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Méndez-Yáñez A, Carrasco-Orellana C, Ramos P, Morales-Quintana L. Alpha-expansins: more than three decades of wall creep and loosening in fruits. PLANT MOLECULAR BIOLOGY 2024; 114:84. [PMID: 38995453 DOI: 10.1007/s11103-024-01481-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 06/21/2024] [Indexed: 07/13/2024]
Abstract
Expansins are proteins without catalytic activity, but able to break hydrogen bonds between cell wall polysaccharides hemicellulose and cellulose. This proteins were reported for the first time in 1992, describing cell wall extension in cucumber hypocotyls caused particularly by alpha-expansins. Although these proteins have GH45 and CBM63 domains, characteristic of enzymes related with the cleavage of cell wall polysaccharides, demonstrating in vitro that they extend plant cell wall. Its participation has been associated to molecular processes such as development and growing, fruit ripening and softening, tolerance and resistance to biotic and abiotic stress and seed germination. Structural insights, facilitated by bioinformatics approaches, are highlighted, shedding light on the intricate interactions between alpha-expansins and cell wall polysaccharides. After more than thirty years of its discovery, we want to celebrate the knowledge of alpha-expansins and emphasize their importance to understand the phenomena of disassembly and loosening of the cell wall, specifically in the fruit ripening phenomena, with this state-of-the-art dedicated to them.
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Affiliation(s)
- Angela Méndez-Yáñez
- Multidisciplinary Agroindustry Research Laboratory, Facultad de Ciencias de La Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Cinco Poniente No. 1670, Talca, Chile.
| | - Cristian Carrasco-Orellana
- División Agroindustrial de Empresas Carozzi S. A., Desarrollo E Innovación Aplicada Agrozzi, Centro Tecnológico de Investigación, Teno, Chile
| | - Patricio Ramos
- Plant Microorganism Interaction Laboratory, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Facultad de Ciencias de La Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Cinco Poniente No. 1670, Talca, Chile.
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2
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Chen Z, Shen D, Shi Y, Chen Y, He H, Jiang J, Wang F, Jiang J, Wang X, Li X, Zeng W. Genome-Wide Identification of Expansins in Rubus chingii and Profiling Analysis during Fruit Ripening and Softening. PLANTS (BASEL, SWITZERLAND) 2024; 13:431. [PMID: 38337963 PMCID: PMC10857257 DOI: 10.3390/plants13030431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024]
Abstract
Improving fruit size or weight, firmness, and shelf life is a major target for horticultural crop breeding. It is associated with the depolymerization and rearrangement of cell components, including pectin, hemicellulose, cellulose, and other structural (glyco)proteins. Expansins are structural proteins to loosen plant cell wall polysaccharides in a pH-dependent manner and play pivotal roles in the process of fruit development, ripening, and softening. Rubus chingii Hu, a unique Chinese red raspberry, is a prestigious pharmaceutical and nutraceutical dual-function food with great economic value. Thirty-three RchEXPs were predicted by genome-wide identification in this study, containing twenty-seven α-expansins (EXPAs), three β-expansins (EXPBs), one expansin-like A (EXPLA), and two expansin-like B (EXPLBs). Subsequently, molecular characteristics, gene structure and motif compositions, phylogenetic relationships, chromosomal location, collinearity, and regulatory elements were further profiled. Furthermore, transcriptome sequencing (RNA-seq) and real-time quantitative PCR assays of fruits from different developmental stages and lineages showed that the group of RchEXPA5, RchEXPA7, and RchEXPA15 were synergistically involved in fruit expanding and ripening, while another group of RchEXPA6 and RchEXPA26 might be essential for fruit ripening and softening. They were regulated by both abscisic acid and ethylene and were collinear with phylogenetic relationships in the same group. Our new findings laid the molecular foundation for improving the fruit texture and shelf life of R. chingii medicinal and edible fruit.
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Affiliation(s)
- Zhen Chen
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Danwei Shen
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Yujie Shi
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Yiquan Chen
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Honglian He
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Junfeng Jiang
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Fan Wang
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Jingyong Jiang
- Institute of Horticulture, Taizhou Academy of Agricultural Sciences, Linhai 317000, China;
| | - Xiaoyan Wang
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
| | - Xiaobai Li
- Institute of Horticulture, Zhejiang Academy of Agricultral Sciences, Hangzhou 310021, China
| | - Wei Zeng
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, China; (Z.C.); (D.S.); (Y.S.); (X.W.)
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3
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Faris Abdulkhadum Al-Mamoorı D, Celik Altunoglu Y, Horuz E, Özkan Kök B. Investigation of the expansin gene family in sugar beet (Beta vulgaris) by the genome-wide level and their expression responses under abiotic stresses. Biol Futur 2023; 74:295-307. [PMID: 37642915 DOI: 10.1007/s42977-023-00176-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 08/13/2023] [Indexed: 08/31/2023]
Abstract
Sugar beet (Beta vulgaris ssp. vulgaris) is primarily used in sugar production worldwide. Expansins are a gene family of cell wall proteins effective in regulating cell wall structure. They also participate in developmental stages, including cell and leaf growth, root development, and fruit ripening. This study comprehensively characterizes the expansin gene family members found in the sugar beet genome. In addition, in silico expression analysis of sugar beet expansin genes under variable abiotic stress conditions and expression profiles of expansin genes under combined drought and heat stresses by the qRT-PCR method were evaluated in the study. A total of 31 sugar beet expansin genes were identified. BvuEXLA-02 and BvuEXLB-02 genes can have abiotic stress tolerance roles besides their roles in normal development. Determining the properties of sugar beet expansin, family members can help enable the cellulose hydrolysis mechanism and raise plant biomass. Elucidating expression profiles of the sugar beet expansin genes under variable stress conditions can support improving plant productivity. The results of the current study may also contribute to the deep understanding of sugar beet expansin genes in the future.
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Affiliation(s)
| | - Yasemin Celik Altunoglu
- Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey.
| | - Erdoğan Horuz
- Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey
| | - Büşra Özkan Kök
- Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey
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Gaete-Eastman C, Mattus-Araya E, Herrera R, Moya-León MA. Evaluation of reference genes for transcript normalization in Fragaria chiloensis fruit and vegetative tissues. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:1535-1544. [PMID: 36389093 PMCID: PMC9530087 DOI: 10.1007/s12298-022-01227-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 06/01/2023]
Abstract
UNLABELLED Quantitative real-time PCR (RT-qPCR) is used extensively in gene expression studies. For adequate comparisons, the identification and use of reliable reference genes are crucial. Nevertheless, the availability of such genes in strawberry species is limited and has yet to be described for the Chilean strawberry, Fragaria chiloensis. In this study, the expression dynamics of a set of 10 candidate reference genes were analyzed in various F. chiloensis vegetative tissues (root, runners, stem, leaf, and flower), and fruits at different ripening stages or subjected to different hormonal treatments (ABA, auxin). The expression stability of candidate genes was examined by a series of algorithms, such as geNorm, NormFinder, BestKeeper, and ΔCt, for comparisons and rankings. Finally, by using RefFinder, a comprehensive and comparative ranking of the four methods was achieved. The results highlight that the expression stability of candidate reference genes fluctuates depending on tissue type, fruit stage, and hormonal treatment. As reference genes, the use of FcCHP2 and FcACTIN1 is recommended for F. chiloensis vegetative tissues; FcDBP and FcCHP1 for fruit ripening stages; FcGAPDH and FcDBP for fruit subjected to ABA and NDGA treatments; FcCHP1 and FcCHP2 for fruit under AUXIN and TIBA treatments; and FcDBP and FcCHP2 when all fruit stages and hormonal treatments are compared. If just one reference gene is employed as a normalizer, FcDBP should be chosen as it is the most stable internal control in most conditions. Therefore, the present study delivers a set of reliable reference genes for RT-qPCR expression analysis in F. chiloensis tissues and fruits subjected to several hormonal treatments. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-022-01227-y.
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Affiliation(s)
- Carlos Gaete-Eastman
- Laboratorio de Fisiología Vegetal y Genética Molecular, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Elena Mattus-Araya
- Laboratorio de Fisiología Vegetal y Genética Molecular, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Raúl Herrera
- Laboratorio de Fisiología Vegetal y Genética Molecular, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - María Alejandra Moya-León
- Laboratorio de Fisiología Vegetal y Genética Molecular, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
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Characterization of the Cell Wall Component through Thermogravimetric Analysis and Its Relationship with an Expansin-like Protein in Deschampsia antarctica. Int J Mol Sci 2022; 23:ijms23105741. [PMID: 35628551 PMCID: PMC9143908 DOI: 10.3390/ijms23105741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 02/06/2023] Open
Abstract
Deschampsia antarctica Desv. (Poaceae) is one of the two vascular plants that have colonized the Antarctic Peninsula, which is usually exposed to extreme environmental conditions. To support these conditions, the plant carries out modifications in its morphology and metabolism, such as modifications to the cell wall. Thus, we performed a comparative study of the changes in the physiological properties of the cell-wall-associated polysaccharide contents of aerial and root tissues of the D. antarctica via thermogravimetric analysis (TGA) combined with a computational approach. The result showed that the thermal stability was lower in aerial tissues with respect to the root samples, while the DTG curve describes four maximum peaks of degradation, which occurred between 282 and 358 °C. The carbohydrate polymers present in the cell wall have been depolymerized showing mainly cellulose and hemicellulose fragments. Additionally, a differentially expressed sequence encoding for an expansin-like (DaEXLA2), which is characterized by possessing cell wall remodeling function, was found in D. antarctica. To gain deep insight into a probable mechanism of action of the expansin protein identified, a comparative model of the structure was carried out. DaEXLA2 protein model displayed two domains with an open groove in the center. Finally, using a cell wall polymer component as a ligand, the protein-ligand interaction was evaluated by molecular dynamic (MD) simulation. The MD simulations showed that DaEXLA2 could interact with cellulose and XXXGXXXG polymers. Finally, the cell wall component description provides the basis for a model for understanding the changes in the cell wall polymers in response to extreme environmental conditions.
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Samalova M, Gahurova E, Hejatko J. Expansin-mediated developmental and adaptive responses: A matter of cell wall biomechanics? QUANTITATIVE PLANT BIOLOGY 2022; 3:e11. [PMID: 37077967 PMCID: PMC10095946 DOI: 10.1017/qpb.2022.6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 03/16/2022] [Accepted: 03/29/2022] [Indexed: 05/03/2023]
Abstract
Biomechanical properties of the cell wall (CW) are important for many developmental and adaptive responses in plants. Expansins were shown to mediate pH-dependent CW enlargement via a process called CW loosening. Here, we provide a brief overview of expansin occurrence in plant and non-plant species, their structure and mode of action including the role of hormone-regulated CW acidification in the control of expansin activity. We depict the historical as well as recent CW models, discuss the role of expansins in the CW biomechanics and address the developmental importance of expansin-regulated CW loosening in cell elongation and new primordia formation. We summarise the data published so far on the role of expansins in the abiotic stress response as well as the rather scarce evidence and hypotheses on the possible mechanisms underlying expansin-mediated abiotic stress resistance. Finally, we wrap it up by highlighting possible future directions in expansin research.
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Affiliation(s)
- Marketa Samalova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Evelina Gahurova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jan Hejatko
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
- Author for correspondence: J. Hejatko, E-mail:
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Morales-Quintana L, Barrera A, Hereme R, Jara K, Rivera-Mora C, Valenzuela-Riffo F, Gundel PE, Pollmann S, Ramos P. Molecular and structural characterization of expansins modulated by fungal endophytes in the Antarctic Colobanthus quitensis (Kunth) Bartl. Exposed to drought stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 168:465-476. [PMID: 34717178 DOI: 10.1016/j.plaphy.2021.10.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/19/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
Expansins are proteins involved in cell wall metabolism that play an important role in plant growth, development, fruit ripening and abiotic stress tolerance. In the present study, we analyzed putative expansins that respond to drought stress. Five expansin genes were identified in cDNA libraries isolated from Colobanthus quitensis gown either with or without endophytic fungi under hydric stress. A differential transcript abundance was observed by qPCR analysis upon drought stress. To compare these expansin genes, and to suggest a possible mechanism of action at the molecular level, the structural model of the deduced proteins was obtained by comparative modeling methodology. The structures showed two domains and an open groove on the surface of the proteins was observed in the five structural models. The proteins were evaluated in terms of their protein-ligand interactions using four different ligands. The results suggested differences in their mode of protein-ligand interaction, in particular concerning the residues involved in the protein-ligand interaction. The presented evidence supports the participation of some members of the expansin multiprotein family in the response to drought stress in C. quitensis and suggest that the response is modulated by endophytic fungi.
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Affiliation(s)
- Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédica, Facultad Ciencias de la Salud, Universidad Autónoma de Chile, Talca, 3467987, Chile
| | - Andrea Barrera
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Rasme Hereme
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Karla Jara
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | | | | | - Pedro E Gundel
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile; IFEVA (Facultad de Agronomía, Universidad de Buenos Aires - CONICET), Argentina
| | - Stephan Pollmann
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Spain
| | - Patricio Ramos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile; Centro de Biotecnología de los Recursos Naturales (CenBio), Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca, Chile.
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Valenzuela-Riffo F, Parra-Palma C, Ramos P, Morales-Quintana L. Molecular and structural insights into FaEXPA5, an alpha-expansin protein related with cell wall disassembly during ripening of strawberry fruit. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 154:581-589. [PMID: 32711363 DOI: 10.1016/j.plaphy.2020.06.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 06/05/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
Cell wall modification is one of the main factors that produce the tissue softening during ripening of many fruit including strawberry (Fragaria x ananassa). Expansins have been studied for over 20 years as a class of the important cell growth regulators, and in the last years these have been related with the fruit softening. In strawberry, five partial sequences of the expansins genes were described in the past, this analysis showed that FaEXP5 partial gene was present throughout fruit development, but was more strongly expressed during ripening. Now, we reported the full length of this α-expansin (FaEXPA5), whose had been related with fruit softening, and the protein structural was described by homology model. Their transcript accumulation during softening was confirmed by qRT-PCR, displaying a high accumulation rate during fruit ripening. In silico analysis of promoter sequence showed four ABA and two auxin cis-regulatory elements, potentially responsible for the expression patterns observed in response to the hormone treatments. Additionally, 3D protein model displayed two domains and one open groove characteristic of expansin structures. The protein-ligand interactions were evaluated by molecular dynamic (MD) simulation using three different long structure ligands (a cellulose fiber, a xyloglucan fiber (XXXG type), and a pectin fiber as control). Favorable interactions were observed with xyloglucan and cellulose, being cellulose the best ligand with lower RMSD value. Additionally, MD simulations showed that FaEXPA5 can interact with the ligands through residues present in the open groove along the two domains.
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Affiliation(s)
- Felipe Valenzuela-Riffo
- Programa de Doctorado en Ciencias Mención Ingeniería Genética, Instituto de Ciencias Biológicas, Universidad de Talca, Chile
| | - Carolina Parra-Palma
- Programa de Doctorado en Ciencias Mención Ingeniería Genética, Instituto de Ciencias Biológicas, Universidad de Talca, Chile
| | - Patricio Ramos
- Instituto de Ciencias Biológicas, Universidad de Talca, Chile; Núcleo Científico Multidisciplinario-DI, Universidad de Talca, Chile.
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédica, Facultad Ciencias de La Salud, Universidad Autónoma de Chile, Talca, Chile.
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Valenzuela-Riffo F, Morales-Quintana L. Study of the structure and binding site features of FaEXPA2, an α-expansin protein involved in strawberry fruit softening. Comput Biol Chem 2020; 87:107279. [PMID: 32505880 DOI: 10.1016/j.compbiolchem.2020.107279] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 04/09/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
Tissue softening accompanies the ripening of many fruits and initiates the processes of irreversible deterioration. Expansins are plant cell wall proteins that have been proposed to disrupt hydrogen bonds within the cell wall polymer matrix. Several authors have shown that FaEXPA2 is a key gene that shows an increased expression level during ripening and softening of the strawberry fruit. For this reason, FaEXPA2 is frequently used as a molecular marker of softening in strawberry fruit, and changes in its relative expression have been related to changes in fruit firmness. In this context, we previously reported that FaEXPA2 has a high accumulation rate during fruit ripening in four different strawberry cultivars; however, the molecular mechanism of FaEXPA2 or expansins in general is not yet clear. Herein, a 3D model of the FaEXPA2 protein was built by comparative modeling to understand how FaEXPA2 interacts with different cell wall components at the molecular level. First, the structure was shown to display two domains characteristic of the other expansins that were previously described. The protein-ligand interaction was evaluated by molecular dynamic (MD) simulation using four different long ligands (a cellulose fiber, two of the more important xyloglucan (XG) fibers found in strawberry (XXXG and XXFG type), and a pectin (homogalacturonic acid type)). The results showed that FaEXPA2 formed a more stable complex with cellulose than other ligands via the different residues present in the open groove surface of its two domains, while FaEXPA2 did not interact with the pectin ligand.
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Affiliation(s)
- Felipe Valenzuela-Riffo
- Instituto de Ciencias Biológicas, Universidad de Talca, Chile; Programa de Doctorado en Ciencias Mención Ingeniería Genética Vegetal, Universidad de Talca, Chile
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédica, Facultad Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile.
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10
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Morales-Quintana L, Beltrán D, Mendez-Yañez Á, Valenzuela-Riffo F, Herrera R, Moya-León MA. Characterization of FcXTH2, a Novel Xyloglucan Endotransglycosylase/Hydrolase Enzyme of Chilean Strawberry with Hydrolase Activity. Int J Mol Sci 2020; 21:E3380. [PMID: 32403246 PMCID: PMC7247008 DOI: 10.3390/ijms21093380] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 12/12/2022] Open
Abstract
Xyloglucan endotransglycosylase/hydrolases (XTHs) are cell wall enzymes with hydrolase (XEH) and/or endotransglycosylase (XET) activities. As they are involved in the modification of the xyloglucans, a type of hemicellulose present in the cell wall, they are believed to be very important in different processes, including growth, development, and fruit ripening. Previous studies suggest that XTHs might play a key role in development and ripening of Fragaria chiloensis fruit, and its characterization is pending. Therefore, in order to provide a biochemical characterization of the FcXTH2 enzyme to explain its possible role in strawberry development, the molecular cloning and the heterologous expression of FcXTH2 were performed. The recombinant FcXTH2 was active and displayed mainly XEH activity. The optimal pH and temperature are 5.5 and 37 °C, respectively. A KM value of 0.029 mg mL-1 was determined. Additionally, its protein structural model was built through comparative modeling methodology. The model showed a typically β-jelly-roll type folding in which the catalytic motif was oriented towards the FcXTH2 central cavity. Using molecular docking, protein-ligand interactions were explored, finding better interaction with xyloglucan than with cellulose. The data provided groundwork for understanding, at a molecular level, the enzymatic mechanism of FcXTH2, an important enzyme acting during the development of the Chilean strawberry.
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Affiliation(s)
- Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, 3460000 Talca, Chile
| | - Dina Beltrán
- Functional Genomics, Biochemistry and Plant Physiology group, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile; (D.B.); (R.H.)
| | - Ángela Mendez-Yañez
- Functional Genomics, Biochemistry and Plant Physiology group, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile; (D.B.); (R.H.)
- Programa de Doctorado en Ciencias Mención Ingeniería Genética Vegetal, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile;
| | - Felipe Valenzuela-Riffo
- Programa de Doctorado en Ciencias Mención Ingeniería Genética Vegetal, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile;
| | - Raúl Herrera
- Functional Genomics, Biochemistry and Plant Physiology group, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile; (D.B.); (R.H.)
| | - María Alejandra Moya-León
- Functional Genomics, Biochemistry and Plant Physiology group, Instituto de Ciencias Biológicas, Universidad de Talca, 3460000 Talca, Chile; (D.B.); (R.H.)
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Expression of Two α-Type Expansins from Ammopiptanthus nanus in Arabidopsis thaliana Enhance Tolerance to Cold and Drought Stresses. Int J Mol Sci 2019; 20:ijms20215255. [PMID: 31652768 PMCID: PMC6862469 DOI: 10.3390/ijms20215255] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/11/2019] [Accepted: 10/17/2019] [Indexed: 12/25/2022] Open
Abstract
Expansins, cell-wall loosening proteins, play an important role in plant growth and development and abiotic stress tolerance. Ammopiptanthus nanus (A. nanus) is an important plant to study to understand stress resistance in forestry. In our previous study, two α-type expansins from A. nanus were cloned and named AnEXPA1 and AnEXPA2. In this study, we found that they responded to different abiotic stress and hormone signals. It suggests that they may play different roles in response to abiotic stress. Their promoters show some of the same element responses to abiotic stress and hormones, but some special elements were identified between the expansins that could be essential for their expression. In order to further testify the reliability of the above results, we conducted an analysis of β-glucuronidase (GUS) dyeing. The analysis showed that AnEXPA1 was only induced by cold stress, whereas AnEXPA2 responded to hormone induction. AnEXPA1 and AnEXPA2 transgenic Arabidopsis plants showed better tolerance to cold and drought stresses. Moreover, the ability to scavenge reactive oxygen species (ROS) was significantly improved in the transgenic plants, and expansin activity was enhanced. These results suggested that AnEXPA1 and AnEXPA2 play an important role in the response to abiotic stress. Our research contributes to a better understanding of the regulatory network of expansins and may benefit agricultural production.
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Molecular Insights into FaEG1, a Strawberry Endoglucanase Enzyme Expressed during Strawberry Fruit Ripening. PLANTS 2019; 8:plants8060140. [PMID: 31141938 PMCID: PMC6631567 DOI: 10.3390/plants8060140] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/18/2019] [Accepted: 05/25/2019] [Indexed: 01/04/2023]
Abstract
The endo-β-1,4-glucanases (EGs) that belong to the glycosyl hydrolase family 9 (GH9) have roles in cell wall synthesis, remodeling and degradation. Previous studies have suggested that EGs may play a key role in the ripening of different fruits including strawberries. In this study, we used reverse-transcription quantitative polymerase chain reaction (RT-qPCR) assays to determine the transcript accumulation of an endo-β-1,4-glucanase (FaEG1) during fruit development in two different strawberry ‘Camarosa’ and ‘Monterey’ with contrasting softening ratios. Phylogenetic analyses suggest that FaEG1 belongs to the α group of the GH9 family with other proteins previously described with roles in elongation, abscission and ripening. Comparative modeling was used to obtain the FaEG1 structure. The model displays a α-barrel–type structure that is typical of the GH9 enzyme family, and comprises 12 α-helices, 2 310 helices and 6 β-sheets. The catalytic residues were oriented to the solvent in the middle of an open groove. Protein–ligand interactions were explored with cellulose and two xyloglucans as ligands; the results suggest that the FaEG1-cellulose and FaEG1-XXXGXXXG (the most abundant xyloglucan in strawberries) complexes were more stable complexes than XXFGXXFG. The cell wall degradation was observed by scanning electron microscopy (SEM). The data are congruent with the probable role of the FaEG1 protein in the dissembly of the cellulose-hemicellulose fraction during the ripening of strawberry fruit.
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Moya-León MA, Mattus-Araya E, Herrera R. Molecular Events Occurring During Softening of Strawberry Fruit. FRONTIERS IN PLANT SCIENCE 2019; 10:615. [PMID: 31156678 PMCID: PMC6529986 DOI: 10.3389/fpls.2019.00615] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/25/2019] [Indexed: 05/08/2023]
Abstract
Changes in fruit texture taking place during ripening, described as softening, are mainly due to alterations in structure and/or composition of the cell wall. Several non-covalent interactions between the three carbohydrate polymers of the cell wall, cellulose, pectins and hemicellulose, and many structural proteins and ions, enable a complex structure. During softening, the disassembly of the cell wall structure takes place, mediated by a complete set of cell wall degrading enzymes or proteins. Softening is a coordinated event that requires the orchestrated participation of a wide variety of proteins. Plant hormones and a set of transcription factors are the organizers of this multi-protein effort. Strawberry is a non climacteric fruit that softens intensively during the last stages of development. The Chilean strawberry fruit (Fragaria chiloensis), the maternal relative of the commercial strawberry (F. × ananassa), softens even faster than commercial strawberry. Softening of the Chilean strawberry fruit has been studied at different levels: changes in cell wall polymers, activity of cell wall degrading enzymes and transcriptional changes of their genes, providing a general view of the complex process. The search for the 'orchestra director' that could coordinate softening events in strawberry fruit has been focussed on hormones like ABA and auxins, and more precisely the relation ABA/AUX. These hormones regulate the expression of many cell wall degrading enzyme genes, and this massive transcriptional change that takes place involves the participation of key transcriptional factors (TF). This review provides an update of the present knowledge regarding the softening of strawberry fruit. Nevertheless, the entire softening process is still under active research especially for the great influence of texture on fruit quality and its high impact on fruit shelf life, and therefore it is expected that new and promising information will illuminate the field in the near future.
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Affiliation(s)
| | | | - Raul Herrera
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
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