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Xia Y, Sun G, Xiao J, He X, Jiang H, Zhang Z, Zhang Q, Li K, Zhang S, Shi X, Wang Z, Liu L, Zhao Y, Yang Y, Duan K, Ye W, Wang Y, Dong S, Wang Y, Ma Z, Wang Y. AlphaFold-guided redesign of a plant pectin methylesterase inhibitor for broad-spectrum disease resistance. MOLECULAR PLANT 2024; 17:1344-1368. [PMID: 39030909 DOI: 10.1016/j.molp.2024.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/18/2024] [Accepted: 07/15/2024] [Indexed: 07/22/2024]
Abstract
Plant cell walls are a critical site where plants and pathogens continuously struggle for physiological dominance. Here we show that dynamic remodeling of pectin methylesterification of plant cell walls is a component of the physiological and co-evolutionary struggles between hosts and pathogens. A pectin methylesterase (PsPME1) secreted by Phytophthora sojae decreases the degree of pectin methylesterification, thus synergizing with an endo-polygalacturonase (PsPG1) to weaken plant cell walls. To counter PsPME1-mediated susceptibility, a plant-derived pectin methylesterase inhibitor protein, GmPMI1, protects pectin to maintain a high methylesterification status. GmPMI1 protects plant cell walls from enzymatic degradation by inhibiting both soybean and P. sojae pectin methylesterases during infection. However, constitutive expression of GmPMI1 disrupted the trade-off between host growth and defense responses. We therefore used AlphaFold structure tools to design a modified form of GmPMI1 (GmPMI1R) that specifically targets and inhibits pectin methylesterases secreted from pathogens but not from plants. Transient expression of GmPMI1R enhanced plant resistance to oomycete and fungal pathogens. In summary, our work highlights the biochemical modification of the cell wall as an important focal point in the physiological and co-evolutionary conflict between hosts and microbes, providing an important proof of concept that AI-driven structure-based tools can accelerate the development of new strategies for plant protection.
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Affiliation(s)
- Yeqiang Xia
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Guangzheng Sun
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Junhua Xiao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Xinyi He
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Haibin Jiang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Zhichao Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Qi Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Kainan Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Sicong Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Xuechao Shi
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Zhaoyun Wang
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei 230036, China
| | - Lin Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yao Zhao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yuheng Yang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Kaixuan Duan
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yiming Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Suomeng Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Zhenchuan Ma
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Key Laboratory of Soybean Disease and Pest Control (Ministry of Agriculture and Rural Affairs), Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
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Dou N, Li L, Fang Y, Fan S, Wu C. Comparative Physiological and Transcriptome Analyses of Tolerant and Susceptible Cultivars Reveal the Molecular Mechanism of Cold Tolerance in Anthurium andraeanum. Int J Mol Sci 2023; 25:250. [PMID: 38203421 PMCID: PMC10779044 DOI: 10.3390/ijms25010250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 12/16/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Anthurium andraeanum is a tropical ornamental flower. The cost of Anthurium production is higher under low temperature (non-freezing) conditions; therefore, it is important to increase its cold tolerance. However, the molecular mechanisms underlying the response of Anthurium to cold stress remain elusive. In this study, comparative physiological and transcriptome sequencing analyses of two cultivars with contrasting cold tolerances were conducted to evaluate the cold stress response at the flowering stage. The activities of superoxide dismutase and peroxidase and the contents of proline, soluble sugar, and malondialdehyde increased under cold stress in the leaves of the cold tolerant cultivar Elegang (E) and cold susceptible cultivar Menghuang (MH), while the soluble protein content decreased in MH and increased in E. Using RNA sequencing, 24,695 differentially expressed genes (DEGs) were identified from comparisons between cultivars under the same conditions or between the treatment and control groups of a single cultivar, 9132 of which were common cold-responsive DEGs. Heat-shock proteins and pectinesterases were upregulated in E and downregulated in MH, indicating that these proteins are essential for Anthurium cold tolerance. Furthermore, four modules related to cold treatment were obtained by weighted gene co-expression network analysis. The expression of the top 20 hub genes in these modules was induced by cold stress in E or MH, suggesting they might be crucial contributors to cold tolerance. DEGs were significantly enriched in plant hormone signal transduction pathways, trehalose metabolism, and ribosomal proteins, suggesting these processes play important roles in Anthurium's cold stress response. This study provides a basis for elucidating the mechanism of cold tolerance in A. andraeanum and potential targets for molecular breeding.
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Affiliation(s)
- Na Dou
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan 250014, China (S.F.)
| | - Li Li
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan 250014, China (S.F.)
| | - Yifu Fang
- Institute of Ornamental Plants, Shandong Provincial Academy of Forestry, Wenhua East Road 42, Jinan 250010, China;
| | - Shoujin Fan
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan 250014, China (S.F.)
| | - Chunxia Wu
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan 250014, China (S.F.)
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3
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Yang L, Huang S, Liu Y, Zheng S, Liu H, Rensing C, Fan Z, Feng R. Selenate regulates the activity of cell wall enzymes to influence cell wall component concentration and thereby affects the uptake and translocation of Cd in the roots of Brassica rapa L. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 821:153156. [PMID: 35041952 DOI: 10.1016/j.scitotenv.2022.153156] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 12/22/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
Selenium (Se) can be used to counteract cadmium (Cd) toxicity in plants. However, mechanisms underlying the alleviation of Cd toxicity by Se have not been completely elucidated, especially those by which Se reduces Cd translocation. A hydroponic experiment was performed to illustrate the regulatory mechanisms of Cd transport by selenate (Se (VI)) in pakchoi (Brassica rapa L., LvYou 102). The results showed that this plant had a high accumulation capacity for Cd, and Se(VI) addition restricted Cd translocation from roots to shoots. Se(VI) exposure stimulated the concentrations of pectins and hemicellulose II but reduced the concentration of hemicellulose I in the roots. In many cases, the enzymes pectin methylesterase, polygalacturonase, and β-galactosidase were dose-dependently triggered by Se(VI) under Cd exposure, but root calcium concentration was significantly lowered (p < 0.05). Xyloglucan endoglycosidase (hydrolase) was triggered by Se(VI) under 2 mg L-1 Cd exposure and cellulase was generally activated by Se(VI) under Cd stress. The above results suggest that Se(VI) up-regulates pectin methylesterase activity, stimulates synthesis of pectins, and down-regulates root Ca concentration to release free carboxyl groups to combine Cd. In this study, the relationships between enzyme activity (e.g., peroxidase, superoxidase and β-galactosidase), hydrogen peroxide, cell wall structure strengthening/loosening, and Cd toxicity affected by Se(VI) were also discussed.
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Affiliation(s)
- Li Yang
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - ShuangQin Huang
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - Yang Liu
- Agricultural College, Guangxi University, Nanning, China
| | - ShunAn Zheng
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing 100125, China.
| | - Hong Liu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - Christopher Rensing
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - ZhiLian Fan
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing 100125, China
| | - RenWei Feng
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China.
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The moisture plasticizing effect on enzyme-catalyzed reactions in model and real systems in view of legume ageing and their hard to cook development. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2021.110781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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5
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Shin Y, Chane A, Jung M, Lee Y. Recent Advances in Understanding the Roles of Pectin as an Active Participant in Plant Signaling Networks. PLANTS (BASEL, SWITZERLAND) 2021; 10:1712. [PMID: 34451757 PMCID: PMC8399534 DOI: 10.3390/plants10081712] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 01/02/2023]
Abstract
Pectin is an abundant cell wall polysaccharide with essential roles in various biological processes. The structural diversity of pectins, along with the numerous combinations of the enzymes responsible for pectin biosynthesis and modification, plays key roles in ensuring the specificity and plasticity of cell wall remodeling in different cell types and under different environmental conditions. This review focuses on recent progress in understanding various aspects of pectin, from its biosynthetic and modification processes to its biological roles in different cell types. In particular, we describe recent findings that cell wall modifications serve not only as final outputs of internally determined pathways, but also as key components of intercellular communication, with pectin as a major contributor to this process. The comprehensive view of the diverse roles of pectin presented here provides an important basis for understanding how cell wall-enclosed plant cells develop, differentiate, and interact.
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Affiliation(s)
- Yesol Shin
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea; (Y.S.); (A.C.); (M.J.)
| | - Andrea Chane
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea; (Y.S.); (A.C.); (M.J.)
| | - Minjung Jung
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea; (Y.S.); (A.C.); (M.J.)
| | - Yuree Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea; (Y.S.); (A.C.); (M.J.)
- Research Center for Plant Plasticity, Seoul National University, Seoul 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
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6
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Lu Y, Moran Lauter AN, Makkena S, Scott MP, Evans MMS. Insights into the molecular control of cross-incompatibility in Zea mays. PLANT REPRODUCTION 2020; 33:117-128. [PMID: 32865620 DOI: 10.1007/s00497-020-00394-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/18/2020] [Indexed: 06/11/2023]
Abstract
Gametophytic cross-incompatibility systems in corn have been the subject of genetic studies for more than a century. They have tremendous economic potential as a genetic mechanism for controlling fertilization without controlling pollination. Three major genetically distinct and functionally equivalent cross-incompatibility systems exist in Zea mays: Ga1, Tcb1, and Ga2. All three confer reproductive isolation between maize or teosinte varieties with different haplotypes at any one locus. These loci confer genetically separable functions to the silk and pollen: a female function that allows the silk to block fertilization by non-self-type pollen and a male function that overcomes the block of the female function from the same locus. Identification of some of these genes has shed light on the reproductive isolation they confer. The identification of both male and female factors as pectin methylesterases reveals the importance of pectin methylesterase activity in controlling the decision between pollen acceptance versus rejection, possibly by regulating the degree of methylesterification of the pollen tube cell wall. The appropriate level and spatial distribution of pectin methylesterification is critical for pollen tube growth and is affected by both pectin methylesterases and pectin methylesterase inhibitors. We present a molecular model that explains how cross-incompatibility systems may function that can be tested in Zea and uncharacterized cross-incompatibility systems. Molecular characterization of these loci in conjunction with further refinement of the underlying molecular and cellular mechanisms will allow researchers to bring new and powerful tools to bear on understanding reproductive isolation in Zea mays and related species.
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Affiliation(s)
- Yongxian Lu
- Department of Plant Biology, Carnegie Institute for Science, Stanford, CA, 94305, USA
| | | | | | - M Paul Scott
- Corn Insects and Crop Genetics Research Unit, USDA ARS, Ames, IA, 50011, USA
| | - Matthew M S Evans
- Department of Plant Biology, Carnegie Institute for Science, Stanford, CA, 94305, USA.
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7
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Abstract
In plant tissues, cells are glued to each other by a pectic polysaccharide rich material known as middle lamella (ML). Along with many biological functions, the ML plays a crucial role in maintaining the structural integrity of plant tissues and organs, as it prevents the cells from separating or sliding against each other. The macromolecular organization and the material properties of the ML are different from those of the adjacent primary cell walls that envelop all plant cells and provide them with a stiff casing. Due to its nanoscale dimensions and the extreme challenge to access the structure for material characterization, the ML is poorly characterized in terms of its distinct material properties. This review explores the ML beyond its functionality as a gluing agent. The putative molecular interactions of constituent macromolecules within the ML and at the interface between ML and primary cell wall are discussed. The correlation between the spatiotemporal distribution of pectic polysaccharides in the different portions of the ML and the subcellular distribution of mechanical stresses within the plant tissue are analyzed.
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Affiliation(s)
- M S Zamil
- Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
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Lütz-Meindl U. Micrasterias as a Model System in Plant Cell Biology. FRONTIERS IN PLANT SCIENCE 2016; 7:999. [PMID: 27462330 PMCID: PMC4940373 DOI: 10.3389/fpls.2016.00999] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/24/2016] [Indexed: 05/18/2023]
Abstract
The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.
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Affiliation(s)
- Ursula Lütz-Meindl
- Plant Physiology Division, Cell Biology Department, University of SalzburgSalzburg, Austria
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Bidhendi AJ, Geitmann A. Relating the mechanics of the primary plant cell wall to morphogenesis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:449-61. [PMID: 26689854 DOI: 10.1093/jxb/erv535] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Regulation of the mechanical properties of the cell wall is a key parameter used by plants to control the growth behavior of individual cells and tissues. Modulation of the mechanical properties occurs through the control of the biochemical composition and the degree and nature of interlinking between cell wall polysaccharides. Preferentially oriented cellulose microfibrils restrict cellular expansive growth, but recent evidence suggests that this may not be the trigger for anisotropic growth. Instead, non-uniform softening through the modulation of pectin chemistry may be an initial step that precedes stress-induced stiffening of the wall through cellulose. Here we briefly review the major cell wall polysaccharides and their implication for plant cell wall mechanics that need to be considered in order to study the growth behavior of the primary plant cell wall.
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Affiliation(s)
- Amir J Bidhendi
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, Montreal, Quebec H1X 2B2, Canada
| | - Anja Geitmann
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, Montreal, Quebec H1X 2B2, Canada
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10
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Kent LM, Loo TS, Melton LD, Mercadante D, Williams MAK, Jameson GB. Structure and Properties of a Non-processive, Salt-requiring, and Acidophilic Pectin Methylesterase from Aspergillus niger Provide Insights into the Key Determinants of Processivity Control. J Biol Chem 2015; 291:1289-306. [PMID: 26567911 DOI: 10.1074/jbc.m115.673152] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Indexed: 12/17/2022] Open
Abstract
Many pectin methylesterases (PMEs) are expressed in plants to modify plant cell-wall pectins for various physiological roles. These pectins are also attacked by PMEs from phytopathogens and phytophagous insects. The de-methylesterification by PMEs of the O6-methyl ester groups of the homogalacturonan component of pectin, exposing galacturonic acids, can occur processively or non-processively, respectively, describing sequential versus single de-methylesterification events occurring before enzyme-substrate dissociation. The high resolution x-ray structures of a PME from Aspergillus niger in deglycosylated and Asn-linked N-acetylglucosamine-stub forms reveal a 10⅔-turn parallel β-helix (similar to but with less extensive loops than bacterial, plant, and insect PMEs). Capillary electrophoresis shows that this PME is non-processive, halophilic, and acidophilic. Molecular dynamics simulations and electrostatic potential calculations reveal very different behavior and properties compared with processive PMEs. Specifically, uncorrelated rotations are observed about the glycosidic bonds of a partially de-methyl-esterified decasaccharide model substrate, in sharp contrast to the correlated rotations of processive PMEs, and the substrate-binding groove is negatively not positively charged.
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Affiliation(s)
- Lisa M Kent
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Trevor S Loo
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Laurence D Melton
- From Riddet Institute and School of Chemical Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Davide Mercadante
- From Riddet Institute and Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg, 69118 Heidelberg, Germany, and
| | - Martin A K Williams
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand, MacDiarmid Institute for Advanced Materials and Nanotechnology, Palmerston North 4442, New Zealand
| | - Geoffrey B Jameson
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand, MacDiarmid Institute for Advanced Materials and Nanotechnology, Palmerston North 4442, New Zealand
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Stancheva R, Hall JD, Herburger K, Lewis LA, McCourt RM, Sheath RG, Holzinger A. Phylogenetic position of Zygogonium ericetorum (zygnematophyceae, charophyta) from a high alpine habitat and ultrastructural characterization of unusual aplanospores. JOURNAL OF PHYCOLOGY 2014; 50:790-803. [PMID: 25810560 PMCID: PMC4370237 DOI: 10.1111/jpy.12229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Characeae (Charophyceae, Charophyta) contains two tribes with six genera: tribe Chareae with four genera and tribe Nitelleae, which includes Tolypella and Nitella. This paper uses molecular and morphological data to elucidate the phylogeny of Tolypella species in North America. In the most comprehensive taxonomic treatment of Characeae, 16 Tolypella species worldwide were subsumed into two species, T. intricata and T. nidifica, in two sections, Rothia and Tolypella respectively. It was further suggested that Tolypella might be a derived group within Nitella. In this investigation into species diversity and relationships in North American Tolypella, sequence data from the plastid genes atpB, psbC, and rbcL were assembled for a broad range of charophycean and land plant taxa. Molecular data were used in conjunction with morphology to test monophyly of the genus and species within it. Phylogenetic analyses of the sequence data showed that Characeae is monophyletic but that Nitelleae is paraphyletic with Tolypella sister to a monophyletic Nitella + Chareae. The results also supported the monophyly of Tolypella and the sections Rothia and Tolypella. Morphologically defined species were supported as clades with little or no DNA sequence differences. In addition, molecular data revealed several lineages and a new species (T. ramosissima sp. nov.), which suggests greater species diversity in Tolypella than previously recognized.
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Affiliation(s)
- Rosalina Stancheva
- Department of Biological Sciences, California State University San Marcos, San Marcos, California 92096, USA
| | - John D. Hall
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742, USA, Department of Botany, Academy of Natural Sciences, Philadelphia, Pennsylvania 19103, USA
| | - Klaus Herburger
- Institute of Botany, University of Innsbruck, Sternwartestraße 15, Innsbruck A-6020, Austria
| | - Louise A. Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Richard M. McCourt
- Department of Botany, Academy of Natural Sciences, Philadelphia, Pennsylvania 19103, USA, Department of Biodiversity, Earth, and Environmental Sciences, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Robert G. Sheath
- Department of Biological Sciences, California State University San Marcos, San Marcos, California 92096, USA
| | - Andreas Holzinger
- Institute of Botany, University of Innsbruck, Sternwartestraße 15, Innsbruck A-6020, Austria
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12
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Lionetti V, Cervone F, Bellincampi D. Methyl esterification of pectin plays a role during plant-pathogen interactions and affects plant resistance to diseases. JOURNAL OF PLANT PHYSIOLOGY 2012; 169:1623-30. [PMID: 22717136 DOI: 10.1016/j.jplph.2012.05.006] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 05/18/2023]
Abstract
The cell wall is a complex structure mainly composed by a cellulose-hemicellulose network embedded in a cohesive pectin matrix. Pectin is synthesized in a highly methyl esterified form and is de-esterified in muro by pectin methyl esterases (PMEs). The degree and pattern of methyl esterification affect the cell wall structure and properties with consequences on both the physiological processes of the plants and their resistance to pathogens. PME activity displays a crucial role in the outcome of the plant-pathogen interactions by making pectin more susceptible to the action of the enzymes produced by the pathogens. This review focuses on the impact of pectin methyl esterification in plant-pathogen interactions and on the dynamic role of its alteration during pathogenesis.
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Affiliation(s)
- Vincenzo Lionetti
- Dipartimento di Biologia e Biotecnologie Charles Darwin, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
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Jimenez-Lopez JC, Kotchoni SO, Rodríguez-García MI, Alché JD. Structure and functional features of olive pollen pectin methylesterase using homology modeling and molecular docking methods. J Mol Model 2012; 18:4965-84. [DOI: 10.1007/s00894-012-1492-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 06/04/2012] [Indexed: 01/08/2023]
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Cameron RG, Luzio GA, Vasu P, Savary BJ, Williams MAK. Enzymatic modification of a model homogalacturonan with the thermally tolerant pectin methylesterase from Citrus: 1. Nanostructural characterization, enzyme mode of action, and effect of pH. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:2717-2724. [PMID: 21366294 DOI: 10.1021/jf104845j] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Methyl ester distribution in pectin homogalacturonan has a major influence on functionality. Enzymatic engineering of the pectin nanostructure for tailoring functionality can expand the role of pectin as a food-formulating agent and the use of in situ modification in prepared foods. We report on the mode of action of a unique citrus thermally tolerant pectin methylesterase (TT-PME) and the nanostructural modifications that it produces. The enzyme was used to produce a controlled demethylesterification series from a model homogalacturonan. Oligogalacturonides released from the resulting demethylesterified blocks introduced by TT-PME using a limited endopolygalacturonase digestion were separated and quantified by high-pressure anion-exchange chromatography (HPAEC) coupled to an evaporative light-scattering detector (ELSD). The results were consistent with the predictions of a numerical simulation, which assumed a multiple-attack mechanism and a degree of processivity ∼10, at both pH 4.5 and 7.5. The average demethylesterified block size (0.6-2.8 nm) and number of average-sized blocks per molecule (0.8-1.9) differed, depending upon pH of the enzyme treatment. The mode of action of this enzyme and consequent nanostructural modifications of pectin differ from a previously characterized citrus salt-independent pectin methylesterase (SI-PME).
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Affiliation(s)
- Randall G Cameron
- Citrus and Subtropical Products Laboratory, Agricultural Research Service, United States Department of Agriculture, 600 Avenue S., Northwest, Winter Haven, Florida 33881, United States.
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15
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Pectin methylesterase and its proteinaceous inhibitor: a review. Carbohydr Res 2010; 345:2583-95. [DOI: 10.1016/j.carres.2010.10.002] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/30/2010] [Accepted: 10/03/2010] [Indexed: 11/23/2022]
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16
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Characteristics of enzymatically-deesterified pectin gels produced in the presence of monovalent ionic salts. Food Hydrocoll 2009. [DOI: 10.1016/j.foodhyd.2009.02.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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17
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Øbro J, Sørensen I, Derkx P, Madsen CT, Drews M, Willer M, Mikkelsen JD, Willats WGT. High-throughput screening of Erwinia chrysanthemi pectin methylesterase variants using carbohydrate microarrays. Proteomics 2009; 9:1861-8. [PMID: 19333997 DOI: 10.1002/pmic.200800349] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pectin methylesterases (PMEs) catalyse the removal of methyl esters from the homogalacturonan (HG) backbone domain of pectin, a ubiquitous polysaccharide in plant cell walls. The degree of methyl esterification (DE) impacts upon the functional properties of HG within cell walls and plants produce numerous PMEs that act upon HG in muro. Many microbial plant pathogens also produce PMEs, the activity of which renders HG more susceptible to cleavage by pectin lyase and polygalacturonase enzymes and hence aids cell wall degradation. We have developed a novel microarray-based approach to investigate the activity of a series of variant enzymes based on the PME from the important pathogen Erwinia chrysanthemi. A library of 99 E. chrysanthemi PME mutants was created in which seven amino acids were altered by various different substitutions. Each mutant PME was incubated with a highly methyl esterified lime pectin substrate and, after digestion the enzyme/substrate mixtures were printed as microarrays. The loss of activity that resulted from certain mutations was detected by probing arrays with a mAb (JIM7) that preferentially binds to HG with a relatively high DE. Active PMEs therefore resulted in diminished JIM7 binding to the lime pectin substrate, whereas inactive PMEs did not. Our findings demonstrate the feasibility of our approach for rapidly testing the effects on PME activity of substituting a wide variety of amino acids at different positions.
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Affiliation(s)
- Jens Øbro
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
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18
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Eder M, Lütz-Meindl U. Pectin-like carbohydrates in the green alga Micrasterias characterized by cytochemical analysis and energy filtering TEM. J Microsc 2008; 231:201-14. [PMID: 18778418 DOI: 10.1111/j.1365-2818.2008.02036.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pectins are the major matrix polysaccharides of plant cell walls and are important for controlling growth, wall porosity and regulation of the ionic environment in plant cells. Pectic epitopes recognized by the monoclonal antibodies JIM5, JIM7 and 2F4 could be localized in the primary wall during development of the green alga Micrasterias. As the degree of pectin esterification determines the calcium-binding capacity and thus the physical properties of the cell wall, chemical and enzymatic in situ de-esterification was performed. This resulted in displacement of epitopes recognized by JIM5, JIM7 and 2F4, respectively, in changes in the intensity of the antibody labelling as visualized in CLSM. In addition, calcium-binding capacities of cell walls and components of the secretory apparatus were determined in transmission electron microscopy by electron energy loss spectroscopy and electron spectroscopic imaging. These analyses revealed that pectic polysaccharides are transported to the cell wall in a de-esterified form. At the primary wall, pectins get methyl-esterified at the inner side, thus allowing flexibility of the wall. At the outer side of the wall they become again de-esterified and bind high amounts of calcium which leads to cell wall stiffening. Mucilage vesicles possess the highest calcium-binding capacity of all structures observed in Micrasterias, indicating that the pectic polysaccharides of mucilage are secreted in a de-esterified, compact form. When mucilage is excreted through the cell wall, it loses its ability to bind calcium. The esterification of pectins involved is obviously required for swelling of mucilage by water uptake, which generates the motive force for orientation of this unicellular organism in respect to light. Incubation of Micrasterias in pectin methylesterase (PME), which de-esterifies pectic polymers in higher plants, resulted in growth inhibition, cell shape malformation and primary wall thickening. A PME-like enzyme could be found in Micrasterias by PME activity assays.
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Affiliation(s)
- M Eder
- Cell Biology Department, Plant Physiology Division, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria
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19
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Hall JD, McCourt RM, Delwiche CF. Patterns of cell division in the filamentous Desmidiaceae, close green algal relatives of land plants. AMERICAN JOURNAL OF BOTANY 2008; 95:643-654. [PMID: 21632389 DOI: 10.3732/ajb.2007210] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Patterns of cell division and cross wall formation vary among the charophytes, green algae closely related to land plants. One group of charophytes, the conjugating green algae (Zygnematophyceae), is species-rich and is known to vary substantially in the mode of cell division, but the details of these cell division patterns and their phylogenetic distribution remain poorly understood. We studied cross wall development in filamentous Desmidiaceae (a clade of conjugating green algae) using differential interference contrast and fluorescence light microscopy. All strains investigated had centripetal encroachment of a septum, but with several different developmental patterns. In most cases, cell wall formation was delayed with respect to the Cosmarium-type of cell division, and the cross wall was modified considerably after deposition in a manner specific to the particular clade of filamentous desmids. These characteristics were mapped on a phylogeny estimated from a data set of two organellar genes, and the evolutionary implications of the character state distribution were evaluated. The data suggest a complex history of evolution of cell division in this lineage and also imply that Desmidium and Spondylosium are polyphyletic. These results indicate that many features of the cell shape are determined at the time of cell division in conjugating green algae.
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Affiliation(s)
- John D Hall
- Cullman Program for Molecular Systematics Studies, New York Botanical Garden, Bronx, New York 10458 USA
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Röckel N, Wolf S, Kost B, Rausch T, Greiner S. Elaborate spatial patterning of cell-wall PME and PMEI at the pollen tube tip involves PMEI endocytosis, and reflects the distribution of esterified and de-esterified pectins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:133-43. [PMID: 17971035 DOI: 10.1111/j.1365-313x.2007.03325.x] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In dicots, pectins are the major structural determinant of the cell wall at the pollen tube tip. Recently, immunological studies revealed that esterified pectins are prevalent at the apex of growing pollen tubes, where the cell wall needs to be expandable. In contrast, lateral regions of the cell wall contain mostly de-esterified pectins, which can be cross-linked to rigid gels by Ca(2+) ions. In pollen tubes, several pectin methylesterases (PMEs), enzymes that de-esterify pectins, are co-expressed with different PME inhibitors (PMEIs). This raises the possibility that interactions between PMEs and PMEIs play a key role in the regulation of cell-wall stability at the pollen tube tip. Our data establish that the PME isoform AtPPME1 (At1g69940) and the PMEI isoform AtPMEI2 (At3g17220), which are both specifically expressed in Arabidopsis pollen, physically interact, and that AtPMEI2 inactivates AtPPME1 in vitro. Furthermore, transient expression in tobacco pollen tubes revealed a growth-promoting activity of AtPMEI2, and a growth-inhibiting effect of AtPPME1. Interestingly, AtPPME1:YFP accumulated to similar levels throughout the cell wall of tobacco pollen tubes, including the tip region, whereas AtPMEI2:YFP was exclusively detected at the apex. In contrast to AtPPME1, AtPMEI2 localized to Brefeldin A-induced compartments, and was found in FYVE-induced endosomal aggregates. Our data strongly suggest that the polarized accumulation of PMEI isoforms at the pollen tube apex, which depends at least in part on local PMEI endocytosis at the flanks of the tip, regulates cell-wall stability by locally inhibiting PME activity.
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Affiliation(s)
- Nina Röckel
- Heidelberg Institute for Plant Sciences, INF 360, 69120 Heidelberg, Germany
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Demethylation of a model homogalacturonan with a salt-independent pectin methylesterase from citrus: I. Effect of pH on demethylated block size, block number and enzyme mode of action. Carbohydr Polym 2008. [DOI: 10.1016/j.carbpol.2007.07.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Ciardiello MA, D'Avino R, Amoresano A, Tuppo L, Carpentieri A, Carratore V, Tamburrini M, Giovane A, Pucci P, Camardella L. The peculiar structural features of kiwi fruit pectin methylesterase: Amino acid sequence, oligosaccharides structure, and modeling of the interaction with its natural proteinaceous inhibitor. Proteins 2008; 71:195-206. [DOI: 10.1002/prot.21681] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Fraeye I, Duvetter T, Verlent I, Ndaka Sila D, Hendrickx M, Van Loey A. Comparison of enzymatic de-esterification of strawberry and apple pectin at elevated pressure by fungal pectinmethylesterase. INNOV FOOD SCI EMERG 2007. [DOI: 10.1016/j.ifset.2006.07.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Duvetter T, Fraeye I, Sila DN, Verlent I, Smout C, Hendrickx M, Van Loey A. Mode of de-esterification of alkaline and acidic pectin methyl esterases at different pH conditions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:7825-31. [PMID: 17002458 DOI: 10.1021/jf060013h] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Highly esterified citrus pectin was de-esterified at pH 4.5 and 8.0 by a fungal pectin methyl esterase (PME) that was shown to have an acidic isoelectric pH (pI) and an acidic pH optimum and by a plant PME that was characterized by an alkaline pI and an alkaline pH optimum. Interchain and intrachain de-esterification patterns were studied by digestion of the pectin products with endo-polygalacturonase and subsequent analysis using size exclusion and anion-exchange chromatography. No effect of pH was observed on the de-esterification mode of either of the two enzymes. Acidic, fungal PME converted pectin according to a multiple-chain mechanism, with a limited degree of multiple attack at the intrachain level, both at pH 4.5 and at pH 8.0. A multiple-attack mechanism, with a high degree of multiple attack, was more appropriate to describe the action mode of alkaline, plant PME, both at pH 4.5 and at pH 8.0.
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Affiliation(s)
- Thomas Duvetter
- Center for Food and Microbial Technology, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Heverlee, Belgium
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25
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Thonar C, Liners F, Van Cutsem P. Polymorphism and modulation of cell wall esterase enzyme activities in the chicory root during the growing season. JOURNAL OF EXPERIMENTAL BOTANY 2005; 57:81-9. [PMID: 16339785 DOI: 10.1093/jxb/erj006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Pectins are major components of the primary plant cell wall. They can be both methylesterified and acetylesterified and de-esterification occurs by specific esterases. Proteins extracted by NaCl treatment from root cell walls of two chicory varieties (Cichorium intybus L. cv. Nausica and Arancha) sampled in an experimental field every 2 weeks between July 2002 and January 2003 were analysed by isoelectrofocalization, semi-denaturing SDS-PAGE, and quantitative assays for their esterase activity. Zymograms showed that chicory root pectin methylesterases belong to a multigene family. The isoelectric points of the pectin methylesterase isoforms ranged from pI 3.8 to pI 9.0. Concerning acetylesterases, only acidic isoforms between pI 4.1 and pI 5.2 were observed, but a large polymorphism of this class of enzymes could be identified in one variety. The results indicate that the root pectin methylesterase activity of the Nausica variety was correlated with ambient temperature, while no significant effect of temperature could be detected on any acetylesterase isoform.
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Affiliation(s)
- Cécile Thonar
- Unité de Recherche en Biologie cellulaire végétale, Facultés Universitaires Notre-Dame de la Paix, Rue de Bruxelles 61, B-5000 Namur, Belgium
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26
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Lewis LA, McCourt RM. Green algae and the origin of land plants. AMERICAN JOURNAL OF BOTANY 2004; 91:1535-56. [PMID: 21652308 DOI: 10.3732/ajb.91.10.1535] [Citation(s) in RCA: 384] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Over the past two decades, molecular phylogenetic data have allowed evaluations of hypotheses on the evolution of green algae based on vegetative morphological and ultrastructural characters. Higher taxa are now generally recognized on the basis of ultrastructural characters. Molecular analyses have mostly employed primarily nuclear small subunit rDNA (18S) and plastid rbcL data, as well as data on intron gain, complete genome sequencing, and mitochondrial sequences. Molecular-based revisions of classification at nearly all levels have occurred, from dismemberment of long-established genera and families into multiple classes, to the circumscription of two major lineages within the green algae. One lineage, the chlorophyte algae or Chlorophyta sensu stricto, comprises most of what are commonly called green algae and includes most members of the grade of putatively ancestral scaly flagellates in Prasinophyceae plus members of Ulvophyceae, Trebouxiophyceae, and Chlorophyceae. The other lineage (charophyte algae and embryophyte land plants), comprises at least five monophyletic groups of green algae, plus embryophytes. A recent multigene analysis corroborates a close relationship between Mesostigma (formerly in the Prasinophyceae) and the charophyte algae, although sequence data of the Mesostigma mitochondrial genome analysis places the genus as sister to charophyte and chlorophyte algae. These studies also support Charales as sister to land plants. The reorganization of taxa stimulated by molecular analyses is expected to continue as more data accumulate and new taxa and habitats are sampled.
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Affiliation(s)
- Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269 USA
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Markovic O, Janecek S. Pectin methylesterases: sequence-structural features and phylogenetic relationships. Carbohydr Res 2004; 339:2281-95. [PMID: 15337457 DOI: 10.1016/j.carres.2004.06.023] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Accepted: 06/25/2004] [Indexed: 11/26/2022]
Abstract
Pectin methylesterases (PMEs) are enzymes produced by bacteria, fungi and higher plants. They belong to the carbohydrate esterase family CE-8. This study deals with comparison of 127 amino acid sequences of this family containing the five characteristic sequence segments: 44_GxYxE, 113_QAVAL, 135_QDTL, 157_DFIFG, 223_LGRPW (Daucus carota numbering). Six strictly conserved residues (Gly44, Gly154, Asp157, Gly161, Arg225 and Trp227) and six conservative ones (Ile39, Ser86, Ser137, Ile152, Ile159 and Leu223) were identified. A set of 70 representative PMEs was created. The sequences were aligned and the evolutionary tree based on the alignment was calculated. The tree reflected the taxonomy: the fungal and bacterial PMEs formed their own clusters and the plant enzymes were grouped into eight separate clades. The plant PME from Vitis riparia was placed in a common clade with fungi. Three plant clades (Plant 1, 2 and 3) were relatively homogenous reflecting high degree of mutual sequence identity. The clade Plant 4 contained PMEs from flower parts (mostly form pollen) and was heterogenous, like the clades Plant 1a and 2a, which moreover exhibit an intermediate character. The clades Plant X1 and X2 were situated in the tree close to microbial clades and represented atypical plant PMEs. Taking into account the remaining plant PMEs, an expanded plant alignment and tree (with most Arabidopsis thaliana and Oryza sativa enzymes), were prepared. An exclusive Arabidopsis alignment and tree indicated the existence of a new plant clade X3. In the pre pro region of most plant enzymes a longer conserved segment containing basic dipeptide, R(K)/R(K), that precedes the N-terminal end of PME was revealed. This was not observed in the clade Plant X1 and majority of the clade Plant X2. This study brings further the description of occurrence of potential glycosylation sites in pre pro sequences and in mature enzymes as well as important amino acid residues, such as aspartates, cysteines, histidines and other aromatic residues (Tyr, Phe and Trp), with discussion of their possible function in the activity of PMEs.
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Affiliation(s)
- Oskar Markovic
- Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84538 Bratislava, Slovakia
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Giovane A, Servillo L, Balestrieri C, Raiola A, D'Avino R, Tamburrini M, Ciardiello MA, Camardella L. Pectin methylesterase inhibitor. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1696:245-52. [PMID: 14871665 DOI: 10.1016/j.bbapap.2003.08.011] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2003] [Accepted: 08/07/2003] [Indexed: 11/25/2022]
Abstract
Pectin methylesterase (PME) is the first enzyme acting on pectin, a major component of plant cell wall. PME action produces pectin with different structural and functional properties, having an important role in plant physiology. Regulation of plant PME activity is obtained by the differential expression of several isoforms in different tissues and developmental stages and by subtle modifications of cell wall local pH. Inhibitory activities from various plant sources have also been reported. A proteinaceous inhibitor of PME (PMEI) has been purified from kiwi fruit. The kiwi PMEI is active against plant PMEs, forming a 1:1 non-covalent complex. The polypeptide chain comprises 152 amino acid residues and contains five Cys residues, four of which are connected by disulfide bridges, first to second and third to fourth. The sequence shows significant similarity with the N-terminal pro-peptides of plant PME, and with plant invertase inhibitors. In particular, the four Cys residues involved in disulfide bridges are conserved. On the basis of amino acid sequence similarity and Cys residues conservation, a large protein family including PMEI, invertase inhibitors and related proteins of unknown function has been identified. The presence of at least two sequences in the Arabidopsis genome having high similarity with kiwi PMEI suggests the ubiquitous presence of this inhibitor. PMEI has an interest in food industry as inhibitor of endogenous PME, responsible for phase separation and cloud loss in fruit juice manufacturing. Affinity chromatography on resin-bound PMEI can also be used to concentrate and detect residual PME activity in fruit and vegetable products.
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Affiliation(s)
- A Giovane
- Department of Biochemistry and Biophysics, 2nd University of Napoli, Via Costantinopoli 16, I-80138, Naples, Italy
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D'Avino R, Camardella L, Christensen TMIE, Giovane A, Servillo L. Tomato pectin methylesterase: Modeling, fluorescence, and inhibitor interaction studies?comparison with the bacterial (Erwinia chrysanthemi) enzyme. Proteins 2003; 53:830-9. [PMID: 14635125 DOI: 10.1002/prot.10487] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The molecular model of Lycopersicon esculentum (tomato) pectin methylesterase (PME) was built by using the X-ray crystal structure of PME from the phytopathogenic bacterium Erwinia chrysanthemi as a template. The overall structure and the position of catalytically important residues (Asp132, Asp 153, and Arg 221, located at the bottom of the active site cleft) are conserved. Instead, loop regions forming the walls of the catalytic site are much shorter and form a less deep cleft, as already revealed by the carrot PME crystal structure. The protein inhibitor of pectin methylesterase (PMEI) isolated from kiwi fruit binds tomato PME with high affinity. Conversely, no complex formation between the inhibitor and PME from E. chrysanthemi is observed, and the activity of this enzyme is unaffected by the presence of the inhibitor. Fluorescence quenching experiments on tomato PME and on PME-PMEI complex suggest that tryptophanyl residues present in the active site region are involved in the interaction and that the inhibitor interacts with plant PME at the level of the active site. We also suggest that the more open active site cleft of tomato PME allows the interaction with the inhibitor. Conversely, the narrow and deep cleft of the active site of E. chrysanthemi PME hinders this interaction. The pH-dependent changes in fluorescence emission intensity observed in tomato PME could arise as the result of protonation of an Asp residue with unusually high pKa, thus supporting the hypothesis that Asp132 acts as acid/base in the catalytic cycle.
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Johansson K, El-Ahmad M, Friemann R, Jörnvall H, Markovic O, Eklund H. Crystal structure of plant pectin methylesterase. FEBS Lett 2002; 514:243-9. [PMID: 11943159 DOI: 10.1016/s0014-5793(02)02372-4] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pectin is a principal component in the primary cell wall of plants. During cell development, pectin is modified by pectin methylesterases to give different properties to the cell wall. This report describes the first crystal structure of a plant pectin methylesterase. The beta-helical structure embodies a central cleft, lined by several aromatic residues, that has been deduced to be suitable for pectin binding. The active site is found at the center of this cleft where Asp157 is suggested to act as the nucleophile, Asp136 as an acid/base and Gln113/Gln135 to form an anion hole to stabilize the transition state.
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Affiliation(s)
- Kenth Johansson
- Department of Molecular Biology, Swedish University of Agricultural Sciences, S-751 24 Uppsala, Sweden
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