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Xiong M, Xu J, Zhou Z, Peng B, Shen Y, Shen H, Xu X, Li C, Deng L, Feng G. Salinity inhibits seed germination and embryo growth by reducing starch mobilization efficiency in barley. PLANT DIRECT 2024; 8:e564. [PMID: 38312996 PMCID: PMC10835642 DOI: 10.1002/pld3.564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/21/2023] [Accepted: 12/12/2023] [Indexed: 02/06/2024]
Abstract
Barley is one of the world's earliest domesticated crops, which is widely used for beer production, animal feeding, and health care. Barley seed germination, particularly in increasingly saline soils, is key to ensure the safety of crop production. However, the mechanism of salt-affected seed germination in barley remains elusive. Here, two different colored barley varieties were used to independently study the regulation mechanism of salt tolerance during barley seed germination. High salinity delays barley seed germination by slowing down starch mobilization efficiency in seeds. The starch plate test revealed that salinity had a significant inhibitory effect on α-amylase activity in barley seeds. Further, NaCl treatment down-regulated the expression of Amy1, Amy2 and Amy3 genes in germinated seeds, thereby inhibiting α-amylase activity. In addition, the result of embryogenic culture system in vitro showed that the shoot elongation of barley was significantly inhibited by salt stress. These findings indicate that it is a feasible idea to study the regulation mechanism of salinity on barley seed germination and embryo growth from the aspect of starch-related source-sink communication.
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Affiliation(s)
- Min Xiong
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Jian Xu
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Zhou Zhou
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Bin Peng
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Yuxiang Shen
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Huiquan Shen
- Jiangsu Coastal Area Institute of Agricultural SciencesYanchengJiangsuChina
| | - Xiao Xu
- Jiangsu Coastal Area Institute of Agricultural SciencesYanchengJiangsuChina
| | - Changya Li
- Yancheng Grain and Oil Crop Technical Guidance StationYanchengJiangsuChina
| | - Lina Deng
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Gongneng Feng
- College of Marine and Biology EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
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Xiong M, Yu J, Wang J, Gao Q, Huang L, Chen C, Zhang C, Fan X, Zhao D, Liu QQ, Li QF. Brassinosteroids regulate rice seed germination through the BZR1-RAmy3D transcriptional module. PLANT PHYSIOLOGY 2022; 189:402-418. [PMID: 35139229 PMCID: PMC9070845 DOI: 10.1093/plphys/kiac043] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/07/2022] [Indexed: 05/03/2023]
Abstract
Seed dormancy and germination, two physiological processes unique to seed-bearing plants, are critical for plant growth and crop production. The phytohormone brassinosteroid (BR) regulates many aspects of plant growth and development, including seed germination. The molecular mechanisms underlying BR control of rice (Oryza sativa) seed germination are mostly unknown. We investigated the molecular regulatory cascade of BR in promoting rice seed germination and post-germination growth. Physiological assays indicated that blocking BR signaling, including introducing defects into the BR-insensitive 1 (BRI1) receptor or overexpressing the glycogen synthase kinase 2 (GSK2) kinase delayed seed germination and suppressed embryo growth. Our results also indicated that brassinazole-resistant 1 (BZR1) is the key downstream transcription factor that mediates BR regulation of seed germination by binding to the alpha-Amylase 3D (RAmy3D) promoter, which affects α-amylase expression and activity and the degradation of starch in the endosperm. The BZR1-RAmy3D module functions independently from the established Gibberellin MYB-alpha-amylase 1A (RAmy1A) module of the gibberellin (GA) pathway. We demonstrate that the BZR1-RAmy3D module also functions in embryo-related tissues. Moreover, RNA-sequencing (RNA-seq) analysis identified more potential BZR1-responsive genes, including those involved in starch and sucrose metabolism. Our study successfully identified the role of the BZR1-RAmy3D transcriptional module in regulating rice seed germination.
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Affiliation(s)
| | | | | | - Qiang Gao
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Lichun Huang
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Chen Chen
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Changquan Zhang
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Xiaolei Fan
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Dongsheng Zhao
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China
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Herburger K, Franková L, Pičmanová M, Xin A, Meulewaeter F, Hudson A, Fry SC. Defining natural factors that stimulate and inhibit cellulose:xyloglucan hetero-transglucosylation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1549-1565. [PMID: 33314395 PMCID: PMC8611796 DOI: 10.1111/tpj.15131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/24/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Certain transglucanases can covalently graft cellulose and mixed-linkage β-glucan (MLG) as donor substrates onto xyloglucan as acceptor substrate and thus exhibit cellulose:xyloglucan endotransglucosylase (CXE) and MLG:xyloglucan endotransglucosylase (MXE) activities in vivo and in vitro. However, missing information on factors that stimulate or inhibit these hetero-transglucosylation reactions limits our insight into their biological functions. To explore factors that influence hetero-transglucosylation, we studied Equisetum fluviatile hetero-trans-β-glucanase (EfHTG), which exhibits both CXE and MXE activity, exceeding its xyloglucan:xyloglucan homo-transglucosylation (XET) activity. Enzyme assays employed radiolabelled and fluorescently labelled oligomeric acceptor substrates, and were conducted in vitro and in cell walls (in situ). With whole denatured Equisetum cell walls as donor substrate, exogenous EfHTG (extracted from Equisetum or produced in Pichia) exhibited all three activities (CXE, MXE, XET) in competition with each other. Acting on pure cellulose as donor substrate, the CXE action of Pichia-produced EfHTG was up to approximately 300% increased by addition of methanol-boiled Equisetum extracts; there was no similar effect when the same enzyme acted on soluble donors (MLG or xyloglucan). The methanol-stable factor is proposed to be expansin-like, a suggestion supported by observations of pH dependence. Screening numerous low-molecular-weight compounds for hetero-transglucanase inhibition showed that cellobiose was highly effective, inhibiting the abundant endogenous CXE and MXE (but not XET) action in Equisetum internodes. Furthermore, cellobiose retarded Equisetum stem elongation, potentially owing to its effect on hetero-transglucosylation reactions. This work provides insight and tools to further study the role of cellulose hetero-transglucosylation in planta by identifying factors that govern this reaction.
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Affiliation(s)
- Klaus Herburger
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
- Present address:
Section for Plant GlycobiologyDepartment of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg1871Denmark
| | - Lenka Franková
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Martina Pičmanová
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Anzhou Xin
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Frank Meulewaeter
- BBCC Innovation Center Gent – Trait ResearchBASFGent (Zwijnaarde)9052Belgium
| | - Andrew Hudson
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Stephen C. Fry
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
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Møller MS, Svensson B. Enzymes in grain processing. Curr Opin Food Sci 2021. [DOI: 10.1016/j.cofs.2020.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Rugen MD, Vernet MMJL, Hantouti L, Soenens A, Andriotis VME, Rejzek M, Brett P, van den Berg RJBHN, Aerts JMFG, Overkleeft HS, Field RA. A chemical genetic screen reveals that iminosugar inhibitors of plant glucosylceramide synthase inhibit root growth in Arabidopsis and cereals. Sci Rep 2018; 8:16421. [PMID: 30401902 PMCID: PMC6219604 DOI: 10.1038/s41598-018-34749-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/19/2018] [Indexed: 01/11/2023] Open
Abstract
Iminosugars are carbohydrate mimics that are useful as molecular probes to dissect metabolism in plants. To analyse the effects of iminosugar derivatives on germination and seedling growth, we screened a library of 390 N-substituted iminosugar analogues against Arabidopsis and the small cereal Eragrostis tef (Tef). The most potent compound identified in both systems, N-5-(adamantane-1-yl-ethoxy)pentyl- L-ido-deoxynojirimycin (L-ido-AEP-DNJ), inhibited root growth in agar plate assays by 92% and 96% in Arabidopsis and Tef respectively, at 10 µM concentration. Phenocopying the effect of L-ido-AEP-DNJ with the commercial inhibitor (PDMP) implicated glucosylceramide synthase as the target responsible for root growth inhibition. L-ido-AEP-DNJ was twenty-fold more potent than PDMP. Liquid chromatography-mass spectrometry (LC-MS) analysis of ceramide:glucosylceramide ratios in inhibitor-treated Arabidopsis seedlings showed a decrease in the relative quantity of the latter, confirming that glucosylceramide synthesis is perturbed in inhibitor-treated plants. Bioinformatic analysis of glucosylceramide synthase indicates gene conservation across higher plants. Previous T-DNA insertional inactivation of glucosylceramide synthase in Arabidopsis caused seedling lethality, indicating a role in growth and development. The compounds identified herein represent chemical alternatives that can overcome issues caused by genetic intervention. These inhibitors offer the potential to dissect the roles of glucosylceramides in polyploid crop species.
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Affiliation(s)
- Michael D Rugen
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Mathieu M J L Vernet
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Laila Hantouti
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Amalia Soenens
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Vasilios M E Andriotis
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- School of Natural and Environmental Sciences, Devonshire Building, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Paul Brett
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Richard J B H N van den Berg
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Johannes M F G Aerts
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands
| | - Hermen S Overkleeft
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
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Noronha H, Silva A, Dai Z, Gallusci P, Rombolà AD, Delrot S, Gerós H. A molecular perspective on starch metabolism in woody tissues. PLANTA 2018; 248:559-568. [PMID: 30022278 PMCID: PMC6096779 DOI: 10.1007/s00425-018-2954-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 07/11/2018] [Indexed: 05/20/2023]
Abstract
MAIN CONCLUSION The elucidation of the molecular mechanisms of starch synthesis and mobilization in perennial woody tissues is of the utmost scientific and agricultural importance. Starch is the main carbohydrate reserve in plants and is fundamental in human nutrition and several industrial processes. In leaves, starch accumulated during the day is degraded throughout the night and the resulting sugars, glucose and maltose, are exported to the cytosol by the specialized transmembrane translocators pGT and MEX, respectively. Nevertheless, the degradation of the starch granule is a complex process not completely elucidated. While the mechanisms of starch mobilization during germination in the dead endosperm of cereal seeds are well described, the molecular and biochemical mechanisms involved in starch storage in the heterotrophic tissues of woody plants and its utilization in spring and winter are still puzzling. It is known that some biochemical steps of starch synthesis are conserved in heterotrophic tissues and in the leaves, but some aspects are particular to sink organs. From an agronomic standpoint, the knowledge on starch storage and mobilization in woody tissues is pivotal to understand (and to optimize) some common practices in the field that modify source-sink relationships, such as pruning and defoliation. Soluble sugars resulting from starch are also pivotal to cold adaptation, and in several fruits, such as banana and kiwifruit, starch may provide soluble sugars during ripening. In this review, we explore the recent advances on the molecular mechanisms and regulations involved in starch synthesis and mobilization, with a focus on perennial woody tissues.
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Affiliation(s)
- Henrique Noronha
- Centre of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal
| | - Angélica Silva
- Centre of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal
| | - Zhanwu Dai
- UMR EGFV, Bordeaux Science Agro, INRA, Université de Bordeaux, Villenave D'Ornon, France
| | - Philippe Gallusci
- UMR EGFV, Bordeaux Science Agro, INRA, Université de Bordeaux, Villenave D'Ornon, France
| | - Adamo D Rombolà
- Department of Agricultural Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Serge Delrot
- UMR EGFV, Bordeaux Science Agro, INRA, Université de Bordeaux, Villenave D'Ornon, France
| | - Hernâni Gerós
- Centre of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal.
- Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas (CITAB), Vila Real, Portugal.
- Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal.
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Rugen MD, Rejzek M, Naested H, Svensson B, Field RA. High-Throughput In Vitro Screening for Inhibitors of Cereal α-Glucosidase. Methods Mol Biol 2018; 1795:101-115. [PMID: 29846922 DOI: 10.1007/978-1-4939-7874-8_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The hydrolysis of starch is a key step in plant germination, which also has relevance in the malting and brewing processes for beer and spirit production. Gaps in knowledge about this metabolic process exist that cannot easily be addressed using traditional genetic techniques, due to functional redundancy in many of the enzyme activities required for alpha-glucan metabolism in cereal crop species. Chemical inhibitors provide opportunities to probe the role of carbohydrate-active enzymes and the phenotypes associated with inhibition of specific enzymes. Iminosugars are the largest group of carbohydrate-active enzyme inhibitors and represent an underused resource for the dissection of plant carbohydrate metabolism. Herein we report a method for carrying out a reverse chemical genetic screen on α-glucosidase, the enzyme that catalyzes the final step in starch degradation during plant germination, namely the hydrolysis of maltose to release glucose. This chapter outlines the use of a high-throughput screen of small molecules for inhibition of α-glucosidase using a colorimetric assay which involves the substrate p-nitrophenyl α-D-glucopyranoside. Identified inhibitors can be further utilized in phenotypic screens to probe the roles played by amylolytic enzymes. Furthermore this 96-well plate-based method can be adapted to assay exo-glycosidase activities involved in other aspects of carbohydrate metabolism.
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Affiliation(s)
- Michael D Rugen
- Department of Biological Chemistry, John Innes Centre, Norwich, UK
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich, UK
| | - Henrik Naested
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich, UK.
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