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Castilleux R, Plancot B, Ropitaux M, Carreras A, Leprince J, Boulogne I, Follet-Gueye ML, Popper ZA, Driouich A, Vicré M. Cell wall extensins in root-microbe interactions and root secretions. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4235-4247. [PMID: 29945246 DOI: 10.1093/jxb/ery238] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/18/2018] [Indexed: 05/27/2023]
Abstract
Extensins are cell wall glycoproteins, belonging to the hydroxyproline-rich glycoprotein (HRGP) family, which are involved in many biological functions, including plant growth and defence. Several reviews have described the involvement of HRGPs in plant immunity but little focus has been given specifically to cell wall extensins. Yet, a large set of recently published data indicates that extensins play an important role in plant protection, especially in root-microbe interactions. Here, we summarise the current knowledge on this topic and discuss the importance of extensins in root defence. We first provide an overview of the distribution of extensin epitopes recognised by different monoclonal antibodies among plants and discuss the relevance of some of these epitopes as markers of the root defence response. We also highlight the implication of extensins in different types of plant interactions elicited by either pathogenic or beneficial micro-organisms. We then present and discuss the specific importance of extensins in root secretions, as these glycoproteins are not only found in the cell walls but are also released into the root mucilage. Finally, we propose a model to illustrate the impact of cell wall extensin on root secretions.
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Affiliation(s)
- Romain Castilleux
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Barbara Plancot
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Marc Ropitaux
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Alexis Carreras
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Jérôme Leprince
- INSERM U1239, Différenciation et Communication Neuronale et Neuroendocrine, Normandie Université, Rouen, France
| | - Isabelle Boulogne
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Marie-Laure Follet-Gueye
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Zoë A Popper
- Botany and Plant Science and The Ryan Institute for Environmental, Marine and Energy Research, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Azeddine Driouich
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
| | - Maïté Vicré
- Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France
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Liu Y, Wei M, Hou C, Lu T, Liu L, Wei H, Cheng Y, Wei Z. Functional Characterization of Populus PsnSHN2 in Coordinated Regulation of Secondary Wall Components in Tobacco. Sci Rep 2017; 7:42. [PMID: 28246387 PMCID: PMC5428377 DOI: 10.1038/s41598-017-00093-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/03/2017] [Indexed: 11/13/2022] Open
Abstract
Wood formation is a biological process during which the most abundant lignocellulosic biomass on earth is produced. Although a number of transcription factors have been linked to the regulation of wood formation process, none of them has been demonstrated to be a higher hierarchical regulator that coordinately regulates secondary wall biosynthesis genes. Here, we identified a Populus gene, PsnSHN2, a counterpart of the Arabidopsis AP2/ERF type transcription factor, SHINE2. PsnSHN2 is predominantly expressed in xylem tissues and acted evidently as a high hierarchical transcriptional activator. Overexpression of PsnSHN2 in tobacco significantly altered the expression of both transcription factors and biosynthesis genes involved in secondary wall formation, leading to the thickened secondary walls and the changed cell wall composition. The most significant changes occurred in the contents of cellulose and hemicellulose that increased 37% and 28%, respectively, whereas the content of lignin that decreased 34%. Furthermore, PsnSHN2 activated or repressed the promoter activities of transcription factors involved in secondary wall biosynthesis and bound to five cis-acting elements enriched in the promoter regions of these transcription factors. Taken together, our results suggest PsnSHN2 coordinately regulate secondary wall formation through selective up/down-regulation of its downstream transcription factors that control secondary wall formation.
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Affiliation(s)
- Yingying Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China
| | - Minjing Wei
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China
| | - Cong Hou
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China
| | - Tingting Lu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China
| | | | - Hairong Wei
- School of Forest Resource and Environmental Science, Michigan Technological University, Houghton, MI, 49931, USA
| | - Yuxiang Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China.
| | - Zhigang Wei
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin, 150040, P.R. China.
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Mittal A, Balasubramanian R, Cao J, Singh P, Subramanian S, Hicks G, Nothnagel EA, Abidi N, Janda J, Galbraith DW, Rock CD. TOPOISOMERASE 6B is involved in chromatin remodelling associated with control of carbon partitioning into secondary metabolites and cell walls, and epidermal morphogenesis in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:4217-39. [PMID: 24821950 PMCID: PMC4112631 DOI: 10.1093/jxb/eru198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plant growth is continuous and modular, a combination that allows morphogenesis by cell division and elongation and serves to facilitate adaptation to changing environments. The pleiotropic phenotypes of the harlequin (hlq) mutant, isolated on the basis of ectopic expression of the abscisic acid (ABA)- and auxin-inducible proDc3:GUS reporter gene, were previously characterized. Mutants are skotomorphogenic, have deformed and collapsed epidermal cells which accumulate callose and starch, cell walls abundant in pectins and cell wall proteins, and abnormal and reduced root hairs and leaf trichomes. hlq and two additional alleles that vary in their phenotypic severity of starch accumulation in the light and dark have been isolated, and it is shown that they are alleles of bin3/hyp6/rhl3/Topoisomerase6B. Mutants and inhibitors affecting the cell wall phenocopy several of the traits displayed in hlq. A microarray analysis was performed, and coordinated expression of physically adjacent pairs/sets of genes was observed in hlq, suggesting a direct effect on chromatin. Histones, WRKY and IAA/AUX transcription factors, aquaporins, and components of ubiquitin-E3-ligase-mediated proteolysis, and ABA or biotic stress response markers as well as proteins involved in cellular processes affecting carbon partitioning into secondary metabolites were also identified. A comparative analysis was performed of the hlq transcriptome with other previously published TopoVI mutant transcriptomes, namely bin3, bin5, and caa39 mutants, and limited concordance between data sets was found, suggesting indirect or genotype-specific effects. The results shed light on the molecular mechanisms underlying the det/cop/fus-like pleiotropic phenotypes of hlq and support a broader role for TopoVI regulation of chromatin remodelling to mediate development in response to environmental and hormonal signals.
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Affiliation(s)
- Amandeep Mittal
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA
| | - Rajagopal Balasubramanian
- Tamil Nadu Agricultural University, Department of Plant Breeding and Genetics, Agricultural College and Research Institute, Madurai-625 104, India
| | - Jin Cao
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA
| | - Prabhjeet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar-143 005, Punjab, India
| | - Senthil Subramanian
- South Dakota State University, Department of Plant Science, Brookings, SD 57007, USA
| | - Glenn Hicks
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA Department of Botany and Plant Sciences, University of California, Riverside CA 92521-0124, USA
| | - Eugene A Nothnagel
- Department of Botany and Plant Sciences, University of California, Riverside CA 92521-0124, USA
| | - Noureddine Abidi
- Texas Tech University, Department of Plant and Soil Science and Fiber and Biopolymer Research Institute, 1001 East Loop 289, Lubbock, TX 79409-5019, USA
| | - Jaroslav Janda
- University of Arizona, Department of Plant Sciences and BIO5 Institute, 341 Keating Bldg, Tucson, AZ 85721, USA
| | - David W Galbraith
- University of Arizona, Department of Plant Sciences and BIO5 Institute, 341 Keating Bldg, Tucson, AZ 85721, USA
| | - Christopher D Rock
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA
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Xu C, Takáč T, Burbach C, Menzel D, Šamaj J. Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA). BMC PLANT BIOLOGY 2011; 11:38. [PMID: 21349190 PMCID: PMC3048498 DOI: 10.1186/1471-2229-11-38] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 02/24/2011] [Indexed: 05/07/2023]
Abstract
BACKGROUND Hydroxyproline rich glycoproteins (HRGPs) are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs) and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis), and by immunomodulation with the JIM11 antibody. RESULTS Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs), mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs), proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM). This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages) of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP treatment showed aberrant non-compact epidermis with discontinuous ECM at the outer surface as well as much less immunolabelling with the JIM11 antibody. This treatment also decreased the plant regeneration capacity in embryogenic banana cultures. Finally, immunomodulation of surface hydroxyproline rich glycoproteins by co-culture of embryos with the JIM11 antibody resulted in a much lower germination capacity of these embryos. CONCLUSIONS These results suggest that hydroxyproline rich glycoproteins play an important developmental role, especially in the process of regeneration and germination of embryos during plant regeneration via somatic embryogenesis. Proper content and localization of hydroxyproline rich glycoproteins seem to be essential for the formation and regeneration of banana somatic embryos.
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Affiliation(s)
- Chunxiang Xu
- College of Horticulture, South China Agricultural University, Guangzhou, 510642 Guangdong, PR China
| | - Tomáš Takáč
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
| | - Christian Burbach
- Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Diedrik Menzel
- Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Jozef Šamaj
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
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Abstract
Structurally similar to retinoic acid (RA), the phytohormone abscisic acid (ABA) controls many developmental and physiological processes via complicated signaling networks that are composed of receptors, secondary messengers, protein kinase/phosphatase cascades, transcription factors, and chromatin-remodeling factors. In addition, ABA signaling is further modulated by mRNA maturation and stability, microRNA (miRNA) levels, nuclear speckling, and protein degradation. This chapter highlights the identified regulators of ABA signaling and reports their homologues in dicotyledonous and monocotyledonous plants.
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Affiliation(s)
- Zhen Xie
- Department of Biological Sciences, University of Nevada, Las Vegas, Nevada 89154, USA
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Sun W, Kieliszewski MJ, Showalter AM. Overexpression of tomato LeAGP-1 arabinogalactan-protein promotes lateral branching and hampers reproductive development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 40:870-881. [PMID: 15584953 DOI: 10.1111/j.1365-313x.2004.02274.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
LeAGP-1 is a glycosylphosphatidylinositol (GPI)-anchored arabinogalactan-protein (AGP) in tomato (Lycopersicon esculentum). Patterns of mRNA expression and protein localization for LeAGP-1 indicate that it likely functions in certain aspects of plant growth and development. To elucidate LeAGP-1 function(s), transgenic tomato plants expressing enhanced green fluorescent protein (GFP) fused to LeAGP-1 [GFP-LeAGP-1] or two LeAGP-1 variants, one lacking the C-terminal GPI-anchor domain [GFP-LeAGP-1DeltaC] and the other lacking the lysine-rich domain [GFP-LeAGP-1DeltaK], under the control of the CaMV35S promoter were produced using Agrobacterium-mediated transformation. Transgenic T0 and T1 lines with high levels of both GFP-LeAGP-1 mRNA and protein: (i) were significantly shorter; (ii) were highly branched; (iii) produced more flower buds, but most of these flowers did not mature, resulting in less fruit production; and (iv) produced seeds that were significantly smaller than normal seeds. Overexpression of LeAGP-1DeltaK had a similar or even more pronounced effect on plant vegetative and reproductive growth, while the effect of LeAGP-1DeltaC overexpression on plant reproduction was minimal. These results indicate that the GPI anchor is critical for LeAGP-1 function. As the phenotype of GFP-LeAGP-1 overexpressing transgenic plants is similar to that of cytokinin-overproducing plants, mRNA expression patterns of LeAGP-1 under different hormone treatments were examined. Cytokinins upregulated LeAGP-1 mRNA expression, while auxins and ABA inhibited LeAGP-1 mRNA expression. Based on these results, GPI-anchored LeAGP-1 most likely functions in plant growth and development in concert with auxin/cytokinin signaling.
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Affiliation(s)
- Wenxian Sun
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701-2979, USA
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7
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Finkelstein RR, Rock CD. Abscisic Acid biosynthesis and response. THE ARABIDOPSIS BOOK 2002; 1:e0058. [PMID: 22303212 PMCID: PMC3243367 DOI: 10.1199/tab.0058] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- Ruth R. Finkelstein
- Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, CA 93106
- Corresponding author: Telephone: (805) 893-4800, Fax: (805) 893-4724,
| | - Christopher D. Rock
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131
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Gampala SSL, Finkelstein RR, Sun SSM, Rock CD. ABI5 interacts with abscisic acid signaling effectors in rice protoplasts. J Biol Chem 2002; 277:1689-94. [PMID: 11704678 DOI: 10.1074/jbc.m109980200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Abscisic acid (ABA) regulates seed maturation, germination, and adaptation of vegetative tissues to environmental stresses. The mechanisms of ABA action and the specificity conferred by signaling components in overlapping pathways are not completely understood. The ABI5 gene (ABA insensitive 5) of Arabidopsis encodes a basic leucine zipper factor required for ABA response in the seed and vegetative tissues. Using transient gene expression in rice protoplasts, we provide evidence for the functional interactions of ABI5 with ABA signaling effectors VP1 (viviparous 1) and ABI1 (ABA insensitive 1). Co-transformation experiments with ABI5 cDNA constructs resulted in specific transactivation of the ABA-inducible wheat Em, Arabidopsis AtEm6, bean beta-Phaseolin, and barley HVA1 and HVA22 promoters. Furthermore, ABI5 interacted synergistically with ABA and co-expressed VP1, indicating that ABI5 is involved in ABA-regulated transcription mediated by VP1. ABI5-mediated transactivation was inhibited by overexpression of abi1-1, the dominant-negative allele of the protein phosphatase ABI1, and by 1-butanol, a competitive inhibitor of phospholipase D involved in ABA signaling. Lanthanum, a trivalent ion that acts as an agonist of ABA signaling, potentiated ABI5 transactivation. These results demonstrate that ABI5 is a key target of a conserved ABA signaling pathway in plants.
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Affiliation(s)
- Srinivas S L Gampala
- Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Hagenbeek D, Rock CD. Quantitative analysis by flow cytometry of abscisic acid-inducible gene expression in transiently transformed rice protoplasts. CYTOMETRY 2001; 45:170-9. [PMID: 11746085 DOI: 10.1002/1097-0320(20011101)45:3<170::aid-cyto1160>3.0.co;2-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Quantifying plant gene expression by flow cytometry (FCM) would allow multidimensional cell-parameter analysis on a per-cell basis, thereby providing insight into the cellular mechanisms of plant gene regulation. Here we sought to establish quantitation by FCM of plant hormone (abscisic acid, ABA)-inducible green fluorescent protein (GFP) expression and to compare the method directly with traditional reporter enzyme assays. MATERIALS AND METHODS GFP, beta-glucuronidase, and luciferase reporter genes driven by ABA-inducible or constitutive promoter constructs were expressed in transiently cotransformed rice protoplasts and reporter activities quantified by FCM (for GFP) or traditional enzyme assays. Treatments included cotransformations with specific ABA signaling effector cDNA constructs (encoding VIVIPAROUS-1, an ABA transcription factor, and ABA-INSENSITIVE1-1, a dominant-negative protein phosphatase regulator) and the ABA agonist lanthanum chloride. Dual-color FCM was also performed on GFP-expressing cells immunodecorated with an mAb recognizing a rice cell surface epitope. RESULTS Quantitative analysis of ABA-inducible gene expression by FCM using GFP as reporter gave comparable results to traditional reporter enzyme assays, although the signal-to-noise ratio was less for FCM, which can be a limitation of the method at low promoter strengths. Multiparameter-correlated analysis of ABA-inducible GFP expression with a plasma membrane marker showed no apparent correlation between ABA sensitivity, marked by GFP, and presence of a cell surface arabinogalactan glycoprotein. CONCLUSIONS Quantitative FCM of GFP-expressing plant cells is a rapid, robust, reproducible, and value-added method relative to traditional enzymatic reporter gene assays.
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Affiliation(s)
- D Hagenbeek
- Department of Biology, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
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Gampala SS, Hagenbeek D, Rock CD. Functional interactions of lanthanum and phospholipase D with the abscisic acid signaling effectors VP1 and ABI1-1 in rice protoplasts. J Biol Chem 2001; 276:9855-60. [PMID: 11139577 DOI: 10.1074/jbc.m009168200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
cis,trans-Abscisic acid (ABA) plays an important role in plant growth and development, regulation of seed maturation, germination, and adaptation to environmental stresses. Knowledge of ABA mechanisms of action and the interactions of components required for ABA signal transduction is far from complete. Using transient gene expression in rice protoplasts, we observed additive and inhibitory effects between maize VP1 (Viviparous-1, a transcriptional activator) and a dominant-negative mutant protein phosphatase, ABI1-1 (ABA-insensitive-1-1), from Arabidopsis. Lanthanide ions were shown to be specific agonists of ABA-inducible gene expression and to interact synergistically with ABA and overexpressed VP1. Both VP1 and lanthanum activities could be antagonized by coexpression of ABI1-1, which demonstrates the specific ABA dependence of these effectors on ABA-regulated gene expression. We obtained pharmacological evidence that phospholipase D (PLD) functions in ABA-inducible gene expression in rice. Antagonism of ABA, VP1, and lanthanum synergy by 1-butanol, a specific inhibitor of PLD, was similar to the inhibition by coexpression of ABI1-1. These results demonstrate that ABA, VP1, lanthanum, PLD, and ABI1 are all involved in ABA-regulated gene expression and are consistent with an integrated model whereby La(3+) acts upstream of PLD.
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Affiliation(s)
- S S Gampala
- Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Abstract
The application of surface plasmon resonance biosensors in life sciences and pharmaceutical research continues to increase. This review provides a comprehensive list of the commercial 1999 SPR biosensor literature and highlights emerging applications that are of general interest to users of the technology. Given the variability in the quality of published biosensor data, we present some general guidelines to help increase confidence in the results reported from biosensor analyses.
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Affiliation(s)
- R L Rich
- Center for Biomolecular Interaction Analysis, University of Utah School of Medicine, Salt Lake City 84132, USA
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12
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Hagenbeek D, Quatrano RS, Rock CD. Trivalent ions activate abscisic acid-inducible promoters through an ABI1-dependent pathway in rice protoplasts. PLANT PHYSIOLOGY 2000; 123:1553-60. [PMID: 10938371 PMCID: PMC59112 DOI: 10.1104/pp.123.4.1553] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/1999] [Accepted: 04/25/2000] [Indexed: 05/21/2023]
Abstract
The plant hormone abscisic acid (ABA) mediates many vital processes in plant growth and development, including seed dormancy, cell division, water use efficiency, and adaptation to drought, salinity, chilling, pathogen attack, and UV light. Our understanding of ABA signal transduction is fragmentary and would benefit from specific and facile probes of the process. Protoplasts from rice (Oryza sativa L. cv IR54) embryonic suspension cultures cotransformed with effector plasmids encoding the maize (Zea mays) VIVIPAROUS1 cDNA and/or the Arabidopsis dominant negative mutant (abi1-1) ABA-insensitive cDNA demonstrated genetic interactions of VIVIPAROUS1 and abi1-1 in transactivation of the ABA-inducible HVA1 promoter from barley (Hordeum vulgare), suggesting the mechanisms of these effectors are conserved among monocots and dicots. Trivalent ions have been shown to act as an effector of gene expression in plants and animals, although the mechanism of action is unknown. We show in two complementary transient ABA-inducible gene expression assays (beta-glucuronidase and luciferase enzymatic activities and quantitative flow cytometry of green fluorescent protein) that trivalent ions specifically interact with an ABI1-dependent ABA-signaling pathway leading to gene expression. Trivalent ions mimic ABA effects on gene expression and may be a useful tool to study ABA signaling.
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Affiliation(s)
- D Hagenbeek
- Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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