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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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2
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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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3
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Wang A, Baskin CC, Baskin JM, Ding J. Trade-offs between diaspore dispersal and dormancy within a spike of the invasive annual grass Aegilops tauschii. PLANTA 2023; 257:121. [PMID: 37198315 DOI: 10.1007/s00425-023-04156-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/11/2023] [Indexed: 05/19/2023]
Abstract
MAIN CONCLUSION Differences in dispersal and dormancy of heteromorphic diaspores of Aegilos tauschii may increase its flexibility to invade/occupy weedy unpredictable habitats by spreading risk in space and time. In plant species that produce dimorphic seeds, there often is a negative relationship between dispersal and dormancy, with high dispersal-low dormancy in one morph and low dispersal-high dormancy in the other, which may function as a bet-hedging strategy that spreads the risk of survival and ensures reproductive success. However, the relationship between dispersal and dormancy and its ecological consequences in invasive annual grasses that produce heteromorphic diaspores is not well studied. We compared dispersal and dormancy responses of diaspores from the basal (proximal) to the distal position on compound spikes of Aegilops tauschii, an invasive grass with heteromorphic diaspores. Dispersal ability increased and degree of dormancy decreased as diaspore position on a spike increased from basal to distal. There was a significant positive correlation between length of awns and dispersal ability, and awn removal significantly promoted seed germination. Germination was positively correlated with GA concentration and negatively correlated with ABA concentration, and the ABA: GA ratio was high in seeds with low germination/high dormancy. Thus, there was a continuous inverse-linear relationship between diaspore dispersal ability and degree of dormancy. This negative relationship between diaspore dispersal and degree of dormancy at different positions on a spike of Aegilops tauschii may facilitate seedling survival in space and time.
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Affiliation(s)
- AiBo Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, Henan, China.
| | - Carol C Baskin
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, 40546, USA
| | - Jerry M Baskin
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
| | - Jianqing Ding
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, Henan, China.
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4
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Cao D. To germinate or not? Transcriptional gradients underlie the seed dormancy continuum. PLANT PHYSIOLOGY 2022; 190:1559-1561. [PMID: 35961049 PMCID: PMC9614443 DOI: 10.1093/plphys/kiac367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Dechang Cao
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
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5
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Song S, Willems LAJ, Jiao A, Zhao T, Eric Schranz M, Bentsink L. The membrane associated NAC transcription factors ANAC060 and ANAC040 are functionally redundant in the inhibition of seed dormancy in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5514-5528. [PMID: 35604925 PMCID: PMC9467645 DOI: 10.1093/jxb/erac232] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
The NAC family of transcription factors is involved in plant development and various biotic and abiotic stresses. The Arabidopsis thaliana ANAC genes ANAC060, ANAC040, and ANAC089 are highly homologous based on protein and nucleotide sequence similarity. These three genes are predicted to be membrane bound transcription factors (MTFs) containing a conserved NAC domain, but divergent C-terminal regions. The anac060 mutant shows increased dormancy when compared with the wild type. Mutations in ANAC040 lead to higher seed germination under salt stress, and a premature stop codon in ANAC089 Cvi allele results in seeds exhibiting insensitivity to high concentrations of fructose. Thus, these three homologous MTFs confer distinct functions, although all related to germination. To investigate whether the differences in function are caused by a differential spatial or temporal regulation, or by differences in the coding sequence (CDS), we performed swapping experiments in which the promoter and CDS of the three MTFs were exchanged. Seed dormancy and salt and fructose sensitivity analyses of transgenic swapping lines in mutant backgrounds showed that there is functional redundancy between ANAC060 and ANAC040, but not between ANAC060 and ANAC089.
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Affiliation(s)
- Shuang Song
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, PB Wageningen, The Netherlands
| | - Leo A J Willems
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, PB Wageningen, The Netherlands
| | - Ao Jiao
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, PB Wageningen, The Netherlands
| | - Tao Zhao
- Present address: State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - M Eric Schranz
- Biosystematics Group, Wageningen University, PB Wageningen, The Netherlands
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6
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Jaganathan GK. Unravelling the paradox in physically dormant species: elucidating the onset of dormancy after dispersal and dormancy-cycling. ANNALS OF BOTANY 2022; 130:121-129. [PMID: 35737935 PMCID: PMC9445591 DOI: 10.1093/aob/mcac084] [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: 04/17/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND For species that produce seeds with a water-impermeable coat, i.e. physical dormancy (PY), it has been widely recognized that (1) seeds shed at a permeable state cannot become impermeable after dispersal; and (2) dormancy-cycling, i.e. a permeable ↔ impermeable transition, does not occur. Given a tight relationship between moisture content and onset of seed-coat impermeability, seeds maturing at low relative humidity (RH) and occurring in a high-temperature environment are inferred to produce impermeable coats, and ex situ drying of permeable seeds can lead to the onset of impermeability. SCOPE AND CONCLUSION It is proposed here that permeable seeds dispersed at low RH and in high-temperature soils might become impermeable due to continuous drying. Similarly, seeds with shallow PY dormancy (with higher moisture content immediately after becoming impermeable) can cycle back to a permeable state or absolute PY (complete dry state) when RH increases or decreases, respectively. A conceptual model is developed to propose that seeds from several genera of 19 angiosperm families at the time of natural dispersal can be (1) impermeable (dormant), i.e. primary dormancy; (2) impermeable (dormant) and become permeable (non-dormant) and then enter a dormant state in the soil, often referred to as secondary dormancy; (3) permeable (non-dormant) and become impermeable (dormant) in the soil, i.e. enforced dormancy; or (4) dormant or non-dormant, but cycle between permeable and non-permeable states depending on the soil conditions, i.e. dormancy-cycling, which is different from sensitivity-cycling occurring during dormancy break. It is suggested that this phenomenon could influence the dormancy-breaking pattern, but detailed studies of this are lacking.
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7
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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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8
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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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9
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Maurya AK, Pazouki L, Frost CJ. Priming Seeds with Indole and (Z)-3-Hexenyl Acetate Enhances Resistance Against Herbivores and Stimulates Growth. J Chem Ecol 2022; 48:441-454. [PMID: 35394556 DOI: 10.1007/s10886-022-01359-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 02/14/2022] [Accepted: 03/07/2022] [Indexed: 11/28/2022]
Abstract
A striking feature of plant ecology is the ability of plants to detect and respond to environmental cues such as herbivore-induced plant volatiles (HIPVs) by priming or directly activating defenses against future herbivores. However, whether seeds also respond to compounds that are common constituents of HIPV blends and initiate future plant resistance is unknown. Considering that seeds depend on other environmental cues to determine basic survival traits such as germination timing, we predicted that seeds exposed to synthetic constituents of HIPV blends would generate well-defended plants. We investigated the effect of seed exposure to common volatiles on growth, reproduction, and resistance characteristics in the model plants Arabidopsis thaliana and Medicago truncatula using herbivores from two feeding guilds. After seed scarification and vernalization, we treated seeds with one of seven different plant-derived volatile compounds for 24 h. Seeds were then germinated and the resulting plants were assayed for growth, herbivore resistance, and expression of inducible defense genes. Of all the synthetic volatiles tested, indole specifically reduced both beet armyworm growth on A. thaliana and pea aphid fecundity on M. truncatula. The induction of defense genes was not affected by seed exposure to indole in either plant species, indicating that activation of direct resistance rather than inducible resistance is the mechanism by which seed priming operates. Moreover, neither plant species showed any negative effect of seed exposure to any synthetic volatile on vegetative and reproductive growth. Rather, M. truncatula plants derived from seeds exposed to (Z)-3-hexanol and (Z)-3-hexenyl acetate grew larger compared to controls. Our results indicate that seeds are sensitive to specific volatiles in ways that enhance resistance profiles with no apparent costs in terms of growth. Seed priming by HIPVs may represent a novel ecological mechanism of plant-to-plant interactions, with broad potential applications in agriculture and seed conservation.
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Affiliation(s)
- Abhinav K Maurya
- Department of Biology, University of Louisville, 40292, Louisville, KY, USA
| | - Leila Pazouki
- Department of Biology, University of Louisville, 40292, Louisville, KY, USA
| | - Christopher J Frost
- Department of Biology, University of Louisville, 40292, Louisville, KY, USA. .,BIO5 Institute, University of Arizona, 85721, Tucson, AZ, USA.
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10
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Zacchello G, Bomers S, Böhme C, Postma FM, Ågren J. Seed dormancy varies widely among
Arabidopsis thaliana
populations both between and within Fennoscandia and Italy. Ecol Evol 2022; 12:e8670. [PMID: 35261752 PMCID: PMC8888264 DOI: 10.1002/ece3.8670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 09/27/2021] [Accepted: 11/05/2021] [Indexed: 11/10/2022] Open
Abstract
The timing of germination is a key life‐history trait in plants, which is strongly affected by the strength of seed dormancy. Continental‐wide genetic variation in seed dormancy has been related to differences in climate and the timing of conditions suitable for seedling establishment. However, for predictions of adaptive potential and consequences of climatic change, information is needed regarding the extent to which seed dormancy varies within climatic regions and the factors driving such variation. We quantified dormancy of seeds produced by 17 Italian and 28 Fennoscandian populations of Arabidopsis thaliana when grown in the greenhouse and at two field sites in Italy and Sweden. To identify possible drivers of among‐population variation in seed dormancy, we examined the relationship between seed dormancy and climate at the site of population origin, and between seed dormancy and flowering time. Seed dormancy was on average stronger in the Italian compared to the Fennoscandian populations, but also varied widely within both regions. Estimates of seed dormancy in the three maternal environments were positively correlated. Among Fennoscandian populations, seed dormancy tended to increase with increasing summer temperature and decreasing precipitation at the site of population origin. In the smaller sample of Italian populations, no significant association was detected between mean seed dormancy and climate at the site of origin. The correlation between population mean seed dormancy and flowering time was weak and not statistically significant within regions. The correlation between seed dormancy and climatic factors in Fennoscandia suggests that at least some of the among‐population variation is adaptive and that climate change will affect selection on this trait. The weak correlation between population mean seed dormancy and flowering time indicates that the two traits can evolve independently.
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Affiliation(s)
- Giulia Zacchello
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Svenja Bomers
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
- Institute for Seed and Propagating Material, Phytosanitary Service and Apiculture Austrian Agency for Health and Food Safety Vienna Austria
| | - Cecilia Böhme
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Froukje M. Postma
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Jon Ågren
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
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11
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The Seed and the Metabolism Regulation. BIOLOGY 2022; 11:biology11020168. [PMID: 35205035 PMCID: PMC8869448 DOI: 10.3390/biology11020168] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 12/14/2022]
Abstract
Simple Summary Seeds are the reproductive units of higher plants. They have a significant place in agriculture and plant diversity maintenance. Because they are dehydrated, they can remain viable in the environment for centuries. This review explores the dry seed as a metabolically inactive organism, but well organized to protect its components and enter intensive repair to restore metabolic activities upon imbibition for the completion of germination. Metabolism regulation is also critical for the most important seed traits, dormancy, and ageing recovery capacity. Abstract The seed represents a critical stage in the life cycle of flowering plants. It corresponds to a dry structure carrying the plant embryo in dormant or quiescent state. Orthodox seeds possess a very low water content, preventing biochemical reactions, especially respiration. If the desiccation of living organisms leads to a loss of homeostasis, structure, and metabolism, the seeds go through it successfully thanks to their structure, cellular organization, and growth regulation. Seeds set up a certain number of sophisticated molecules to protect valuable macromolecules or organelles from dehydration/rehydration cycles. Moreover, dormancy takes place in a coordinated process with environmental cues in order to ensure embryo development at the most appropriate conditions for the establishment of the new plant. Moreover, repair processes are programmed to be ready to operate to maximize germination success and seed longevity. This review focuses on the physiology of the seed as related to hydration forces, respiration, and biochemical reactions in the transition from thermodynamically undefined dry state to self-sustained living system. Such processes are of importance for basic knowledge of the regulation of metabolism of living organisms, but also for the control of germination in the context of climate change due to global warming.
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12
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Wang S, Shen Y, Bao H. Morphological, physiological and biochemical changes in Magnolia zenii Cheng seed during development. PHYSIOLOGIA PLANTARUM 2021; 172:2129-2141. [PMID: 33937990 PMCID: PMC8362153 DOI: 10.1111/ppl.13445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/16/2021] [Accepted: 04/29/2021] [Indexed: 05/05/2023]
Abstract
An understanding of the seed dynamics of endangered plant species, such as Magnolia zenii Cheng, is important for successful conservation. This study examined the morphological, physiological and biochemical changes that occur in M. zenii Cheng during seed development to determine the appropriate harvest stage. The appearance of the seeds was influenced by the physiological and biochemical changes occurring during the developmental period, during which the colour of the fruits changed from green to red, while that of the seed changed from light brown to dark brown. There was a significant decrease in the seed moisture content from 90 to 120 days after flowering (DAF); however, there was no significant change from 135 to 165 DAF. The seeds from 135 DAF onwards showed developed cotyledonary embryos. The seed viability exceeded 95% from 135 DAF onwards; however, the germination percentage was 0, hypothesising that the seeds of M. zenii Cheng might exhibit physiological dormancy under certain conditions of this experiment. There was a significant increase in the fat, soluble sugar and soluble starch content of the seeds while approaching maturity. There were significant changes in malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6-PDH), 6-phosphogluconate dehydrogenase (6-PGDH) and β-amylase activities in the seeds during the developmental period. At 135-165 DAF, the MDH activity remained stable, whereas that of 6-PGDH reached its maximum, indicating that the seeds underwent vigorous metabolism. The findings of this study provide a theoretical basis for researching seed dormancy and seed harvest time.
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Affiliation(s)
- Shan Wang
- Co‐Innovation Center for the Sustainable Forestry in Southern ChinaNanjing Forestry UniversityNanjingChina
- College of ForestryNanjing Forestry UniversityNanjingChina
- Southern Tree Seed Inspection CenterNational Forestry AdministrationNanjingChina
- Jiangsu Engineering and Technology Center for Modern HorticultureJiangsu Vocational College of Agriculture and ForestryZhenjiangChina
- Jiangsu Agricultural Expo ParkJiangsu Vocational College of Agriculture and ForestryZhenjiangChina
| | - Yongbao Shen
- Co‐Innovation Center for the Sustainable Forestry in Southern ChinaNanjing Forestry UniversityNanjingChina
- College of ForestryNanjing Forestry UniversityNanjingChina
- Southern Tree Seed Inspection CenterNational Forestry AdministrationNanjingChina
| | - Huapeng Bao
- Jiangsu Agricultural Expo ParkJiangsu Vocational College of Agriculture and ForestryZhenjiangChina
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13
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Klupczyńska EA, Pawłowski TA. Regulation of Seed Dormancy and Germination Mechanisms in a Changing Environment. Int J Mol Sci 2021; 22:1357. [PMID: 33572974 PMCID: PMC7866424 DOI: 10.3390/ijms22031357] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 01/10/2023] Open
Abstract
Environmental conditions are the basis of plant reproduction and are the critical factors controlling seed dormancy and germination. Global climate change is currently affecting environmental conditions and changing the reproduction of plants from seeds. Disturbances in germination will cause disturbances in the diversity of plant communities. Models developed for climate change scenarios show that some species will face a significant decrease in suitable habitat area. Dormancy is an adaptive mechanism that affects the probability of survival of a species. The ability of seeds of many plant species to survive until dormancy recedes and meet the requirements for germination is an adaptive strategy that can act as a buffer against the negative effects of environmental heterogeneity. The influence of temperature and humidity on seed dormancy status underlines the need to understand how changing environmental conditions will affect seed germination patterns. Knowledge of these processes is important for understanding plant evolution and adaptation to changes in the habitat. The network of genes controlling seed dormancy under the influence of environmental conditions is not fully characterized. Integrating research techniques from different disciplines of biology could aid understanding of the mechanisms of the processes controlling seed germination. Transcriptomics, proteomics, epigenetics, and other fields provide researchers with new opportunities to understand the many processes of plant life. This paper focuses on presenting the adaptation mechanism of seed dormancy and germination to the various environments, with emphasis on their prospective roles in adaptation to the changing climate.
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Affiliation(s)
| | - Tomasz A. Pawłowski
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland;
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Luján-Soto E, Dinkova TD. Time to Wake Up: Epigenetic and Small-RNA-Mediated Regulation during Seed Germination. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10020236. [PMID: 33530470 PMCID: PMC7911344 DOI: 10.3390/plants10020236] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 05/03/2023]
Abstract
Plants make decisions throughout their lifetime based on complex networks. Phase transitions during seed growth are not an exception. From embryo development through seedling growth, several molecular pathways control genome stability, environmental signal transduction and the transcriptional landscape. Particularly, epigenetic modifications and small non-coding RNAs (sRNAs) have been extensively studied as significant handlers of these processes in plants. Here, we review key epigenetic (histone modifications and methylation patterns) and sRNA-mediated regulatory networks involved in the progression from seed maturation to germination, their relationship with seed traits and crosstalk with environmental inputs.
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The complexity of PRC2 catalysts CLF and SWN in plants. Biochem Soc Trans 2020; 48:2779-2789. [PMID: 33170267 DOI: 10.1042/bst20200660] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/14/2020] [Accepted: 10/21/2020] [Indexed: 11/17/2022]
Abstract
Polycomb repressive complex 2 (PRC2) is an evolutionally conserved multisubunit complex essential for the development of eukaryotes. In Arabidopsis thaliana (Arabidopsis), CURLY LEAF (CLF) and SWINGER (SWN) are PRC2 catalytic subunits that repress gene expression through trimethylating histone H3 at lysine 27 (H3K27me3). CLF and SWN function to safeguard the appropriate expression of key developmental regulators throughout the plant life cycle. Recent researches have advanced our knowledge of the biological roles and the regulation of the activity of CLF and SWN. In this review, we summarize these recent findings and highlight the redundant and differential roles of CLF and SWN in plant development. Further, we discuss the molecular mechanisms underlying CLF and SWN recruitment to specific genomic loci, as well as their interplays with Trithorax-group (TrxG) proteins in plants.
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Network Analysis Prioritizes DEWAX and ICE1 as the Candidate Genes for Major eQTL Hotspots in Seed Germination of Arabidopsis thaliana. G3-GENES GENOMES GENETICS 2020; 10:4215-4226. [PMID: 32963085 PMCID: PMC7642920 DOI: 10.1534/g3.120.401477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Seed germination is characterized by a constant change of gene expression across different time points. These changes are related to specific processes, which eventually determine the onset of seed germination. To get a better understanding on the regulation of gene expression during seed germination, we performed a quantitative trait locus mapping of gene expression (eQTL) at four important seed germination stages (primary dormant, after-ripened, six-hour after imbibition, and radicle protrusion stage) using Arabidopsis thaliana Bay x Sha recombinant inbred lines (RILs). The mapping displayed the distinctness of the eQTL landscape for each stage. We found several eQTL hotspots across stages associated with the regulation of expression of a large number of genes. Interestingly, an eQTL hotspot on chromosome five collocates with hotspots for phenotypic and metabolic QTL in the same population. Finally, we constructed a gene co-expression network to prioritize the regulatory genes for two major eQTL hotspots. The network analysis prioritizes transcription factors DEWAX and ICE1 as the most likely regulatory genes for the hotspot. Together, we have revealed that the genetic regulation of gene expression is dynamic along the course of seed germination.
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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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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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Carrera-Castaño G, Calleja-Cabrera J, Pernas M, Gómez L, Oñate-Sánchez L. An Updated Overview on the Regulation of Seed Germination. PLANTS 2020; 9:plants9060703. [PMID: 32492790 PMCID: PMC7356954 DOI: 10.3390/plants9060703] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 02/07/2023]
Abstract
The ability of a seed to germinate and establish a plant at the right time of year is of vital importance from an ecological and economical point of view. Due to the fragility of these early growth stages, their swiftness and robustness will impact later developmental stages and crop yield. These traits are modulated by a continuous interaction between the genetic makeup of the plant and the environment from seed production to germination stages. In this review, we have summarized the established knowledge on the control of seed germination from a molecular and a genetic perspective. This serves as a “backbone” to integrate the latest developments in the field. These include the link of germination to events occurring in the mother plant influenced by the environment, the impact of changes in the chromatin landscape, the discovery of new players and new insights related to well-known master regulators. Finally, results from recent studies on hormone transport, signaling, and biophysical and mechanical tissue properties are underscoring the relevance of tissue-specific regulation and the interplay of signals in this crucial developmental process.
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Katsuya-Gaviria K, Caro E, Carrillo-Barral N, Iglesias-Fernández R. Reactive Oxygen Species (ROS) and Nucleic Acid Modifications During Seed Dormancy. PLANTS (BASEL, SWITZERLAND) 2020; 9:E679. [PMID: 32471221 PMCID: PMC7356579 DOI: 10.3390/plants9060679] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/24/2020] [Accepted: 05/26/2020] [Indexed: 12/15/2022]
Abstract
The seed is the propagule of higher plants and allows its dissemination and the survival of the species. Seed dormancy prevents premature germination under favourable conditions. Dormant seeds are only able to germinate in a narrow range of conditions. During after-ripening (AR), a mechanism of dormancy release, seeds gradually lose dormancy through a period of dry storage. This review is mainly focused on how chemical modifications of mRNA and genomic DNA, such as oxidation and methylation, affect gene expression during late stages of seed development, especially during dormancy. The oxidation of specific nucleotides produced by reactive oxygen species (ROS) alters the stability of the seed stored mRNAs, being finally degraded or translated into non-functional proteins. DNA methylation is a well-known epigenetic mechanism of controlling gene expression. In Arabidopsis thaliana, while there is a global increase in CHH-context methylation through embryogenesis, global DNA methylation levels remain stable during seed dormancy, decreasing when germination occurs. The biological significance of nucleic acid oxidation and methylation upon seed development is discussed.
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Affiliation(s)
- Kai Katsuya-Gaviria
- Centro de Biotecnología y Genómica de Plantas-Severo Ochoa (CBGP, UPM-INIA), Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223-Pozuelo de Alarcón, Spain; (K.K.-G.); (E.C.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, 28040-Madrid, Spain
| | - Elena Caro
- Centro de Biotecnología y Genómica de Plantas-Severo Ochoa (CBGP, UPM-INIA), Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223-Pozuelo de Alarcón, Spain; (K.K.-G.); (E.C.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, 28040-Madrid, Spain
| | - Néstor Carrillo-Barral
- Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad da Coruña (UdC), 15008-A Coruña, Spain;
| | - Raquel Iglesias-Fernández
- Centro de Biotecnología y Genómica de Plantas-Severo Ochoa (CBGP, UPM-INIA), Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223-Pozuelo de Alarcón, Spain; (K.K.-G.); (E.C.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, 28040-Madrid, Spain
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de Souza Vidigal D, He H, Hilhorst HWM, Willems LAJ, Bentsink L. Arabidopsis in the Wild-The Effect of Seasons on Seed Performance. PLANTS (BASEL, SWITZERLAND) 2020; 9:E576. [PMID: 32370066 PMCID: PMC7285089 DOI: 10.3390/plants9050576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 06/11/2023]
Abstract
Climate changes play a central role in the adaptive life histories of organisms all over the world. In higher plants, these changes may impact seed performance, both during seed development and after dispersal. To examine the plasticity of seed performance as a response to environmental fluctuations, eight genotypes known to be affected in seed dormancy and longevity were grown in the field in all seasons of two years. Soil and air temperature, day length, precipitation, and sun hours per day were monitored. We show that seed performance depends on the season. Seeds produced by plants grown in the summer, when the days began to shorten and the temperature started to decrease, were smaller with deeper dormancy and lower seed longevity compared to the other seasons when seeds were matured at higher temperature over longer days. The performance of seeds developed in the different seasons was compared to seeds produced in controlled conditions. This revealed that plants grown in a controlled environment produced larger seeds with lower dormancy than those grown in the field. All together the results show that the effect of the environment largely overrules the genetic effects, and especially, differences in seed dormancy caused by the different seasons were larger than the differences between the genotypes.
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Affiliation(s)
- Deborah de Souza Vidigal
- Wageningen Seed Science Centre Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands; (D.d.S.V.); (H.H.); (H.W.M.H.); (L.A.J.W.)
- Bejo Zaden B.V., Trambaan 1, 1749 CZ Warmenhuizen, The Netherlands
| | - Hanzi He
- Wageningen Seed Science Centre Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands; (D.d.S.V.); (H.H.); (H.W.M.H.); (L.A.J.W.)
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Henk W. M. Hilhorst
- Wageningen Seed Science Centre Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands; (D.d.S.V.); (H.H.); (H.W.M.H.); (L.A.J.W.)
| | - Leo A. J. Willems
- Wageningen Seed Science Centre Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands; (D.d.S.V.); (H.H.); (H.W.M.H.); (L.A.J.W.)
| | - Leónie Bentsink
- Wageningen Seed Science Centre Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands; (D.d.S.V.); (H.H.); (H.W.M.H.); (L.A.J.W.)
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Lost in Translation: Physiological Roles of Stored mRNAs in Seed Germination. PLANTS 2020; 9:plants9030347. [PMID: 32164149 PMCID: PMC7154877 DOI: 10.3390/plants9030347] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023]
Abstract
Seeds characteristics such as germination ability, dormancy, and storability/longevity are important traits in agriculture, and various genes have been identified that are involved in its regulation at the transcriptional and post-transcriptional level. A particularity of mature dry seeds is a special mechanism that allows them to accumulate more than 10,000 mRNAs during seed maturation and use them as templates to synthesize proteins during germination. Some of these stored mRNAs are also referred to as long-lived mRNAs because they remain translatable even after seeds have been exposed to long-term stressful conditions. Mature seeds can germinate even in the presence of transcriptional inhibitors, and this ability is acquired in mid-seed development. The type of mRNA that accumulates in seeds is affected by the plant hormone abscisic acid and environmental factors, and most of them accumulate in seeds in the form of monosomes. Release of seed dormancy during after-ripening involves the selective oxidation of stored mRNAs and this prevents translation of proteins that function in the suppression of germination after imbibition. Non-selective oxidation and degradation of stored mRNAs occurs during long-term storage of seeds so that the quality of stored RNAs is linked to the degree of seed deterioration. After seed imbibition, a population of stored mRNAs are selectively loaded into polysomes and the mRNAs, involved in processes such as redox, glycolysis, and protein synthesis, are actively translated for germination.
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