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Chandler JO, Wilhelmsson PKI, Fernandez-Pozo N, Graeber K, Arshad W, Pérez M, Steinbrecher T, Ullrich KK, Nguyen TP, Mérai Z, Mummenhoff K, Theißen G, Strnad M, Scheid OM, Schranz ME, Petřík I, Tarkowská D, Novák O, Rensing SA, Leubner-Metzger G. The dimorphic diaspore model Aethionema arabicum (Brassicaceae): Distinct molecular and morphological control of responses to parental and germination temperatures. THE PLANT CELL 2024; 36:2465-2490. [PMID: 38513609 PMCID: PMC11218780 DOI: 10.1093/plcell/koae085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 03/23/2024]
Abstract
Plants in habitats with unpredictable conditions often have diversified bet-hedging strategies that ensure fitness over a wider range of variable environmental factors. A striking example is the diaspore (seed and fruit) heteromorphism that evolved to maximize species survival in Aethionema arabicum (Brassicaceae) in which external and endogenous triggers allow the production of two distinct diaspores on the same plant. Using this dimorphic diaspore model, we identified contrasting molecular, biophysical, and ecophysiological mechanisms in the germination responses to different temperatures of the mucilaginous seeds (M+ seed morphs), the dispersed indehiscent fruits (IND fruit morphs), and the bare non-mucilaginous M- seeds obtained by pericarp (fruit coat) removal from IND fruits. Large-scale comparative transcriptome and hormone analyses of M+ seeds, IND fruits, and M- seeds provided comprehensive datasets for their distinct thermal responses. Morph-specific differences in co-expressed gene modules in seeds, as well as in seed and pericarp hormone contents, identified a role of the IND pericarp in imposing coat dormancy by generating hypoxia affecting abscisic acid (ABA) sensitivity. This involved expression of morph-specific transcription factors, hypoxia response, and cell wall remodeling genes, as well as altered ABA metabolism, transport, and signaling. Parental temperature affected ABA contents and ABA-related gene expression and altered IND pericarp biomechanical properties. Elucidating the molecular framework underlying the diaspore heteromorphism can provide insight into developmental responses to globally changing temperatures.
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Affiliation(s)
- Jake O Chandler
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Per K I Wilhelmsson
- Plant Cell Biology, Faculty of Biology, University of Marburg, Marburg 35043, Germany
| | - Noe Fernandez-Pozo
- Plant Cell Biology, Faculty of Biology, University of Marburg, Marburg 35043, Germany
- Institute for Mediterranean and Subtropical Horticulture “La Mayora” (IHSM-CSIC-UMA), Málaga 29010, Spain
| | - Kai Graeber
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Waheed Arshad
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Marta Pérez
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Tina Steinbrecher
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Kristian K Ullrich
- Plant Cell Biology, Faculty of Biology, University of Marburg, Marburg 35043, Germany
| | - Thu-Phuong Nguyen
- Biosystematics Group, Wageningen University, PB Wageningen 6708, The Netherlands
| | - Zsuzsanna Mérai
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna 1030, Austria
| | - Klaus Mummenhoff
- Department of Biology, Botany, University of Osnabrück, Osnabrück 49076, Germany
| | - Günter Theißen
- Matthias Schleiden Institute/Department of Genetics, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc 78371, Czech Republic
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna 1030, Austria
| | - M Eric Schranz
- Biosystematics Group, Wageningen University, PB Wageningen 6708, The Netherlands
| | - Ivan Petřík
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc 78371, Czech Republic
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc 78371, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc 78371, Czech Republic
| | - Stefan A Rensing
- Plant Cell Biology, Faculty of Biology, University of Marburg, Marburg 35043, Germany
- Centre for Biological Signalling Studies (BIOSS), University of Freiburg, Freiburg 79104, Germany
| | - Gerhard Leubner-Metzger
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc 78371, Czech Republic
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2
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Wang Y, Sun X, Peng J, Li F, Ali F, Wang Z. Regulation of seed germination: ROS, epigenetic, and hormonal aspects. J Adv Res 2024:S2090-1232(24)00225-X. [PMID: 38838783 DOI: 10.1016/j.jare.2024.06.001] [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: 03/01/2024] [Revised: 05/31/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND The whole life of a plant is regulated by complex environmental or hormonal signaling networks that control genomic stability, environmental signal transduction, and gene expression affecting plant development and viability. Seed germination, responsible for the transformation from seed to seedling, is a key initiation step in plant growth and is controlled by unique physiological and biochemical processes. It is continuously modulated by various factors including epigenetic modifications, hormone transport, ROS signaling, and interaction among them. ROS showed versatile crucial functions in seed germination including various physiological oxidations to nucleic acid, protein, lipid, or chromatin in the cytoplasm, cell wall, and nucleus. AIM of review: This review intends to provide novel insights into underlying mechanisms of seed germination especially associated with the ROS, and considers how these versatile regulatory mechanisms can be developed as useful tools for crop improvement. KEY SCIENTIFIC CONCEPTS OF REVIEW We have summarized the generation and elimination of ROS during seed germination, with a specific focus on uncovering and understanding the mechanisms of seed germination at the level of phytohormones, ROS, and epigenetic switches, as well as the close connections between them. The findings exhibit that ROS plays multiple roles in regulating the ethylene, ABA, and GA homeostasis as well as the Ca2+ signaling, NO signaling, and MAPK cascade in seed germination via either the signal trigger or the oxidative modifier agent. Further, ROS shows the potential in the nuclear genome remodeling and some epigenetic modifiers function, although the detailed mechanisms are unclear in seed germination. We propose that ROS functions as a hub in the complex network regulating seed germination.
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Affiliation(s)
- Yakong Wang
- Zhengzhou Research Base, State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Zhengzhou University, Zhengzhou 450001, China; State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Xiangyang Sun
- Zhengzhou Research Base, State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Zhengzhou University, Zhengzhou 450001, China
| | - Jun Peng
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, Hainan, China; State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Fuguang Li
- Zhengzhou Research Base, State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Zhengzhou University, Zhengzhou 450001, China; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, Hainan, China
| | - Faiza Ali
- Zhengzhou Research Base, State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Zhengzhou University, Zhengzhou 450001, China.
| | - Zhi Wang
- Zhengzhou Research Base, State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Zhengzhou University, Zhengzhou 450001, China; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, Hainan, China; State Key Laboratory of Cotton Bio‑breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China.
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3
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Sajeev N, Koornneef M, Bentsink L. A commitment for life: Decades of unraveling the molecular mechanisms behind seed dormancy and germination. THE PLANT CELL 2024; 36:1358-1376. [PMID: 38215009 PMCID: PMC11062444 DOI: 10.1093/plcell/koad328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/19/2023] [Indexed: 01/14/2024]
Abstract
Seeds are unique time capsules that can switch between 2 complex and highly interlinked stages: seed dormancy and germination. Dormancy contributes to the survival of plants because it allows to delay germination to optimal conditions. The switch between dormancy and germination occurs in response to developmental and environmental cues. In this review we provide a comprehensive overview of studies that have helped to unravel the molecular mechanisms underlying dormancy and germination over the last decades. Genetic and physiological studies provided a strong foundation for this field of research and revealed the critical role of the plant hormones abscisic acid and gibberellins in the regulation of dormancy and germination, and later natural variation studies together with quantitative genetics identified previously unknown genetic components that control these processes. Omics technologies like transcriptome, proteome, and translatomics analysis allowed us to mechanistically dissect these processes and identify new components in the regulation of seed dormancy and germination.
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Affiliation(s)
- Nikita Sajeev
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, 6708PB Wageningen, the Netherlands
| | - Maarten Koornneef
- Laboratory of Genetics, Wageningen University, 6708PB Wageningen, the Netherlands
- Max Planck Institute for Plant Breeding Research, Former Department of Plant Breeding and Genetics, Koeln 50829, Germany
| | - Leónie Bentsink
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, 6708PB Wageningen, the Netherlands
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4
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Krzyszton M, Sacharowski SP, Manjunath VH, Muter K, Bokota G, Wang C, Plewczyński D, Dobisova T, Swiezewski S. Dormancy heterogeneity among Arabidopsis thaliana seeds is linked to individual seed size. PLANT COMMUNICATIONS 2024; 5:100732. [PMID: 37828740 PMCID: PMC10873894 DOI: 10.1016/j.xplc.2023.100732] [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: 07/21/2023] [Revised: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023]
Abstract
Production of morphologically and physiologically variable seeds is an important strategy that helps plants to survive in unpredictable natural conditions. However, the model plant Arabidopsis thaliana and most agronomically essential crops produce visually homogenous seeds. Using automated phenotype analysis, we observed that small seeds in Arabidopsis tend to have higher primary and secondary dormancy levels than large seeds. Transcriptomic analysis revealed distinct gene expression profiles between large and small seeds. Large seeds have higher expression of translation-related genes implicated in germination competence. By contrast, small seeds have elevated expression of many positive regulators of dormancy, including a key regulator of this process, the DOG1 gene. Differences in DOG1 expression are associated with differential production of its alternative cleavage and polyadenylation isoforms; in small seeds, the proximal poly(A) site is selected, resulting in a short mRNA isoform. Furthermore, single-seed RNA sequencing analysis demonstrated that large seeds resemble DOG1 knockout mutant seeds. Finally, on the single-seed level, expression of genes affected by seed size is correlated with expression of genes that position seeds on the path toward germination. Our results demonstrate an unexpected link between seed size and dormancy phenotypes in a species that produces highly homogenous seed pools, suggesting that the correlation between seed morphology and physiology is more widespread than initially assumed.
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Affiliation(s)
- Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland.
| | - Sebastian P Sacharowski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland
| | - Veena Halale Manjunath
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland
| | - Katarzyna Muter
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland
| | - Grzegorz Bokota
- Laboratory of Functional and Structural Genomics, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Ce Wang
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland
| | - Dariusz Plewczyński
- Laboratory of Functional and Structural Genomics, Centre of New Technologies, University of Warsaw, Warsaw, Poland; Laboratory of Bioinformatics and Computational Genomics, Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland
| | | | - Szymon Swiezewski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, 02-106 Warsaw, Poland.
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5
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Vollmeister E, Phokas A, Meyberg R, Böhm CV, Peter M, Kohnert E, Yuan J, Grosche C, Göttig M, Ullrich KK, Perroud PF, Hiltbrunner A, Kreutz C, Coates JC, Rensing SA. A DELAY OF GERMINATION 1 (DOG1)-like protein regulates spore germination in the moss Physcomitrium patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:909-923. [PMID: 37953711 DOI: 10.1111/tpj.16537] [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: 11/12/2022] [Revised: 10/22/2023] [Accepted: 10/26/2023] [Indexed: 11/14/2023]
Abstract
DELAY OF GERMINATION 1 is a key regulator of dormancy in flowering plants before seed germination. Bryophytes develop haploid spores with an analogous function to seeds. Here, we investigate whether DOG1 function during germination is conserved between bryophytes and flowering plants and analyse the underlying mechanism of DOG1 action in the moss Physcomitrium patens. Phylogenetic and in silico expression analyses were performed to identify and characterise DOG1 domain-containing genes in P. patens. Germination assays were performed to characterise a Ppdog1-like1 mutant, and replacement with AtDOG1 was carried out. Yeast two-hybrid assays were used to test the interaction of the PpDOG1-like protein with DELLA proteins from P. patens and A. thaliana. P. patens possesses nine DOG1 domain-containing genes. The DOG1-like protein PpDOG1-L1 (Pp3c3_9650) interacts with PpDELLAa and PpDELLAb and the A. thaliana DELLA protein AtRGA in yeast. Protein truncations revealed the DOG1 domain as necessary and sufficient for interaction with PpDELLA proteins. Spores of Ppdog1-l1 mutant germinate faster than wild type, but replacement with AtDOG1 reverses this effect. Our data demonstrate a role for the PpDOG1-LIKE1 protein in moss spore germination, possibly alongside PpDELLAs. This suggests a conserved DOG1 domain function in germination, albeit with differential adaptation of regulatory networks in seed and spore germination.
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Affiliation(s)
- Evelyn Vollmeister
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Alexandros Phokas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Rabea Meyberg
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Clemens V Böhm
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Marlies Peter
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Eva Kohnert
- Institute of Medical Biometry and Statistics, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, 79104, Germany
| | - Jinhong Yuan
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Christopher Grosche
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Marco Göttig
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | - Kristian K Ullrich
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | | | - Andreas Hiltbrunner
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Germany
| | - Clemens Kreutz
- Institute of Medical Biometry and Statistics, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, 79104, Germany
| | - Juliet C Coates
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Stefan A Rensing
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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6
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Otani M, Zheng L, Kawakami N. Genetic, Epigenetic, and Environmental Control of Seed Dormancy and Germination. Methods Mol Biol 2024; 2830:3-12. [PMID: 38977563 DOI: 10.1007/978-1-0716-3965-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Seed germination is controlled by a combination of the seed dormancy level and environmental conditions such as light, temperature, moisture, and nitrate levels. Seed dormancy is programed genetically, but it is also sensitive to maternal environmental conditions before and after anthesis. Recent developments in molecular genetics and bioinformatics have greatly enhanced our understanding of the molecular mechanisms of seed dormancy and germination in model plants and economically important crop species. This chapter focuses on temperature as an environmental factor and discusses the genetic and epigenetic mechanisms of dormancy and germination.
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Affiliation(s)
- Masahiko Otani
- Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan
- Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, Kawasaki, Japan
| | - Lipeng Zheng
- Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, China
| | - Naoto Kawakami
- Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan.
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7
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Liu S, Li L, Wang W, Xia G, Liu S. TaSRO1 interacts with TaVP1 to modulate seed dormancy and pre-harvest sprouting resistance in wheat. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:36-53. [PMID: 38108123 DOI: 10.1111/jipb.13600] [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: 10/14/2023] [Accepted: 12/15/2023] [Indexed: 12/19/2023]
Abstract
Dormancy is an adaptive trait which prevents seeds from germinating under unfavorable environmental conditions. Seeds with weak dormancy undergo pre-harvest sprouting (PHS) which decreases grain yield and quality. Understanding the genetic mechanisms that regulate seed dormancy and resistance to PHS is crucial for ensuring global food security. In this study, we illustrated the function and molecular mechanism of TaSRO1 in the regulation of seed dormancy and PHS resistance by suppressing TaVP1. The tasro1 mutants exhibited strong seed dormancy and enhanced resistance to PHS, whereas the mutants of tavp1 displayed weak dormancy. Genetic evidence has shown that TaVP1 is epistatic to TaSRO1. Biochemical evidence has shown that TaSRO1 interacts with TaVP1 and represses the transcriptional activation of the PHS resistance genes TaPHS1 and TaSdr. Furthermore, TaSRO1 undermines the synergistic activation of TaVP1 and TaABI5 in PHS resistance genes. Finally, we highlight the great potential of tasro1 alleles for breeding elite wheat cultivars that are resistant to PHS.
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Affiliation(s)
- Shupeng Liu
- Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China
| | - Li Li
- Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China
| | - Wenlong Wang
- Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China
| | - Guangmin Xia
- Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China
| | - Shuwei Liu
- Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China
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8
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Ma X, Feng L, Tao A, Zenda T, He Y, Zhang D, Duan H, Tao Y. Identification and validation of seed dormancy loci and candidate genes and construction of regulatory networks by WGCNA in maize introgression lines. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:259. [PMID: 38038768 DOI: 10.1007/s00122-023-04495-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023]
Abstract
KEY MESSAGE Seventeen PHS-QTLs and candidate genes were obtained, including eleven major loci, three under multiple environments and two with co-localization by the other mapping methods; The functions of three candidate genes were validated using mutants; nine target proteins and five networks were filtered by joint analysis of GWAS and WGCNA. Seed dormancy (SD) and pre-harvest sprouting (PHS) affect yield, as well as grain and hybrid quality in seed production. Therefore, identification of genetic and regulatory pathways underlying PHS and SD is key to gene function analysis, allelic variation mining and genetic improvement. In this study, 78,360 SNPs by SLAF-seq of 230 maize chromosome segment introgression lines (ILs), PHS under five environments were used to conduct GWAS (genome wide association study) (a threshold of 1/n), and seventeen unreported PHS QTLs were obtained, including eleven QTLs with PVE > 10% and three QTLs under multiple environments. Two QTL loci were co-located between the other two genetic mapping methods. Using differential gene expression analyses at two stages of grain development, gene functional analysis of Arabidopsis mutants, and gene functional analysis in the QTL region, seventeen PHS QTL-linked candidate genes were identified, and their five molecular regulatory networks constructed. Based on the Arabidopsis T-DNA mutations, three candidate genes were shown to regulate for SD and PHS. Meanwhile, using RNA-seq of grain development, the weighted correlation network analysis (WGCNA) was performed, deducing five regulatory pathways and target genes that regulate PHS and SD. Based on the conjoint analysis of GWAS and WGCNA, four pathways, nine target proteins and target genes were revealed, most of which regulate cell wall metabolism, cell proliferation and seed dehydration tolerance. This has important theoretical and practical significance for elucidating the genetic basis of maize PHS and SD, as well as mining of genetic resources and genetic improvement of traits.
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Affiliation(s)
- Xiaolin Ma
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Liqing Feng
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Anyan Tao
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Tinashe Zenda
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Yuan He
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Daxiao Zhang
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China
| | - Huijun Duan
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China.
| | - Yongsheng Tao
- State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, College of Agronomy, Hebei Agricultural University, Baoding, 071001, China.
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9
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Wang J, Wang XY, Pan W, Li JY, Xue L, Li S. Seed germination traits and dormancy classification of 27 species from a degraded karst mountain in central Yunnan-Guizhou Plateau: seed mass and moisture content correlate with germination capacity. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1043-1056. [PMID: 35793164 DOI: 10.1111/plb.13451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
In degraded karst ecosystem, vegetation restoration efforts almost exclusively rely on planted seedlings, but this is not effective to maintain community diversity and resilience. As seed functional traits, seed dormancy and germination are key to community assembly. Unfortunately, these elements are commonly overlooked in restoring degraded ecosystems. This work classifies seed dormancy of 27 species with different life forms that are common on a degraded karst mountain. We examined the effects of temperature regime and light conditions on percentage germination and assessed the relationships between seed traits and germination index using a partial least squares regression (PLSR). Approximately 48% of the investigated species had physiological dormancy, 37% were non-dormant, 7% had morphophysiological dormancy, 4% had morphological dormancy and 4% had physical dormancy. We found that 94% (15 out of 16) species had maximum germination in warm temperature regimes (20/13 and 25/18 °C), while the remaining species required cool temperatures (10/4 °C). PLSR analysis indicated a significant positive correlation between seed mass and T50m (time to 50% final germination), and a negative correlation between seed moisture content and percentage germination. Our findings indicate that seed traits are important factors in seed-based restoration practice. F. esculentum, O. opipara, P. fortuneana and S. salicifolia are recommended for direct seeding during the early rainy season to restore seriously degraded lands in subtropical karst regions.
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Affiliation(s)
- J Wang
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, China
- Observation and Research Station for Rock Desert Ecosystem, Puding, China
| | - X Y Wang
- Chun'an County Forestry Administration, Hangzhou, China
| | - W Pan
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, China
| | - J Y Li
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, China
| | - L Xue
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, China
- Observation and Research Station for Rock Desert Ecosystem, Puding, China
| | - S Li
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, China
- Observation and Research Station for Rock Desert Ecosystem, Puding, China
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10
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Krzyszton M, Yatusevich R, Wrona M, Sacharowski SP, Adamska D, Swiezewski S. Single seeds exhibit transcriptional heterogeneity during secondary dormancy induction. PLANT PHYSIOLOGY 2022; 190:211-225. [PMID: 35670742 PMCID: PMC9438484 DOI: 10.1093/plphys/kiac265] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Seeds are highly resilient to the external environment, which allows plants to persist in unpredictable and unfavorable conditions. Some plant species have adopted a bet-hedging strategy to germinate a variable fraction of seeds in any given condition, and this could be explained by population-based threshold models. Here, in the model plant Arabidopsis (Arabidopsis thaliana), we induced secondary dormancy (SD) to address the transcriptional heterogeneity among seeds that leads to binary germination/nongermination outcomes. We developed a single-seed RNA-seq strategy that allowed us to observe a reduction in seed transcriptional heterogeneity as seeds enter stress conditions, followed by an increase during recovery. We identified groups of genes whose expression showed a specific pattern through a time course and used these groups to position the individual seeds along the transcriptional gradient of germination competence. In agreement, transcriptomes of dormancy-deficient seeds (mutant of DELAY OF GERMINATION 1) showed a shift toward higher values of the germination competence index. Interestingly, a significant fraction of genes with variable expression encoded translation-related factors. In summary, interrogating hundreds of single-seed transcriptomes during SD-inducing treatment revealed variability among the transcriptomes that could result from the distribution of population-based sensitivity thresholds. Our results also showed that single-seed RNA-seq is the method of choice for analyzing seed bet-hedging-related phenomena.
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Affiliation(s)
| | | | - Magdalena Wrona
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, Warsaw 02-106, Poland
| | - Sebastian P Sacharowski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, PAS, Warsaw 02-106, Poland
| | - Dorota Adamska
- Genomics Core Facility, Centre of New Technologies, University of Warsaw, Warsaw 02-097, Poland
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11
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Iwasaki M, Penfield S, Lopez-Molina L. Parental and Environmental Control of Seed Dormancy in Arabidopsis thaliana. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:355-378. [PMID: 35138879 DOI: 10.1146/annurev-arplant-102820-090750] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Seed dormancy-the absence of seed germination under favorable germination conditions-is a plant trait that evolved to enhance seedling survival by avoiding germination under unsuitable environmental conditions. In Arabidopsis, dormancy levels are influenced by the seed coat composition, while the endosperm is essential to repress seed germination of dormant seeds upon their imbibition. Recent research has shown that the mother plant modulates its progeny seed dormancy in response to seasonal temperature changes by changing specific aspects of seed coat and endosperm development. This process involves genomic imprinting by means of epigenetic marks deposited in the seed progeny and regulators previously known to regulate flowering time. This review discusses and summarizes these discoveries and provides an update on our present understanding of the role of DOG1 and abscisic acid, two key contributors to dormancy.
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Affiliation(s)
- Mayumi Iwasaki
- Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland;
| | - Steven Penfield
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Luis Lopez-Molina
- Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland;
- Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
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12
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Batlla D, Malavert C, Farnocchia RBF, Footitt S, Benech-Arnold RL, Finch-Savage WE. A quantitative analysis of temperature-dependent seasonal dormancy cycling in buried Arabidopsis thaliana seeds can predict seedling emergence in a global warming scenario. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2454-2468. [PMID: 35106531 DOI: 10.1093/jxb/erac038] [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: 10/22/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Understanding how the environment regulates seed-bank dormancy changes is essential for forecasting seedling emergence in actual and future climatic scenarios, and to interpret studies of dormancy mechanisms at physiological and molecular levels. Here, we used a population threshold modelling approach to analyse dormancy changes through variations in the thermal range permissive for germination in buried seeds of Arabidopsis thaliana Cvi, a winter annual ecotype. Results showed that changes in dormancy level were mainly associated with variations in the higher limit of the thermal range permissive for germination. Changes in this limit were positively related to soil temperature during dormancy release and induction, and could be predicted using thermal time. From this, we developed a temperature-driven simulation to predict the fraction of the seed bank able to germinate in a realistic global warming scenario that approximated seedling emergence timing. Simulations predicted, in accordance with seedling emergence observed in the field, an increase in the fraction of the seed bank able to emerge as a result of global warming. In addition, our results suggest that buried seeds perceive changes in the variability of the mean daily soil temperature as the signal to change between dormancy release and induction according to the seasons.
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Affiliation(s)
- Diego Batlla
- Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Producción Vegetal, Cátedra de Cerealicultura, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología y Ecología Vinculado a la Agricultura, Consejo Nacional de Investigaciones Científicas y Técnicas (IFEVA-CONICET), Ciudad de Buenos Aires, Argentina
| | - Cristian Malavert
- Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Producción Vegetal, Cátedra de Cultivos Industriales, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología y Ecología Vinculado a la Agricultura, Consejo Nacional de Investigaciones Científicas y Técnicas (IFEVA-CONICET), Ciudad de Buenos Aires, Argentina
| | - Rocío Belén Fernández Farnocchia
- Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Producción Vegetal, Cátedra de Cultivos Industriales, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología y Ecología Vinculado a la Agricultura, Consejo Nacional de Investigaciones Científicas y Técnicas (IFEVA-CONICET), Ciudad de Buenos Aires, Argentina
| | - Steven Footitt
- Department of Molecular Biology and Genetics, Boğaziçi University, Bebek, Istanbul, Turkey
| | - Roberto Luis Benech-Arnold
- Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Producción Vegetal, Cátedra de Cultivos Industriales, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología y Ecología Vinculado a la Agricultura, Consejo Nacional de Investigaciones Científicas y Técnicas (IFEVA-CONICET), Ciudad de Buenos Aires, Argentina
| | - William E Finch-Savage
- School of Life Sciences, University of Warwick, Wellesbourne Campus, Warwickshire CV35 9EF, UK
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13
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Hourston JE, Steinbrecher T, Chandler JO, Pérez M, Dietrich K, Turečková V, Tarkowská D, Strnad M, Weltmeier F, Meinhard J, Fischer U, Fiedler‐Wiechers K, Ignatz M, Leubner‐Metzger G. Cold-induced secondary dormancy and its regulatory mechanisms in Beta vulgaris. PLANT, CELL & ENVIRONMENT 2022; 45:1315-1332. [PMID: 35064681 PMCID: PMC9305896 DOI: 10.1111/pce.14264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 10/26/2021] [Accepted: 11/18/2021] [Indexed: 06/14/2023]
Abstract
The dynamic behaviour of seeds in soil seed banks depends on their ability to act as sophisticated environmental sensors to adjust their sensitivity thresholds for germination by dormancy mechanisms. Here we show that prolonged incubation of sugar beet fruits at low temperature (chilling at 5°C, generally known to release seed dormancy of many species) can induce secondary nondeep physiological dormancy of an apparently nondormant crop species. The physiological and biophysical mechanisms underpinning this cold-induced secondary dormancy include the chilling-induced accumulation of abscisic acid in the seeds, a reduction in the embryo growth potential and a block in weakening of the endosperm covering the embryonic root. Transcriptome analysis revealed distinct gene expression patterns in the different temperature regimes and upon secondary dormancy induction and maintenance. The chilling caused reduced expression of cell wall remodelling protein genes required for embryo cell elongation growth and endosperm weakening, as well as increased expression of seed maturation genes, such as for late embryogenesis abundant proteins. A model integrating the hormonal signalling and master regulator expression with the temperature-control of seed dormancy and maturation programmes is proposed. The revealed mechanisms of the cold-induced secondary dormancy are important for climate-smart agriculture and food security.
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Affiliation(s)
- James E. Hourston
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Tina Steinbrecher
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Jake O. Chandler
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Marta Pérez
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | | | - Veronika Turečková
- Laboratory of Growth Regulators, Palacký University and Institute of Experimental BotanyCzech Academy of SciencesOlomoucCzech Republic
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Palacký University and Institute of Experimental BotanyCzech Academy of SciencesOlomoucCzech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Palacký University and Institute of Experimental BotanyCzech Academy of SciencesOlomoucCzech Republic
| | | | | | | | | | - Michael Ignatz
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Gerhard Leubner‐Metzger
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
- Laboratory of Growth Regulators, Palacký University and Institute of Experimental BotanyCzech Academy of SciencesOlomoucCzech Republic
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14
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Seed germination and vigor: ensuring crop sustainability in a changing climate. Heredity (Edinb) 2022; 128:450-459. [PMID: 35013549 DOI: 10.1038/s41437-022-00497-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 12/29/2021] [Accepted: 01/02/2022] [Indexed: 11/08/2022] Open
Abstract
In the coming decades, maintaining a steady food supply for the increasing world population will require high-yielding crop plants which can be productive under increasingly variable conditions. Maintaining high yields will require the successful and uniform establishment of plants in the field under altered environmental conditions. Seed vigor, a complex agronomic trait that includes seed longevity, germination speed, seedling growth, and early stress tolerance, determines the duration and success of this establishment period. Elevated temperature during early seed development can decrease seed size, number, and fertility, delay germination and reduce seed vigor in crops such as cereals, legumes, and vegetable crops. Heat stress in mature seeds can reduce seed vigor in crops such as lettuce, oat, and chickpea. Warming trends and increasing temperature variability can increase seed dormancy and reduce germination rates, especially in crops that require lower temperatures for germination and seedling establishment. To improve seed germination speed and success, much research has focused on selecting quality seeds for replanting, priming seeds before sowing, and breeding varieties with improved seed performance. Recent strides in understanding the genetic basis of variation in seed vigor have used genomics and transcriptomics to identify candidate genes for improving germination, and several studies have explored the potential impact of climate change on the percentage and timing of germination. In this review, we discuss these recent advances in the genetic underpinnings of seed performance as well as how climate change is expected to affect vigor in current varieties of staple, vegetable, and other crops.
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15
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Smolikova G, Strygina K, Krylova E, Leonova T, Frolov A, Khlestkina E, Medvedev S. Transition from Seeds to Seedlings: Hormonal and Epigenetic Aspects. PLANTS (BASEL, SWITZERLAND) 2021; 10:1884. [PMID: 34579418 PMCID: PMC8467299 DOI: 10.3390/plants10091884] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 01/21/2023]
Abstract
Transition from seed to seedling is one of the critical developmental steps, dramatically affecting plant growth and viability. Before plants enter the vegetative phase of their ontogenesis, massive rearrangements of signaling pathways and switching of gene expression programs are required. This results in suppression of the genes controlling seed maturation and activation of those involved in regulation of vegetative growth. At the level of hormonal regulation, these events are controlled by the balance of abscisic acid and gibberellins, although ethylene, auxins, brassinosteroids, cytokinins, and jasmonates are also involved. The key players include the members of the LAFL network-the transcription factors LEAFY COTYLEDON1 and 2 (LEC 1 and 2), ABSCISIC ACID INSENSITIVE3 (ABI3), and FUSCA3 (FUS3), as well as DELAY OF GERMINATION1 (DOG1). They are the negative regulators of seed germination and need to be suppressed before seedling development can be initiated. This repressive signal is mediated by chromatin remodeling complexes-POLYCOMB REPRESSIVE COMPLEX 1 and 2 (PRC1 and PRC2), as well as PICKLE (PKL) and PICKLE-RELATED2 (PKR2) proteins. Finally, epigenetic methylation of cytosine residues in DNA, histone post-translational modifications, and post-transcriptional downregulation of seed maturation genes with miRNA are discussed. Here, we summarize recent updates in the study of hormonal and epigenetic switches involved in regulation of the transition from seed germination to the post-germination stage.
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Affiliation(s)
- Galina Smolikova
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia;
| | - Ksenia Strygina
- Postgenomic Studies Laboratory, Federal Research Center N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190121 St. Petersburg, Russia; (K.S.); (E.K.); (E.K.)
| | - Ekaterina Krylova
- Postgenomic Studies Laboratory, Federal Research Center N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190121 St. Petersburg, Russia; (K.S.); (E.K.); (E.K.)
| | - Tatiana Leonova
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany; (T.L.); (A.F.)
- Department of Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Andrej Frolov
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany; (T.L.); (A.F.)
- Department of Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena Khlestkina
- Postgenomic Studies Laboratory, Federal Research Center N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190121 St. Petersburg, Russia; (K.S.); (E.K.); (E.K.)
| | - Sergei Medvedev
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia;
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16
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Tognacca RS, Botto JF. Post-transcriptional regulation of seed dormancy and germination: Current understanding and future directions. PLANT COMMUNICATIONS 2021; 2:100169. [PMID: 34327318 PMCID: PMC8299061 DOI: 10.1016/j.xplc.2021.100169] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/26/2021] [Accepted: 02/13/2021] [Indexed: 05/06/2023]
Abstract
Seed dormancy is a developmental checkpoint that prevents mature seeds from germinating under conditions that are otherwise favorable for germination. Temperature and light are the most relevant environmental factors that regulate seed dormancy and germination. These environmental cues can trigger molecular and physiological responses including hormone signaling, particularly that of abscisic acid and gibberellin. The balance between the content and sensitivity of these hormones is the key to the regulation of seed dormancy. Temperature and light tightly regulate the transcription of thousands of genes, as well as other aspects of gene expression such as mRNA splicing, translation, and stability. Chromatin remodeling determines specific transcriptional outputs, and alternative splicing leads to different outcomes and produces transcripts that encode proteins with altered or lost functions. Proper regulation of chromatin remodeling and alternative splicing may be highly relevant to seed germination. Moreover, microRNAs are also critical for the control of gene expression in seeds. This review aims to discuss recent updates on post-transcriptional regulation during seed maturation, dormancy, germination, and post-germination events. We propose future prospects for understanding how different post-transcriptional processes in crop seeds can contribute to the design of genotypes with better performance and higher productivity.
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Affiliation(s)
- Rocío Soledad Tognacca
- Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CP1428 Buenos Aires, Argentina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomía, CP1417 Buenos Aires, Argentina
| | - Javier Francisco Botto
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomía, CP1417 Buenos Aires, Argentina
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17
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Abley K, Formosa-Jordan P, Tavares H, Chan EY, Afsharinafar M, Leyser O, Locke JC. An ABA-GA bistable switch can account for natural variation in the variability of Arabidopsis seed germination time. eLife 2021; 10:59485. [PMID: 34059197 PMCID: PMC8169117 DOI: 10.7554/elife.59485] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/01/2021] [Indexed: 12/31/2022] Open
Abstract
Genetically identical plants growing in the same conditions can display heterogeneous phenotypes. Here we use Arabidopsis seed germination time as a model system to examine phenotypic variability and its underlying mechanisms. We show extensive variation in seed germination time variability between Arabidopsis accessions and use a multiparent recombinant inbred population to identify two genetic loci involved in this trait. Both loci include genes implicated in modulating abscisic acid (ABA) sensitivity. Mutually antagonistic regulation between ABA, which represses germination, and gibberellic acid (GA), which promotes germination, underlies the decision to germinate and can act as a bistable switch. A simple stochastic model of the ABA-GA network shows that modulating ABA sensitivity can generate the range of germination time distributions we observe experimentally. We validate the model by testing its predictions on the effects of exogenous hormone addition. Our work provides a foundation for understanding the mechanism and functional role of phenotypic variability in germination time.
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Affiliation(s)
- Katie Abley
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Pau Formosa-Jordan
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Hugo Tavares
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Emily Yt Chan
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Mana Afsharinafar
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Ottoline Leyser
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - James Cw Locke
- The Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
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18
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Nakabayashi K, Leubner-Metzger G. Seed dormancy and weed emergence: from simulating environmental change to understanding trait plasticity, adaptive evolution, and population fitness. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4181-4185. [PMID: 34048571 PMCID: PMC8163051 DOI: 10.1093/jxb/erab150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
This article comments on: Fernández Farnocchia RB, Benech-Arnold RL, Mantese A, Batlla D. 2021. Optimization of timing of next-generation emergence in Amaranthus hybridus is determined via modulation of seed dormancy by the maternal environment. Journal of Experimental Botany 72, 4283–4297.
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Affiliation(s)
- Kazumi Nakabayashi
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Gerhard Leubner-Metzger
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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19
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Gianella M, Bradford KJ, Guzzon F. Ecological, (epi)genetic and physiological aspects of bet-hedging in angiosperms. PLANT REPRODUCTION 2021; 34:21-36. [PMID: 33449209 PMCID: PMC7902588 DOI: 10.1007/s00497-020-00402-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/28/2020] [Indexed: 06/01/2023]
Abstract
KEY MESSAGE Bet-hedging is a complex evolutionary strategy involving morphological, eco-physiological, (epi)genetic and population dynamics aspects. We review these aspects in flowering plants and propose further research needed for this topic. Bet-hedging is an evolutionary strategy that reduces the temporal variance in fitness at the expense of a lowered arithmetic mean fitness. It has evolved in organisms subjected to variable cues from the external environment, be they abiotic or biotic stresses such as irregular rainfall or predation. In flowering plants, bet-hedging is exhibited by hundreds of species and is mainly exerted by reproductive organs, in particular seeds but also embryos and fruits. The main example of bet-hedging in angiosperms is diaspore heteromorphism in which the same individual produces different seed/fruit morphs in terms of morphology, dormancy, eco-physiology and/or tolerance to biotic and abiotic stresses in order to 'hedge its bets' in unpredictable environments. The objective of this review is to provide a comprehensive overview of the ecological, genetic, epigenetic and physiological aspects involved in shaping bet-hedging strategies, and how these can affect population dynamics. We identify several open research questions about bet-hedging strategies in plants: 1) understanding ecological trade-offs among different traits; 2) producing more comprehensive phylogenetic analyses to understand the diffusion and evolutionary implications of this strategy; 3) clarifying epigenetic mechanisms related to bet-hedging and plant responses to environmental cues; and 4) applying multi-omics approaches to study bet-hedging at different levels of detail. Clarifying those aspects of bet-hedging will deepen our understanding of this fascinating evolutionary strategy.
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Affiliation(s)
- Maraeva Gianella
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100, Pavia, Italy
| | - Kent J Bradford
- Department of Plant Sciences, Seed Biotechnology Center, University of California, Davis, USA
| | - Filippo Guzzon
- International Maize and Wheat Improvement Center (CIMMYT), Carretera México-Veracruz, Km. 45, El Batán, 56237, Texcoco, Mexico State, Mexico.
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20
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Footitt S, Hambidge AJ, Finch-Savage WE. Changes in phenological events in response to a global warming scenario reveal greater adaptability of winter annual compared with summer annual arabidopsis ecotypes. ANNALS OF BOTANY 2021; 127:111-122. [PMID: 32722794 PMCID: PMC7750725 DOI: 10.1093/aob/mcaa141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS The impact of global warming on life cycle timing is uncertain. We investigated changes in life cycle timing in a global warming scenario. We compared Arabidopsis thaliana ecotypes adapted to the warm/dry Cape Verdi Islands (Cvi), Macaronesia, and the cool/wet climate of the Burren (Bur), Ireland, Northern Europe. These are obligate winter and summer annuals, respectively. METHODS Using a global warming scenario predicting a 4 °C temperature rise from 2011 to approx. 2080, we produced F1 seeds at each end of a thermogradient tunnel. Each F1 cohort (cool and warm) then produced F2 seeds at both ends of the thermal gradient in winter and summer annual life cycles. F2 seeds from the winter life cycle were buried at three positions along the gradient to determine the impact of temperature on seedling emergence in a simulated winter life cycle. KEY RESULTS In a winter life cycle, increasing temperatures advanced flowering time by 10.1 d °C-1 in the winter annual and 4.9 d °C-1 in the summer annual. Plant size and seed yield responded positively to global warming in both ecotypes. In a winter life cycle, the impact of increasing temperature on seedling emergence timing was positive in the winter annual, but negative in the summer annual. Global warming reduced summer annual plant size and seed yield in a summer life cycle. CONCLUSIONS Seedling emergence timing observed in the north European summer annual ecotype may exacerbate the negative impact of predicted increased spring and summer temperatures on their establishment and reproductive performance. In contrast, seedling establishment of the Macaronesian winter annual may benefit from higher soil temperatures that will delay emergence until autumn, but which also facilitates earlier spring flowering and consequent avoidance of high summer temperatures. Such plasticity gives winter annual arabidopsis ecotypes a distinct advantage over summer annuals in expected global warming scenarios. This highlights the importance of variation in the timing of seedling establishment in understanding plant species responses to anthropogenic climate change.
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Affiliation(s)
- Steven Footitt
- School of Life Sciences, Wellesbourne Campus, University of Warwick, Warwickshire, UK
- Department of Molecular Biology and Genetics, Boğaziçi University, Bebek, Istanbul, Turkey
| | - Angela J Hambidge
- School of Life Sciences, Wellesbourne Campus, University of Warwick, Warwickshire, UK
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21
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Matilla AJ. Seed Dormancy: Molecular Control of Its Induction and Alleviation. PLANTS 2020; 9:plants9101402. [PMID: 33096840 PMCID: PMC7589034 DOI: 10.3390/plants9101402] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 12/15/2022]
Abstract
A set of seed dormancy traits is included in this Special Issue. Thus, DELAY OF GERMINATION1 (DOG1) is reviewed in depth. Binding of DOG1 to Protein Phosphatase 2C ABSCISIC ACID (PP2C ABA) Hypersensitive Germination (AHG1) and heme are independent processes, but both are essential for DOG1’s function in vivo. AHG1 and DOG1 constitute a regulatory system for dormancy and germination. DOG1 affects the ABA INSENSITIVE5 (ABI5) expression level. Moreover, reactive oxygen species (ROS) homeostasis is linked with seed after-ripening (AR) process and the oxidation of a portion of seed long-lived (SLL) mRNAs seems to be related to dormancy release. The association of SLL mRNAs to monosomes is required for their transcriptional upregulation at the beginning of germination. Global DNA methylation levels remain stable during dormancy, decreasing when germination occurs. The remarkable intervention of auxin in the life of the seed is increasingly evident year after year. Here, its synergistic cooperation with ABA to promote the dormancy process is extensively reviewed. ABI3 participation in this process is critical. New data on the effect of alternating temperatures (ATs) on dormancy release are contained in this Special Issue. On the one hand, the transcriptome patterns stimulated at ATs comprised ethylene and ROS signaling and metabolism together with ABA degradation. On the other hand, a higher physical dormancy release was observed in Medicago truncatula under 35/15 °C than under 25/15 °C, and genome-wide association analysis identified 136 candidate genes related to secondary metabolite synthesis, hormone regulation, and modification of the cell wall. Finally, it is suggested that changes in endogenous γ-aminobutyric acid (GABA) may prevent chestnut germination, and a possible relation with H2O2 production is considered.
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Affiliation(s)
- Angel J Matilla
- Department of Functional Biology, Life Campus, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain
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Zinsmeister J, Berriri S, Basso DP, Ly-Vu B, Dang TT, Lalanne D, da Silva EAA, Leprince O, Buitink J. The seed-specific heat shock factor A9 regulates the depth of dormancy in Medicago truncatula seeds via ABA signalling. PLANT, CELL & ENVIRONMENT 2020; 43:2508-2522. [PMID: 32683703 DOI: 10.1111/pce.13853] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/10/2020] [Accepted: 07/11/2020] [Indexed: 05/15/2023]
Abstract
During the later stages of seed maturation, two key adaptive traits are acquired that contribute to seed lifespan and dispersal, longevity and dormancy. The seed-specific heat shock transcription factor A9 is an important hub gene in the transcriptional network of late seed maturation. Here, we demonstrate that HSFA9 plays a role in thermotolerance rather than in ex situ seed conservation. Storage of hsfa9 seeds of Medicago truncatula and Arabidopsis had comparable lifespan at moderate storage relative humidity (RH), whereas at high RH, hsfa9 seeds lost their viability much faster than wild type seeds. Furthermore, we show that in M. truncatula, Mthsfa9 seeds acquired more dormancy during late maturation than wild type. Transient expression of MtHSFA9 in hairy roots and transcriptome analysis of Mthsfa9 Tnt1 insertion mutants identified a deregulation of genes involved in ABA biosynthesis, catabolism and signalling. Consistent with these results, Mthsfa9 seeds exhibited increased ABA levels and higher sensitivity to ABA. These data suggest that in legumes, HSFA9 acts as a negative regulator of the depth of seed dormancy during seed development via the modulation of hormonal balance.
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Affiliation(s)
- Julia Zinsmeister
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | - Souha Berriri
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | - Denise Puntel Basso
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
- Departamento de Produção Vegetal, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, Brazil
| | - Benoit Ly-Vu
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | - Thi-Thu Dang
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | - David Lalanne
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | | | - Olivier Leprince
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
| | - Julia Buitink
- IRHS-UMR1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, Beaucouzé, France
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23
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Lamar SK, Beddows I, Partridge CG. Examining the molecular mechanisms contributing to the success of an invasive species across different ecosystems. Ecol Evol 2020; 10:10254-10270. [PMID: 33005380 PMCID: PMC7520182 DOI: 10.1002/ece3.6688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 11/16/2022] Open
Abstract
Invasive species provide an opportune system to investigate how populations respond to new environments. Baby's breath (Gypsophila paniculata) was introduced to North America in the 1800s and has since spread throughout the United States and western Canada. We used an RNA-seq approach to explore how molecular processes contribute to the success of invasive populations with similar genetic backgrounds across distinct habitats. Transcription profiles were constructed from seedlings collected from a sand dune ecosystem in Petoskey, MI (PSMI), and a sagebrush ecosystem in Chelan, WA (CHWA). We assessed differential gene expression and identified SNPs within differentially expressed genes. We identified 1,146 differentially expressed transcripts across all sampled tissues between the two populations. GO processes enriched in PSMI were associated with nutrient starvation, while enriched processes in CHWA were associated with abiotic stress. Only 7.4% of the differentially expressed transcripts contained SNPs differing in allele frequencies of at least 0.5 between populations. Common garden studies found the two populations differed in germination rate and seedling emergence success. Our results suggest the success of G. paniculata in these two environments is likely due to plasticity in specific molecular processes responding to different environmental conditions, although some genetic divergence may be contributing to these differences.
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Affiliation(s)
- Sarah K. Lamar
- Annis Water Resources InstituteGrand Valley State UniversityMuskegonMichiganUSA
- Present address:
School of Biological SciencesVictoria University of WellingtonWellingtonNew Zealand
| | - Ian Beddows
- Center for EpigeneticsVan Andel InstituteGrand RapidsMichiganUSA
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24
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Yu B, Wang Y, Zhou H, Li P, Liu C, Chen S, Peng Y, Zhang Y, Teng S. Genome-wide binding analysis reveals that ANAC060 directly represses sugar-induced transcription of ABI5 in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:965-979. [PMID: 32314488 DOI: 10.1111/tpj.14777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/18/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
The sugar status of a plant acts as a signal affecting growth and development. The phenomenon by which high levels of sugars inhibit seedling establishment has been widely used to gain insight into sugar-signaling pathways. Natural allelic variation has been identified at the ANAC060 locus. The Arabidopsis Columbia ecotype produces a short ANAC060 protein without a transmembrane domain that is constitutively located to the nucleus, causing sugar insensitivity when overexpressed. In this study, we generated a genome-wide DNA-binding map of ANAC060 via chromatin immunoprecipitation sequencing using transgenic lines that express a functional ANAC060-GFP fusion protein in an anac060 background. A total of 3282 genes associated with ANAC060-binding sites were identified. These genes were enriched in biotic and abiotic stress responses, and the G-box binding motif was highly enriched in ANAC060-bound genomic regions. Expression microarray analysis resulted in the identification of 8350 genes whose activities were altered in the anac060 mutant and upon sugar treatment. Cluster analysis revealed that ANAC060 attenuates sugar-regulated gene expression. Direct target genes of ANAC060 included equivalent numbers of genes that were upregulated or downregulated by ANAC060. The various functions of these target genes indicate that ANAC060 has several functions. Our results demonstrate that ANAC060 directly binds to the promoter of ABI5 and represses the sugar-induced transcription of ABI5. Genetic data indicate that ABI5 is epistatic to ANAC060 in both sugar and abscisic acid responses.
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Affiliation(s)
- Bo Yu
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing, 100049, China
| | - Yuejun Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing, 100049, China
| | - Hua Zhou
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Ping Li
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Chunmei Liu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing, 100049, China
| | - Sunlu Chen
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Agriculture, Nanjing Agricultural University, 1 Weigang Road, Nanjing, 210095, China
| | - Yu Peng
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Yijing Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing, 100049, China
| | - Sheng Teng
- Laboratory of Photosynthesis and Environmental Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing, 100049, China
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25
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A Perspective on Secondary Seed Dormancy in Arabidopsis thaliana. PLANTS 2020; 9:plants9060749. [PMID: 32549219 PMCID: PMC7355504 DOI: 10.3390/plants9060749] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 01/01/2023]
Abstract
Primary seed dormancy is the phenomenon whereby seeds newly shed by the mother plant are unable to germinate under otherwise favorable conditions for germination. Primary dormancy is released during dry seed storage (after-ripening), and the seeds acquire the capacity to germinate upon imbibition under favorable conditions, i.e., they become non-dormant. Primary dormancy can also be released from the seed by various treatments, for example, by cold imbibition (stratification). Non-dormant seeds can temporarily block their germination if exposed to unfavorable conditions upon seed imbibition until favorable conditions are available. Nevertheless, prolonged unfavorable conditions will re-induce dormancy, i.e., germination will be blocked upon exposure to favorable conditions. This phenomenon is referred to as secondary dormancy. Relative to primary dormancy, the mechanisms underlying secondary dormancy remain understudied in Arabidopsis thaliana and largely unknown. This is partly due to the experimental difficulty in observing secondary dormancy in the laboratory and the absence of established experimental protocols. Here, an overview is provided of the current knowledge on secondary dormancy focusing on A. thaliana, and a working model describing secondary dormancy is proposed, focusing on the interaction of primary and secondary dormancy.
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26
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Carrillo-Barral N, Rodríguez-Gacio MDC, Matilla AJ. Delay of Germination-1 (DOG1): A Key to Understanding Seed Dormancy. PLANTS 2020; 9:plants9040480. [PMID: 32283717 PMCID: PMC7238029 DOI: 10.3390/plants9040480] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 01/19/2023]
Abstract
DELAY OF GERMINATION-1 (DOG1), is a master regulator of primary dormancy (PD) that acts in concert with ABA to delay germination. The ABA and DOG1 signaling pathways converge since DOG1 requires protein phosphatase 2C (PP2C) to control PD. DOG1 enhances ABA signaling through its binding to PP2C ABA HYPERSENSITIVE GERMINATION (AHG1/AHG3). DOG1 suppresses the AHG1 action to enhance ABA sensitivity and impose PD. To carry out this suppression, the formation of DOG1-heme complex is essential. The binding of DOG1-AHG1 to DOG1-Heme is an independent processes but essential for DOG1 function. The quantity of active DOG1 in mature and viable seeds is correlated with the extent of PD. Thus, dog1 mutant seeds, which have scarce endogenous ABA and high gibberellin (GAs) content, exhibit a non-dormancy phenotype. Despite being studied extensively in recent years, little is known about the molecular mechanism underlying the transcriptional regulation of DOG1. However, it is well-known that the physiological function of DOG1 is tightly regulated by a complex array of transformations that include alternative splicing, alternative polyadenylation, histone modifications, and a cis-acting antisense non-coding transcript (asDOG1). The DOG1 becomes modified (i.e., inactivated) during seed after-ripening (AR), and its levels in viable seeds do not correlate with germination potential. Interestingly, it was recently found that the transcription factor (TF) bZIP67 binds to the DOG1 promoter. This is required to activate DOG1 expression leading to enhanced seed dormancy. On the other hand, seed development under low-temperature conditions triggers DOG1 expression by increasing the expression and abundance of bZIP67. Together, current data indicate that DOG1 function is not strictly limited to PD process, but that it is also required for other facets of seed maturation, in part by also interfering with the ethylene signaling components. Otherwise, since DOG1 also affects other processes such us flowering and drought tolerance, the approaches to understanding its mechanism of action and control are, at this time, still inconclusive.
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Affiliation(s)
- Néstor Carrillo-Barral
- Departamento de Biología, Facultad de Ciencias, Universidad de A Coruña, Campus Zapateira, 15071-A Coruña, Spain;
| | - María del Carmen Rodríguez-Gacio
- Departamento de Biología Funcional (Área Fisiología Vegetal), Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - Angel Jesús Matilla
- Departamento de Biología Funcional (Área Fisiología Vegetal), Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
- Correspondence: ; Tel.: +34-981-563-100
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27
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Buijs G, Vogelzang A, Nijveen H, Bentsink L. Dormancy cycling: translation-related transcripts are the main difference between dormant and non-dormant seeds in the field. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:327-339. [PMID: 31785171 PMCID: PMC7217185 DOI: 10.1111/tpj.14626] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 05/20/2023]
Abstract
Primary seed dormancy is a mechanism that orchestrates the timing of seed germination in order to prevent out-of-season germination. Secondary dormancy can be induced in imbibed seeds when they encounter prolonged unfavourable conditions. Secondary dormancy is not induced during dry storage, and therefore the mechanisms underlying this process have remained largely unexplored. Here, a 2-year seed burial experiment in which dormancy cycling was studied at the physiological and transcriptional level is presented. For these analyses six different Arabidopsis thaliana genotypes were used: Landsberg erecta (Ler) and the dormancy associated DELAY OF GERMINATION (DOG) near-isogenic lines 1, 2, 3, 6 and 22 (NILDOG1, 2, 3, 6 and 22). The germination potential of seeds exhumed from the field showed that these seeds go through dormancy cycling and that the dynamics of this cycling is genotype dependent. RNA-seq analysis revealed large transcriptional changes during dormancy cycling, especially at the time points preceding shifts in dormancy status. Dormancy cycling is driven by soil temperature and the endosperm is important in the perception of the environment. Genes that are upregulated in the low- to non-dormant stages are enriched for genes involved in translation, indicating that the non-dormant seeds are prepared for rapid seed germination.
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Affiliation(s)
- Gonda Buijs
- Wageningen Seed LaboratoryLaboratory of Plant PhysiologyWageningen UniversityWageningenthe Netherlands
| | - Afke Vogelzang
- Wageningen Seed LaboratoryLaboratory of Plant PhysiologyWageningen UniversityWageningenthe Netherlands
| | - Harm Nijveen
- Bioinformatics GroupWageningen UniversityWageningenthe Netherlands
| | - Leónie Bentsink
- Wageningen Seed LaboratoryLaboratory of Plant PhysiologyWageningen UniversityWageningenthe Netherlands
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28
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Affiliation(s)
- Steven M Smith
- School of Natural Sciences, University of Tasmania, Hobart, TAS, 7001, Australia
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing, 100101, China
| | - James L Weller
- School of Natural Sciences, University of Tasmania, Hobart, TAS, 7001, Australia
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