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Handford M, Rodríguez-Furlán C, Marchant L, Segura M, Gómez D, Alvarez-Buylla E, Xiong GY, Pauly M, Orellana A. Arabidopsis thaliana AtUTr7 encodes a golgi-localized UDP-glucose/UDP-galactose transporter that affects lateral root emergence. MOLECULAR PLANT 2012; 5:1263-80. [PMID: 22933714 DOI: 10.1093/mp/sss074] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nucleotide sugar transporters (NSTs) are antiporters comprising a gene family that plays a fundamental role in the biosynthesis of complex cell wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most NSTs in cell wall biosynthesis and assembly have remained elusive. Here, we report the characterization of AtUTr7 from Arabidopsis (Arabidopsis thaliana (L.) Heynh.), which is homologous to multi-specific UDP-sugar transporters from Drosophila melanogaster, humans, and Caenorhabditis elegans. We show that AtUTr7 possesses the common structural characteristics conserved among NSTs. Using a green fluorescent protein (GFP) tagged version, we demonstrate that AtUTr7 is localized in the Golgi apparatus. We also show that AtUTr7 is widely expressed, especially in the roots and in specific floral organs. Additionally, the results of an in vitro nucleotide sugar transport assay carried out with a tobacco and a yeast expression system suggest that AtUTr7 is capable of transferring UDP-Gal and UDP-Glc, but not a range of other UDP- and GDP-sugars, into the Golgi lumen. Mutants lacking expression of AtUTr7 exhibited an early proliferation of lateral roots as well as distorted root hairs when cultivated at high sucrose concentrations. Furthermore, the distribution of homogalacturonan with a low degree of methyl esterification differed in lateral root tips of the mutant compared to wild-type plants, although additional analytical procedures revealed no further differences in the composition of the root cell walls. This evidence suggests that the transport of UDP-Gal and UDP-Glc into the Golgi under conditions of high root biomass production plays a role in lateral root and root hair development.
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102
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Ouyang B, Fei Z, Joung JG, Kolenovsky A, Koh C, Nowak J, Caplan A, Keller WA, Cui Y, Cutler AJ, Tsang EWT. Transcriptome profiling and methyl homeostasis of an Arabidopsis mutant deficient in S-adenosylhomocysteine hydrolase1 (SAHH1). PLANT MOLECULAR BIOLOGY 2012; 79:315-31. [PMID: 22555436 DOI: 10.1007/s11103-012-9914-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 04/11/2012] [Indexed: 05/10/2023]
Abstract
Transcriptome profiling was conducted to detect genes whose expression is significantly changed in an Arabidopsis mutant deficient in S-adenosylhomocysteine hydrolase1 (SAHH1) during early seedling development when mutant phenotypes could be clearly observed. A total of 2,040 differentially expressed genes were identified, representing approximately 6.7% of the 30,385 DNA oligonucleotide targets on the microarray. Among these differential expressed genes, many were mapped to pathways essential to plant growth and development including those of primary, secondary and hormone metabolisms. A significant proportion of up-regulated genes encoded transposable elements which were mapped to the centromeric and pericentromeric regions of the Arabidopsis chromosomes that were analyzed. A number of down-regulated genes were found to be involved in root hair formation, which might have contributed to the root hair defective phenotype of the mutant. Analysis of genes encoding transposable elements and those associating with root hair development indicated that these genes were highly co-expressed during seedling development. Despite SAHH1 deficiency, the expression of genes encoding methyltransferase remained largely unchanged in the sahh1 mutant. Bisulfite sequencing analysis of the transposable elements and the FWA gene revealed that their sequences in the mutant were deficient of 5-methylcytosines. Analysis of mutant genomic DNA using restriction endonucleases that were unable to cut methylated DNA suggested a genome-wide hypomethylation had occurred in the mutant. These results indicated that SAHH1 plays a critical role in methyl homeostasis, and its deficiency is a major contributing factor to the change of global gene expression, metabolic pathways and activation of transposable elements in the sahh1 mutant.
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Affiliation(s)
- Bo Ouyang
- Plant Biotechnology Institute, National Research Council of Canada (NRC), 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada
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Velasquez M, Salter JS, Dorosz JG, Petersen BL, Estevez JM. Recent Advances on the Posttranslational Modifications of EXTs and Their Roles in Plant Cell Walls. FRONTIERS IN PLANT SCIENCE 2012; 3:93. [PMID: 22639676 PMCID: PMC3355594 DOI: 10.3389/fpls.2012.00093] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 04/23/2012] [Indexed: 05/08/2023]
Abstract
The genetic set up and the enzymes that define the O-glycosylation sites and transfer the activated sugars to cell wall glycoprotein Extensins (EXTs) have remained unknown for a long time. We are now beginning to see the emerging components of the molecular machinery that assembles these complex O-glycoproteins on the plant cell wall. Genes conferring the posttranslational modifications, i.e., proline hydroxylation and subsequent O-glycosylation, of the EXTs have been recently identified. In this review we summarize the enzymes that define the O-glycosylation sites on the O-glycoproteins, i.e., the prolyl 4-hydroxylases (P4Hs), the glycosyltransferases that transfer arabinose units (named arabinosyltransferases, AraTs), and the one responsible for transferring a single galactose (galactosyltransferase, GalT) on the protein EXT backbones. We discuss the effects of posttranslational modifications on the structure and function of extensins in plant cell walls.
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Affiliation(s)
- Melina Velasquez
- Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE-CONICET), Universidad de Buenos AiresBuenos Aires, Argentina
| | - Juan Salgado Salter
- Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE-CONICET), Universidad de Buenos AiresBuenos Aires, Argentina
| | - Javier Gloazzo Dorosz
- Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE-CONICET), Universidad de Buenos AiresBuenos Aires, Argentina
| | - Bent L. Petersen
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of CopenhagenCopenhagen, Denmark
| | - José M. Estevez
- Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE-CONICET), Universidad de Buenos AiresBuenos Aires, Argentina
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104
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Seo E, Yeom SI, Jo S, Jeong H, Kang BC, Choi D. Ectopic expression of Capsicum-specific cell wall protein Capsicum annuum senescence-delaying 1 (CaSD1) delays senescence and induces trichome formation in Nicotiana benthamiana. Mol Cells 2012; 33:415-22. [PMID: 22441673 PMCID: PMC3887797 DOI: 10.1007/s10059-012-0017-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 11/27/2022] Open
Abstract
Secreted proteins are known to have multiple roles in plant development, metabolism, and stress response. In a previous study to understand the roles of secreted proteins, Capsicum annuum secreted proteins (CaS) were isolated by yeast secretion trap. Among the secreted proteins, we further characterized Capsicum annuum senescence-delaying 1 (CaSD1), a gene encoding a novel secreted protein that is present only in the genus Capsicum. The deduced CaSD1 contains multiple repeats of the amino acid sequence KPPIHNHKPTDYDRS. Interestingly, the number of repeats varied among cultivars and species in the Capsicum genus. CaSD1 is constitutively expressed in roots, and Agrobacterium-mediated transient overexpression of CaSD1 in Nicotiana benthamiana leaves resulted in delayed senescence with a dramatically increased number of trichomes and enlarged epidermal cells. Furthermore, senescence- and cell division-related genes were differentially regulated by CaSD1-overexpressing plants. These observations imply that the pepper-specific cell wall protein CaSD1 plays roles in plant growth and development by regulating cell division and differentiation.
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Affiliation(s)
- Eunyoung Seo
- Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921,
Korea
| | - Seon-In Yeom
- Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921,
Korea
| | | | - Heejin Jeong
- Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921,
Korea
| | - Byoung-Cheorl Kang
- Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921,
Korea
| | - Doil Choi
- Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921,
Korea
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105
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Bruex A, Kainkaryam RM, Wieckowski Y, Kang YH, Bernhardt C, Xia Y, Zheng X, Wang JY, Lee MM, Benfey P, Woolf PJ, Schiefelbein J. A gene regulatory network for root epidermis cell differentiation in Arabidopsis. PLoS Genet 2012; 8:e1002446. [PMID: 22253603 PMCID: PMC3257299 DOI: 10.1371/journal.pgen.1002446] [Citation(s) in RCA: 245] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 10/28/2011] [Indexed: 11/18/2022] Open
Abstract
The root epidermis of Arabidopsis provides an exceptional model for studying the molecular basis of cell fate and differentiation. To obtain a systems-level view of root epidermal cell differentiation, we used a genome-wide transcriptome approach to define and organize a large set of genes into a transcriptional regulatory network. Using cell fate mutants that produce only one of the two epidermal cell types, together with fluorescence-activated cell-sorting to preferentially analyze the root epidermis transcriptome, we identified 1,582 genes differentially expressed in the root-hair or non-hair cell types, including a set of 208 "core" root epidermal genes. The organization of the core genes into a network was accomplished by using 17 distinct root epidermis mutants and 2 hormone treatments to perturb the system and assess the effects on each gene's transcript accumulation. In addition, temporal gene expression information from a developmental time series dataset and predicted gene associations derived from a Bayesian modeling approach were used to aid the positioning of genes within the network. Further, a detailed functional analysis of likely bHLH regulatory genes within the network, including MYC1, bHLH54, bHLH66, and bHLH82, showed that three distinct subfamilies of bHLH proteins participate in root epidermis development in a stage-specific manner. The integration of genetic, genomic, and computational analyses provides a new view of the composition, architecture, and logic of the root epidermal transcriptional network, and it demonstrates the utility of a comprehensive systems approach for dissecting a complex regulatory network.
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Affiliation(s)
- Angela Bruex
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Raghunandan M. Kainkaryam
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yana Wieckowski
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yeon Hee Kang
- Department of Biology, Yonsei University, Seoul, Korea
| | - Christine Bernhardt
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yang Xia
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xiaohua Zheng
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jean Y. Wang
- Department of Biology and IGSP Center for Systems Biology, Duke University, Durham, North Carolina, United States of America
| | | | - Philip Benfey
- Department of Biology and IGSP Center for Systems Biology, Duke University, Durham, North Carolina, United States of America
| | - Peter J. Woolf
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - John Schiefelbein
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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106
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Abstract
Plant cell walls have the remarkable property of combining extreme tensile strength with extensibility. The maintenance of such an exoskeleton creates nontrivial challenges for the plant cell: How can it control cell wall assembly and remodeling during growth while maintaining mechanical integrity? How can it deal with cell wall damage inflicted by herbivores, pathogens, or abiotic stresses? These processes likely require mechanisms to keep the cell informed about the status of the cell wall. In yeast, a cell wall integrity (CWI) signaling pathway has been described in great detail; in plants, the existence of CWI signaling has been demonstrated, but little is known about the signaling pathways involved. In this review, we first describe cell wall-related processes that may require or can be targets of CWI signaling and then discuss our current understanding of CWI signaling pathways and future prospects in this emerging field of plant biology.
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Affiliation(s)
- Sebastian Wolf
- Institut Jean-Pierre Bourgin, UMR 1318 INRA/AgroParisTech, Versailles Cedex, France.
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107
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Abstract
Cell growth is a process that needs to be tightly regulated. Cells must be able to sense environmental factors like nutrient abundance, the energy level or stress signals and coordinate growth accordingly. The Target Of Rapamycin (TOR) pathway is a major controller of growth-related processes in all eukaryotes. If environmental conditions are favorable, the TOR pathway promotes cell and organ growth and restrains catabolic processes like autophagy. Rapamycin is a specific inhibitor of the TOR kinase and acts as a potent inhibitor of TOR signaling. As a consequence, interfering with TOR signaling has a strong impact on plant development. This review summarizes the progress in the understanding of the biological significance and the functional analysis of the TOR pathway in plants.
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108
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Datta S, Kim CM, Pernas M, Pires ND, Proust H, Tam T, Vijayakumar P, Dolan L. Root hairs: development, growth and evolution at the plant-soil interface. PLANT AND SOIL 2011. [PMID: 0 DOI: 10.1007/s11104-011-0845-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
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109
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Pereira CS, Ribeiro JML, Vatulescu AD, Findlay K, MacDougall AJ, Jackson PAP. Extensin network formation in Vitis vinifera callus cells is an essential and causal event in rapid and H(2)O(2)-induced reduction in primary cell wall hydration. BMC PLANT BIOLOGY 2011; 11:106. [PMID: 21672244 PMCID: PMC3141637 DOI: 10.1186/1471-2229-11-106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 06/14/2011] [Indexed: 05/18/2023]
Abstract
BACKGROUND Extensin deposition is considered important for the correct assembly and biophysical properties of primary cell walls, with consequences to plant resistance to pathogens, tissue morphology, cell adhesion and extension growth. However, evidence for a direct and causal role for the extensin network formation in changes to cell wall properties has been lacking. RESULTS Hydrogen peroxide treatment of grapevine (Vitis vinifera cv. Touriga) callus cell walls was seen to induce a marked reduction in their hydration and thickness. An analysis of matrix proteins demonstrated this occurs with the insolubilisation of an abundant protein, GvP1, which displays a primary structure and post-translational modifications typical of dicotyledon extensins. The hydration of callus cell walls free from saline-soluble proteins did not change in response to H(2)O(2), but fully regained this capacity after addition of extensin-rich saline extracts. To assay the specific contribution of GvP1 cross-linking and other wall matrix proteins to the reduction in hydration, GvP1 levels in cell walls were manipulated in vitro by binding selected fractions of extracellular proteins and their effect on wall hydration during H(2)O(2) incubation assayed. CONCLUSIONS This approach allowed us to conclude that a peroxidase-mediated formation of a covalently linked network of GvP1 is essential and causal in the reduction of grapevine callus wall hydration in response to H(2)O(2). Importantly, this approach also indicated that extensin network effects on hydration was only partially irreversible and remained sensitive to changes in matrix charge. We discuss this mechanism and the importance of these changes to primary wall properties in the light of extensin distribution in dicotyledons.
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Affiliation(s)
- Cristina Silva Pereira
- Plant Cell Wall Laboratory, Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - José ML Ribeiro
- Plant Cell Wall Laboratory, Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Ada D Vatulescu
- Plant Cell Wall Laboratory, Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Kim Findlay
- Cell and Developmental Biology Department, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Alistair J MacDougall
- Department of Food Biophysics, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK
| | - Phil AP Jackson
- Plant Cell Wall Laboratory, Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
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110
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Bosch M, Mayer CD, Cookson A, Donnison IS. Identification of genes involved in cell wall biogenesis in grasses by differential gene expression profiling of elongating and non-elongating maize internodes. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:3545-61. [PMID: 21402660 PMCID: PMC3130177 DOI: 10.1093/jxb/err045] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 01/20/2011] [Accepted: 02/01/2011] [Indexed: 05/18/2023]
Abstract
Despite the economic importance of grasses as food, feed, and energy crops, little is known about the genes that control their cell wall synthesis, assembly, and remodelling. Here a detailed transcriptome analysis that allowed the identification of genes involved in grass cell wall biogenesis is provided. Differential gene expression profiling, using maize oligonucleotide arrays, was used to identify genes differentially expressed between an elongating internode, containing cells exhibiting primary cell wall synthesis, and an internode that had just ceased elongation and in which many cells were depositing secondary cell wall material. This is one of only a few studies specifically aimed at the identification of cell wall-related genes in grasses. Analysis identified new candidate genes for a role in primary and secondary cell wall biogenesis in grasses. The results suggest that many proteins involved in cell wall processes during normal development are also recruited during defence-related cell wall remodelling events. This work provides a platform for studies in which candidate genes will be functionally tested for involvement in cell wall-related processes, increasing our knowledge of cell wall biogenesis and its regulation in grasses. Since several grasses are currently being developed as lignocellulosic feedstocks for biofuel production, this improved understanding of grass cell wall biogenesis is timely, as it will facilitate the manipulation of traits favourable for sustainable food and biofuel production.
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Affiliation(s)
- Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EB, UK.
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111
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Liao YY, Buckhout TJ, Schmidt W. Phosphate deficiency-induced cell wall remodeling: linking gene networks with polysaccharide meshworks. PLANT SIGNALING & BEHAVIOR 2011; 6:700-702. [PMID: 21448004 PMCID: PMC3172841 DOI: 10.4161/psb.6.5.15051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 02/03/2011] [Indexed: 05/28/2023]
Abstract
The formation of root hairs is a unique developmental process that requires the concerted action of a multitude of proteins. Root hair development is controlled by intrinsic programs, but fine-tuning of these programs occurs in response to environmental signals, dictating the shape and function of epidermal cells. In particular, low availability of soil-immobile mineral nutrients such as phosphate (Pi) affects the density and length of root hairs, resulting in an increased absorptive surface area. We recently reported on a time-course transcriptional profiling study aimed at identifying gene networks that signal Pi deficiency and mediate adaptation to Pi shortage. Using root-specific coexpression analysis of early Pi-responsive genes, we identified a subset of novel loci crucial for the development of root hairs under Pi-deficient conditions. Remodeling of cell wall structures may be associated with the TOR (Target of Rapamycin) pathway, a highly conserved central regulator of growth and development in eukaryotic cells that senses nutrient availability.
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Affiliation(s)
- Ya-Yun Liao
- Institute of Plant and Microbial Biology; Academia Sinica; Taipei, Taiwan
| | | | - Wolfgang Schmidt
- Institute of Plant and Microbial Biology; Academia Sinica; Taipei, Taiwan
- Graduate Institute of Biotechnology; National Chung Hsing University; Taichung, Taiwan
- Genome and Systems Biology Degree Program; College of Life Science; National Taiwan University; Taipei, Taiwan
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112
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Lamport DT, Kieliszewski MJ, Chen Y, Cannon MC. Role of the extensin superfamily in primary cell wall architecture. PLANT PHYSIOLOGY 2011; 156:11-9. [PMID: 21415277 PMCID: PMC3091064 DOI: 10.1104/pp.110.169011] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 03/13/2011] [Indexed: 05/17/2023]
Affiliation(s)
| | | | | | - Maura C. Cannon
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom (D.T.A.L.); Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701 (M.J.K., Y.C.); and Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (M.C.C.)
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113
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Lin C, Choi HS, Cho HT. Root hair-specific EXPANSIN A7 is required for root hair elongation in Arabidopsis. Mol Cells 2011; 31:393-7. [PMID: 21359675 PMCID: PMC3933966 DOI: 10.1007/s10059-011-0046-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 01/17/2011] [Indexed: 10/18/2022] Open
Abstract
Expansins are non-hydrolytic cell wall-loosening proteins that are involved in the cell wall modifications that underlie many plant developmental processes. Root hair growth requires the accumulation of cell wall materials and dynamic cell wall modification at the tip region. Although several lines of indirect evidence support the idea that expansin-mediated wall modification occurs during root hair growth, the involvement of these proteins remains to be demonstrated in vivo. In this study, we used RNA interference (RNAi) to examine the biological function of Arabidopsis thaliana EXPANSIN A7 (AtEXPA7), which is expressed specifically in the root hair cell. The root hairspecific AtEXPA7 promoter was used to drive RNAi expression, which targeted two independent regions in the AtEXPA7 transcript. Quantitative reverse transcriptase-PCR analyses were used to examine AtEXPA7 transcript levels. In four independent RNAi transformant lines, RNAi expression reduced AtEXPA7 transcript levels by 25-58% compared to controls. Accordingly, the root hairs of RNAi transformant lines were 25-48% shorter than control plants and exhibited a broader range of lengths than the controls. Our results provide in vivo evidence that expansins are required for root hair tip growth.
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Affiliation(s)
- Changfa Lin
- Department of Biological Sciences and Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Korea
| | - Hee-Seung Choi
- Department of Biological Sciences and Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Korea
| | - Hyung-Taeg Cho
- Department of Biological Sciences and Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Korea
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114
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Nestler J, Schütz W, Hochholdinger F. Conserved and unique features of the maize (Zea mays L.) root hair proteome. J Proteome Res 2011; 10:2525-37. [PMID: 21417484 DOI: 10.1021/pr200003k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Root hairs are unicellular extensions of specialized epidermis cells. Under limiting conditions, they significantly increase the water and nutrient uptake capacity of plants by enlarging their root surface. Thus far, little is known about the initiation and growth of root hairs in the monocot model species maize. To gain a first insight into the protein composition of these specialized cells, the 2573 most abundant proteins of maize root hairs attached to four-day-old primary roots of the inbred line B73 were identified by combining 1DE with nanoLC-MS/MS in a shotgun proteomic experiment. Among the identified proteins, homologues of 252 proteins have been previously associated with root hair formation and development in other species. Comparison of the root hair reference proteome of the monocot species maize with the previously published root hair proteome of the dicot species soybean revealed conserved, but also unique, protein functions in root hairs of these two major groups of flowering plants.
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Affiliation(s)
- Josefine Nestler
- INRES, Institute of Crop Science and Resource Conservation, Chair for Crop Functional Genomics, University of Bonn, 53115 Bonn, Germany
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115
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Tominaga-Wada R, Ishida T, Wada T. New insights into the mechanism of development of Arabidopsis root hairs and trichomes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 286:67-106. [PMID: 21199780 DOI: 10.1016/b978-0-12-385859-7.00002-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Epidermis cell differentiation in Arabidopsis thaliana is a model system for understanding the mechanisms leading to the developmental end state of plant cells. Both root hairs and trichomes differentiate from epidermal cells and molecular genetic analyses using Arabidopsis mutants have demonstrated that the differentiation of root hairs and trichomes is regulated by similar molecular mechanisms. Molecular-genetic approaches have led to the identification of many genes that are involved in epidermal cell differentiation, most of which encode transcription factors that induce the expression of genes active in both root hair and trichome development. Control of cell growth after fate determination has also been studied using Arabidopsis mutants.
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Affiliation(s)
- Rumi Tominaga-Wada
- Interdisciplinary Research Organization, University of Miyazaki, Gakuen Kibanadai-nishi, Miyazaki, Japan
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116
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Won SK, Choi SB, Kumari S, Cho M, Lee SH, Cho HT. Root hair-specific EXPANSIN B genes have been selected for Graminaceae root hairs. Mol Cells 2010; 30:369-76. [PMID: 20811811 DOI: 10.1007/s10059-010-0127-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 07/05/2010] [Indexed: 11/29/2022] Open
Abstract
Cell differentiation ultimately relies on the regulation of cell type-specific genes. For a root hair cell to undergo morphogenesis, diverse cellular processes including cell-wall loosening must occur in a root hair cell-specific manner. Previously, we identified and characterized root hairspecific cis-elements (RHE) from the genes encoding the cell wall-loosening protein EXPANSIN A (EXPA) which functions preferentially on dicot cell walls. This study reports two root hair-specific grass EXPB genes that contain RHEs. These genes are thought to encode proteins that function more efficiently on grass cell walls. The proximal promoter regions of two orthologous EXPB genes from rice (Oryza sativa; OsEXPB5) and barley (Hordeum vulgare; HvEXPB1) included RHE motifs. These promoters could direct root hair-specific expression of green fluorescent protein (GFP) in the roots of rice and Arabidopsis (Arabidopsis thaliana). Promoter deletion analyses demonstrated that the RHE motifs are necessary for root hairspecific expression of these EXPB promoters. Phylogenetic analysis of EXP protein sequences indicated that grass EXPBs are the only orthologs to these root hair-specific EXPBs, separating dicot EXPBs to distal branches of the tree. These results suggest that RHE-containing root hair-specific EXPB genes have evolved for grass-specific cell wall modification during root hair morphogenesis.
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Affiliation(s)
- Su-Kyung Won
- Department of Biological Sciences and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-742, Korea
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117
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Ringli C. Monitoring the outside: cell wall-sensing mechanisms. PLANT PHYSIOLOGY 2010; 153:1445-52. [PMID: 20508141 PMCID: PMC2923904 DOI: 10.1104/pp.110.154518] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 05/23/2010] [Indexed: 05/18/2023]
Affiliation(s)
- Christoph Ringli
- Institute of Plant Biology, University of Zurich, 8008 Zurich, Switzerland.
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118
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Ringli C. The hydroxyproline-rich glycoprotein domain of the Arabidopsis LRX1 requires Tyr for function but not for insolubilization in the cell wall. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:662-9. [PMID: 20545889 DOI: 10.1111/j.1365-313x.2010.04270.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Extensins, hydroxyproline-rich repetitive glycoproteins with Ser-Hyp(4) motifs, are structural proteins in plant cell walls. The leucine-rich repeat extensin 1 (LRX1) of Arabidopsis thaliana is an extracellular protein with both a leucine-rich repeat and an extensin domain, and has been demonstrated to be important for cell-wall formation in root hairs. lrx1 mutants develop defective cell walls, resulting in a strong root hair phenotype. The extensin domain is essential for protein function and is thought to confer insolubilization of LRX1 in the cell wall. Here, in vivo characterization of the LRX1 extensin domain is described. First, a series of LRX1 extensin deletion constructs was produced that led to identification of a much shorter, functional extensin domain. Tyr residues can induce intra- and inter-molecular cross-links in extensins, and substitution of Tyr in the extensin domain by Phe led to reduced activity of the corresponding LRX1 protein. An additional function of Tyr (or Phe) is provided by the aromatic nature of the side chain. This suggests that these residues might be involved in hydrophobic stacking, possibly as a mechanism of protein assembly. Finally, modified LRX1 proteins lacking Tyr in the extensin domain are still insolubilized in the cell wall, indicating strong interactions of extensins within the cell wall in addition to the well-described Tyr cross-links.
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Affiliation(s)
- Christoph Ringli
- Institute of Plant Biology, University of Zürich, Zollikerstraße 107, 8008 Zürich, Switzerland.
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119
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Libault M, Farmer A, Joshi T, Takahashi K, Langley RJ, Franklin LD, He J, Xu D, May G, Stacey G. An integrated transcriptome atlas of the crop model Glycine max, and its use in comparative analyses in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:86-99. [PMID: 20408999 DOI: 10.1111/j.1365-313x.2010.04222.x] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Soybean (Glycine max L.) is a major crop providing an important source of protein and oil, which can also be converted into biodiesel. A major milestone in soybean research was the recent sequencing of its genome. The sequence predicts 69,145 putative soybean genes, with 46,430 predicted with high confidence. In order to examine the expression of these genes, we utilized the Illumina Solexa platform to sequence cDNA derived from 14 conditions (tissues). The result is a searchable soybean gene expression atlas accessible through a browser (http://digbio.missouri.edu/soybean_atlas). The data provide experimental support for the transcription of 55,616 annotated genes and also demonstrate that 13,529 annotated soybean genes are putative pseudogenes, and 1736 currently unannotated sequences are transcribed. An analysis of this atlas reveals strong differences in gene expression patterns between different tissues, especially between root and aerial organs, but also reveals similarities between gene expression in other tissues, such as flower and leaf organs. In order to demonstrate the full utility of the atlas, we investigated the expression patterns of genes implicated in nodulation, and also transcription factors, using both the Solexa sequence data and large-scale qRT-PCR. The availability of the soybean gene expression atlas allowed a comparison with gene expression documented in the two model legume species, Medicago truncatula and Lotus japonicus, as well as data available for Arabidopsis thaliana, facilitating both basic and applied aspects of soybean research.
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Affiliation(s)
- Marc Libault
- Division of Plant Sciences, National Center for Soybean Biotechnology, C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
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120
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Showalter AM, Keppler B, Lichtenberg J, Gu D, Welch LR. A bioinformatics approach to the identification, classification, and analysis of hydroxyproline-rich glycoproteins. PLANT PHYSIOLOGY 2010; 153:485-513. [PMID: 20395450 PMCID: PMC2879790 DOI: 10.1104/pp.110.156554] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Accepted: 04/12/2010] [Indexed: 05/19/2023]
Abstract
Hydroxyproline-rich glycoproteins (HRGPs) are a superfamily of plant cell wall proteins that function in diverse aspects of plant growth and development. This superfamily consists of three members: hyperglycosylated arabinogalactan proteins (AGPs), moderately glycosylated extensins (EXTs), and lightly glycosylated proline-rich proteins (PRPs). Hybrid and chimeric versions of HRGP molecules also exist. In order to "mine" genomic databases for HRGPs and to facilitate and guide research in the field, the BIO OHIO software program was developed that identifies and classifies AGPs, EXTs, PRPs, hybrid HRGPs, and chimeric HRGPs from proteins predicted from DNA sequence data. This bioinformatics program is based on searching for biased amino acid compositions and for particular protein motifs associated with known HRGPs. HRGPs identified by the program are subsequently analyzed to elucidate the following: (1) repeating amino acid sequences, (2) signal peptide and glycosylphosphatidylinositol lipid anchor addition sequences, (3) similar HRGPs via Basic Local Alignment Search Tool, (4) expression patterns of their genes, (5) other HRGPs, glycosyl transferase, prolyl 4-hydroxylase, and peroxidase genes coexpressed with their genes, and (6) gene structure and whether genetic mutants exist in their genes. The program was used to identify and classify 166 HRGPs from Arabidopsis (Arabidopsis thaliana) as follows: 85 AGPs (including classical AGPs, lysine-rich AGPs, arabinogalactan peptides, fasciclin-like AGPs, plastocyanin AGPs, and other chimeric AGPs), 59 EXTs (including SP(5) EXTs, SP(5)/SP(4) EXTs, SP(4) EXTs, SP(4)/SP(3) EXTs, a SP(3) EXT, "short" EXTs, leucine-rich repeat-EXTs, proline-rich extensin-like receptor kinases, and other chimeric EXTs), 18 PRPs (including PRPs and chimeric PRPs), and AGP/EXT hybrid HRGPs.
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Affiliation(s)
- Allan M Showalter
- Molecular and Cellular Biology Program, Department of Environmental and Plant Biology , Ohio University, Athens, OH 45701-2979, USA.
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121
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Leiber RM, John F, Verhertbruggen Y, Diet A, Knox JP, Ringli C. The TOR pathway modulates the structure of cell walls in Arabidopsis. THE PLANT CELL 2010; 22:1898-908. [PMID: 20530756 PMCID: PMC2910960 DOI: 10.1105/tpc.109.073007] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Revised: 05/12/2010] [Accepted: 05/23/2010] [Indexed: 05/18/2023]
Abstract
Plant cell growth is limited by the extension of cell walls, which requires both the synthesis and rearrangement of cell wall components in a controlled fashion. The target of rapamycin (TOR) pathway is a major regulator of cell growth in eukaryotes, and inhibition of this pathway by rapamycin reduces cell growth. Here, we show that in plants, the TOR pathway affects cell wall structures. LRR-extensin1 (LRX1) of Arabidopsis thaliana is an extracellular protein involved in cell wall formation in root hairs, and lrx1 mutants develop aberrant root hairs. rol5 (for repressor of lrx1) was identified as a suppressor of lrx1. The functionally similar ROL5 homolog in yeast, Ncs6p (needs Cla4 to survive 6), was previously found to affect TOR signaling. Inhibition of TOR signaling by rapamycin led to suppression of the lrx1 mutant phenotype and caused specific changes to galactan/rhamnogalacturonan-I and arabinogalactan protein components of cell walls that were similar to those observed in the rol5 mutant. The ROL5 protein accumulates in mitochondria, a target of the TOR pathway and major source of reactive oxygen species (ROS), and rol5 mutants show an altered response to ROS. This suggests that ROL5 might function as a mitochondrial component of the TOR pathway that influences the plant's response to ROS.
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Affiliation(s)
- Ruth-Maria Leiber
- University of Zürich, Institute of Plant Biology, 8008 Zurich, Switzerland
| | - Florian John
- University of Zürich, Institute of Plant Biology, 8008 Zurich, Switzerland
| | - Yves Verhertbruggen
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Anouck Diet
- University of Zürich, Institute of Plant Biology, 8008 Zurich, Switzerland
| | - J. Paul Knox
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Christoph Ringli
- University of Zürich, Institute of Plant Biology, 8008 Zurich, Switzerland
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122
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A polygalacturonase inhibitory protein gene (BcMF19) expressed during pollen development in Chinese cabbage-pak-choi. Mol Biol Rep 2010; 38:545-52. [DOI: 10.1007/s11033-010-0139-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 03/23/2010] [Indexed: 11/27/2022]
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123
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Zhou L, Cheung MY, Zhang Q, Lei CL, Zhang SH, Sun SSM, Lam HM. A novel simple extracellular leucine-rich repeat (eLRR) domain protein from rice (OsLRR1) enters the endosomal pathway and interacts with the hypersensitive-induced reaction protein 1 (OsHIR1). PLANT, CELL & ENVIRONMENT 2009; 32:1804-20. [PMID: 19712067 DOI: 10.1111/j.1365-3040.2009.02039.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Receptor-like protein kinases (RLKs) containing an extracellular leucine-rich repeat (eLRR) domain, a transmembrane domain and a cytoplasmic kinase domain play important roles in plant disease resistance. Simple eLRR domain proteins structurally resembling the extracellular portion of the RLKs may also participate in signalling transduction and plant defence response. Yet the molecular mechanisms and subcellular localization in regulating plant disease resistance of these simple eLRR domain proteins are still largely unclear. We provided the first experimental evidence to demonstrate the subcellular localization and trafficking of a novel simple eLRR domain protein (OsLRR1) in the endosomal pathway, using both confocal and electron microscopy. Yeast two-hybrid and in vitro pull-down assays show that OsLRR1 interacts with the rice hypersensitive-induced response protein 1 (OsHIR1) which is localized on plasma membrane. The interaction between LRR1 and HIR1 homologs was shown to be highly conserved among different plant species, suggesting a close functional relationship between the two proteins. The function of OsLRR1 in plant defence response was examined by gain-of-function tests using transgenic Arabidopsis thaliana. The protective effects of OsLRR1 against bacterial pathogen infection were shown by the alleviating of disease symptoms, lowering of pathogen titres and higher expression of defence marker genes.
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Affiliation(s)
- Liang Zhou
- Department of Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
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124
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Thiel H, Varrelmann M. Identification of Beet necrotic yellow vein virus P25 pathogenicity factor-interacting sugar beet proteins that represent putative virus targets or components of plant resistance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:999-1010. [PMID: 19589075 DOI: 10.1094/mpmi-22-8-0999] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Beet necrotic yellow vein virus (BNYVV) induces the most important disease threatening sugar beet. The growth of partially resistant hybrids carrying monogenic dominant resistance genes stabilize yield but are unable to entirely prevent virus infection and replication. P25 is responsible for symptom development and previous studies have shown that recently occurring resistance-breaking isolates possess increased P25 variability. To better understand the viral pathogenicity factor's interplay with plant proteins and to possibly unravel the molecular basis of sugar beet antivirus resistance, P25 was applied in a yeast two-hybrid screen of a resistant sugar beet cDNA library. This screen identified candidate proteins recognized as orthologues from other plant species which are known to be expressed following pathogen infection and involved in plant defense response. Most of the candidates potentially related to host-pathogen interactions were involved in the ubiquitylation process and plants response to stress, and were part of cell and metabolism components. The interaction of several candidate genes with P25 was confirmed in Nicotiana benthamiana leaf cells by transient agrobacterium-mediated expression applying bimolecular fluorescence complementation assay. The putative functions of several of the candidates identified support previous findings and present first targets for understanding the BNYVV pathogenicity and antivirus resistance mechanism.
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Affiliation(s)
- Heike Thiel
- Department of Crop Sciences, Section Plant Virology, University of Göttingen, Grisebachstrasse 6, D-37077 Göttingen, Germany
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125
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Song LI, Zhou XY, Li LI, Xue LJ, Yang XI, Xue HW. Genome-wide analysis revealed the complex regulatory network of brassinosteroid effects in photomorphogenesis. MOLECULAR PLANT 2009; 2:755-772. [PMID: 19825654 DOI: 10.1093/mp/ssp039] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Light and brassinosteroids (BRs) have been proved to be crucial in regulating plant growth and development; however, the mechanism of how they synergistically function is still largely unknown. To explore the underlying mechanisms in photomorphogenesis, genome-wide analyses were carried out through examining the gene expressions of the dark-grown WT or BR biosynthesis-defective mutant det2 seedlings in the presence of light stimuli or exogenous Brassinolide (BL). Results showed that BR deficiency stimulates, while BL treatment suppresses, the expressions of light-responsive genes and photomorphogenesis, confirming the negative effects of BR in photomorphogenesis. This is consistent with the specific effects of BR on the expression of genes involved in cell wall modification, cellular metabolism and energy utilization during dark-light transition. Further analysis revealed that hormone biosynthesis and signaling-related genes, especially those of auxin, were altered under BL treatment or light stimuli, indicating that BR may modulate photomorphogenesis through synergetic regulation with other hormones. Additionally, suppressed ubiquitin-cycle pathway during light-dark transition hinted the presence of a complicated network among light, hormone, and protein degradation. The study provides the direct evidence of BR effects in photomorphogenesis and identified the genes involved in BR and light signaling pathway, which will help to elucidate the molecular mechanism of plant photomorphogenesis.
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MESH Headings
- Arabidopsis/drug effects
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis/metabolism
- Arabidopsis/radiation effects
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/physiology
- Brassinosteroids
- Cholestanols/metabolism
- Cholestanols/pharmacology
- Chromatin Immunoprecipitation
- Cluster Analysis
- Gene Expression Regulation, Plant/drug effects
- Gene Expression Regulation, Plant/radiation effects
- Genome, Plant/genetics
- Genome-Wide Association Study
- Light
- Morphogenesis/drug effects
- Morphogenesis/radiation effects
- Plants, Genetically Modified/drug effects
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plants, Genetically Modified/radiation effects
- Promoter Regions, Genetic
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/drug effects
- Signal Transduction/radiation effects
- Steroids, Heterocyclic/metabolism
- Steroids, Heterocyclic/pharmacology
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Affiliation(s)
- L I Song
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
| | - Xiao-Yi Zhou
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
| | - L I Li
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
| | - Liang-Jiao Xue
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
| | - X I Yang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
| | - Hong-Wei Xue
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China.
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126
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Won SK, Lee YJ, Lee HY, Heo YK, Cho M, Cho HT. Cis-element- and transcriptome-based screening of root hair-specific genes and their functional characterization in Arabidopsis. PLANT PHYSIOLOGY 2009; 150:1459-73. [PMID: 19448035 PMCID: PMC2705046 DOI: 10.1104/pp.109.140905] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 05/11/2009] [Indexed: 05/18/2023]
Abstract
Understanding the cellular differentiation of multicellular organisms requires the characterization of genes whose expression is modulated in a cell type-specific manner. The Arabidopsis (Arabidopsis thaliana) root hair cell is one model for studying cellular differentiation. In this study, root hair cell-specific genes were screened by a series of in silico and experimental filtration procedures. This process included genome-wide screening for genes with a root hair-specific cis-element in their promoters, filtering root-specific genes from the root hair-specific cis-element-containing genes, further filtering of genes that were suppressed in root hair-defective plant lines, and experimental confirmation by promoter assay. These procedures revealed 19 root hair-specific genes, including many protein kinases and cell wall-related genes, most of which have not been characterized thus far. Functional analyses of these root hair-specific genes with loss-of-function mutants and overexpressing transformants revealed that they play roles in hair growth and morphogenesis. This study demonstrates that a defined cis-element can serve as a filter to screen certain cell type-specific genes and implicates many new root hair-specific genes in root hair development.
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Affiliation(s)
- Su-Kyung Won
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
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127
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Wang J, Ji Q, Jiang L, Shen S, Fan Y, Zhang C. Overexpression of a cytosol-localized rhamnose biosynthesis protein encoded by Arabidopsis RHM1 gene increases rhamnose content in cell wall. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:86-93. [PMID: 19056285 DOI: 10.1016/j.plaphy.2008.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2008] [Revised: 10/19/2008] [Accepted: 10/28/2008] [Indexed: 05/15/2023]
Abstract
l-Rhamnose (Rha) is an important constituent of pectic polysaccharides, a major component of the cell walls of Arabidopsis, which is synthesized by three enzymes encoded by AtRHM1, AtRHM2/AtMUM4, and AtRHM3. Despite the finding that RHM1 is involved in root hair formation in Arabidopsis, experimental evidence is still lacking for the in vivo enzymatic activity and subcellular compartmentation of AtRHM1 protein. AtRHM1 displays high similarity to the other members of RHM family in Arabidopsis and in other plant species such as rice and grape. Expression studies with AtRHM1 promoter-GUS fusion gene showed that AtRHM1 was expressed almost ubiquitously, with stronger expression in roots and cotyledons of young seedlings and inflorescences. GFP::AtRHM1 fusion protein was found to be localized in the cytosol of cotyledon cells and of petiole cells of cotyledon, indicating that AtRHM1 is a cytosol-localized protein. The overexpression of AtRHM1 gene in Arabidopsis resulted in an increase of rhamnose content as much as 40% in the leaf cell wall compared to the wild type as well as an alteration in the contents of galactose and glucose. Fourier-transform infrared analyses revealed that surplus rhamnose upon AtRHM1 overexpression contributes to the construction of rhamnogalacturonan.
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Affiliation(s)
- Jinfeng Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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128
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129
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Nielsen E. Plant Cell Wall Biogenesis During Tip Growth in Root Hair Cells. PLANT CELL MONOGRAPHS 2009. [DOI: 10.1007/978-3-540-79405-9_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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130
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Bernal AJ, Yoo CM, Mutwil M, Jensen JK, Hou G, Blaukopf C, Sørensen I, Blancaflor EB, Scheller HV, Willats WGT. Functional analysis of the cellulose synthase-like genes CSLD1, CSLD2, and CSLD4 in tip-growing Arabidopsis cells. PLANT PHYSIOLOGY 2008; 148:1238-53. [PMID: 18768911 PMCID: PMC2577265 DOI: 10.1104/pp.108.121939] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 08/29/2008] [Indexed: 05/18/2023]
Abstract
A reverse genetic approach was used to investigate the functions of three members of the cellulose synthase superfamily in Arabidopsis (Arabidopsis thaliana), CELLULOSE SYNTHASE-LIKE D1 (CSLD1), CSLD2, and CSLD4. CSLD2 is required for normal root hair growth but has a different role from that previously described for CSLD3 (KOJAK). CSLD2 is required during a later stage of hair development than CSLD3, and CSLD2 mutants produce root hairs with a range of abnormalities, with many root hairs rupturing late in development. Remarkably, though, it was often the case that in CSLD2 mutants, tip growth would resume after rupturing of root hairs. In silico, semiquantitative reverse transcription-polymerase chain reaction, and promoter-reporter construct analyses indicated that the expression of both CSLD2 and CSLD3 is elevated at reduced temperatures, and the phenotypes of mutants homozygous for insertions in these genes were partially rescued by reduced temperature growth. However, this was not the case for a double mutant homozygous for insertions in both CSLD2 and CSLD3, suggesting that there may be partial redundancy in the functions of these genes. Mutants in CSLD1 and CSLD4 had a defect in male transmission, and plants heterozygous for insertions in CSLD1 or CSLD4 were defective in their ability to produce pollen tubes, although the number and morphology of pollen grains was normal. We propose that the CSLD family of putative glycosyltransferases synthesize a polysaccharide that has a specialized structural role in the cell walls of tip-growing cells.
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Affiliation(s)
- Adriana J Bernal
- Department of Biology, University of Copenhagen, Copenhagen Biocentre, 2200 Copenhagen, Denmark
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131
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Frank J, Kaulfürst-Soboll H, Rips S, Koiwa H, von Schaewen A. Comparative analyses of Arabidopsis complex glycan1 mutants and genetic interaction with staurosporin and temperature sensitive3a. PLANT PHYSIOLOGY 2008; 148:1354-67. [PMID: 18768906 PMCID: PMC2577240 DOI: 10.1104/pp.108.127027] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 08/24/2008] [Indexed: 05/18/2023]
Abstract
We compare three Arabidopsis (Arabidopsis thaliana) complex glycan1 (cgl1) alleles and report on genetic interaction with staurosporin and temperature sensitive3a (stt3a). STT3a encodes a subunit of oligosaccharyltransferase that affects efficiency of N-glycan transfer to nascent secretory proteins in the endoplasmic reticulum; cgl1 mutants lack N-acetyl-glucosaminyltransferase I activity and are unable to form complex N-glycans in the Golgi apparatus. By studying CGL1-green fluorescent protein fusions in transient assays, we show that the extra N-glycosylation site created by a point mutation in cgl1 C5 is used in planta and interferes with folding of full-length membrane-anchored polypeptides in the endoplasmic reticulum. Tunicamycin treatment or expression in the stt3a-2 mutant relieved the folding block, and migration to Golgi stacks resumed. Complementation tests with C5-green fluorescent protein and other N-glycosylation variants of CGL1 demonstrated that suppression of aberrant N-glycosylation restores activity. Interestingly, CGL1 seems to be functional also as nonglycosylated enzyme. Two other cgl1 alleles showed splicing defects of their transcripts. In cgl1 C6, a point mutation affects the 3' splice site of intron 14, resulting in frame shifts; in cgl1-T, intron 11 fails to splice due to insertion of a T-DNA copy. Introgression of stt3a-2 did not restore complex glycan formation in cgl1 C6 or cgl1-T but suppressed the N-acetyl-glucosaminyltransferase I defect in cgl1 C5. Root growth assays revealed synergistic effects in double mutants cgl1 C6 stt3a-2 and cgl1-T stt3a-2 only. Besides demonstrating the conditional nature of cgl1 C5 in planta, our observations with loss-of-function alleles cgl1 C6 and cgl1-T in the stt3a-2 underglycosylation background prove that correct N-glycosylation is important for normal root growth and morphology in Arabidopsis.
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Affiliation(s)
- Julia Frank
- Institut für Botanik, Westfälische Wilhelms-Universität Münster, 48149 Munster, Germany
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132
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Hayashi S, Ishii T, Matsunaga T, Tominaga R, Kuromori T, Wada T, Shinozaki K, Hirayama T. The glycerophosphoryl diester phosphodiesterase-like proteins SHV3 and its homologs play important roles in cell wall organization. PLANT & CELL PHYSIOLOGY 2008; 49:1522-35. [PMID: 18718934 DOI: 10.1093/pcp/pcn120] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Despite the importance of extracellular events in cell wall organization and biogenesis, the mechanisms and related factors are largely unknown. We isolated an allele of the shaven3 (shv3) mutant of Arabidopsis thaliana, which exhibits ruptured root hair cells during tip growth. SHV3 encodes a novel protein with two tandemly repeated glycerophosphoryl diester phosphodiesterase-like domains and a glycosylphosphatidylinositol anchor, and several of its paralogs are found in Arabidopsis. Here, we report the detailed characterization of mutants of SHV3 and one of its paralogs, SVL1. The shv3 and svl1 double mutant exhibited additional defects, including swollen guard cells, aberrant expansion of the hypocotyl epidermis and ectopic lignin deposits, suggesting decreased rigidity of the cell wall. Fourier-transform infrared spectroscopy and measurement of the cell wall components indicated an altered cellulose content and pectin modification with cross-linking in the double mutant. Furthermore, we found that the ruptured root hair phenotype of shv3 was suppressed by increasing the amount of borate, which is supposed to be involved in pectic polysaccharide cross-linking, in the medium. These findings indicate that SHV3 and its paralogs are novel important factors involved in primary cell wall organization.
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Affiliation(s)
- Shimpei Hayashi
- International Graduate School of Arts and Sciences, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045 Japan
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133
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Riewe D, Grosman L, Fernie AR, Wucke C, Geigenberger P. The potato-specific apyrase is apoplastically localized and has influence on gene expression, growth, and development. PLANT PHYSIOLOGY 2008; 147:1092-109. [PMID: 18480378 PMCID: PMC2442552 DOI: 10.1104/pp.108.117564] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 05/12/2008] [Indexed: 05/18/2023]
Abstract
Apyrases hydrolyze nucleoside triphosphates and diphosphates and are found in all eukaryotes and a few prokaryotes. Although their enzymatic properties have been well characterized, relatively little is known regarding their subcellular localization and physiological function in plants. In this study, we used reverse genetic and biochemical approaches to investigate the role of potato (Solanum tuberosum)-specific apyrase. Silencing of the apyrase gene family with RNA interference constructs under the control of the constitutive 35S promoter led to a strong decrease in apyrase activity to below 10% of the wild-type level. This decreased activity led to phenotypic changes in the transgenic lines, including a general retardation in growth, an increase in tuber number per plant, and differences in tuber morphology. Silencing of apyrase under the control of a tuber-specific promoter led to similar changes in tuber morphology; however, there were no direct effects of apyrase inhibition on tuber metabolism. DNA microarrays revealed that decreased expression of apyrase leads to increased levels of transcripts coding for cell wall proteins involved in growth and genes involved in energy transfer and starch synthesis. To place these results in context, we determined the subcellular localization of the potato-specific apyrase. Using a combination of approaches, we were able to demonstrate that this enzyme is localized to the apoplast. We describe the evidence that underlies both this fact and that potato-specific apyrase has a crucial role in regulating growth and development.
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Affiliation(s)
- David Riewe
- Max-Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
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134
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Cavalier DM, Lerouxel O, Neumetzler L, Yamauchi K, Reinecke A, Freshour G, Zabotina OA, Hahn MG, Burgert I, Pauly M, Raikhel NV, Keegstra K. Disrupting two Arabidopsis thaliana xylosyltransferase genes results in plants deficient in xyloglucan, a major primary cell wall component. THE PLANT CELL 2008; 20:1519-37. [PMID: 18544630 PMCID: PMC2483363 DOI: 10.1105/tpc.108.059873] [Citation(s) in RCA: 315] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 05/09/2008] [Accepted: 05/21/2008] [Indexed: 05/17/2023]
Abstract
Xyloglucans are the main hemicellulosic polysaccharides found in the primary cell walls of dicots and nongraminaceous monocots, where they are thought to interact with cellulose to form a three-dimensional network that functions as the principal load-bearing structure of the primary cell wall. To determine whether two Arabidopsis thaliana genes that encode xylosyltransferases, XXT1 and XXT2, are involved in xyloglucan biosynthesis in vivo and to determine how the plant cell wall is affected by the lack of expression of XXT1, XXT2, or both, we isolated and characterized xxt1 and xxt2 single and xxt1 xxt2 double T-DNA insertion mutants. Although the xxt1 and xxt2 mutants did not have a gross morphological phenotype, they did have a slight decrease in xyloglucan content and showed slightly altered distribution patterns for xyloglucan epitopes. More interestingly, the xxt1 xxt2 double mutant had aberrant root hairs and lacked detectable xyloglucan. The reduction of xyloglucan in the xxt2 mutant and the lack of detectable xyloglucan in the xxt1 xxt2 double mutant resulted in significant changes in the mechanical properties of these plants. We conclude that XXT1 and XXT2 encode xylosyltransferases that are required for xyloglucan biosynthesis. Moreover, the lack of detectable xyloglucan in the xxt1 xxt2 double mutant challenges conventional models of the plant primary cell wall.
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Affiliation(s)
- David M Cavalier
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
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135
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Ringli C, Bigler L, Kuhn BM, Leiber RM, Diet A, Santelia D, Frey B, Pollmann S, Klein M. The modified flavonol glycosylation profile in the Arabidopsis rol1 mutants results in alterations in plant growth and cell shape formation. THE PLANT CELL 2008; 20:1470-81. [PMID: 18567791 PMCID: PMC2483361 DOI: 10.1105/tpc.107.053249] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 06/02/2008] [Accepted: 06/05/2008] [Indexed: 05/18/2023]
Abstract
Flavonoids are secondary metabolites known to modulate plant growth and development. A primary function of flavonols, a subgroup of flavonoids, is thought to be the modification of auxin fluxes in the plant. Flavonols in the cell are glycosylated, and the repressor of lrx1 (rol1) mutants of Arabidopsis thaliana, affected in rhamnose biosynthesis, have a modified flavonol glycosylation profile. A detailed analysis of the rol1-2 allele revealed hyponastic growth, aberrant pavement cell and stomatal morphology in cotyledons, and defective trichome formation. Blocking flavonoid biosynthesis suppresses the rol1-2 shoot phenotype, suggesting that it is induced by the modified flavonol profile. The hyponastic cotyledons of rol1-2 are likely to be the result of a flavonol-induced increase in auxin concentration. By contrast, the pavement cell, stomata, and trichome formation phenotypes appear not to be induced by the modified auxin distribution. Together, these results suggest that changes in the composition of flavonols can have a tremendous impact on plant development through both auxin-induced and auxin-independent processes.
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Affiliation(s)
- Christoph Ringli
- Institute of Plant Biology, University of Zürich, 8008 Zurich, Switzerland.
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136
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Ishida T, Kurata T, Okada K, Wada T. A genetic regulatory network in the development of trichomes and root hairs. ANNUAL REVIEW OF PLANT BIOLOGY 2008; 59:365-86. [PMID: 18257710 DOI: 10.1146/annurev.arplant.59.032607.092949] [Citation(s) in RCA: 342] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Trichomes and root hairs differentiate from epidermal cells in the aerial tissues and roots, respectively. Because trichomes and root hairs are easily accessible, particularly in the model plant Arabidopsis, their development has become a well-studied model of cell differentiation and growth. Molecular genetic analyses using Arabidopsis mutants have demonstrated that the differentiation of trichomes and root hair/hairless cells is regulated by similar molecular mechanisms. Transcriptional complexes regulate differentiation into trichome cells and root hairless cells, and formation of the transcriptional complexes is inhibited in neighboring cells. Control of cell growth after fate determination has also been analyzed using Arabidopsis mutants. The progression of endoreduplication cycles, reorientation of microtubules, and organization of the actin cytoskeleton play important roles in trichome growth. Various cellular components such as ion channels, the actin cytoskeleton, microtubules and cell wall materials, and intracellular signal transduction act to establish and maintain root hair tip growth.
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Affiliation(s)
- Tetsuya Ishida
- Plant Science Center, RIKEN, Yokohama, Kanagawa 230-0045, Japan.
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137
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Shimizu T, Satoh K, Kikuchi S, Omura T. The repression of cell wall- and plastid-related genes and the induction of defense-related genes in rice plants infected with Rice dwarf virus. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:247-54. [PMID: 17378427 DOI: 10.1094/mpmi-20-3-0247] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
An analysis, using microarrays, of gene expression in rice plants infected with Rice dwarf virus revealed significant decreases in levels of expression of genes that are involved in the formation of cell walls, reflecting the stunted growth of diseased plants. The expression of plastid-related genes also was suppressed, as anticipated from the white chlorotic appearance of infected leaves. By contrast, the expression of defense- and stress-related genes was enhanced after viral infection. These results suggest that virus-infected rice plants attempt to survive viral infection and replication by raising the levels of expression of defense- and stress-related genes while suppressing the expression of genes required for the elongation of cells and photosynthesis.
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Affiliation(s)
- Takumi Shimizu
- Research Team for Vectorborne Diseases, National Agricultural Research Center, Kannondai 3-1-1, Tsukuba, Ibaraki 305-8666, Japan
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138
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Kim CM, Park SH, Je BI, Park SH, Park SJ, Piao HL, Eun MY, Dolan L, Han CD. OsCSLD1, a cellulose synthase-like D1 gene, is required for root hair morphogenesis in rice. PLANT PHYSIOLOGY 2007; 143:1220-30. [PMID: 17259288 PMCID: PMC1820921 DOI: 10.1104/pp.106.091546] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Root hairs are long tubular outgrowths that form on the surface of specialized epidermal cells. They are required for nutrient and water uptake and interact with the soil microflora. Here we show that the Oryza sativa cellulose synthase-like D1 (OsCSLD1) gene is required for root hair development, as rice (Oryza sativa) mutants that lack OsCSLD1 function develop abnormal root hairs. In these mutants, while hair development is initiated normally, the hairs elongate less than the wild-type hairs and they have kinks and swellings along their length. Because the csld1 mutants develop the same density and number of root hairs along their seminal root as the wild-type plants, we propose that OsCSLD1 function is required for hair elongation but not initiation. Both gene trap expression pattern and in situ hybridization analyses indicate that OsCSLD1 is expressed in only root hair cells. Furthermore, OsCSLD1 is the only member of the four rice CSLD genes that shows root-specific expression. Given that the Arabidopsis (Arabidopsis thaliana) gene KOJAK/AtCSLD3 is required for root hair elongation and is expressed in the root hair, it appears that OsCSLD1 may be the functional ortholog of KOJAK/AtCSLD3 and that these two genes represent the root hair-specific members of this family of proteins. Thus, at least part of the mechanism of root hair morphogenesis in Arabidopsis is conserved in rice.
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Affiliation(s)
- Chul Min Kim
- Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center, Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea
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139
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Humphrey TV, Bonetta DT, Goring DR. Sentinels at the wall: cell wall receptors and sensors. THE NEW PHYTOLOGIST 2007; 176:7-21. [PMID: 17803638 DOI: 10.1111/j.1469-8137.2007.02192.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The emerging view of the plant cell wall is of a dynamic and responsive structure that exists as part of a continuum with the plasma membrane and cytoskeleton. This continuum must be responsive and adaptable to normal processes of growth as well as to stresses such as wounding, attack from pathogens and mechanical stimuli. Cell expansion involving wall loosening, deposition of new materials, and subsequent rigidification must be tightly regulated to allow the maintenance of cell wall integrity and co-ordination of development. Similarly, sensing and feedback are necessary for the plant to respond to mechanical stress or pathogen attack. Currently, understanding of the sensing and feedback mechanisms utilized by plants to regulate these processes is limited, although we can learn from yeast, where the signalling pathways have been more clearly defined. Plant cell walls possess a unique and complicated structure, but it is the protein components of the wall that are likely to play a crucial role at the forefront of perception, and these are likely to include a variety of sensor and receptor systems. Recent plant research has yielded a number of interesting candidates for cell wall sensors and receptors, and we are beginning to understand the role that they may play in this crucial aspect of plant biology.
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Affiliation(s)
- Tania V Humphrey
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2 Canada
| | - Dario T Bonetta
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe St North, Science Building UA4000, Oshawa, Ontario, L1H 7K4 Canada
| | - Daphne R Goring
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2 Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
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140
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Bosca S, Barton CJ, Taylor NG, Ryden P, Neumetzler L, Pauly M, Roberts K, Seifert GJ. Interactions between MUR10/CesA7-dependent secondary cellulose biosynthesis and primary cell wall structure. PLANT PHYSIOLOGY 2006; 142:1353-63. [PMID: 17041031 PMCID: PMC1676063 DOI: 10.1104/pp.106.087700] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 10/05/2006] [Indexed: 05/02/2023]
Abstract
Primary cell walls are deposited and remodeled during cell division and expansion. Secondary cell walls are deposited in specialized cells after the expansion phase. It is presently unknown whether and how these processes are interrelated. The Arabidopsis (Arabidopsis thaliana) MUR10 gene is required for normal primary cell wall carbohydrate composition in mature leaves as well as for normal plant growth, hypocotyl strength, and fertility. The overall sugar composition of young mur10 seedlings is not significantly altered; however, the relative proportion of pectin side chains is shifted toward an increase in 1 --> 5-alpha-arabinan relative to 1 --> 4-beta-galactan. mur10 seedlings display reduced fucogalactosylation of tightly cell wall-bound xyloglucan. Expression levels of genes encoding either nucleotide sugar interconversion enzymes or glycosyl transferases, known to be involved in primary and secondary cell wall biosynthesis, are generally unaffected; however, the CesA7 transcript is specifically suppressed in the mur10-1 allele. The MUR10 locus is identical with the CesA7 gene, which encodes a cellulose catalytic subunit previously thought to be specifically involved in secondary cell wall formation. The xylem vessels in young mur10 hypocotyls are collapsed and their birefringence is lost. Moreover, a fucogalactosylated xyloglucan epitope is reduced and a 1 --> 5-alpha-arabinan epitope increased in every cell type in mur10 hypocotyls, including cells that do not deposit secondary walls. mur10 also displays altered distribution of an arabinogalactan-protein epitope previously associated with xylem differentiation and secondary wall thickening. This work indicates the existence of a mechanism that senses secondary cell wall integrity and controls biosynthesis or structural remodeling of primary cell walls and cellular differentiation.
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Affiliation(s)
- Sonia Bosca
- John Innes Centre, Norwich NR4 7UH, United Kingdom
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141
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Kim DW, Lee SH, Choi SB, Won SK, Heo YK, Cho M, Park YI, Cho HT. Functional conservation of a root hair cell-specific cis-element in angiosperms with different root hair distribution patterns. THE PLANT CELL 2006; 18:2958-70. [PMID: 17098810 PMCID: PMC1693936 DOI: 10.1105/tpc.106.045229] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Vascular plants develop distinctive root hair distribution patterns in the root epidermis, depending on the taxon. The three patterns, random (Type 1), asymmetrical cell division (Type 2), and positionally cued (Type 3), are controlled by different upstream fate-determining factors that mediate expression of root hair cell-specific genes for hair morphogenesis. Here, we address whether these root hair genes possess a common transcriptional regulatory module (cis-element) determining cell-type specificity despite differences in the final root hair pattern. We identified Arabidopsis thaliana expansinA7 (At EXPA7) orthologous (and paralogous) genes from diverse angiosperm species with different hair distribution patterns. The promoters of these genes contain conserved root hair-specific cis-elements (RHEs) that were functionally verified in the Type-3 Arabidopsis root. The promoter of At EXPA7 (Type-3 pattern) also showed hair cell-specific expression in the Type 2 rice (Oryza sativa) root. Root hair-specific genes other than EXPAs also carry functionally homologous RHEs in their promoters. The RHE core consensus was established by a multiple alignment of functionally characterized RHEs from different species and by high-resolution analysis of At EXPA7 RHE1. Our results suggest that this regulatory module of root hair-specific genes has been conserved across angiosperms despite the divergence of upstream fate-determining machinery.
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Affiliation(s)
- Dong Wook Kim
- Department of Biology, Chungnam National University, Daejeon 305-764, Korea
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142
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Haffani YZ, Silva-Gagliardi NF, Sewter SK, Grace Aldea M, Zhao Z, Nakhamchik A, Cameron RK, Goring DR. Altered Expression of PERK Receptor Kinases in Arabidopsis Leads to Changes in Growth and Floral Organ Formation. PLANT SIGNALING & BEHAVIOR 2006; 1:251-60. [PMID: 19516986 PMCID: PMC2634126 DOI: 10.4161/psb.1.5.3324] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Accepted: 08/16/2006] [Indexed: 05/23/2023]
Abstract
The proline-rich, extensin-like receptor kinase (PERK) family is characterized by a putative extracellular domain related to cell wall proteins, followed by a transmembrane domain and kinase domain. The original member, PERK1, was isolated from Brassica napus (BnPERK1) and 15 PERK1-related members were subsequently identified in the Arabidopsis thaliana genome. Ectopic expression and antisense suppression studies were performed using the BnPERK1 cDNA under the control of the 35S CaMV constitutive promoter and introduced into Arabidopsis. In the case of antisense suppression, the BnPERK1 cDNA shared sufficient sequence similarity to suppress several members of the At PERK family. In both sets of transgenic Arabidopsis, several heritable changes in growth and development were observed. Antisense BnPERK1 transgenic Arabidopsis showed various growth defects including loss of apical dominance, increased secondary branching, and floral organ defects. In contrast, Arabidopsis plants ectopically expressing BnPERK1 displayed a prolonged lifespan with increased lateral shoot production and seed set. Along with these phenotypic changes, aberrant deposits of callose and cellulose were also observed, suggestive of cell wall changes as a consequence of altered PERK expression.
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Affiliation(s)
- Yosr Z Haffani
- Department of Cell and Systems Biology; University of Toronto; Toronto, Ontario, Canada
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143
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Diet A, Link B, Seifert GJ, Schellenberg B, Wagner U, Pauly M, Reiter WD, Ringli C. The Arabidopsis root hair cell wall formation mutant lrx1 is suppressed by mutations in the RHM1 gene encoding a UDP-L-rhamnose synthase. THE PLANT CELL 2006; 18:1630-41. [PMID: 16766693 PMCID: PMC1488927 DOI: 10.1105/tpc.105.038653] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 05/04/2006] [Accepted: 05/15/2006] [Indexed: 05/10/2023]
Abstract
Cell and cell wall growth are mutually dependent processes that must be tightly coordinated and controlled. LRR-extensin1 (LRX1) of Arabidopsis thaliana is a potential regulator of cell wall development, consisting of an N-terminal leucine-rich repeat domain and a C-terminal extensin-like domain typical for structural cell wall proteins. LRX1 is expressed in root hairs, and lrx1 mutant plants develop distorted root hairs that often swell, branch, or collapse. The aberrant cell wall structures found in lrx1 mutants point toward a function of LRX1 during the establishment of the extracellular matrix. To identify genes that are involved in an LRX1-dependent developmental pathway, a suppressor screen was performed on the lrx1 mutant, and two independent rol1 (for repressor of lrx1) alleles were isolated. ROL1 is allelic to Rhamnose Biosynthesis1, which codes for a protein involved in the biosynthesis of rhamnose, a major monosaccharide component of pectin. The rol1 mutations modify the pectic polysaccharide rhamnogalacturonan I and, for one allele, rhamnogalacturonan II. Furthermore, the rol1 mutations cause a change in the expression of a number of cell wall-related genes. Thus, the lrx1 mutant phenotype is likely to be suppressed by changes in pectic polysaccharides or other cell wall components.
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Affiliation(s)
- Anouck Diet
- Institute of Plant Biology, University of Zürich, 8008 Zürich, Switzerland
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144
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Dahiya P, Findlay K, Roberts K, McCann MC. A fasciclin-domain containing gene, ZeFLA11, is expressed exclusively in xylem elements that have reticulate wall thickenings in the stem vascular system of Zinnia elegans cv Envy. PLANTA 2006; 223:1281-91. [PMID: 16328545 DOI: 10.1007/s00425-005-0177-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 11/04/2005] [Indexed: 05/05/2023]
Abstract
The vascular cylinder of the mature stem of Zinnia elegans cv Envy contains two anatomically distinct sets of vascular bundles, stem bundles and leaf-trace bundles. We isolated a full-length cDNA of ZeFLA11, a fasciclin-domain-containing gene, from a zinnia cDNA library derived from in vitro cultures of mesophyll cells induced to form tracheary elements. Using RNA in situ hybridization, we show that ZeFLA11 is expressed in the differentiating xylem vessels with reticulate type wall thickenings and adjacent parenchyma cells of zinnia stem bundles, but not in the leaf-trace bundles that deposit spiral thickenings. Our results suggest a function for this cell-surface GPI-anchored glycoprotein in secondary wall deposition during differentiation of metaxylem tissue with reticulate vessels.
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Affiliation(s)
- Preeti Dahiya
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, NR4 7UH Norwich, UK
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145
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Galway M. Root hair cell walls: filling in the frameworkThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology. ACTA ACUST UNITED AC 2006. [DOI: 10.1139/b06-006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Rapid progress is being made in determining the composition, synthesis, and mechanical properties of plant cell walls. Although tip-growing root hairs provide an excellent example of high-speed cell wall assembly, they have been relatively neglected by researchers interested in cell walls and those interested in tip growth. This review aims to present the root hair as an experimental system for future cell wall studies by assembling recent discoveries about the walls onto the existing framework based on older information. Most recent data come from arabidopsis ( Arabidopsis thaliana (L.) Heynh) and model legumes. Evidence supporting the turgor-mediated expansion of hair cell walls is considered, along with a survey of three components needed for cell wall expansion without rupture: cellulose (the role of CesA cellulose synthases is also addressed), Csld3, a cellulose synthase-like protein, and Lrx1, a cell wall protein. Further clues about hair cell wall composition have been obtained from gene expression studies and the use of monoclonal antibodies. Finally, there is a review of the experimental evidence that (i) hairs near the hypocotyl differ developmentally and structurally from other hairs and (ii) biosynthesis of wall components in hairs may differ significantly from the epidermal cells that they grew from. All of these recent advances suggest that root hairs could provide valuable data to augment models of plant cell walls based on more conventional cell types.
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Affiliation(s)
- M.E. Galway
- Department of Biology, St. Francis Xavier University, P.O. Box 5000, Antigonish, NS B2G 2W5, Canada (e-mail: )
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146
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Hewezi T, Mouzeyar S, Thion L, Rickauer M, Alibert G, Nicolas P, Kallerhoff J. Antisense expression of a NBS-LRR sequence in sunflower (Helianthus annuus L.) and tobacco (Nicotiana tabacum L.): evidence for a dual role in plant development and fungal resistance. Transgenic Res 2006; 15:165-80. [PMID: 16604458 DOI: 10.1007/s11248-005-3518-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2005] [Accepted: 09/21/2005] [Indexed: 10/24/2022]
Abstract
A partial sunflower cDNA clone, PLFOR48, segregating with a resistance marker to Plasmopara halstedii, the causal agent of downy mildew, has been cloned from the mildew resistant sunflower line, RHA 266. PLFOR48 encodes a putative protein with a nucleotide-binding site and a leucine-rich repeat domain, showing significant homology with previously cloned resistance genes belonging to the TIR-NBS-LRR family. Southern blot analysis of non-transgenic sunflower suggests that PLFOR48 is part of a multigenic family. The potential role of PLFOR48 sequence in sunflower resistance to mildew was studied, by assessing loss of function, using expression of the antisense cDNA in RHA 266 sunflower line. Quite unexpectedly, transgenic sunflower lines displayed severe developmental abnormalities, and in particular, on the main meristems of homozygote T2 progeny, thus hampering any further challenge inoculation with Plasmopara halstedii. The presence of homologous sequences to PLFOR48 in Nicotiana tabacum var Samsun NN, as demonstrated by Southern blotting, drove us to consider tobacco as an additional model to investigate the potential role of this sequence in fungal resistance. Expression of the same antisense cDNA in transgenic tobacco lines gave rise to higher degree of susceptibility to Phytophthora parasitica, as well as to severe alterations in seed development. These results suggest that PLFOR48 and homologous sequences could be involved in both regulating developmental pathways and controlling resistance to fungal pathogens.
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Affiliation(s)
- Tarek Hewezi
- Laboratoire de Biotechnologies et Amélioration des Plantes (BAP), INP-ENSAT, Pôle de Biotechnologies Végétales, IFR 40, Auzeville, Castanet Tolosan, France
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147
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Federici L, Di Matteo A, Fernandez-Recio J, Tsernoglou D, Cervone F. Polygalacturonase inhibiting proteins: players in plant innate immunity? TRENDS IN PLANT SCIENCE 2006; 11:65-70. [PMID: 16406303 DOI: 10.1016/j.tplants.2005.12.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 11/16/2005] [Accepted: 12/21/2005] [Indexed: 05/06/2023]
Abstract
Polygalacturonase-inhibiting proteins (PGIPs) are extracellular leucine-rich repeat (LRR) proteins that recognize and inhibit fungal polygalacturonases (PGs). The PG-PGIP interaction favours the accumulation of elicitor-active oligogalacturonides and causes the activation of defence responses. Small gene families encode PGIP isoforms that differ in affinity and specificity for PGs secreted by different pathogens. The consensus motif within the LRR structure of PGIPs is the same as that of the extracellular receptors of the plant innate immune system. Structural and functional evidence suggest that PGIPs are versatile proteins involved in innate immunity and that they are capable of recognizing different surface motifs of functionally related but structurally variable PGs.
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Affiliation(s)
- Luca Federici
- Ce.S.I. Centro Studi sull'Invecchiamento and Dipartimento di Scienze Biomediche. Universita' di Chieti "G. D'Annunzio". Via dei Vestini 31, 66013 Chieti, Italy.
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148
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Bayer EM, Bottrill AR, Walshaw J, Vigouroux M, Naldrett MJ, Thomas CL, Maule AJ. Arabidopsis cell wall proteome defined using multidimensional protein identification technology. Proteomics 2006; 6:301-11. [PMID: 16287169 DOI: 10.1002/pmic.200500046] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
With the completion of the sequencing of the Arabidopsis genome and the recent advances in proteomic technology, the identification of proteins from highly complex mixtures is now possible. Rather than using gel electrophoresis and peptide mass fingerprinting, we have used multidimensional protein identification technology (MudPIT) to analyse the "tightly-bound" proteome for purified cell walls from Arabidopsis cell suspension cultures. Using bioinformatics for the prediction of signal peptides for targeting to the secretory pathway and for the absence of ER retention signal, 89 proteins were selected as potential extracellular proteins. Only 33% of these were identified in previous proteomic analyses of Arabidopsis cell walls. A functional classification revealed that a large proportion of the proteins were enzymes, notably carbohydrate active enzymes, peroxidases and proteases. Comparison of all the published proteomic analyses for the Arabidopsis cell wall identified 268 non-redundant genes encoding wall proteins. Sixty of these (22%) were derived from our analysis of tightly-bound wall proteins.
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149
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Ringli C, Baumberger N, Keller B. The Arabidopsis root hair mutants der2-der9 are affected at different stages of root hair development. PLANT & CELL PHYSIOLOGY 2005; 46:1046-53. [PMID: 15863435 DOI: 10.1093/pcp/pci115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Root hairs are an excellent model system to study cell developmental processes as they are easily accessible, single-celled, long tubular extensions of root epidermal cells. In a genetic approach to identify loci important for root hair development, we have isolated eight der (deformed root hairs) mutants from an ethylmethanesulfonate (EMS)-mutagenized Arabidopsis population. The der lines represent five new loci involved in root hair development and show a variety of abnormalities in root hair morphology, indicating that different root hair developmental stages are affected. A double mutant analysis with the short root hair actin2 mutant der1-2 confirmed that the der mutants are disturbed at different time points of root hair formation. Auxin and ethylene are known to be important for trichoblast cell fate determination and root hair elongation. Here, we show that they are able to suppress the phenotype of two der mutants. As the auxin- and ethylene-responsive der mutants are affected at different stages of root hair formation, our results demonstrate that the function of auxin and ethylene is not limited to cell differentiation and root hair elongation but that the two hormones are effective throughout the whole root hair developmental process.
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Affiliation(s)
- Christoph Ringli
- Institute of Plant Biology, University of Zürich, Zollikerstr. 107, 8008 Zurich, Switzerland.
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Forsthoefel NR, Cutler K, Port MD, Yamamoto T, Vernon DM. PIRLs: A Novel Class of Plant Intracellular Leucine-rich Repeat Proteins. ACTA ACUST UNITED AC 2005; 46:913-22. [PMID: 15809230 DOI: 10.1093/pcp/pci097] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Leucine-rich repeat (LRR) proteins feature tandem leucine-rich motifs that form a protein-protein interaction domain. Plants contain diverse classes of LRR proteins, many of which take part in signal transduction. We have identified a novel family of nine Arabidopsis LRR proteins that, based on predicted intracellular location and LRR motif consensus sequence, are related to Ras-binding LRR proteins found in signaling complexes in animals and yeast. This new class has been named plant intracellular Ras group-related LRR proteins (PIRLs). We have characterized PIRL cDNAs, rigorously defined gene and protein annotations, investigated gene family evolution and surveyed mRNA expression. While LRR regions suggested a relationship to Ras group LRR proteins, outside of their LRR domains PIRLs differed from Ras group proteins, exhibiting N- and C-terminal regions containing low complexity stretches and clusters of charged amino acids. PIRL genes grouped into three subfamilies based on sequence relationships and gene structures. Related gene pairs and dispersed chromosomal locations suggested family expansion by ancestral genomic or segmental duplications. Expression surveys revealed that all PIRL mRNAs are actively transcribed, with three expressed differentially in leaves, roots or flowers. These results define PIRLs as a distinct, plant-specific class of intracellular LRR proteins that probably mediate protein interactions, possibly in the context of signal transduction. T-DNA knock-out mutants have been isolated as a starting point for systematic functional analysis of this intriguing family.
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Affiliation(s)
- Nancy R Forsthoefel
- Program in Biochemistry, Biophysics and Molecular Biology, Department of Biology, Whitman College, Walla Walla, WA 99362, USA
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