BOTANY 2007; 58:1301-12. [PMID: 17314079 DOI: 10.1093/jxb/erl292] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
There is circumstantial evidence implicating reactive oxygen species (ROS) in the highly ordered temporal and spatial regulation of expression of the Cat and Sod antioxidant genes during seed development and germination in maize. In order to understand and provide experimental data for the regulatory role of ROS, the expression patterns of the Cat1, Cat2, Cat3, GstI, Sod3, Sod4, and Sod4A genes, as well as catalase (CAT) and superoxide dismutase (SOD) activity responses, were examined after treatments with ROS-generating xenobiotics in developing and germinated maize scutella. CAT and SOD activities increased at both stages in response to each xenobiotic examined in a dose-dependent and stage-specific manner. Individual Cat gene expression patterns were co-ordinated with isozyme patterns of enzymatic activity in scutella of developing seeds. This was not observed in germinated seeds where, although Cat1 expression was highly induced by ROS, there was not a similar increase of enzymatic CAT1 activity, suggesting the involvement of post-transcriptional regulation. Enhanced enzyme activities were synchronous with increases in steady-state transcript levels of specific Sod genes. The steady-state transcript level of GstI was elevated in all samples examined. Gene expression responses derived from this study along with similar results documented in previous reports were subjected to cluster analysis, revealing that ROS-generating compounds provoke similar effects in the expression patterns of the tested antioxidant genes. This could be attributable to common stress-related motifs present in the promoters of these genes.
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Affiliation(s)
- Photini V Mylona
- Agricultural Recearch Center of Northern Greece, NAGREF, 570 01 Thermi, Greece.
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Hofius D, Tsitsigiannis DI, Jones JDG, Mundy J. Inducible cell death in plant immunity. Semin Cancer Biol 2006; 17:166-87. [PMID: 17218111 DOI: 10.1016/j.semcancer.2006.12.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 12/02/2006] [Indexed: 01/06/2023]
Abstract
Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways and their molecular components in plants are reviewed here.
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Affiliation(s)
- Daniel Hofius
- Department of Molecular Biology, University of Copenhagen, Øster Farimagsgade 2A, 1353 Copenhagen K, Denmark
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Domínguez F, Cejudo F. Identification of a nuclear-localized nuclease from wheat cells undergoing programmed cell death that is able to trigger DNA fragmentation and apoptotic morphology on nuclei from human cells. Biochem J 2006; 397:529-36. [PMID: 16613587 PMCID: PMC1533310 DOI: 10.1042/bj20051809] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PCD (programmed cell death) in plants presents important morphological and biochemical differences compared with apoptosis in animal cells. This raises the question of whether PCD arose independently or from a common ancestor in plants and animals. In the present study we describe a cell-free system, using wheat grain nucellar cells undergoing PCD, to analyse nucleus dismantling, the final stage of PCD. We have identified a Ca2+/Mg2+ nuclease and a serine protease localized to the nucleus of dying nucellar cells. Nuclear extracts from nucellar cells undergoing PCD triggered DNA fragmentation and other apoptotic morphology in nuclei from different plant tissues. Inhibition of the serine protease did not affect DNA laddering. Furthermore, we show that the nuclear extracts from plant cells triggered DNA fragmentation and apoptotic morphology in nuclei from human cells. The inhibition of the nucleolytic activity with Zn2+ or EDTA blocked the morphological changes of the nucleus. Moreover, nuclear extracts from apoptotic human cells triggered DNA fragmentation and apoptotic morphology in nuclei from plant cells. These results show that degradation of the nucleus is morphologically and biochemically similar in plant and animal cells. The implication of this finding on the origin of PCD in plants and animals is discussed.
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Affiliation(s)
- Fernando Domínguez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla-CSIC, 41092-Sevilla, Spain
| | - Francisco J. Cejudo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla-CSIC, 41092-Sevilla, Spain
- To whom correspondence should be addressed (email )
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DeBono AG, Greenwood JS. Characterization of programmed cell death in the endosperm cells of tomato seed: two distinct death programs. ACTA ACUST UNITED AC 2006. [DOI: 10.1139/b06-034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Programmed cell death (PCD) is a requisite, genetically controlled process in plants resulting in the death of particular cells and tissues and the recycling of the cellular constituents back to the organism. PCD in the lateral and micropylar endosperm cells during and following germination of tomato ( Solanum lycopersicum L.) seeds was characterized by transmission electron microscopy, by terminal d-UTP nick-end labelling of nuclei, and agarose gel electrophoretic analysis of genomic DNA. Postgerminative cells of lateral and micropylar endosperm displayed morphologies and terminal d-UTP nick-end labelling positive nuclei consistent with PCD. PCD was not detected in the lateral endosperm in the absence of the embryo. The embryo’s effect on promoting lateral endosperm PCD could be substituted with gibberellic acid at 50 μmol/L. Micropylar endosperm cells undergo PCD irrespective of incubation with or without the embryo; gibberellic acid only hastens the onset of PCD morphology. Precursor protease vesicles, novel endoplasmic reticulum derived organelles considered markers of PCD, were observed in postgerminative lateral and micropylar endosperm cells. Internucleosomal laddering was not detected in endospermic DNA. These results suggest that a late postimbibition gibberellic acid linked mechanism promotes PCD in the lateral endosperm, whereas the promotion of PCD in the micropylar endosperm occurs early in, or prior to, imbibition.
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Affiliation(s)
- Allan G. DeBono
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - John S. Greenwood
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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Abstract
Programmed cell death (PCD) is an important feature of plant development; however, the mechanisms responsible for its regulation in plants are far less well understood than those operating in animals. In this review data from a wide variety of plant PCD systems is analyzed to compare what is known about the underlying mechanisms. Although senescence is clearly an important part of plant development, only what is known about PCD during senescence is dealt with here. In each PCD system the extracellular and intracellular signals triggering PCD are considered and both cytological and molecular data are discussed to determine whether a unique model for plant PCD can be derived. In the majority of cases reviewed, PCD is accompanied by the formation of a large vacuole, which ruptures to release hydrolytic enzymes that degrade the cell contents, although this model is clearly not universal. DNA degradation and the activation of proteases is also common to most plant PCD systems, where they have been studied; however, breakdown of DNA into nucleosomal units (DNA laddering) is not observed in all systems. Caspase-like activity has also been reported in several systems, but the extent to which it is a necessary feature of all plant PCD has not yet been established. The trigger for tonoplast rupture is not fully understood, although active oxygen species (AOS) have been implicated in several systems. In two systems, self incompatibility and tapetal breakdown as a result of cytoplasmic male sterility, there is convincing evidence for the involvement of mitochondria including release of cytochrome c. However, in other systems, the role of the mitochondrion is not clear-cut. How cells surrounding the cell undergoing PCD protect themselves against death is also discussed as well as whether there is a link between the eventual fate of the cell corpse and the mechanism of its death.
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Affiliation(s)
- Hilary J Rogers
- School of Biosciences, Cardiff University, Cardiff United Kingdom CF10 3TL
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