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Jeong M, Park JW, Kim HE, Lee JY, Lee AR, Choi YG, Lee JH. Hydrogen Exchange Study of DNA Duplexes Containing the Consensus Binding Site for Arabidopsis thaliana SPL14 Transcription Factor. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.8.2511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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52
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Di Giacomo E, Iannelli MA, Frugis G. TALE and Shape: How to Make a Leaf Different. PLANTS (BASEL, SWITZERLAND) 2013. [PMID: 27137378 DOI: 10.3390/plantas2020317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Three Amino acid Loop Extension (TALE) proteins constitute an ancestral superclass of homeodomain transcription factors conserved in animals, plants and fungi. In plants they comprise two classes, KNOTTED1-LIKE homeobox (KNOX) and BEL1-like homeobox (BLH or BELL, hereafter referred to as BLH), which are involved in shoot apical meristem (SAM) function, as well as in the determination and morphological development of leaves, stems and inflorescences. Selective protein-protein interactions between KNOXs and BLHs affect heterodimer subcellular localization and target affinity. KNOXs exert their roles by maintaining a proper balance between undifferentiated and differentiated cell state through the modulation of multiple hormonal pathways. A pivotal function of KNOX in evolutionary diversification of leaf morphology has been assessed. In the SAM of both simple- and compound-leafed seed species, downregulation of most class 1 KNOX (KNOX1) genes marks the sites of leaf primordia initiation. However, KNOX1 expression is re-established during leaf primordia development of compound-leafed species to maintain transient indeterminacy and morphogenetic activity at the leaf margins. Despite the increasing knowledge available about KNOX1 protein function in plant development, a comprehensive view on their downstream effectors remains elusive. This review highlights the role of TALE proteins in leaf initiation and morphological plasticity with a focus on recent advances in the identification of downstream target genes and pathways.
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Affiliation(s)
- Elisabetta Di Giacomo
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
| | - Maria Adelaide Iannelli
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
| | - Giovanna Frugis
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
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Di Giacomo E, Iannelli MA, Frugis G. TALE and Shape: How to Make a Leaf Different. PLANTS 2013; 2:317-42. [PMID: 27137378 PMCID: PMC4844364 DOI: 10.3390/plants2020317] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 04/10/2013] [Accepted: 04/19/2013] [Indexed: 11/25/2022]
Abstract
The Three Amino acid Loop Extension (TALE) proteins constitute an ancestral superclass of homeodomain transcription factors conserved in animals, plants and fungi. In plants they comprise two classes, KNOTTED1-LIKE homeobox (KNOX) and BEL1-like homeobox (BLH or BELL, hereafter referred to as BLH), which are involved in shoot apical meristem (SAM) function, as well as in the determination and morphological development of leaves, stems and inflorescences. Selective protein-protein interactions between KNOXs and BLHs affect heterodimer subcellular localization and target affinity. KNOXs exert their roles by maintaining a proper balance between undifferentiated and differentiated cell state through the modulation of multiple hormonal pathways. A pivotal function of KNOX in evolutionary diversification of leaf morphology has been assessed. In the SAM of both simple- and compound-leafed seed species, downregulation of most class 1 KNOX (KNOX1) genes marks the sites of leaf primordia initiation. However, KNOX1 expression is re-established during leaf primordia development of compound-leafed species to maintain transient indeterminacy and morphogenetic activity at the leaf margins. Despite the increasing knowledge available about KNOX1 protein function in plant development, a comprehensive view on their downstream effectors remains elusive. This review highlights the role of TALE proteins in leaf initiation and morphological plasticity with a focus on recent advances in the identification of downstream target genes and pathways.
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Affiliation(s)
- Elisabetta Di Giacomo
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
| | - Maria Adelaide Iannelli
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
| | - Giovanna Frugis
- Istituto di Biologia e Biotecnologia Agraria, UOS Roma, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, 00015 Roma, Italy.
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Mulisch M, Asp T, Krupinska K, Hollmann J, Holm PB. The Tr-cp 14 cysteine protease in white clover (Trifolium repens) is localized to the endoplasmic reticulum and is associated with programmed cell death during development of tracheary elements. PROTOPLASMA 2013; 250:623-9. [PMID: 22707085 DOI: 10.1007/s00709-012-0427-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 06/03/2012] [Indexed: 05/08/2023]
Abstract
Cysteine proteases are known to be associated with programmed cell death, developmental senescence and some types of pathogen and stress-induced responses. In the present study, we have characterized the cysteine protease Tr-cp 14 in white clover (Trifolium repens). Tr-cp 14 belongs to the C1A family of cysteine proteases with homology to XCP1 and XCP2 from Arabidopsis thaliana and p48h-17 from Zinnia elegans, which previously have been reported to be associated with tracheary element differentiation. The proform as well as the processed form of the protein was detected in petioles, flowers and leaves, but the processed form was more abundant in leaves and petioles than in flowers. The Tr-cp 14 protein was localized to differentiating tracheary elements within the xylem, indicating that the cysteine protease is involved in protein re-mobilization during tracheary element differentiation. Immunogold studies suggest that the protease prior to the burst of the vacuole was associated to the ER cisternae. After disruption of the tonoplast, it was found in the cytoplasm, and, in later stages, associated with disintegrating material dispersed throughout the cell.
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Affiliation(s)
- Maria Mulisch
- Institute of Botany and Central Microscopy, Christian-Albrechts-University Kiel, Olshausenstrasse 40, 24098, Kiel, Germany
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55
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Yordanova ZP, Woltering EJ, Kapchina-Toteva VM, Iakimova ET. Mastoparan-induced programmed cell death in the unicellular alga Chlamydomonas reinhardtii. ANNALS OF BOTANY 2013; 111:191-205. [PMID: 23250917 PMCID: PMC3555528 DOI: 10.1093/aob/mcs264] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 11/07/2012] [Indexed: 05/07/2023]
Abstract
BACKGROUND AND AIMS Under stress-promoting conditions unicellular algae can undergo programmed cell death (PCD) but the mechanisms of algal cellular suicide are still poorly understood. In this work, the involvement of caspase-like proteases, DNA cleavage and the morphological occurrence of cell death in wasp venom mastoparan (MP)-treated Chlamydomonas reinhardtii were studied. METHODS Algal cells were exposed to MP and cell death was analysed over time. Specific caspase inhibitors were employed to elucidate the possible role of caspase-like proteases. YVADase activity (presumably a vacuolar processing enzyme) was assayed by using a fluorogenic caspase-1 substrate. DNA breakdown was evaluated by DNA laddering and Comet analysis. Cellular morphology was examined by confocal laser scanning microscopy. KEY RESULTS MP-treated C. reinhardtii cells expressed several features of necrosis (protoplast shrinkage) and vacuolar cell death (lytic vesicles, vacuolization, empty cell-walled corpse-containing remains of digested protoplast) sometimes within one single cell and in different individual cells. Nucleus compaction and DNA fragmentation were detected. YVADase activity was rapidly stimulated in response to MP but the early cell death was not inhibited by caspase inhibitors. At later time points, however, the caspase inhibitors were effective in cell-death suppression. Conditioned medium from MP-treated cells offered protection against MP-induced cell death. CONCLUSIONS In C. reinhardtii MP triggered PCD of atypical phenotype comprising features of vacuolar and necrotic cell deaths, reminiscent of the modality of hypersensitive response. It was assumed that depending on the physiological state and sensitivity of the cells to MP, the early cell-death phase might be not mediated by caspase-like enzymes, whereas later cell death may involve caspase-like-dependent proteolysis. The findings substantiate the hypothesis that, depending on the mode of induction and sensitivity of the cells, algal PCD may take different forms and proceed through different pathways.
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Affiliation(s)
- Zhenya P. Yordanova
- Department Plant Physiology, Faculty of Biology, Sofia University ‘St Kliment Ohridski’, 8 Dragan Tzankov Blvd, 1164 Sofia, Bulgaria
| | - Ernst J. Woltering
- Wageningen University, Horticultural Supply Chains Group, Droevendaalsesteeg 1, PO Box 630, 6700AP, Wageningen, The Netherlands
- Wageningen University, Food and Biobased Research, Bornse weilanden 9, PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Veneta M. Kapchina-Toteva
- Department Plant Physiology, Faculty of Biology, Sofia University ‘St Kliment Ohridski’, 8 Dragan Tzankov Blvd, 1164 Sofia, Bulgaria
| | - Elena T. Iakimova
- Wageningen University, Horticultural Supply Chains Group, Droevendaalsesteeg 1, PO Box 630, 6700AP, Wageningen, The Netherlands
- Institute of Ornamental Plants, 1222 Negovan, Sofia, Bulgaria
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56
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Fromm J. Xylem Development in Trees: From Cambial Divisions to Mature Wood Cells. PLANT CELL MONOGRAPHS 2013. [DOI: 10.1007/978-3-642-36491-4_1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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57
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Han JJ, Lin W, Oda Y, Cui KM, Fukuda H, He XQ. The proteasome is responsible for caspase-3-like activity during xylem development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 72:129-41. [PMID: 22680239 DOI: 10.1111/j.1365-313x.2012.05070.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Xylem development is a process of xylem cell terminal differentiation that includes initial cell division, cell expansion, secondary cell wall formation and programmed cell death (PCD). PCD in plants and apoptosis in animals share many common characteristics. Caspase-3, which displays Asp-Glu-Val-Asp (DEVD) specificity, is a crucial executioner during animal cells apoptosis. Although a gene orthologous to caspase-3 is absent in plants, caspase-3-like activity is involved in many cases of PCD and developmental processes. However, there is no direct evidence that caspase-3-like activity exists in xylem cell death. In this study, we showed that caspase-3-like activity is present and is associated with secondary xylem development in Populus tomentosa. The protease responsible for the caspase-3-like activity was purified from poplar secondary xylem using hydrophobic interaction chromatography (HIC), Q anion exchange chromatography and gel filtration chromatography. After identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS), it was revealed that the 20S proteasome (20SP) was responsible for the caspase-3-like activity in secondary xylem development. In poplar 20SP, there are seven α subunits encoded by 12 genes and seven β subunits encoded by 12 genes. Pharmacological assays showed that Ac-DEVD-CHO, a caspase-3 inhibitor, suppressed xylem differentiation in the veins of Arabidopsis cotyledons. Furthermore, clasto-lactacystin β-lactone, a proteasome inhibitor, inhibited PCD of tracheary element in a VND6-induced Arabidopsis xylogenic culture. In conclusion, the 20S proteasome is responsible for caspase-3-like activity and is involved in xylem development.
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Affiliation(s)
- Jia-Jia Han
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
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58
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Moschou PN, Wu J, Cona A, Tavladoraki P, Angelini R, Roubelakis-Angelakis KA. The polyamines and their catabolic products are significant players in the turnover of nitrogenous molecules in plants. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:5003-15. [PMID: 22936828 DOI: 10.1093/jxb/ers202] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Polyamines (PAs) are nitrogenous molecules which play a well-established role in most cellular processes during growth and development under physiological or biotic/abiotic stress conditions. The molecular mode(s) of PA action have only recently started to be unveiled, and comprehensive models for their molecular interactions have been proposed. Their multiple roles are exerted, at least partially, through signalling by hydrogen peroxide (H(2)O(2)), which is generated by the oxidation/back-conversion of PAs by copper amine oxidases and PA oxidases. Accumulating evidence suggests that in plants the cellular titres of PAs are affected by other nitrogenous compounds. Here, we discuss the state of the art on the possible nitrogen flow in PAs, their interconnection with nitrogen metabolism, as well as the signalling roles of PA-derived H(2)O(2) during some developmental processes and stress responses.
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Affiliation(s)
- P N Moschou
- Department of Biology, University of Crete, 71409 Heraklion, Greece
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59
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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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60
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Liao C, Liu R, Zhang F, Li C, Li X. Nitrogen under- and over-supply induces distinct protein responses in maize xylem sap. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012; 54:374-387. [PMID: 22501030 DOI: 10.1111/j.1744-7909.2012.01122.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Xylem sap primarily transports water and mineral nutrients such as nitrogen (N) from roots to shoots in vascular plants. However, it remains largely unknown how nitrogenous compounds, especially proteins in xylem sap, respond to N under- or over-supply. We found that reducing N supply increased amino-N percentage of total N in maize (Zea mays L.) xylem sap. Proteomic analysis showed that 23 proteins in the xylem sap of maize plants, including 12 newly identified ones, differentially accumulated in response to various N supplies. Fifteen of these 23 proteins were primarily involved in general abiotic or biotic stress responses, whereas the other five proteins appeared to respond largely to N under- or over-supply, suggesting distinct protein responses in maize xylem upon N under- and over-supply. Furthermore, one putative xylanase inhibitor and two putative O-glycosyl hydrolases had preferential gene expression in shoots.
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Affiliation(s)
- Chengsong Liao
- Department of Plant Nutrition, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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61
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Petzold HE, Zhao M, Beers EP. Expression and functions of proteases in vascular tissues. PHYSIOLOGIA PLANTARUM 2012; 145:121-9. [PMID: 22022801 DOI: 10.1111/j.1399-3054.2011.01538.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
With the emergence of new models for wood formation and the increasing emphasis on improving the efficiency of cellulosic biofuel production, research on vascular tissue biology has intensified in recent years. Some of the most active areas of research focus on manipulating activity of enzymes in the cellulose, hemicellulose, pectin and lignin pathways. In addition, great strides have been made in the characterization of transcriptional networks controlling genes that affect differentiation, secondary cell wall synthesis and programmed cell death in xylem. Less attention has been devoted to the characterization of proteases that may be important regulators of post-translational events that affect vascular cell differentiation and function and cell wall composition. Several genes for proteases and components of the ubiquitin/26S proteasome pathway are upregulated in xylem and phloem and in cell culture systems for studying the differentiation of xylem tracheary elements (TEs). Although small molecule protease inhibitors have been used to explore the roles of proteases during the differentiation of cultured TEs, only a small number of vascular tissue-associated protease genes have been directly tested to determine whether they play roles in vascular tissue biology. In this report, we review roles for proteases in vascular cell differentiation and function as determined through the use of protease inhibitors and genetic analyses and conclude by identifying opportunities for future research in this area.
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Affiliation(s)
- H Earl Petzold
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
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62
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Teper-Bamnolker P, Buskila Y, Lopesco Y, Ben-Dor S, Saad I, Holdengreber V, Belausov E, Zemach H, Ori N, Lers A, Eshel D. Release of apical dominance in potato tuber is accompanied by programmed cell death in the apical bud meristem. PLANT PHYSIOLOGY 2012; 158:2053-67. [PMID: 22362870 PMCID: PMC3320206 DOI: 10.1104/pp.112.194076] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 02/23/2012] [Indexed: 05/21/2023]
Abstract
Potato (Solanum tuberosum) tuber, a swollen underground stem, is used as a model system for the study of dormancy release and sprouting. Natural dormancy release, at room temperature, is initiated by tuber apical bud meristem (TAB-meristem) sprouting characterized by apical dominance (AD). Dormancy is shortened by treatments such as bromoethane (BE), which mimics the phenotype of dormancy release in cold storage by inducing early sprouting of several buds simultaneously. We studied the mechanisms governing TAB-meristem dominance release. TAB-meristem decapitation resulted in the development of increasing numbers of axillary buds with time in storage, suggesting the need for autonomous dormancy release of each bud prior to control by the apical bud. Hallmarks of programmed cell death (PCD) were identified in the TAB-meristems during normal growth, and these were more extensive when AD was lost following either extended cold storage or BE treatment. Hallmarks included DNA fragmentation, induced gene expression of vacuolar processing enzyme1 (VPE1), and elevated VPE activity. VPE1 protein was semipurified from BE-treated apical buds, and its endogenous activity was fully inhibited by a cysteinyl aspartate-specific protease-1-specific inhibitor N-Acetyl-Tyr-Val-Ala-Asp-CHO (Ac-YVAD-CHO). Transmission electron microscopy further revealed PCD-related structural alterations in the TAB-meristem of BE-treated tubers: a knob-like body in the vacuole, development of cytoplasmic vesicles, and budding-like nuclear segmentations. Treatment of tubers with BE and then VPE inhibitor induced faster growth and recovered AD in detached and nondetached apical buds, respectively. We hypothesize that PCD occurrence is associated with the weakening of tuber AD, allowing early sprouting of mature lateral buds.
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Bollhöner B, Prestele J, Tuominen H. Xylem cell death: emerging understanding of regulation and function. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1081-94. [PMID: 22213814 DOI: 10.1093/jxb/err438] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Evolutionary, as well as genetic, evidence suggests that vascular development evolved originally as a cell death programme that allowed enhanced movement of water in the extinct protracheophytes, and that secondary wall formation in the water-conducting cells evolved afterwards, providing mechanical support for effective long-distance transport of water. The extant vascular plants possess a common regulatory network to coordinate the different phases of xylem maturation, including secondary wall formation, cell death, and finally autolysis of the cell contents, by the action of recently identified NAC domain transcription factors. Consequently, xylem cell death is an inseparable part of the xylem maturation programme, making it difficult to uncouple cell death mechanistically from secondary wall formation, and thus identify the key factors specifically involved in regulation of cell death. Current knowledge suggests that the necessary components for xylem cell death are produced early during xylem differentiation, and cell death is prevented through the action of inhibitors and storage of hydrolytic enzymes in inactive forms in compartments such as the vacuole. Bursting of the central vacuole triggers autolytic hydrolysis of the cell contents, which ultimately leads to cell death. This cascade of events varies between the different xylem cell types. The water-transporting tracheary elements rely on a rapid cell death programme, with hydrolysis of cell contents taking place for the most part, if not entirely, after vacuolar bursting, while the xylem fibres disintegrate cellular contents at a slower pace, well before cell death. This review includes a detailed description of cell morphology, function of plant growth regulators, such as ethylene and thermospermine, and the action of hydrolytic nucleases and proteases during cell death of the different xylem cell types.
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Affiliation(s)
- Benjamin Bollhöner
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90187 Umeå, Sweden
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64
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Zhou YF, Liu WZ. Laticiferous canal formation in fruits of Decaisnea fargesii: a programmed cell death process? PROTOPLASMA 2011; 248:683-694. [PMID: 21058023 DOI: 10.1007/s00709-010-0229-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Accepted: 10/19/2010] [Indexed: 05/30/2023]
Abstract
Programmed cell death (PCD), a topic of abiding interest, remodels plants at the cell, tissue, and organ levels involving various developmental processes of plants. The aim of this study is to provide a morphological characterization of evidence of PCD involvement in the laticiferous canal formation in fruit of Decaisnea fargesii. Several ultrastructural features of PCD have been observed including disintegration of vacuole and plasma membranes, cell wall degeneration, degenerated cytoplasm, abundant membrane structures and flocculent material, mitochondria and misshapen nuclei coupled with degraded plastids in vacuoles, and nuclei enveloped by rubber granule. In D. fargesii, the nuclei of the secretory epidermal cells become TUNEL-positive from the sunken stage to the late expanding stage, then DAPI-negative during the mature stage, indicating an early event of deoxyribonucleic acid (DNA) cleavage and a late event of complete DNA degeneration. Gel electrophoresis indicates that DNA cleavage is random and does not result in the laddering pattern indicating multiples of internucleosomal units. During the PCD of secretory epidermal cells, the rubber granules continue to be synthesized and accumulated in the secretory epidermal cells despite nuclear degradation. The PCD's role in laticiferous canal formation suggests that PCD may play important roles in gland development of plants.
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Affiliation(s)
- Ya-Fu Zhou
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Science, Northwest University, 229 Taibai Bei Road, Xi'an, 710069, China
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65
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Che YZ, Li YR, Zou HS, Zou LF, Zhang B, Chen GY. A novel antimicrobial protein for plant protection consisting of a Xanthomonas oryzae harpin and active domains of cecropin A and melittin. Microb Biotechnol 2011; 4:777-93. [PMID: 21895994 PMCID: PMC3815413 DOI: 10.1111/j.1751-7915.2011.00281.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Discoveries about antimicrobial peptides and plant defence activators have made possible the de novo and rational design of novel peptides for use in crop protection. Here we report a novel chimeric protein, Hcm1, which was made by linking the active domains of cecropin A and melittin to the hypersensitive response (HR)‐elicitor Hpa1 of Xanthomonas oryzae pv. oryzicola, the causal agent of rice bacterial leaf streak. The resulting chimeric protein maintained not only the HR‐inducing property of the harpin, but also the antimicrobial activity of the cecropin A‐melittin hybrid. Hcm1 was purified from engineered Escherichia coli and evaluated in terms of the minimal inhibitory concentration (MIC) and the 50% effective dose (ED50) against important plant pathogenic bacteria and fungi. Importantly, the protein acted as a potential pesticide by inducing disease resistance for viral, bacterial and fungal pathogens. This designed drug can be considered as a lead compound for use in plant protection, either for the development of new broad‐spectrum pesticides or for expression in transgenic plants.
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Affiliation(s)
- Yi-Zhou Che
- Department of Plant Pathology, Nanjing Agricultural University/Key Laboratory of Monitoring and Management for Plant Diseases and Insects, Ministry of Agriculture of China, Nanjing 210095, China
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González-Rábade N, Badillo-Corona JA, Aranda-Barradas JS, Oliver-Salvador MDC. Production of plant proteases in vivo and in vitro--a review. Biotechnol Adv 2011; 29:983-96. [PMID: 21889977 DOI: 10.1016/j.biotechadv.2011.08.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/10/2011] [Accepted: 08/19/2011] [Indexed: 12/30/2022]
Abstract
In the latest two decades, the interest received by plant proteases has increased significantly. Plant enzymes such as proteases are widely used in medicine and the food industry. Some proteases, like papain, bromelain and ficin are used in various processes such as brewing, meat softening, milk-clotting, cancer treatment, digestion and viral disorders. These enzymes can be obtained from their natural source or through in vitro cultures, in order to ensure a continuous source of plant enzymes. The focus of this review will be the production of plant proteases both in vivo and in vitro, with particular emphasis on the different types of commercially important plant proteases that have been isolated and characterized from naturally grown plants. In vitro approaches for the production of these proteases is also explored, focusing on the techniques that do not involve genetic transformation of the plants and the attempts that have been made in order to enhance the yield of the desired proteases.
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Mondego JMC, Duarte MP, Kiyota E, Martínez L, de Camargo SR, De Caroli FP, Alves BSC, Guerreiro SMC, Oliva MLV, Guerreiro-Filho O, Menossi M. Molecular characterization of a miraculin-like gene differentially expressed during coffee development and coffee leaf miner infestation. PLANTA 2011; 233:123-37. [PMID: 20931223 DOI: 10.1007/s00425-010-1284-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 09/15/2010] [Indexed: 05/03/2023]
Abstract
The characterization of a coffee gene encoding a protein similar to miraculin-like proteins, which are members of the plant Kunitz serine trypsin inhibitor (STI) family of proteinase inhibitors (PIs), is described. PIs are important proteins in plant defence against insects and in the regulation of proteolysis during plant development. This gene has high identity with the Richadella dulcifica taste-modifying protein miraculin and with the tomato protein LeMir; and was named as CoMir (Coffea miraculin). Structural protein modelling indicated that CoMir had structural similarities with the Kunitz STI proteins, but suggested specific folding structures. CoMir was up-regulated after coffee leaf miner (Leucoptera coffella) oviposition in resistant plants of a progeny derived from crosses between C. racemosa (resistant) and C. arabica (susceptible). Interestingly, this gene was down-regulated during coffee leaf miner herbivory in susceptible plants. CoMir expression was up-regulated after abscisic acid application and wounding stress and was prominent during the early stages of flower and fruit development. In situ hybridization revealed that CoMir transcripts accumulated in the anther tissues that display programmed cell death (tapetum, endothecium and stomium) and in the metaxylem vessels of the petals, stigma and leaves. In addition, the recombinant protein CoMir shows inhibitory activity against trypsin. According to the present results CoMir may act in proteolytic regulation during coffee development and in the defence against L. coffeella. The similarity of CoMir with other Kunitz STI proteins and the role of CoMir in plant development and plant stress are discussed.
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Affiliation(s)
- Jorge Maurício Costa Mondego
- Laboratório de Genoma Funcional Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil.
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68
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Molina-Rueda JJ, Pascual MB, Cánovas FM, Gallardo F. Characterization and developmental expression of a glutamate decarboxylase from maritime pine. PLANTA 2010; 232:1471-1483. [PMID: 20859639 DOI: 10.1007/s00425-010-1268-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 08/28/2010] [Indexed: 05/29/2023]
Abstract
Glutamate decarboxylase (GAD, EC 4.1.1.15) is a key enzyme in the synthesis of γ-aminobutyric acid (GABA) in higher plants. A complete cDNA encoding glutamate decarboxylase (GAD, EC 4.1.1.15) was characterized from Pinus pinaster Ait, and its expression pattern was studied to gain insight into the role of GAD in the differentiation of the vascular system. Pine GAD contained a C-terminal region with conserved residues and a predicted secondary structure similar to the calmodulin (CaM)-binding domains of angiosperm GADs. The enzyme was able to bind to a bovine CaM-agarose column and GAD activity was higher at acidic pH, suggesting that the pine GAD can be regulated in vivo by Ca(2+)/CaM and pH. A polyclonal antiserum was prepared against the pine protein. GAD expression was studied at activity, protein, and mRNA level and was compared with the expression of other genes during the differentiation of the hypocotyl and induction of reaction wood. In seedling organs, GABA levels closely matched GAD expression, with high levels in the root and during lignification of the hypocotyl. GAD expression was also induced in response to the production of compression wood and its expression matched the pattern of other genes involved in ethylene and 2-oxoglutarate synthesis. The results suggest of a role of GAD in hypocotyl and stem development in pine.
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Affiliation(s)
- Juan Jesús Molina-Rueda
- Departmento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Instituto Andaluz de Biotecnología, 29071, Málaga, Spain
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69
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Kwon SI, Cho HJ, Jung JH, Yoshimoto K, Shirasu K, Park OK. The Rab GTPase RabG3b functions in autophagy and contributes to tracheary element differentiation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 64:151-64. [PMID: 20659276 DOI: 10.1111/j.1365-313x.2010.04315.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The tracheary elements (TEs) of the xylem serve as the water-conducting vessels of the plant vascular system. To achieve this, TEs undergo secondary cell wall thickening and cell death, during which the cell contents are completely removed. Cell death of TEs is a typical example of developmental programmed cell death that has been suggested to be autophagic. However, little evidence of autophagy in TE differentiation has been provided. The present study demonstrates that the small GTP binding protein RabG3b plays a role in TE differentiation through its function in autophagy. Differentiating wild type TE cells were found to undergo autophagy in an Arabidopsis culture system. Both autophagy and TE formation were significantly stimulated by overexpression of a constitutively active mutant (RabG3bCA), and were inhibited in transgenic plants overexpressing a dominant negative mutant (RabG3bDN) or RabG3b RNAi (RabG3bRNAi), a brassinosteroid insensitive mutant bri1-301, and an autophagy mutant atg5-1. Taken together, our results suggest that autophagy occurs during TE differentiation, and that RabG3b, as a component of autophagy, regulates TE differentiation.
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Affiliation(s)
- Soon Il Kwon
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea RIKEN Plant Science Center, Yokohama 230-0045, Japan
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70
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Twumasi P, Iakimova ET, Qian T, van Ieperen W, Schel JHN, Emons AMC, van Kooten O, Woltering EJ. Caspase inhibitors affect the kinetics and dimensions of tracheary elements in xylogenic Zinnia (Zinnia elegans) cell cultures. BMC PLANT BIOLOGY 2010; 10:162. [PMID: 20691058 PMCID: PMC3017784 DOI: 10.1186/1471-2229-10-162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 08/06/2010] [Indexed: 05/20/2023]
Abstract
BACKGROUND The xylem vascular system is composed of fused dead, hollow cells called tracheary elements (TEs) that originate through trans-differentiation of root and shoot cambium cells. TEs undergo autolysis as they differentiate and mature. The final stage of the formation of TEs in plants is the death of the involved cells, a process showing some similarities to programmed cell death (PCD) in animal systems. Plant proteases with functional similarity to proteases involved in mammalian apoptotic cell death (caspases) are suggested as an integral part of the core mechanism of most PCD responses in plants, but participation of plant caspase-like proteases in TE PCD has not yet been documented. RESULTS Confocal microscopic images revealed the consecutive stages of TE formation in Zinnia cells during trans-differentiation. Application of the caspase inhibitors Z-Asp-CH2-DCB, Ac-YVAD-CMK and Ac-DEVD-CHO affected the kinetics of formation and the dimensions of the TEs resulting in a significant delay of TE formation, production of larger TEs and in elimination of the 'two-wave' pattern of TE production. DNA breakdown and appearance of TUNEL-positive nuclei was observed in xylogenic cultures and this was suppressed in the presence of caspase inhibitors. CONCLUSIONS To the best of our knowledge this is the first report showing that caspase inhibitors can modulate the process of trans-differentiation in Zinnia xylogenic cell cultures. As caspase inhibitors are closely associated with cell death inhibition in a variety of plant systems, this suggests that the altered TE formation results from suppression of PCD. The findings presented here are a first step towards the use of appropriate PCD signalling modulators or related molecular genetic strategies to improve the hydraulic properties of xylem vessels in favour of the quality and shelf life of plants or plant parts.
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Affiliation(s)
- Peter Twumasi
- Wageningen University, Plant Sciences Group, Horticultural Supply Chains, P.O. Box 630, 6700 AP Wageningen, The Netherlands
- Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Elena T Iakimova
- Wageningen University, Food and Biobased Research, PO Box 17, 6700 AA Wageningen, The Netherlands
- Institute of Ornamental Plants, 1222 Negovan, Sofia, Bulgaria
| | - Tian Qian
- Wageningen University, Plant Sciences Group, Horticultural Supply Chains, P.O. Box 630, 6700 AP Wageningen, The Netherlands
| | - Wim van Ieperen
- Wageningen University, Plant Sciences Group, Horticultural Supply Chains, P.O. Box 630, 6700 AP Wageningen, The Netherlands
| | - Jan HN Schel
- Wageningen University, Laboratory of Plant Cell Biology, P.O. Box 633, 6700 AP Wageningen, The Netherlands
| | - Anne Mie C Emons
- Wageningen University, Laboratory of Plant Cell Biology, P.O. Box 633, 6700 AP Wageningen, The Netherlands
| | - Olaf van Kooten
- Wageningen University, Plant Sciences Group, Horticultural Supply Chains, P.O. Box 630, 6700 AP Wageningen, The Netherlands
| | - Ernst J Woltering
- Wageningen University, Plant Sciences Group, Horticultural Supply Chains, P.O. Box 630, 6700 AP Wageningen, The Netherlands
- Wageningen University, Food and Biobased Research, PO Box 17, 6700 AA Wageningen, The Netherlands
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71
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Irfan M, Hayat S, Hayat Q, Afroz S, Ahmad A. Physiological and biochemical changes in plants under waterlogging. PROTOPLASMA 2010; 241:3-17. [PMID: 20066446 DOI: 10.1007/s00709-009-0098-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 12/10/2009] [Indexed: 05/21/2023]
Abstract
Waterlogging usually results from overuse and/or poor management of irrigation water and is a serious constraint with damaging effects. The rapidly depleting oxygen from submerged root zone is sensed and plant adjusts expressing anaerobic proteins. Plant cells shift their metabolism towards low energy yielding anaerobic fermentation pathways in the absence of oxygen. Structural modifications are also induced as aerenchyma formation and adventitious rootings, etc. Studies at molecular and biochemical levels to facilitate early perception and subsequent responses have also been worked out to produce resistant transgenic plants. This review explores the sequential changes of plant responses at different levels regarding their defense strategies and efforts made to enhance them, tailoring crucial regulators so that they can withstand waterlogging stress.
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Affiliation(s)
- Mohd Irfan
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh 202002, India
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72
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CAMBIUM, a process-based model of daily xylem development in Eucalyptus. J Theor Biol 2010; 264:395-406. [DOI: 10.1016/j.jtbi.2010.02.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 02/03/2010] [Accepted: 02/10/2010] [Indexed: 01/02/2023]
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73
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Kaneda M, Rensing K, Samuels L. Secondary cell wall deposition in developing secondary xylem of poplar. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2010; 52:234-243. [PMID: 20377684 DOI: 10.1111/j.1744-7909.2010.00925.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Although poplar is widely used for genomic and biotechnological manipulations of wood, the cellular basis of wood development in poplar has not been accurately documented at an ultrastructural level. Developing secondary xylem cells from hybrid poplar (Populus deltoides x P. trichocarpa), which were actively making secondary cell walls, were preserved with high pressure freezing/freeze substitution for light and electron microscopy. The distribution of xylans and mannans in the different cell types of developing secondary xylem were detected with immunofluorescence and immuno-gold labeling. While xylans, detected with the monoclonal antibody LM10, had a general distribution across the secondary xylem, mannans were enriched in the S2 secondary cell wall layer of fibers. To observe the cellular structures associated with secondary wall production, cryofixed fibers were examined with transmission electron microscopy during differentiation. There were abundant cortical microtubules and endomembrane activity in cells during the intense phase of secondary cell wall synthesis. Microtubule-associated small membrane compartments were commonly observed, as well as Golgi and secretory vesicles fusing with the plasma membrane.
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Affiliation(s)
- Minako Kaneda
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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74
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Du J, Groover A. Transcriptional regulation of secondary growth and wood formation. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2010; 52:17-27. [PMID: 20074137 DOI: 10.1111/j.1744-7909.2010.00901.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Secondary growth and wood formation are products of the vascular cambium, a lateral meristem. Although the mechanisms have only recently begun to be uncovered, transcriptional regulation appears increasingly central to the regulation of secondary growth. The importance of transcriptional regulation is illustrated by the correlation of expression of specific classes of genes with related biological processes occurring at specific stages of secondary growth, including cell division, cell expansion, and cell differentiation. At the same time, transcription factors have been characterized that affect specific aspects of secondary growth, including regulation of the cambium and differentiation of cambial daughter cells. In the present review, we summarize evidence pointing to transcription as a major mechanism for regulation of secondary growth, and outline future approaches for comprehensively describing transcriptional networks underlying secondary growth.
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Affiliation(s)
- Juan Du
- Institute of Forest Genetics, US Forest Service, Davis, California 95618, USA
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75
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Bushnell WR, Perkins-Veazie P, Russo VM, Collins J, Seeland TM. Effects of deoxynivalenol on content of chloroplast pigments in barley leaf tissues. PHYTOPATHOLOGY 2010; 100:33-41. [PMID: 19968547 DOI: 10.1094/phyto-100-1-0033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To understand further the role of deoxynivalenol (DON) in development of Fusarium head blight (FHB), we investigated effects of the toxin on uninfected barley tissues. Leaf segments, 1 to 1.2 cm long, partially stripped of epidermis were floated with exposed mesophyll in contact with DON solutions. In initial experiments with the leaf segments incubated in light, DON at 30 to 90 ppm turned portions of stripped tissues white after 48 to 96 h. The bleaching effect was greatly enhanced by addition of 1 to 10 mM Ca(2+), so that DON at 10 to 30 ppm turned virtually all stripped tissues white within 48 h. Content of chlorophylls a and b and of total carotenoid pigment was reduced. Loss of electrolytes and uptake of Evans blue indicated that DON had a toxic effect, damaging plasmalemmas in treated tissues before chloroplasts began to lose pigment. When incubated in the dark, leaf segments also lost electrolytes, indicating DON was toxic although the tissues remained green. Thus, loss of chlorophyll in light was due to photobleaching and was a secondary effect of DON, not required for toxicity. In contrast to bleaching effects, some DON treatments that were not toxic kept tissues green without bleaching or other signs of injury, indicating senescence was delayed compared with slow yellowing of untreated leaf segments. Cycloheximide, which like DON, inhibits protein synthesis, also bleached some tissues and delayed senescence of others. Thus, the effects of DON probably relate to its ability to inhibit protein synthesis. With respect to FHB, the results suggest DON may have multiple roles in host cells of infected head tissues, including delayed senescence in early stages of infection and contributing to bleaching and death of cells in later stages.
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Affiliation(s)
- W R Bushnell
- Cereal Disease Laboratory, US Department of Agriculture, Agricultural Research Service, St Paul , MN 55108, USA.
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76
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Hernández-Nistal J, Martín I, Jiménez T, Dopico B, Labrador E. Two cell wall Kunitz trypsin inhibitors in chickpea during seed germination and seedling growth. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:181-7. [PMID: 19091584 DOI: 10.1016/j.plaphy.2008.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Indexed: 05/01/2023]
Abstract
Two Kunitz trypsin inhibitors TPI-1 and TPI-2, encoded by CaTPI-1 and CaTPI-2, previously identified and characterized, have been detected in chickpea (Cicer arietinum L.) embryonic axes from seeds imbibed up to 48 h. Their gene transcription commenced before germination sensu stricto was completed. The transcript amount of CaTPI-1 remained high until 24 h after imbibition, when the epicotyls started to grow, while CaTPI-2 mRNA, which appeared later, reached a maximum at 48 h. Both the temporal and the spatial distribution of TPI-1 and TPI-2 proteins in the embryonic axes suggest that they perform different functions. The early appearance of TPI-1 in imbibed seeds suggests that it plays a protective role, preventing the premature degradation of the proteins stored in the embryonic axes. Its pattern of distribution suggests that the protein is involved in the regulation of vascular tissue differentiation, protecting the cells from some proteinases involved in programmed cell death. With regard to TPI-2, its later synthesis after imbibition, together with its tissue distribution, indicates that it is mainly active following germination, during elongation of the embryonic axes.
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Affiliation(s)
- Josefina Hernández-Nistal
- Dpto de Fisiología Vegetal, E.P.S., Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo, Spain
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Hao X, Qian J, Xu S, Song X, Zhu J. Location of caspase 3-like protease in the development of sieve element and tracheary element of stem in Cucurbita moschata. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2008; 50:1499-1507. [PMID: 19093968 DOI: 10.1111/j.1744-7909.2008.00719.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color (under light microscopy) and gold particles (under transmission electron microscopy) for detecting caspase 3-like protease was mainly displayed in inner phloem, external phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.
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Affiliation(s)
- Xia Hao
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
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78
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Wang L, Zhou Z, Song X, Li J, Deng X, Mei F. Evidence of ceased programmed cell death in metaphloem sieve elements in the developing caryopsis of Triticum aestivum L. PROTOPLASMA 2008; 234:87-96. [PMID: 18985425 DOI: 10.1007/s00709-008-0023-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Accepted: 10/07/2008] [Indexed: 05/26/2023]
Abstract
Transmission electron microscopy (TEM) and fluorescence microscopy studies revealed that the metaphloem sieve elements (MSEs) in the ventral vascular bundle of the caryopses of developing wheat (Triticum aestivum L.) undergo a unique type of programmed cell death (PCD). Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive nuclei were observed at 3 and 4 days after flowering (DAF). Transmission electron microscopy studies of differentiating MSEs revealed increased vacuolation, nuclear degeneration, chromatin condensation and localization to the periphery of the nucleus, and partly dilated perinuclear spaces, all typical characteristics of PCD in plant cells. In addition, vacuoles were disrupted at the last stages of differentiation. These results demonstrate that MSE differentiation is a unique type of PCD with highly selective autophagic processes, in which PCD ceases just prior to death. During this cessation of PCD, vacuoles and the endoplasmic reticulum appear to be associated with selective organelle digestion.
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Affiliation(s)
- Likai Wang
- Laboratory of Cell Biology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
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79
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Kuthanova A, Fischer L, Nick P, Opatrny Z. Cell cycle phase-specific death response of tobacco BY-2 cell line to cadmium treatment. PLANT, CELL & ENVIRONMENT 2008; 31:1634-43. [PMID: 18721263 DOI: 10.1111/j.1365-3040.2008.01876.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The character of programmed cell death (PCD) in plants differs in connection with the context, triggering factors and differentiation state of the target cells. To study the interconnections between cell cycle progression and cell death induction, we treated synchronized tobacco BY-2 cells with cadmium ions that represent a general abiotic stressor influencing both dividing and differentiated cells in planta. Cadmium induced massive cell death after application in all stages of the cell cycle; however, both the progression and the forms of the cell death differed pronouncedly. Apoptosis-like PCD induced by cadmium application in the S and G2 was characterized by pronounced internucleosomal DNA fragmentation. In contrast, application of cadmium in M and G1 phases was not accompanied by DNA cleavage, indicating suppression of autolysis and non-programmed character of the death. We interpret these results in the context of the situation in planta, where the induction of apoptosis-like PCD in the S and G2 phase might be connected with a need to preserve genetic integrity of dividing meristematic cells, whereas suppression of PCD response in differentiated cells (situated in G1/G0 phase) might help to avoid death of the whole plant, and thus enable initiation of the recovery and adaptation processes.
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Affiliation(s)
- Andrea Kuthanova
- Charles University in Prague, Faculty of Science, Department of Plant Physiology, Prague, Czech Republic
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80
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Kang YW, Kim RN, Cho HS, Kim WT, Choi D, Pai HS. Silencing of a BYPASS1 homolog results in root-independent pleiotrophic developmental defects in Nicotiana benthamiana. PLANT MOLECULAR BIOLOGY 2008; 68:423-37. [PMID: 18716882 DOI: 10.1007/s11103-008-9384-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 07/16/2008] [Indexed: 05/20/2023]
Abstract
The Arabidopsis bypass1 mutant (bps1) exhibits defective shoot and root growth that is associated with constitutive production of a root-derived carotenoid-related signal (Van Norman et al., Curr Biol 14:1739-1746, 2004). Since the identity of the signal and the function of BPS1 are still unknown, we investigated effects of BPS1 depletion in Nicotiana benthamiana to elucidate BPS1 function in plant growth and development. The predicted protein of NbBPS1, a BPS1 homolog of N. benthamiana, contains a central transmembrane domain, and a NbBPS1:GFP fusion protein was mainly associated with the endoplasmic reticulum. Virus-induced gene silencing (VIGS) of NbBPS1 resulted in pleiotrophic phenotypes, including growth retardation and abnormal leaf development. At the cellular level, the plants exhibited hyperproliferation of the cambial cells and defective xylem differentiation during stem vascular development. Hyperactivity of the cambium was associated with an elevated auxin and cytokinin response. In contrast, the leaves had reduced numbers of cells with increased cell size and elevated endoreduplication. Cell death in NbBPS1 VIGS leaves started with vacuole collapse, followed by degeneration of the organelles. Interestingly, these phenotypes were mainly caused by silencing of NbBPS1 in the aerial parts of the plants, different from the case of the Arabidopsis bps1 mutant. These results suggest that NbBPS1 plays a role in the control of cell division and differentiation in the cambium of N. benthamiana, and BPS homologs may have a diverse function in different tissues and in different species.
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Affiliation(s)
- Yong Won Kang
- Department of Biology, Yonsei University, Seoul 120-749, Korea
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81
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Avci U, Earl Petzold H, Ismail IO, Beers EP, Haigler CH. Cysteine proteases XCP1 and XCP2 aid micro-autolysis within the intact central vacuole during xylogenesis in Arabidopsis roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 56:303-315. [PMID: 18573193 DOI: 10.1111/j.1365-313x.2008.03592.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Establishing the mechanisms regulating the autolysis of xylem tracheary elements (TEs) is important for understanding this programmed cell death process. These data demonstrate that two paralogous Arabidopsis thaliana proteases, XYLEM CYSTEINE PROTEASE1 (XCP1) and XCP2, participated in micro-autolysis within the intact central vacuole before mega-autolysis was initiated by tonoplast implosion. The data acquisition was aided by the predictable pattern of seedling root xylogenesis, the availability of single and double total knock-out T-DNA lines, anti-sera that recognized XCP1 and XCP2, and the microwave-assisted processing of whole seedlings prior to immunolabeling and observation in the transmission electron microscope. During secondary wall thickening, XCP1 and XCP2 (in wild type), XCP1 (in xcp2 seedlings) or XCP2 (in xcp1 seedlings) were imported into the TE central vacuole. Both XCP1 and XCP2 heavily labeled dense aggregates of material within the vacuole. However, because of XCP1 deficiency in xcp1 and xcp1 xcp2 TEs, non-degraded cellular remnants first accumulated in the vacuole and then persisted in the TE lumen (longer than in the wild type) after the final mega-autolysis was otherwise complete. This delayed TE clearing phenotype in xcp1 was rescued by complementation with wild-type XCP1. Although TEs in the xcp2 single knock-out cleared comparably with wild type, the non-degraded remnants in xcp1 xcp2 TEs were more densely packed than in xcp1 TEs. Therefore, XCP2 has a minor but distinct role in micro-autolysis. After tonoplast implosion, XCP1 and XCP2 remained associated with disintegrating cellular material as mega-autolysis, aided by additional lytic enzymes, destroyed the bulk of the cellular contents.
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Affiliation(s)
- Utku Avci
- Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA,Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, andDepartment of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - H Earl Petzold
- Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA,Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, andDepartment of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Ihab O Ismail
- Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA,Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, andDepartment of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Eric P Beers
- Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA,Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, andDepartment of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Candace H Haigler
- Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA,Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, andDepartment of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA
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82
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Helmersson A, von Arnold S, Bozhkov PV. The level of free intracellular zinc mediates programmed cell death/cell survival decisions in plant embryos. PLANT PHYSIOLOGY 2008; 147:1158-67. [PMID: 18508953 PMCID: PMC2442516 DOI: 10.1104/pp.108.122598] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 05/22/2008] [Indexed: 05/08/2023]
Abstract
Zinc is a potent regulator of programmed cell death (PCD) in animals. While certain, cell-type-specific concentrations of intracellular free zinc are required to protect cells from death, zinc depletion commits cells to death in diverse systems. As in animals, PCD has a fundamental role in plant biology, but its molecular regulation is poorly understood. In particular, the involvement of zinc in the control of plant PCD remains unknown. Here, we used somatic embryos of Norway spruce (Picea abies) to investigate the role of zinc in developmental PCD, which is crucial for correct embryonic patterning. Staining of the early embryos with zinc-specific molecular probes (Zinquin-ethyl-ester and Dansylaminoethyl-cyclen) has revealed high accumulation of zinc in the proliferating cells of the embryonal masses and abrupt decrease of zinc content in the dying terminally differentiated suspensor cells. Exposure of early embryos to a membrane-permeable zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine led to embryonic lethality, as it induced ectopic cell death affecting embryonal masses. This cell death involved the loss of plasma membrane integrity, metacaspase-like proteolytic activity, and nuclear DNA fragmentation. To verify the anti-cell death effect of zinc, we incubated early embryos with increased concentrations of zinc sulfate. Zinc supplementation inhibited developmental PCD and led to suppression of terminal differentiation and elimination of the embryo suspensors, causing inhibition of embryo maturation. Our data demonstrate that perturbation of zinc homeostasis disrupts the balance between cell proliferation and PCD required for plant embryogenesis. This establishes zinc as an important cue governing cell fate decisions in plants.
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Affiliation(s)
- Andreas Helmersson
- Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
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83
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Delannoy M, Alves G, Vertommen D, Ma J, Boutry M, Navarre C. Identification of peptidases in Nicotiana tabacum leaf intercellular fluid. Proteomics 2008; 8:2285-98. [PMID: 18446799 DOI: 10.1002/pmic.200700507] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Indexed: 01/23/2023]
Abstract
Peptidases in the extracellular space might affect the integrity of recombinant proteins expressed in, and secreted from, plant cells. To identify extracellular peptidases, we recovered the leaf intercellular fluid from Nicotiana tabacum plants by an infiltration-centrifugation method. The activity of various peptidases was detected by an in vitro assay in the presence of specific inhibitors, using BSA and human serum gamma-globulin as substrates. Peptidases were detected by 1- and 2-D zymography in a polyacrylamide gel containing gelatin as substrate. Proteolytic activity was observed over a wide range of molecular masses equal to, or higher than, 45 kDa. To identify the peptidases, the extracellular proteins were digested with trypsin and analyzed by LC and MS. Seventeen peptides showing identity or similarity to predicted plant aspartic, cysteine, and serine peptidases have been identified. The extracellular localization of a cysteine peptidase aleurain homolog was also shown.
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Affiliation(s)
- Mélanie Delannoy
- Unité de Biochimie Physiologique, Institut des Sciences de la Vie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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84
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Li J, Brader G, Palva ET. Kunitz trypsin inhibitor: an antagonist of cell death triggered by phytopathogens and fumonisin b1 in Arabidopsis. MOLECULAR PLANT 2008; 1:482-95. [PMID: 19825555 DOI: 10.1093/mp/ssn013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Programmed cell death (PCD) is a central regulatory process in both plant development and in plant responses to pathogens. PCD requires a coordinate activation of pro-apoptotic factors such as proteases and suppressors inhibiting and modulating these processes. In plants, various caspase-like cysteine proteases as well as serine proteases have been implicated in PCD. Here, we show that a serine protease (Kunitz trypsin) inhibitor (KTI1) of Arabidopsis acts as a functional KTI when produced in bacteria and in planta. Expression of AtKTI1 is induced late in response to bacterial and fungal elicitors and to salicylic acid. RNAi silencing of the AtKTI1 gene results in enhanced lesion development after infiltration of leaf tissue with the PCD-eliciting fungal toxin fumonisin B1 (FB1) or the avirulent bacterial pathogen Pseudomonas syringae pv tomato DC3000 carrying avrB (Pst avrB). Overexpression of AtKTI1 results in reduced lesion development after Pst avrB and FB1 infiltration. Interestingly, RNAi silencing of AtKTI1 leads to enhanced resistance to the virulent pathogen Erwinia carotovora subsp. carotovora SCC1, while overexpression of AtKTI1 leads to higher susceptibility towards this pathogen. Together, these data indicate that AtKTI1 is involved in modulating PCD in plant-pathogen interactions.
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Affiliation(s)
- Jing Li
- Viikki Biocenter, Department of Biological and Environmental Sciences, Division of Genetics, University of Helsinki, POB 56, FIN-00014, Helsinki, Finland
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85
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Kuthanova A, Opatrny Z, Fischer L. Is internucleosomal DNA fragmentation an indicator of programmed death in plant cells? JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:2233-40. [PMID: 18436542 PMCID: PMC2413271 DOI: 10.1093/jxb/ern090] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/03/2008] [Accepted: 03/04/2008] [Indexed: 05/24/2023]
Abstract
Specific DNA fragmentation into oligonucleosomal units occurs during programmed cell death (PCD) in both animal and plant cells, usually being regarded as an indicator of its apoptotic character. This internucleosomal DNA fragmentation is demonstrated in tobacco suspension and leaf cells, which were killed immediately by freezing in liquid nitrogen, and homogenization or treatment with Triton X-100. Although these cells could not activate and realize the respective enzymatic processes in a programmed manner, the character of DNA fragmentation was similar to that in the cells undergoing typical gradual PCD induced by 50 microM CdSO4. This internucleosomal DNA fragmentation was connected with the action of cysteine proteases and the loss of membrane, in particular tonoplast, integrity. The mechanisms of DNase activation in the rapidly killed cells, hypothetical biological relevance, and implications for the classification of cell death are discussed.
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Affiliation(s)
| | | | - Lukas Fischer
- Charles University in Prague, Faculty of Science, Department of Plant Physiology, Vinicna 5, CZ 128 44 Prague 2, Czech Republic
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86
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Liang X, Nazarenus TJ, Stone JM. Identification of a consensus DNA-binding site for the Arabidopsis thaliana SBP domain transcription factor, AtSPL14, and binding kinetics by surface plasmon resonance. Biochemistry 2008; 47:3645-53. [PMID: 18302343 DOI: 10.1021/bi701431y] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteins with a conserved Cys- and His-rich SQUAMOSA promoter binding protein (SBP) domain are transcription factors restricted to photosynthetic organisms that possess a novel two Zn-finger structure DNA-binding domain. Despite the fact that altered expression of some SBP-encoding genes has profound effects on organism growth and development, little is known about SBP domain protein target genes. Misexpression of the Arabidopsis thaliana AtSPL14 SBP domain gene confers resistance to programmed cell death and modifies plant architecture. A consensus DNA-binding motif for AtSPL14 was identified by systematic evolution of ligands by exponential enrichment (SELEX) or random binding site selection (RBSS). DNA recognized by AtSPL14 contained the core binding motif (GTAC) found for other SBP domain proteins, but mutational analyses indicated that at least one additional flanking nucleotide is necessary for effective AtSPL14-DNA interaction. Comparison of several SBP domain amino acid sequences allows us to hypothesize which specific amino acids might participate in this sequence-specific DNA recognition. Electrophoretic mobility shift assays (EMSA) with mutant AtSPL14 DNA-binding domain proteins indicated that not all of the Zn (2+) ion coordinating ligands in the second Zn structure are strictly required for DNA binding. Surface plasmon resonance (SPR) was used to evaluate AtSPL14 in vitro binding kinetics for comparison of equilibrium binding constants with other SBP domain proteins. These data provide a strong basis for further experiments aimed at defining and distinguishing the sets of genes regulated by the closely related SBP domain family members.
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Affiliation(s)
- Xinwen Liang
- Department of Biochemistry, Plant Science Initiative, Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588, USA
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87
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Castillo-Olamendi L, Bravo-Garcìa A, Morán J, Rocha-Sosa M, Porta H. AtMCP1b, a chloroplast-localised metacaspase, is induced in vascular tissue after wounding or pathogen infection. FUNCTIONAL PLANT BIOLOGY : FPB 2008; 34:1061-1071. [PMID: 32689436 DOI: 10.1071/fp07153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 10/17/2007] [Indexed: 05/08/2023]
Abstract
cDNA corresponding to the Arabidopsis type I metacaspase AtMCP1b was isolated from plants infected with Pseudomonas syringae. A positive correlation between AtMCP1b expression and cell death was observed in the presence of staurosporine, a protein kinase inhibitor that induces programmed cell death. The tissue localisation of an AtMCP1b promoter-GUS fusion was observed in the vascular tissue of transgenic plants. GUS activity increased in response to an incompatible DC3000 (avrRpm1) or a compatible DC3000 P. syringae infection, or to wounding. Confocal and immunohistochemical analysis of Arabidopsis thaliana (L.) leaves showed that an AtMCP1b-GFP fusion protein was localised in the chloroplasts. Our data support a positive correlation between AtMCP1b gene expression and cell death in response to wounding or pathogenic interactions. Moreover, the localisation of AtMCP1b gene expression within vascular tissue and cells of abscission regions strongly supports a role for AtMCP1b in programmed cell dismantling events in response to environmental and developmental triggers. The AtMCP1b-GFP subcellular localisation infers a role for the plastid organelles in PCD and, thus, in responses to pathogen attack and development.
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Affiliation(s)
- Luis Castillo-Olamendi
- Departmento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
| | - Armando Bravo-Garcìa
- Departmento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
| | - Julio Morán
- Departmento de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
| | - Mario Rocha-Sosa
- Departmento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
| | - Helena Porta
- Departmento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
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88
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Urquhart W, Gunawardena AHLAN, Moeder W, Ali R, Berkowitz GA, Yoshioka K. The chimeric cyclic nucleotide-gated ion channel ATCNGC11/12 constitutively induces programmed cell death in a Ca2+ dependent manner. PLANT MOLECULAR BIOLOGY 2007; 65:747-61. [PMID: 17885810 DOI: 10.1007/s11103-007-9239-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Accepted: 09/05/2007] [Indexed: 05/17/2023]
Abstract
The hypersensitive response (HR) involves programmed cell death (PCD) in response to pathogen infection. To investigate the pathogen resistance signaling pathway, we previously identified the Arabidopsis mutant cpr22, which displays constitutive activation of multiple defense responses including HR like cell death. The cpr22 mutation has been identified as a 3 kb deletion that fuses two cyclic nucleotide-gated ion channel (CNGC)-encoding genes, ATCNGC11 and ATCNGC12, to generate a novel chimeric gene, ATCNGC11/12. In this study, we conducted a characterization of cell death induced by transient expression of ATCNGC11/12 in Nicotiana benthamiana. Electron microscopic analysis of this cell death showed similar characteristics to PCD, such as plasma membrane shrinkage and vesicle formation. The hallmark of animal PCD, fragmentation of nuclear DNA, was also observed in ATCNGC11/12-induced cell death. The development of cell death was significantly suppressed by caspase-1 inhibitors, suggesting the involvement of caspases in this process. Recently, vacuolar processing enzyme (VPE) was isolated as the first plant caspase-like protein, which is involved in HR development. In VPE-silenced plants development of cell death induced by ATCNGC11/12 was much slower and weaker compared to control plants, suggesting the involvement of VPE as a caspase in ATCNGC11/12-induced cell death. Complementation analysis using a Ca2+ uptake deficient yeast mutant demonstrated that the ATCNGC11/12 channel is permeable to Ca2+. Additionally, calcium channel blockers such as GdCl3 inhibited ATCNGC11/12-induced HR formation, whereas potassium channel blockers did not. Taken together, these results indicate that the cell death that develops in the cpr22 mutant is indeed PCD and that the chimeric channel, ATCNGC11/12, is at the point of, or up-stream of the calcium signal necessary for the development of HR.
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Affiliation(s)
- William Urquhart
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, Canada, M5S 3B2
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89
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Etienne P, Desclos M, Le Gou L, Gombert J, Bonnefoy J, Maurel K, Le Dily F, Ourry A, Avice JC. N-protein mobilisation associated with the leaf senescence process in oilseed rape is concomitant with the disappearance of trypsin inhibitor activity. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:895-906. [PMID: 32689418 DOI: 10.1071/fp07088] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Accepted: 07/23/2007] [Indexed: 06/11/2023]
Abstract
Brassica napus L. (oilseed rape) is an important crop plant characterised by low nitrogen (N) use efficiency. This is mainly due to a weak N recycling from leaves that is related to incomplete protein degradation. Assuming that protease inhibitors are involved throughout protein mobilisation, the goal of this study was to determine their role in the control of N mobilisation associated with leaf senescence. Results showed that a 19-kDa polypeptide exhibiting trypsin inhibitor (TI) activity presented an increased gradient from the older to the younger leaves. According to the SAG12/Cab gene expression profile, which is an indicator of leaf senescence, mature leaves of nitrate-deprived plants presented an earlier initiation of senescence and a decrease in protein concentration when compared with nitrate-replete plants. This coincided with disappearance of both TI activity and a reduction in the transcript level of the BnD22 gene (encoding a protein sharing homology with Künitz protease inhibitor). In young leaves of N-deprived plants, initiation of senescence was delayed; soluble protein concentration was maintained while both TI activity and BnD22 transcripts were high. This indicates that in oilseed rape growing under nitrate deprivation, the more efficient N recycling from mature leaves contributes to the maintenance of growth in young leaves. The data suggest a significant role for protease inhibitors in the regulation of proteolytic processes associated with N mobilisation during leaf senescence.
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Affiliation(s)
- Philippe Etienne
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Marie Desclos
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Lucie Le Gou
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Julie Gombert
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Josette Bonnefoy
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Karine Maurel
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Frédérik Le Dily
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Alain Ourry
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
| | - Jean-Christophe Avice
- UMR INRA/UCBN 950 Ecophysiologie Végétale, Agronomie (EVA) & Nutrition NCS; ISBIO, Institut de Biologie Fondamentale et Appliquée, Université de CAEN Basse-Normandie, F-14032 Caen Cedex, France
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90
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Manrique-Trujillo SM, Ramírez-López AC, Ibarra-Laclette E, Gómez-Lim MA. Identification of genes differentially expressed during ripening of banana. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:1037-50. [PMID: 16934912 DOI: 10.1016/j.jplph.2006.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Accepted: 07/12/2006] [Indexed: 05/11/2023]
Abstract
The banana (Musa acuminata, subgroup Cavendish 'Grand Nain') is a climacteric fruit of economic importance. A better understanding of the banana ripening process is needed to improve fruit quality and to extend shelf life. Eighty-four up-regulated unigenes were identified by differential screening of a banana fruit cDNA subtraction library at a late ripening stage. The ripening stages in this study were defined according to the peel color index (PCI). Unigene sequences were analyzed with different databases to assign a putative identification. The expression patterns of 36 transcripts confirmed as positive by differential screening were analyzed comparing the PCI 1, PCI 5 and PCI 7 ripening stages. Expression profiles were obtained for unigenes annotated as orcinol O-methyltransferase, putative alcohol dehydrogenase, ubiquitin-protein ligase, chorismate mutase and two unigenes with non-significant matches with any reported sequence. Similar expression profiles were observed in banana pulp and peel. Our results show differential expression of a group of genes involved in processes associated with fruit ripening, such as stress, detoxification, cytoskeleton and biosynthesis of volatile compounds. Some of the identified genes had not been characterized in banana fruit. Besides providing an overview of gene expression programs and metabolic pathways at late stages of banana fruit ripening, this study contributes to increasing the information available on banana fruit ESTs.
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Affiliation(s)
- Sandra Mabel Manrique-Trujillo
- Departamento de Ingeniería Genética de Plantas, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato. Km 9.6 Libramiento Norte Carretera Irapuato-León, Guanajuato, México
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91
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Jiménez T, Martín I, Labrador E, Dopico B. A chickpea Kunitz trypsin inhibitor is located in cell wall of elongating seedling organs and vascular tissue. PLANTA 2007; 226:45-55. [PMID: 17226027 DOI: 10.1007/s00425-006-0465-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 12/08/2006] [Indexed: 05/13/2023]
Abstract
Kunitz proteinase inhibitors in legumes have mainly been described as defence and storage proteins. Here, we report a Kunitz trypsin inhibitor, encoded by the CaTPI-1 gene from Cicer arietinum. The transcription of this gene mainly occurs in seedling vegetative organs, and is affected by the light and growth stages. The recombinant TPI-1 protein expressed in E. coli was seen to be an efficient inhibitor of trypsin. After the generation of polyclonal antibodies against recombinant TPI-1 protein, the protein was located in the cell wall of elongating epicotyls and radicles by Western-blot experiments, in agreement with the transcription pattern. These results, together with the fact that both CaTPI-1 mRNA and protein levels decreased with epicotyl growth, suggest a possible role in the elongation of seedling epicotyls and radicles. Immunolocalization analyses of the TPI-1 protein indicated that it is abundant in the cell walls of both immature primary xylem cells and surrounding parenchyma cells. This location has led us to explore potential functions for TPI-1 protein in vascular tissue during seedling elongation.
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Affiliation(s)
- Teresa Jiménez
- Dpto. de Fisiología Vegetal, Facultad de Biología, Universidad de Salamanca, Centro Hispano-Luso de Investigaciones Agrarias, Pza Doctores de la Reina s/n, Salamanca, 37007, Spain
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92
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Mino M, Murata N, Date S, Inoue M. Cell death in seedlings of the interspecific hybrid of Nicotiana gossei and N. tabacum; possible role of knob-like bodies formed on tonoplast in vacuolar-collapse-mediated cell death. PLANT CELL REPORTS 2007; 26:407-19. [PMID: 17356884 DOI: 10.1007/s00299-006-0261-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 09/14/2006] [Accepted: 09/21/2006] [Indexed: 05/14/2023]
Abstract
Vacuolar collapse plays a direct role in the cell death of the interspecific hybrid of Nicotiana gossei Domin xN. tabacum L. which exhibits hybrid lethality at the seedling stage. We have previously reported that cell death in these seedlings began at the base of hypocotyls and spread throughout the plant (Mino et al. 2002). A light microscopic analysis revealed that the process involved disruption of the intra-cellular membranes, plasmolysis, and retraction of the wall of the cell in hypocotyls. A transmission electron microscopic analysis showed that there were several abnormal structures, i.e. knob-like bodies on the tonoplast and small vesicles in the cytoplasm, and the disintegration of the tonoplast, in the cells of seedlings grown at 26 degrees C. However, no such cytological defects were observed in the seedlings grown at 37 degrees C, at which temperature the expression of lethality was suppressed. The activity levels of vacuolar processing enzyme (VPE), which might be involved in the vacuolar collapse of plant cells, temporarily increased in the seedlings grown at 26 degrees C before apparent cell death proceeded, but it remained unchanged in the seedlings grown at 37 degrees C. Applications of acetyl-L: -tyrosyl-L: -valyl-L: -alanyl-L: -aspart-1-aldehyde, an inhibitor for VPE, and cycloheximide to the seedlings suppressed VPE's activities, the formation of knob-like bodies on the tonoplast, and cell death. VPE might be involved in the structural anomalies on the tonoplast which lead to cell death triggered by vacuolar collapse in hybrid seedlings.
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Affiliation(s)
- Masanobu Mino
- Graduate School of Agriculture, Kyoto Prefectural University, Shimogamo, Kyoto, Japan,
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93
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Abstract
Tracheary elements (TEs) are cells in the xylem that are highly specialized for transporting water and solutes up the plant. TEs undergo a very well-defined process of differentiation that involves specification, enlargement, patterned cell wall deposition, programmed cell death and cell wall removal. This process is coordinated such that adjacent TEs are joined together to form a continuous network. Expression studies on model systems as diverse as trees and cell cultures have contributed to providing a flood of candidate genes with potential roles in TE differentiation. Analysis of some of these genes has yielded important information on processes such as patterned secondary cell wall deposition. The current challenge is to continue this functional analysis and to use these data and build an integrated model of TE development.
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Affiliation(s)
- Simon Turner
- University of Manchester, Faculty of Life Sciences, Manchester, United Kingdom.
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94
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Abstract
Many plant-associated microbes are pathogens that impair plant growth and reproduction. Plants respond to infection using a two-branched innate immune system. The first branch recognizes and responds to molecules common to many classes of microbes, including non-pathogens. The second responds to pathogen virulence factors, either directly or through their effects on host targets. These plant immune systems, and the pathogen molecules to which they respond, provide extraordinary insights into molecular recognition, cell biology and evolution across biological kingdoms. A detailed understanding of plant immune function will underpin crop improvement for food, fibre and biofuels production.
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Affiliation(s)
- Jonathan D G Jones
- The Sainsbury Laboratory, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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95
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Alvarez S, Goodger JQD, Marsh EL, Chen S, Asirvatham VS, Schachtman DP. Characterization of the maize xylem sap proteome. J Proteome Res 2006; 5:963-72. [PMID: 16602704 DOI: 10.1021/pr050471q] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The xylem in plants has mainly been described as a conduit for water and minerals, but emerging evidence also indicates that the xylem contains protein. To study the proteins in xylem sap, we characterized the identity and composition of the maize xylem sap proteome. The composition of the xylem sap proteome in maize revealed proteins related to different phases of xylem differentiation including cell wall metabolism, secondary cell wall synthesis, and programmed cell death. Many proteins were found to be present as multiple isoforms and some of these isoforms are glycosylated. Proteins involved in defense mechanisms were also present in xylem sap and the sap proteins were shown to have antifungal activity in bioassays.
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Affiliation(s)
- Sophie Alvarez
- Donald Danforth Plant Science Center, 975 North Warson Road, Saint Louis, Missouri 63132, USA
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96
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Gómez Ros LV, Paradiso A, Gabaldón C, Pedreño MA, de Gara L, Ros Barceló A. Two distinct cell sources of H2O2 in the lignifying Zinnia elegans cell culture system. PROTOPLASMA 2006; 227:175-83. [PMID: 16520879 DOI: 10.1007/s00709-005-0128-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Accepted: 05/26/2005] [Indexed: 05/07/2023]
Abstract
The use of transdifferentiating Zinnia elegans mesophyll cells has proved useful in investigations of the process of xylem differentiation from cambial derivatives. Cultured mesophyll cells can be induced by external stimuli to proceed through temporally controlled developmental programs which conclude in the formation of single-cell-derived dead vascular tracheids and parenchyma-like elements. However, there is a gap in our knowledge concerning the role played by reactive oxygen species (O(2) (-) and H(2)O(2)) in the development of these vascular elements. In this study, we show by the following four independent and highly selective methods that transdifferentiating Z. elegans mesophyll cells are capable of producing reactive oxygen species: the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay, which monitors O(2) (-) production, and the xylenol orange, 2,7-dichlorofluorescein diacetate, and CeCl(3) assays, which monitor H(2)O(2) production and localization. The joint use of these biochemical (XTT and xylenol orange) assays and cytochemical (2,7-dichlorofluorescein diacetate and CeCl(3)) probes revealed that transdifferentiating Z. elegans mesophyll cells do not show an oxidative burst but live in a strongly oxidative state during the entire culture period. In this state, H(2)O(2) is produced by both tracheary and parenchyma-like elements, the nonlignifying parenchyma-like cells acting quantitatively as the main source. The existence of these two sources of H(2)O(2) in this in vitro cell culture system may be especially relevant during the later stages of tracheary cell wall lignification, in which lignifying tracheary elements become hollow. In the case of differentiating tracheary elements, H(2)O(2) was located in the same place and at the same time as the onset of tracheary element lignification, i.e., at the primary cell wall during secondary thickening, supporting the view that the H(2)O(2) produced by this in vitro culture system is destined for use during lignin biosynthesis.
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Affiliation(s)
- L V Gómez Ros
- Department of Plant Biology, University of Murcia, Murcia, Spain
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97
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Du J, Xie HL, Zhang DQ, He XQ, Wang MJ, Li YZ, Cui KM, Lu MZ. Regeneration of the secondary vascular system in poplar as a novel system to investigate gene expression by a proteomic approach. Proteomics 2006; 6:881-95. [PMID: 16385474 DOI: 10.1002/pmic.200401348] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Wood formation is a complex process composing many biological events. To access its key developmental stages, we have established a regeneration system that can mimic the initiation and differentiation of cambium cells for Chinese white poplar. Anatomical studies showed that new cambium and xylem re-appeared in sequence within a few weeks after being debarked. This provides the opportunity to follow key stages of wood formation by sampling clonal trees at different regeneration times. We used this system in combination with a proteomic approach to analyze proteins expressed in different regeneration stages. PMFs for 244 proteins differentially displayed were obtained and queried against public databases. Putative functions of 199 of these proteins were assigned and classified. Regulatory genes for cell cycle progression, differentiation and cell fate were expressed in the formation of cambial tissue, while 27 genes involved in secondary wall formation were predominantly found in the xylem developing stage. This indicates that the change of gene expression pattern is corresponding to the progression of second vascular system regeneration when and where the key events of wood development occur. Further exploration of these interesting genes may provide insight into the molecular mechanisms of wood formation.
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Affiliation(s)
- Juan Du
- College of Life Sciences, Peking University, Beijing, P. R. China
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98
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Pesquet E, Ranocha P, Legay S, Digonnet C, Barbier O, Pichon M, Goffner D. Novel markers of xylogenesis in zinnia are differentially regulated by auxin and cytokinin. PLANT PHYSIOLOGY 2005; 139:1821-39. [PMID: 16306148 PMCID: PMC1310562 DOI: 10.1104/pp.105.064337] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The characterization of in vitro xylogenic cultures of zinnia (Zinnia elegans) has led to major discoveries in the understanding of xylem formation in plants. We have constructed and characterized a subtractive library from zinnia cultures enriched in genes that are specifically expressed at the onset of secondary wall deposition and tracheary element (TE) programmed cell death. This Late Xylogenesis Library (LXL) consisted of 236 nonredundant cDNAs, 77% of which encoded novel sequences in comparison with the 17,622 expressed sequence tag sequences publicly available. cDNA arrays were constructed to examine dynamic global gene expression during the course of TE formation. As a first step in dissecting auxin and cytokinin signaling during TE differentiation, macroarrays were probed with cDNAs from cells cultured in different hormonal conditions. Fifty-one percent of the LXL genes were induced by either auxin or cytokinin individually, the large majority by auxin. To determine the potential involvement of these categories of genes in TE differentiation, multiplex in situ-reverse transcription-PCR was performed on cells for two genes encoding putative cell wall proteins: Gibberellin stimulated transcript-1, induced by auxin alone, and expansin 5, induced by cytokinin alone. All transcriptionally active TEs expressed both genes, indicating that, although these genes may not be considered as specific markers for TE differentiation per se, they are nevertheless an integral part of TE differentiation program. Among the non-TE population, four different gene expression-based cell types could be distinguished. Together, these results demonstrate the underlying complexity of hormonal perception and the existence of several different cell types in in vitro TE cell cultures.
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Affiliation(s)
- Edouard Pesquet
- Unité Mixte de Recherche, Centre National de la Recherche Scientifique/Université Paul Sabatier 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, 31326 Castanet, Tolosan, France
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99
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Weir IE, Maddumage R, Allan AC, Ferguson IB. Flow cytometric analysis of tracheary element differentiation inZinnia elegans cells. Cytometry A 2005; 68:81-91. [PMID: 16228979 DOI: 10.1002/cyto.a.20194] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Tracheary element (TE) differentiation in single cells in culture isolated from Zinnia elegans leaves involves programmed cell death (PCD) co-ordinated with key morphological developments. We have used flow cytometry to analyze physiological and nuclear changes in the differentiating cells. Flow cytometry allows the identification of subpopulations, thereby removing the obscuring effect of population heterogeneity that occurs with the use of other techniques. METHODS Cell viability, plasma membrane integrity, oxidative activity, intracellular calcium and pH, cell wall thickening, the possible role of microtubule rearrangement, chromatin condensation, and DNA breakdown were followed by flow cytometry from the first stages of TE induction. RESULTS TE differentiation could be enhanced and made more synchronous by a centrifugation step at 72 h after cell isolation. Size and shape changes were the first changes identified in differentiating cells, and these properties could be used to isolate differentiating populations by back-gating. Chromatin condensation and nDNA breakdown followed patterns characteristic of programmed cell death. CONCLUSIONS We have used flow cytometry to characterize the morphological and physiological changes that occur during TE differentiation, and our findings indicate that this process is a form of autophagic PCD in which microtubule rearrangement appears to play a role.
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Affiliation(s)
- Iona E Weir
- Horticulture and Food Research Institute of New Zealand, Auckland, New Zealand.
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100
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Ellerström M, Reidt W, Ivanov R, Tiedemann J, Melzer M, Tewes A, Moritz T, Mock HP, Sitbon F, Rask L, Bäumlein H. Ectopic expression of EFFECTOR OF TRANSCRIPTION perturbs gibberellin-mediated plant developmental processes. PLANT MOLECULAR BIOLOGY 2005; 59:663-81. [PMID: 16244914 DOI: 10.1007/s11103-005-0669-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Accepted: 07/09/2005] [Indexed: 05/05/2023]
Abstract
The plant hormone gibberellin (GA) is known to modulate various aspects of plant cell differentiation and development. The current model of GA-mediated regulation is based on a de-repressible system and includes specific protein modification and degradation. HRT, a zinc finger protein from barley has been shown to have GA-dependent transcriptional repressing activity on the seed-specific alpha-amylase promoter [Raventos, D., Skriver, K., Schlein, M., Karnahl, K., Rogers, S.W., Rogers, J.C. and Mundy, J. 1998. J. Biol. Chem. 273: 23313-23320]. Here we report the characterization of a dicot homologue from Brassica napus (BnET) and provide evidence for its role in GA response modulation suggesting that this could be a conserved feature of this gene family. When BnET is ectopically expressed in either Arabidopsis or tobacco the phenotypes include dwarfism due to shorter internodes and late flowering, reduced germination rate, increased anthocyanin content and reduced xylem lignification as a marker for terminal cell differentiation. Transient expression in protoplasts supports the notion that this most likely is due to a transcriptional repression of GA controlled genes. Finally, histological analysis showed that in contrast to other GA deficient mutants the shorter internodes were due to fewer but not smaller cells, suggesting a function of BnET in GA-mediated cell division control.
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Affiliation(s)
- M Ellerström
- Botanical Institute, Gothenburg University, Box 461, SE- 405 30 Gothenburg, Sweden
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