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Hu Z, Liu J, Xu H, Tian L, Liu D. Exploring the mechanism of Lycium barbarum fruit cell wall polysaccharide remodeling reveals potential pectin accumulation contributors. Int J Biol Macromol 2024; 258:128958. [PMID: 38154707 DOI: 10.1016/j.ijbiomac.2023.128958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/06/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
The level of polysaccharides in the mature Lycium barbarum fruit (LBF) cell wall depends on their metabolism, trafficking, and reassembly within the cell. In this study, we examined the composition, content, and ultrastructure of the cell wall polysaccharides of LBF during maturation, and further analyzed cell wall polysaccharide remodeling using isotope tagging with relative and absolute quantification (iTRAQ)-based proteomics. The results showed that the contents of cellulose and hemicellulose tended to increase in the pre-maturation stage and decrease in the later stage, while pectin level increased before fruit maturing. The differential expression of the 54 proteins involved in the metabolic pathways for glucose, fructose, galactose, galacturonic acid and arabinose was found to be responsible for these alterations. The work provides a biological framework for the reorganization of polysaccharides in the LBF cell wall, and supports the hypothesis that pectic polysaccharide glycosyl donors come from starch, cellulose, hemicellulose and isomorphic pectin.
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Affiliation(s)
- Ziying Hu
- School of Food Science and Technology, Ningxia University, 750021 Yinchuan, China
| | - Jun Liu
- Hubei Key Laboratory of Edible Wild Plants Conservation & Utilization, College of Life Sciences, Hubei Normal University, Huangshi 435002, China.
| | - Hao Xu
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Lingli Tian
- School of Food Science and Technology, Ningxia University, 750021 Yinchuan, China
| | - Dunhua Liu
- School of Food Science and Technology, Ningxia University, 750021 Yinchuan, China.
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2
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Leitão I, Leclercq CC, Ribeiro DM, Renaut J, Almeida AM, Martins LL, Mourato MP. Stress response of lettuce (Lactuca sativa) to environmental contamination with selected pharmaceuticals: A proteomic study. J Proteomics 2021; 245:104291. [PMID: 34089899 DOI: 10.1016/j.jprot.2021.104291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/29/2021] [Accepted: 05/24/2021] [Indexed: 11/19/2022]
Abstract
Pharmaceutical compounds have been found in rivers and treated wastewaters. They often contaminate irrigation waters and consequently accumulate in edible vegetables, causing changes in plants metabolism. The main objective of this work is to understand how lettuce plants cope with the contamination from three selected pharmaceuticals using a label free proteomic analysis. A lettuce hydroponic culture, grown for 36 days, was exposed to metformin, acetaminophen and carbamazepine (at 1 mg/L), during 8 days, after which roots and leaves were sampled and analysed using a liquid chromatography-mass spectrometry proteomics-based approach. In roots, a total of 612 proteins showed differentially accumulation while in leaves 237 proteins were identified with significant differences over controls. Carbamazepine was the contaminant that most affected protein abundance in roots, while in leaves the highest number of differentially accumulated proteins was observed for acetaminophen. In roots under carbamazepine, stress related protein species such as catalase, superoxide dismutase and peroxidases presented higher abundance. Ascorbate peroxidase increased in roots under metformin. Cell respiration protein species were affected by the presence of the three pharmaceuticals suggesting possible dysregulation of the Krebs cycle. Acetaminophen caused the main differences in respiration pathways, with more emphasis in leaves. Lettuce plants revealed different tolerance levels when contaminants were compared, being more tolerant to metformin presence and less tolerant to carbamazepine. SIGNIFICANCE: The significant increase of emerging contaminants in ecosystems makes essential to understand how these compounds may affect the metabolism of different organisms. Our study contributes with a detailed approach of the main interactions that may occur in plant metabolism when subjected to the stress induced by three different pharmaceuticals (acetaminophen, carbamazepine and metformin).
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Affiliation(s)
- Inês Leitão
- LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal.
| | - Céline C Leclercq
- LIST - Luxembourg Institute of Science and Technology Green Tech Platform, Environmental Research and Innovation Department (ERIN), L-4422 Belvaux, Luxembourg
| | - David M Ribeiro
- LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal
| | - Jenny Renaut
- LIST - Luxembourg Institute of Science and Technology Green Tech Platform, Environmental Research and Innovation Department (ERIN), L-4422 Belvaux, Luxembourg
| | - André M Almeida
- LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal
| | - Luisa L Martins
- LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal
| | - Miguel P Mourato
- LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal
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3
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Li J, Xu C, Yang S, Chen C, Tang S, Wang J, Xie H. A Venom Allergen-Like Protein, RsVAP, the First Discovered Effector Protein of Radopholus similis That Inhibits Plant Defense and Facilitates Parasitism. Int J Mol Sci 2021; 22:4782. [PMID: 33946385 PMCID: PMC8125365 DOI: 10.3390/ijms22094782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/13/2021] [Accepted: 04/28/2021] [Indexed: 12/16/2022] Open
Abstract
Radopholus similis is a migratory endoparasitic nematode that is extremely harmful to host plants. Venom allergen-like proteins (VAPs) are members of the cysteine-rich secretory protein family that are widely present in plants and animals. In this study, we cloned a VAP gene from R. similis, designated as RsVAP. RsVAP contains an open reading frame of 1089 bp encoding 362 amino acids. RsVAP is specifically expressed in the esophageal gland, and the expression levels of RsVAP are significantly higher in juveniles than in other life stages of R. similis. This expression pattern of RsVAP was consistent with the biological characteristics of juveniles of R. similis, which have the ability of infection and are the main infection stages of R. similis. The pathogenicity and reproduction rate of R. similis in tomato was significantly attenuated after RsVAP was silenced. In tobacco leaves transiently expressing RsVAP, the pathogen-associated molecular pattern-triggered immunity (PTI) induced by a bacterial flagellin fragment (flg22) was inhibited, while the cell death induced by two sets of immune elicitors (BAX and Gpa2/RBP-1) was repressed. The RsVAP-interacting, ras-related protein RABA1d (LeRabA1d) was identified in tomato hosts by yeast two-hybrid and co-immunoprecipitation assays. RsVAP may interact with LeRabA1d to affect the host defense response, which in turn facilitates nematode infection. This study provides the first evidence for the inhibition of plant defense response by a VAP from migratory plant-parasitic nematodes, and, for the first time, the target protein of R. similis in its host was identified.
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Affiliation(s)
| | | | | | | | | | | | - Hui Xie
- Research Center of Nematodes of Plant Quarantine, Laboratory of Plant Nematology, Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (J.L.); (C.X.); (S.Y.); (C.C.); (S.T.); (J.W.)
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4
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Hála M, Žárský V. Protein Prenylation in Plant Stress Responses. Molecules 2019; 24:molecules24213906. [PMID: 31671559 PMCID: PMC6866125 DOI: 10.3390/molecules24213906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/23/2019] [Accepted: 10/25/2019] [Indexed: 12/02/2022] Open
Abstract
Protein prenylation is one of the most important posttranslational modifications of proteins. Prenylated proteins play important roles in different developmental processes as well as stress responses in plants as the addition of hydrophobic prenyl chains (mostly farnesyl or geranyl) allow otherwise hydrophilic proteins to operate as peripheral lipid membrane proteins. This review focuses on selected aspects connecting protein prenylation with plant responses to both abiotic and biotic stresses. It summarizes how changes in protein prenylation impact plant growth, deals with several families of proteins involved in stress response and highlights prominent regulatory importance of prenylated small GTPases and chaperons. Potential possibilities of these proteins to be applicable for biotechnologies are discussed.
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Affiliation(s)
- Michal Hála
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic.
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic.
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Pontiggia D, Spinelli F, Fabbri C, Licursi V, Negri R, De Lorenzo G, Mattei B. Changes in the microsomal proteome of tomato fruit during ripening. Sci Rep 2019; 9:14350. [PMID: 31586085 PMCID: PMC6778153 DOI: 10.1038/s41598-019-50575-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 08/23/2019] [Indexed: 11/09/2022] Open
Abstract
The variations in the membrane proteome of tomato fruit pericarp during ripening have been investigated by mass spectrometry-based label-free proteomics. Mature green (MG30) and red ripe (R45) stages were chosen because they are pivotal in the ripening process: MG30 corresponds to the end of cellular expansion, when fruit growth has stopped and fruit starts ripening, whereas R45 corresponds to the mature fruit. Protein patterns were markedly different: among the 1315 proteins identified with at least two unique peptides, 145 significantly varied in abundance in the process of fruit ripening. The subcellular and biochemical fractionation resulted in GO term enrichment for organelle proteins in our dataset, and allowed the detection of low-abundance proteins that were not detected in previous proteomic studies on tomato fruits. Functional annotation showed that the largest proportion of identified proteins were involved in cell wall metabolism, vesicle-mediated transport, hormone biosynthesis, secondary metabolism, lipid metabolism, protein synthesis and degradation, carbohydrate metabolic processes, signalling and response to stress.
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Affiliation(s)
- Daniela Pontiggia
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Francesco Spinelli
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Claudia Fabbri
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Valerio Licursi
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy.,Institute for Systems Analysis and Computer Science "Antonio Ruberti", National Research Council, Rome, Italy
| | - Rodolfo Negri
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy.,Foundation Cenci Bolognetti-Institut Pasteur, Rome, Italy
| | - Giulia De Lorenzo
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy. .,Foundation Cenci Bolognetti-Institut Pasteur, Rome, Italy.
| | - Benedetta Mattei
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
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Chen Y, Chen B, Wang H, Hu W, Wang S, Zhou Z. Combined elevated temperature and soil waterlogging stresses limit fibre biomass accumulation and fibre quality formation by disrupting protein activity during cotton fibre development. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:715-724. [PMID: 31104693 DOI: 10.1071/fp18192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
Soil waterlogging and high temperature conditions generally occur together, especially in the Yangtze River Valley, China, negatively affecting cotton (Gossypium hirsutum L.) fibre development. Therefore, combined elevated temperature (34.1/29.0°C) and soil waterlogging (6 days) were imposed to study their combined effects on fibre biomass and fibre qualities (length, strength and micronaire). The results showed that in the boll cohort exposed to waterlogging and/or elevated air temperature, combined elevated temperature and soil waterlogging decreased final fibre length (by 8.9-11.3%) and fibre biomass (by 25.8-33.9%) more than either stress individually. A total of 113, 263 and 290 differential abundance proteins were identified related to elevated temperature, waterlogging and the two treatments combined, respectively, in fibres at 15 days after anthesis via the isobaric tags for relative and absolute quantitation technique, which were classified as: carbohydrate and energy metabolism (21.7%), protein metabolism (16.6%), amino acid metabolism (12.8%), intracellular structural components (6.6%), transport (7.9%), oxidation-reduction process (7.9%), signal transduction (5.2%), lipid metabolism (5.2%), stress response (5.2%), nucleic acid metabolism (4.5%), organic acid metabolism (3.4%) and others (2.1%). Both vacuolar ATPase (V-ATPase) and plasma membrane H+-ATPase (PMH+-ATPase) were responsible for fibre length formation, although V-ATPase expression may play a major role in determining fibre cell elongation rather than PM H+-ATPase expression. It was concluded that fibre cell elongation and secondary wall thickening were inhibited mainly by reduced accumulation of osmolytes, blocked synthesis and transport of secondary wall components, and disruption of the cytoskeleton system under combined elevated temperature and soil waterlogging.
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Affiliation(s)
- Yinglong Chen
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China; and College of Agriculture, Yangzhou University, Yangzhou 225009, PR China
| | - Binglin Chen
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Haimiao Wang
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Wei Hu
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Shanshan Wang
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Zhiguo Zhou
- College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, PR China; and Corresponding author.
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7
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Bergougnoux V. The history of tomato: From domestication to biopharming. Biotechnol Adv 2014; 32:170-89. [DOI: 10.1016/j.biotechadv.2013.11.003] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 10/24/2013] [Accepted: 11/03/2013] [Indexed: 11/28/2022]
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8
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Lunn D, Gaddipati SR, Tucker GA, Lycett GW. Null mutants of individual RABA genes impact the proportion of different cell wall components in stem tissue of Arabidopsis thaliana. PLoS One 2013; 8:e75724. [PMID: 24124508 PMCID: PMC3790814 DOI: 10.1371/journal.pone.0075724] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/21/2013] [Indexed: 12/18/2022] Open
Abstract
In Arabidopsis, and other plants, the RABA GTPases (orthologous to the Rab11a of mammals) have expanded in number and diversity and have been shown to belong to eight sub clades, some of which have been implicated in controlling vesicles that traffic cell wall polymers and enzymes that synthesise or modify them to the cell wall. In order to investigate this, we have investigated whether T-DNA insertion knockouts of individual RABA genes belonging to different sub clades, impact on the composition of the plant cell wall. Single gene knockouts of the RABA1, RABA2 and RABA4 sub clades primarily affected the percentage composition of pectin, cellulose and hemicellulose within the cell wall, respectively, despite having no obvious phenotype in the whole plant. We hypothesise that vesicles carrying specific types of cargoes from the Golgi to the cell surface may be regulated by particular sub types of RABA proteins, a finding that could have wider implications for how trafficking systems work and could be a useful tool in cell wall research and other fields of plant biology.
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Affiliation(s)
- Daniel Lunn
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Sanyasi R. Gaddipati
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Gregory A. Tucker
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Grantley W. Lycett
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
- * E-mail:
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9
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Katz E, Fon M, Eigenheer RA, Phinney BS, Fass JN, Lin D, Sadka A, Blumwald E. A label-free differential quantitative mass spectrometry method for the characterization and identification of protein changes during citrus fruit development. Proteome Sci 2010; 8:68. [PMID: 21162737 PMCID: PMC3017515 DOI: 10.1186/1477-5956-8-68] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 12/16/2010] [Indexed: 01/03/2023] Open
Abstract
Background Citrus is one of the most important and widely grown commodity fruit crops. In this study a label-free LC-MS/MS based shot-gun proteomics approach was taken to explore three main stages of citrus fruit development. These approaches were used to identify and evaluate changes occurring in juice sac cells in various metabolic pathways affecting citrus fruit development and quality. Results Protein changes in citrus juice sac cells were identified and quantified using label-free shotgun methodologies. Two alternative methods, differential mass-spectrometry (dMS) and spectral counting (SC) were used to analyze protein changes occurring during earlier and late stages of fruit development. Both methods were compared in order to develop a proteomics workflow that could be used in a non-model plant lacking a sequenced genome. In order to resolve the bioinformatics limitations of EST databases from species that lack a full sequenced genome, we established iCitrus. iCitrus is a comprehensive sequence database created by merging three major sources of sequences (HarvEST:citrus, NCBI/citrus/unigenes, NCBI/citrus/proteins) and improving the annotation of existing unigenes. iCitrus provided a useful bioinformatics tool for the high-throughput identification of citrus proteins. We have identified approximately 1500 citrus proteins expressed in fruit juice sac cells and quantified the changes of their expression during fruit development. Our results showed that both dMS and SC provided significant information on protein changes, with dMS providing a higher accuracy. Conclusion Our data supports the notion of the complementary use of dMS and SC for label-free comparative proteomics, broadening the identification spectrum and strengthening the identification of trends in protein expression changes during the particular processes being compared.
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Affiliation(s)
- Ehud Katz
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA.
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10
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Miozzi L, Provero P, Accotto GP. ORTom: a multi-species approach based on conserved co-expression to identify putative functional relationships among genes in tomato. PLANT MOLECULAR BIOLOGY 2010; 73:519-532. [PMID: 20411302 DOI: 10.1007/s11103-010-9638-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 04/11/2010] [Indexed: 05/29/2023]
Abstract
Co-expressed genes are often expected to be functionally related and many bioinformatics approaches based on co-expression have been developed to infer their biological role. However, such annotations may be unreliable, whereas the evolutionary conservation of gene co-expression among species may form a basis for more confident predictions. The huge amount of expression data (microarrays, SAGE, ESTs) has already allowed functional studies based on conserved co-expression in animals. Up to now, the implementation of analogous tools for plants has been strongly limited probably by the paucity and heterogeneity of data. Here we present ORTom, a tomato-centred EST data-mining approach based on conserved co-expression in the Solanaceae family. ORTom can be used to predict functional relationships among genes and to prioritize candidate genes for targeted studies. The method consists in ranking ESTs co-expressed with a gene of interest according to the level of expression pattern conservation in phylogenetically-related plants (potato, tobacco and pepper) to obtain lists of putative functionally-related genes. The lists are then analyzed for Gene Ontology keyword enrichment. The web server ORTom has been implemented to make the results publicly-available and searchable. Few biological examples on how the tool can be used are presented.
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Affiliation(s)
- Laura Miozzi
- Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, 10135 Turin, Italy.
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11
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Falchi R, Cipriani G, Marrazzo T, Nonis A, Vizzotto G, Ruperti B. Identification and differential expression dynamics of peach small GTPases encoding genes during fruit development and ripening. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2829-42. [PMID: 20501747 PMCID: PMC2882273 DOI: 10.1093/jxb/erq116] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 04/02/2010] [Accepted: 04/07/2010] [Indexed: 05/18/2023]
Abstract
The function of monomeric GTPases of the RAS superfamily in fruit development and ripening has been partially characterized. Here the identification of peach (Prunus persica) small GTPases of the RAS superfamily expressed in fruit and the characterization of their expression profiles during fruit development are described. Extensive searches on expressed sequence tag (EST) databases led to the selection of a total of 24 genes from peach encoding proteins with significant similarity to Arabidopsis small GTPases. Sequence similarity analyses and identification of conserved motifs, diagnostic of specific RAS families and subfamilies, enabled bona fide assignment of fourteen PpRAB, seven PpARF/ARL/SAR, two PpROP and one PpRAN GTPases. Transcriptional expression profiles of peach monomeric GTPases, analysed by real-time quantitative reverse transcription-PCR, were obtained for mesocarp samples, collected in two consecutive years. Reproducible patterns of expression could be identified for five peach RAB-encoding genes (PpRABA1-1, PpRABA2, PpRABD2-1, PpRABD2-2, and PpRABC2), two ARFs (PpARFA1-1 and PpARLB1), and two ROPs (PpROP3 and PpROP4). Interestingly, the transient transcriptional up-regulation of PpARF genes and of PpRAB genes of the A and D clades, putatively controlling the exocytic delivery of cell wall components and modifying enzymes, appeared to coincide with peaks of growth speed and sugar accumulation and with the final phases of ripening. To our knowledge, this is the first description of the co-ordinated differential expression of a set of genes encoding small GTPases of the ARF and RAB families which takes place during key moments of fruit development and maturation.
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Affiliation(s)
- Rachele Falchi
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
| | - Guido Cipriani
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
| | - Teresa Marrazzo
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
| | - Alberto Nonis
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
- Present address: Università di Padova, Dipartimento di Agronomia Ambientale e Produzioni Vegetali, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Giannina Vizzotto
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
| | - Benedetto Ruperti
- Università di Udine, Dipartimento di Scienze Agrarie e Ambientali, Via delle Scienze 208, 33100 Udine, Italy
- Present address: Università di Padova, Dipartimento di Agronomia Ambientale e Produzioni Vegetali, Viale dell'Università 16, 35020 Legnaro (PD), Italy
- To whom correspondence should be addressed. E-mail:
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12
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Vesicular fractions of sunflower apoplastic fluids are associated with potential exosome marker proteins. FEBS Lett 2009; 583:3363-6. [PMID: 19796642 DOI: 10.1016/j.febslet.2009.09.041] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 09/22/2009] [Accepted: 09/24/2009] [Indexed: 01/17/2023]
Abstract
Based on the presence of phospholipids in the extracellular fluids (EFs) of sunflower seeds, we have hypothesized on the existence of vesicles in the apoplastic compartment of plants. Ultracentrifugation of sunflower EF allowed the isolation of particles of 50-200 nm with apparent membrane organization. A small GTPase Rab was putatively identified in this vesicular fraction. Since Rab proteins are involved in vesicular traffic and their presence in exosomes from animal fluids has been demonstrated, evidence presented here supports the existence of exosome-like vesicles in apoplastic fluids of sunflower. Their putative contribution to intercellular communication in plants is discussed.
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13
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Blanco FA, Peltzer Meschini E, Zanetti ME, Aguilar OM. A small GTPase of the Rab family is required for root hair formation and preinfection stages of the common bean-Rhizobium symbiotic association. THE PLANT CELL 2009; 21:2797-810. [PMID: 19749154 PMCID: PMC2768941 DOI: 10.1105/tpc.108.063420] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 08/04/2009] [Accepted: 08/17/2009] [Indexed: 05/18/2023]
Abstract
Legume plants are able to establish a symbiotic relationship with soil bacteria from the genus Rhizobium, leading to the formation of nitrogen-fixing root nodules. Successful nodulation requires both the formation of infection threads (ITs) in the root epidermis and the activation of cell division in the cortex to form the nodule primordium. This study describes the characterization of RabA2, a common bean (Phaseolus vulgaris) cDNA previously isolated as differentially expressed in root hairs infected with Rhizobium etli, which encodes a protein highly similar to small GTPases of the RabA2 subfamily. This gene is expressed in roots, particularly in root hairs, where the protein was found to be associated with vesicles that move along the cell. The role of this gene during nodulation has been studied in common bean transgenic roots using a reverse genetic approach. Examination of root morphology in RabA2 RNA interference (RNAi) plants revealed that the number and length of the root hairs were severely reduced in these plants. Upon inoculation with R. etli, nodulation was completely impaired and no induction of early nodulation genes (ENODs), such as ERN1, ENOD40, and Hap5, was detected in silenced hairy roots. Moreover, RabA2 RNAi plants failed to induce root hair deformation and to initiate ITs, indicating that morphological changes that precede bacterial infection are compromised in these plants. We propose that RabA2 acts in polar growth of root hairs and is required for reorientation of the root hair growth axis during bacterial infection.
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14
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Nielsen E, Cheung AY, Ueda T. The regulatory RAB and ARF GTPases for vesicular trafficking. PLANT PHYSIOLOGY 2008; 147:1516-26. [PMID: 18678743 PMCID: PMC2492611 DOI: 10.1104/pp.108.121798] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Accepted: 05/23/2008] [Indexed: 05/18/2023]
Affiliation(s)
- Erik Nielsen
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
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Agarwal PK, Agarwal P, Jain P, Jha B, Reddy MK, Sopory SK. Constitutive overexpression of a stress-inducible small GTP-binding protein PgRab7 from Pennisetum glaucum enhances abiotic stress tolerance in transgenic tobacco. PLANT CELL REPORTS 2008; 27:105-15. [PMID: 17899098 DOI: 10.1007/s00299-007-0446-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 08/07/2007] [Accepted: 09/03/2007] [Indexed: 05/07/2023]
Abstract
The Rab GTPases are important components of endocytic network in plant cells. Endocytosis participates in the cell's reaction to extracellular stimuli by desensitizing, down-regulating or recycling receptors and membrane proteins. Rab7 is a small GTP-binding protein involved in intracellular vesicle trafficking from late endosome to the vacuole. We have isolated Rab7 cDNA from Pennisetum glaucum, a relatively drought-stress tolerant food grain crop grown commonly in India, during cDNA-subtractive hybridization of dehydration-stress treated plants. The PgRab7 ORF, encoding 207 aminoacids, was over-expressed in E. coli. The recombinant PgRab7 protein showed GTP-binding and GTPase activity. Transcript expression of PgRab7 gene was differentially up-regulated by different environmental stimuli such as cold, dehydration and NaCl and also by a plant hormone IAA. Overexpression of PgRab7 gene enhanced tolerance to NaCl and mannitol in transgenic tobacco. Transgenic plants also had increased alkaline phosphatase (ALP) activity. These results show that PgRab7 is a potential candidate gene for developing both salinity and dehydration tolerance in planta.
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Affiliation(s)
- Pradeep K Agarwal
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110 067, India.
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16
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González-Agüero M, Pavez L, Ibáñez F, Pacheco I, Campos-Vargas R, Meisel LA, Orellana A, Retamales J, Silva H, González M, Cambiazo V. Identification of woolliness response genes in peach fruit after post-harvest treatments. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:1973-86. [PMID: 18453640 PMCID: PMC2413281 DOI: 10.1093/jxb/ern069] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 01/28/2008] [Accepted: 01/31/2008] [Indexed: 05/21/2023]
Abstract
Woolliness is a physiological disorder of peaches and nectarines that becomes apparent when fruit are ripened after prolonged periods of cold storage. This disorder is of commercial importance since shipping of peaches to distant markets and storage before selling require low temperature. However, knowledge about the molecular basis of peach woolliness is still incomplete. To address this issue, a nylon macroarray containing 847 non-redundant expressed sequence tags (ESTs) from a ripe peach fruit cDNA library was developed and used. Gene expression changes of peach fruit (Prunus persica cv. O'Henry) ripened for 7 d at 21 degrees C (juicy fruit) were compared with those of fruit stored for 15 d at 4 degrees C and then ripened for 7 d at 21 degrees C (woolly fruit). A total of 106 genes were found to be differentially expressed between juicy and woolly fruit. Data analysis indicated that the activity of most of these genes (>90%) was repressed in the woolly fruit. In cold-stored peaches (cv. O'Henry), the expression level of selected genes (cobra, endopolygalacturonase, cinnamoyl-CoA-reductase, and rab11) was lower than in the juicy fruit, and it remained low in woolly peaches after ripening, a pattern that was conserved in woolly fruit from two other commercial cultivars (cv. Flamekist and cv. Elegant Lady). In addition, the results of this study indicate that molecular changes during fruit woolliness involve changes in the expression of genes associated with cell wall metabolism and endomembrane trafficking. Overall, the results reported here provide an initial characterization of the transcriptome activity of peach fruit under different post-harvest treatments.
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Affiliation(s)
- Mauricio González-Agüero
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
| | - Leonardo Pavez
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
| | - Freddy Ibáñez
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
| | - Igor Pacheco
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
| | | | - Lee A. Meisel
- Millennium Nucleus in Plant Cell Biology and Plant Biotechnology Center, Andres Bello University, Santiago, Chile
| | - Ariel Orellana
- Millennium Nucleus in Plant Cell Biology and Plant Biotechnology Center, Andres Bello University, Santiago, Chile
| | - Julio Retamales
- Faculty of Agricultural Sciences, Universidad de Chile, Santiago, Chile
| | - Herman Silva
- Millennium Nucleus in Plant Cell Biology and Plant Biotechnology Center, Andres Bello University, Santiago, Chile
| | - Mauricio González
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
| | - Verónica Cambiazo
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, Millennium Nucleus Center for Genomics of the Cell (CGC), Santiago, Chile
- To whom correspondence should be addressed. E-mail:
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17
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Saladié M, Matas AJ, Isaacson T, Jenks MA, Goodwin SM, Niklas KJ, Xiaolin R, Labavitch JM, Shackel KA, Fernie AR, Lytovchenko A, O'Neill MA, Watkins CB, Rose JKC. A reevaluation of the key factors that influence tomato fruit softening and integrity. PLANT PHYSIOLOGY 2007; 144:1012-28. [PMID: 17449643 PMCID: PMC1914194 DOI: 10.1104/pp.107.097477] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 04/12/2007] [Indexed: 05/15/2023]
Abstract
The softening of fleshy fruits, such as tomato (Solanum lycopersicum), during ripening is generally reported to result principally from disassembly of the primary cell wall and middle lamella. However, unsuccessful attempts to prolong fruit firmness by suppressing the expression of a range of wall-modifying proteins in transgenic tomato fruits do not support such a simple model. 'Delayed Fruit Deterioration' (DFD) is a previously unreported tomato cultivar that provides a unique opportunity to assess the contribution of wall metabolism to fruit firmness, since DFD fruits exhibit minimal softening but undergo otherwise normal ripening, unlike all known nonsoftening tomato mutants reported to date. Wall disassembly, reduced intercellular adhesion, and the expression of genes associated with wall degradation were similar in DFD fruit and those of the normally softening 'Ailsa Craig'. However, ripening DFD fruit showed minimal transpirational water loss and substantially elevated cellular turgor. This allowed an evaluation of the relative contribution and timing of wall disassembly and water loss to fruit softening, which suggested that both processes have a critical influence. Biochemical and biomechanical analyses identified several unusual features of DFD cuticles and the data indicate that, as with wall metabolism, changes in cuticle composition and architecture are an integral and regulated part of the ripening program. A model is proposed in which the cuticle affects the softening of intact tomato fruit both directly, by providing a physical support, and indirectly, by regulating water status.
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Affiliation(s)
- Montserrat Saladié
- Department of Plant Biology , Cornell University, Ithaca, New York 14853, USA
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18
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Park S, Sugimoto N, Larson MD, Beaudry R, van Nocker S. Identification of genes with potential roles in apple fruit development and biochemistry through large-scale statistical analysis of expressed sequence tags. PLANT PHYSIOLOGY 2006; 141:811-24. [PMID: 16825339 PMCID: PMC1489918 DOI: 10.1104/pp.106.080994] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Advanced studies of apple (Malus domestica Borkh) development, physiology, and biochemistry have been hampered by the lack of appropriate genomics tools. One exception is the recent acquisition of extensive expressed sequence tag (EST) data. The entire available EST dataset for apple resulted from the efforts of at least 20 contributors and was derived from more than 70 cDNA libraries representing diverse transcriptional profiles from a variety of organs, fruit parts, developmental stages, biotic and abiotic stresses, and from at least nine cultivars. We analyzed apple EST sequences available in public databanks using statistical algorithms to identify those apple genes that are likely to be highly expressed in fruit, expressed uniquely or preferentially in fruit, and/or temporally or spatially regulated during fruit growth and development. We applied these results to the analysis of biochemical pathways involved in biosynthesis of precursors for volatile esters and identified a subset of apple genes that may participate in generating flavor and aroma components found in mature fruit.
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Affiliation(s)
- Sunchung Park
- Pomology Group, Michigan State University, East Lansing, Michigan 48824, USA
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19
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de Graaf BHJ, Cheung AY, Andreyeva T, Levasseur K, Kieliszewski M, Wu HM. Rab11 GTPase-regulated membrane trafficking is crucial for tip-focused pollen tube growth in tobacco. THE PLANT CELL 2005; 17:2564-79. [PMID: 16100336 PMCID: PMC1197435 DOI: 10.1105/tpc.105.033183] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Revised: 06/08/2005] [Accepted: 07/08/2005] [Indexed: 05/04/2023]
Abstract
Pollen tube growth is a polarized growth process whereby the tip-growing tubes elongate within the female reproductive tissues to deliver sperm cells to the ovules for fertilization. Efficient and regulated membrane trafficking activity incorporates membrane and deposits cell wall molecules at the tube apex and is believed to underlie rapid and focused growth at the pollen tube tip. Rab GTPases, key regulators of membrane trafficking, are candidates for important roles in regulating pollen tube growth. We show that a green fluorescent protein-tagged Nicotiana tabacum pollen-expressed Rab11b is localized predominantly to an inverted cone-shaped region in the pollen tube tip that is almost exclusively occupied by transport vesicles. Altering Rab11 activity by expressing either a constitutive active or a dominant negative variant of Rab11b in pollen resulted in reduced tube growth rate, meandering pollen tubes, and reduced male fertility. These mutant GTPases also inhibited targeting of exocytic and recycled vesicles to the pollen tube inverted cone region and compromised the delivery of secretory and cell wall proteins to the extracellular matrix. Properly regulated Rab11 GTPase activity is therefore essential for tip-focused membrane trafficking and growth at the pollen tube apex and is pivotal to reproductive success.
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Affiliation(s)
- Barend H J de Graaf
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Lederle Graduate Research Center, Amherst, Massachusetts 01003, USA
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20
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Xiong AS, Yao QH, Peng RH, Li X, Han PL, Fan HQ. Different effects on ACC oxidase gene silencing triggered by RNA interference in transgenic tomato. PLANT CELL REPORTS 2005; 23:639-46. [PMID: 15503033 DOI: 10.1007/s00299-004-0887-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Revised: 08/30/2004] [Accepted: 08/31/2004] [Indexed: 05/03/2023]
Abstract
RNA interference (RNAi) is a potent trigger for specific gene silencing of expression in a number of organisms and is an efficient way of shutting down gene expression. 1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the oxidation of ACC to ethylene, a plant growth regulator that plays an important role in the tomato ripening process. In this research, to produce double-stranded (ds)RNA of tomato ACC oxidase, we linked the sense and antisense configurations of DNA fragments with 1,002-bp or 7-nt artificially synthesized fragments, respectively, and then placed these under the control of a modified cauliflower mosaic virus 35S promoter. The dsRNA expression unit was successfully introduced into tomato cultivar Hezuo 906 by Agrobacterium tumefaciens-mediated transformation. Molecular analysis of 183 transgenic plants revealed that the dsRNA unit was integrated into the tomato genome. With respect to the construct with the 1,002-bp linker, the severity of phenotypes indicated that 72.3% of the transformed plants had non-RNA interference, about 18.1% had semi-RNA interference, and only 9.6% had full-RNA interference. However when the construct with the 7-nt linker was used for transformation, the results were 13.0%, 18.0%, and 69.0%, respectively, indicating that the short linker was more efficient in RNAi of transgenic tomato plants. When we applied this fast way of shutting down the ACC oxidase gene, transgenic tomato plants were produced that had fruit which released traces of ethylene and had a prolonged shelf life of more than 120 days. The RNA and protein analyses indicated that there was non-RNA interference, semi-RNA interference and full-RNA interference of ACC oxidase in the transgenic tomato plants.
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Affiliation(s)
- Ai-Sheng Xiong
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Agro-Biotechnology Research Center, Shanghai Academy of Agricultural Sciences, 2901 Beidi Road, 201106, Shanghai, People's Republic of China
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21
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Schiene K, Donath S, Brecht M, Pühler A, Niehaus K. A Rab-related small GTP binding protein is predominantly expressed in root nodules of Medicago sativa. Mol Genet Genomics 2004; 272:57-66. [PMID: 15221459 DOI: 10.1007/s00438-004-1029-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Accepted: 05/14/2004] [Indexed: 11/25/2022]
Abstract
Rab-related small GTP-binding proteins are known to be involved in the regulation of the vesicular transport system in eucaryotic cells. In this paper we report the isolation of the cDNA clone MS- rab11f from Medicago sativa (alfalfa) root nodules using a combination of RT-PCR and SSCP analysis. MS- rab11f shows high homology to the Rab-related cDNA clone LJ- rab11f from Lotus japonicus root nodules. The MS-Rab11F protein expressed in Escherichia coli was found to bind GTP, confirming that the isolated cDNA indeed codes for a small GTP-binding protein. Expression analysis by RT-PCR demonstrated that MS- rab11f is preferentially expressed in root nodules of alfalfa. Using the cDNA-sequence of MS-rab11f, a peptide-specific antibody was generated. Western blot analysis with this antibody revealed that two Rab11F isoforms, designated MS-Rab11FA and MS-Rab11FB, are found in M. sativa root nodules.
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Affiliation(s)
- K Schiene
- Biologie-Genetik, Universität Bielefeld, Postfach 100 131, 33501 Bielefeld, Germany
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22
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Moshkov IE, Novikova GV, Mur LAJ, Smith AR, Hall MA. Ethylene rapidly up-regulates the activities of both monomeric GTP-binding proteins and protein kinase(s) in epicotyls of pea. PLANT PHYSIOLOGY 2003; 131:1718-26. [PMID: 12692330 PMCID: PMC166927 DOI: 10.1104/pp.102.015057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2002] [Revised: 11/12/2002] [Accepted: 12/20/2002] [Indexed: 05/23/2023]
Abstract
It is demonstrated that, in etiolated pea (Pisum sativum) epicotyls, ethylene affects the activation of both monomeric GTP-binding proteins (monomeric G-proteins) and protein kinases. For monomeric G-proteins, the effect may be a rapid (2 min) and bimodal up-regulation, a transiently unimodal activation, or a transient down-regulation. Pretreatment with 1-methylcyclopropene abolishes the response to ethylene overall. Immunoprecipitation studies indicate that some of the monomeric G-proteins affected may be of the Rab class. Protein kinase activity is rapidly up-regulated by ethylene, the effect is inhibited by 1-methylcyclopropene, and the activation is bimodal. Immunoprecipitation indicates that the kinase(s) are of the MAP kinase ERK1 group. It is proposed that the data support the hypothesis that a transduction chain exists that is separate and antagonistic to that currently revealed by studies on Arabidopsis mutants.
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Affiliation(s)
- Igor E Moshkov
- Timiryazev Institute of Plant Physiology RAS, Botanicheskaya 35, Moscow 127276, Russia
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23
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Moshkov IE, Mur LAJ, Novikova GV, Smith AR, Hall MA. Ethylene regulates monomeric GTP-binding protein gene expression and activity in Arabidopsis. PLANT PHYSIOLOGY 2003; 131:1705-17. [PMID: 12692329 PMCID: PMC166926 DOI: 10.1104/pp.014035] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2002] [Revised: 10/22/2002] [Accepted: 11/30/2002] [Indexed: 05/19/2023]
Abstract
Ethylene rapidly and transiently up-regulates the activity of several monomeric GTP-binding proteins (monomeric G proteins) in leaves of Arabidopsis as determined by two-dimensional gel electrophoresis and autoradiographic analyses. The activation is suppressed by the receptor-directed inhibitor 1-methylcyclopropene. In the etr1-1 mutant, constitutive activity of all the monomeric G proteins activated by ethylene is down-regulated relative to wild type, and ethylene treatment has no effect on the levels of activity. Conversely, in the ctr1-1 mutant, several of the monomeric G proteins activated by ethylene are constitutively up-regulated. However, the activation profile of ctr1-1 does not exactly mimic that of ethylene-treated wild type. Biochemical and molecular evidence suggested that some of these monomeric G proteins are of the Rab class. Expression of the genes for a number of monomeric G proteins in response to ethylene was investigated by reverse transcriptase-PCR. Rab8 and Ara3 expression was increased within 10 min of ethylene treatment, although levels fell back significantly by 40 min. In the etr1-1 mutant, expression of Rab8 was lower than wild type and unaffected by ethylene; in ctr1-1, expression of Rab8 was much higher than wild type and comparable with that seen in ethylene treatments. Expression in ctr1-1 was also unaffected by ethylene. Thus, the data indicate a role for monomeric G proteins in ethylene signal transduction.
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Affiliation(s)
- Igor E Moshkov
- Timiryazev Institute of Plant Physiology Russian Academy of Sciences, Botanicheskaya 35, Moscow, Russia
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24
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Vernoud V, Horton AC, Yang Z, Nielsen E. Analysis of the small GTPase gene superfamily of Arabidopsis. PLANT PHYSIOLOGY 2003; 131:1191-208. [PMID: 12644670 PMCID: PMC166880 DOI: 10.1104/pp.013052] [Citation(s) in RCA: 427] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Small GTP-binding proteins regulate diverse processes in eukaryotic cells such as signal transduction, cell proliferation, cytoskeletal organization, and intracellular membrane trafficking. These proteins function as molecular switches that cycle between "active" and "inactive" states, and this cycle is linked to the binding and hydrolysis of GTP. The Arabidopsis genome contains 93 genes that encode small GTP-binding protein homologs. Phylogenetic analysis of these genes shows that plants contain Rab, Rho, Arf, and Ran GTPases, but no Ras GTPases. We have assembled complete lists of these small GTPases families, as well as accessory proteins that control their activity, and review what is known of the functions of individual members of these families in Arabidopsis. We also discuss the possible roles of these GTPases in relation to their similarity to orthologs with known functions and localizations in yeast and/or animal systems.
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Affiliation(s)
- Vanessa Vernoud
- Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
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25
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Ueda T, Nakano A. Vesicular traffic: an integral part of plant life. CURRENT OPINION IN PLANT BIOLOGY 2002; 5:513-7. [PMID: 12393014 DOI: 10.1016/s1369-5266(02)00299-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Extensive studies on the molecular mechanisms of vesicular traffic have revealed that plants use similar machinery to mammals and fungi for the formation, transport, docking and fusion of vesicles. In addition to conserved components, plant-unique molecules also regulate these phenomena. Recent research has begun to show that the vesicular traffic controlled by these various molecules plays amazing roles in higher-order plant functions, such as tropisms.
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Affiliation(s)
- Takashi Ueda
- Molecular Membrane Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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26
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Lu C, Koroleva OA, Farrar JF, Gallagher J, Pollock CJ, Tomos AD. Rubisco small subunit, chlorophyll a/b-binding protein and sucrose:fructan-6-fructosyl transferase gene expression and sugar status in single barley leaf cells in situ. Cell type specificity and induction by light. PLANT PHYSIOLOGY 2002; 130:1335-48. [PMID: 12427999 PMCID: PMC166653 DOI: 10.1104/pp.008979] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2002] [Accepted: 06/12/2002] [Indexed: 05/20/2023]
Abstract
We describe a highly efficient two-step single-cell reverse transcriptase-polymerase chain reaction technique for analyzing gene expression at the single-cell level. Good reproducibility and a linear dose response indicated that the technique has high specificity and sensitivity for detection and quantification of rare RNA. Actin could be used as an internal standard. The expression of message for Rubisco small subunit (RbcS), chlorophyll a/b-binding protein (Cab), sucrose (Suc):fructan-6-fructosyl transferase (6-SFT), and Actin were measured in individual photosynthetic cells of the barley (Hordeum vulgare) leaf. Only Actin was found in the non-photosynthetic epidermal cells. Cab, RbcS, and 6-SFT genes were expressed at a low level in mesophyll and parenchymatous bundle sheath (BS) cells when sampled from plants held in dark for 40 h. Expression increased considerably after illumination. The amount of 6-SFT, Cab, and RbcS transcript increased more in mesophyll cells than in the parenchymatous BS cells. The difference may be caused by different chloroplast structure and posttranscriptional control in mesophyll and BS cells. When similar single-cell samples were assayed for Suc, glucose, and fructan, there was high correlation between 6-SFT gene expression and Suc and glucose concentrations. This is consistent with Suc concentration being the trigger for transcription. Together with earlier demonstrations that the mesophyll cells have a higher sugar threshold for fructan polymerization, our data may indicate separate control of transcription and enzyme activity. Values for the sugar concentrations of the individual cell types are reported.
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Affiliation(s)
- Chungui Lu
- School of Biological Sciences, University of Wales Bangor, Bangor, Gwynedd LL57 2UW, Wales, United Kingdom
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27
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Cheung AY, Chen CYH, Glaven RH, de Graaf BHJ, Vidali L, Hepler PK, Wu HM. Rab2 GTPase regulates vesicle trafficking between the endoplasmic reticulum and the Golgi bodies and is important to pollen tube growth. THE PLANT CELL 2002; 14:945-62. [PMID: 11971147 PMCID: PMC150694 DOI: 10.1105/tpc.000836] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2001] [Accepted: 02/06/2002] [Indexed: 05/17/2023]
Abstract
Pollen tube elongation depends on the secretion of large amounts of membrane and cell wall materials at the pollen tube tip to sustain rapid growth. A large family of RAS-related small GTPases, Rabs or Ypts, is known to regulate both anterograde and retrograde trafficking of transport vesicles between different endomembrane compartments and the plasma membrane in mammalian and yeast cells. Studies on the functional roles of analogous plant proteins are emerging. We report here that a tobacco pollen-predominant Rab2, NtRab2, functions in the secretory pathway between the endoplasmic reticulum and the Golgi in elongating pollen tubes. Green fluorescent protein-NtRab2 fusion protein localized to the Golgi bodies in elongating pollen tubes. Dominant-negative mutations in NtRab2 proteins inhibited their Golgi localization, blocked the delivery of Golgi-resident as well as plasmalemma and secreted proteins to their normal locations, and inhibited pollen tube growth. On the other hand, when green fluorescent protein-NtRab2 was over-expressed in transiently transformed leaf protoplasts and epidermal cells, in which NtRab2 mRNA have not been observed to accumulate to detectable levels, these proteins did not target efficiently to Golgi bodies. Together, these observations indicate that NtRab2 is important for trafficking between the endoplasmic reticulum and the Golgi bodies in pollen tubes and may be specialized to optimally support the high secretory demands in these tip growth cells.
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Affiliation(s)
- Alice Y Cheung
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA.
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28
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Yang Z. Small GTPases: versatile signaling switches in plants. THE PLANT CELL 2002; 14 Suppl:S375-88. [PMID: 12045289 PMCID: PMC151267 DOI: 10.1105/tpc.001065] [Citation(s) in RCA: 271] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2001] [Accepted: 03/18/2002] [Indexed: 05/17/2023]
Affiliation(s)
- Zhenbiao Yang
- Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.
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