Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1 + 1206 word(s) 1206 2021-01-12 04:27:13 |
2 format change Meta information modification 1206 2021-01-19 04:23:48 |

Video Upload Options

Do you have a full video?

Confirm

Are you sure to Delete?
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
De Angelis, V. Seed Dormancy and Germination. Encyclopedia. Available online: https://encyclopedia.pub/entry/6420 (accessed on 14 June 2024).
De Angelis V. Seed Dormancy and Germination. Encyclopedia. Available at: https://encyclopedia.pub/entry/6420. Accessed June 14, 2024.
De Angelis, Veronica. "Seed Dormancy and Germination" Encyclopedia, https://encyclopedia.pub/entry/6420 (accessed June 14, 2024).
De Angelis, V. (2021, January 14). Seed Dormancy and Germination. In Encyclopedia. https://encyclopedia.pub/entry/6420
De Angelis, Veronica. "Seed Dormancy and Germination." Encyclopedia. Web. 14 January, 2021.
Seed Dormancy and Germination
Edit

Seed dormancy, defined as the inability of seeds to undergo germination under optimal conditions, played a crucial role in the evolution of flowering plants.

Seed Dormancy and Germination

1. Introduction

Indeed, dormancy prevents early germination and vivipary, thus enabling seeds’ dispersal in the environment. Dormancy is established during seed maturation and is finely regulated by a plethora of transcription factors interacting in a complex molecular network which in turn controls hormonal levels and signaling. Abscisic acid (ABA) and gibberellic acid (GA) are the phytohormones mainly involved in the induction, maintenance and release of seed dormancy. These hormones act in an antagonistic manner: ABA promotes the establishment of dormancy and is required for dormancy maintenance while GA triggers dormancy release. Seed germination will then take place properly as for place and time. Indeed, this process only occurs when a special combination of environmental optimal conditions such as light, temperature and water availability are present[1]. Seed germination, in Arabidopsis and most plant species, needs a pulse of red light to activate the photoreceptor, which for this process is mainly represented by phytochrome B (phyB)[2]. Active phytochromes promote seed germination also through the control of ABA and GA levels[3][4][5]; indeed, light induces GA biosynthesis and ABA catabolism while repressing GA catabolism and ABA biosynthesis, resulting in increased GA levels and reduced ABA levels. Therefore, the ABA/GA ratio, rather than ABA and GA levels, establishes whether the seed germinates or remains quiescent.

2. Light Control of Seed Dormancy and Germination

Seed germination is influenced by various environmental cues, the main being temperature, water and light. In particular, red light is an essential requirement for germination of seeds of Arabidopsis and most annuals. Among the phytochromes, phyB plays a key role in the promotion of seed germination[6].

3. Hormonal Control of Seed Dormancy and Germination

Dormancy and germination of seeds are two processes finely regulated by several phytohormones; indeed, although ABA and GA play the main role, auxin, cytokinins (CKs), and jasmonate (JA) have been shown to partly contribute to seed germination[7][8][9][10]. As for brassinosteroids (BRs), the involvement of this class of molecules in the promotion of germination has been shown since a long time[11]. Interestingly, it was recently proved that the transcription factor BRI1-EMS-SUPPRESSOR1 (BES1), which is part of the BR signaling pathway, physically interact with the ABA-responsive bZip transcription factor ABA INSENSITIVE5 (ABI5)[12], to restrain ABI5 from binding the promoters of target genes, thus promoting seed germination[12].

Additionally, the gaseous hormone ethylene plays a role in the control of both dormancy and germination of seeds[13][14][15]. Previous studies have shown that ethylene stimulates dormancy release and seed germination in dicot species, while inhibition of ethylene synthesis is related with repression of germination[13][14]. Consistently, inactivation of the membrane-associated receptor ETHYLENE RESPONSE1 (ETR1) and the downstream factor ETHYLENE INSENSITIVE 2 (EIN2) results in more dormant mutant seeds compared to wild-type seeds[16][17][18]. It has been recently demonstrated that the reduced dormancy 3 (rdo3) loss-of-function mutant[19] is an etr1 mutant allele[20]. rdo3 was isolated for its reduced dormancy; further analysis revealed that rdo3 mutant seeds were not altered in ABA sensitivity or endogenous ABA levels[21]. The recent study by Li et al.[20] proved that ETR1 promotes the establishment of seed dormancy in Arabidopsis, and its function requires DELAY OF GERMINATION1 (DOG1), which has been previously identified as a major quantitative trait locus controlling seed dormancy[22]. The activity of DOG1 in the promotion of seed dormancy is strictly dependent on ABA signaling; indeed, DOG1 controls dormancy at least in part through the control of ABI5 expression[23][24]. Analysis of transcriptomic data of the rdo mutant led to identify ETHYLENE RESPONSE FACTOR12 (ERF12) as a downstream element; indeed, lack of ETR1 results in an increased ERF12 transcript level, suggesting that ERF12 is involved in the ETR1-mediated dormancy, and it is likely to represent a link between ETR1-ethylene and the DOG1 pathway in the regulation of seed dormancy in Arabidopsis. ERF12 belongs to the ERF subfamily of repressors[25], which interact with the TOPLESS (TPL)/TPL-related (TPR) corepressors[26][27][28]. TPL does not bind directly DNA, but is required for DOG1 repression mediated by ERF12, as demonstrated by luciferase assay[20]. Although the molecular elements between the ETR1 receptor and ERF12 are still unidentified, these findings uncovered, at least in part, the molecular pathway which controls seed dormancy, linking ethylene to ABA signaling through ETR1-ERF12/TPL and DOG1. Interestingly, ETR1 is likely to be involved also in the repression of seed germination; indeed, a previous study revealed that etr1 mutant seeds exposed to far-red light or in darkness, showed increased germination rate compared to wild type seeds[29]. Surprisingly, this germination behavior was not dependent on altered endogenous ethylene levels between mutant and wild-type seeds, but on increased GA and reduced ABA levels in etr1 mutant seeds following far red light treatment[29].

4. Translational Control of Seed Dormancy and Germination

The seed is an autonomous structure in which a fully developed embryo is spread in the environment, allowing the establishment of an autotrophic organism. In Arabidopsis, seed development is divided in two major phases: embryo and endosperm development (or morphogenesis), and maturation[30][31]. Once embryogenesis is completed, seeds enter the maturation phase, dormancy is established, storage compounds and mRNAs are accumulated, and seeds become desiccation tolerant[32][33]. Once dormancy is released and the environmental conditions are permissive, seeds can germinate; this step represents a programmed transition from a quiescent to a metabolically active state. Since in the presence of the transcription inhibitor α-amanitin germination can occur, whereas cycloheximide blocks this process, germination of seeds is not strictly dependent on transcription of newly synthetized mRNAs, whilst it requires de novo protein synthesis[34][35][36][37][38][39][40]. The presence of stored mRNAs in dried seeds was discovered 50 years ago[41][42], and so far, they have been detected in a large number of seed species[43][44][45]; nevertheless, only in the last decade many open questions on the seed-stored mRNAs and on the translational control underlying dormancy release and seed germination have been, at least in part, addressed[46].

Genome-wide analysis showed that Arabidopsis mature dry seeds hold more than 12,000 transcripts, whereas rice dry seeds have about 17,000 different stored mRNAs[43][47]; it is assumed that not all these stored mRNAs are required for seed germination and a large number should represent housekeeping genes. Among the transcripts specifically required for seed germination, there are mRNAs related to the translation machinery, as well as ubiquitin and proteasome system, thus corroborating the importance of protein synthesis, and suggesting there should be a dynamic regulation and selective proteolysis during early seed germination[43]. A combined approach based on two-dimensional gel-based differential proteomics and dynamic radiolabeled proteomics demonstrated that germination starts when storage and desiccation tolerance-related proteins are synthesized, to guarantee that germination occurs only under favorable conditions[48]. Interestingly, among the translated mRNAs during the transition phase from seed-to-seedling, there are transcripts from hypoxia stress-related genes, thus pointing out the importance of a molecular control of low-oxygen conditions during germination[49]. ABA and GA control dormancy and germination antagonistically, with the former promoting dormancy and inhibiting germination, and GA inducing release of dormancy and germination; therefore, it is not surprising that, among the most represented stored mRNAs in dry seeds, there are transcripts from ABA-related genes, as they have ABA-regulated motifs or ABA responsive elements (ABREs), suggesting that they are accumulated during the maturation stage[43].

References

  1. Koornneef, M.; Bentsink, L.; Hilhorst, H. Seed dormancy and germination. Curr. Opin. Plant Biol. 2002, 5, 33–36.
  2. Shinomura, T.; Nagatani, A.; Chory, J.; Furuya, M. The Induction of Seed Germination in Arabidopsis thaliana Is Regulated Principally by Phytochrome B and Secondarily by Phytochrome, A. Plant Physiol. 1994, 104, 363–371.
  3. Seo, M.; Hanada, A.; Kuwahara, A.; Endo, A.; Okamoto, M.; Yamauchi, Y.; North, H.; Marion-Poll, A.; Sun, T.P.; Koshiba, T.; et al. Regulation of hormone metabolism in Arabidopsis seeds: Phytochrome regulation of abscisic acid metabolism and abscisic acid regulation of gibberellin metabolism. Plant J. 2006, 48, 354–366.
  4. Seo, M.; Nambara, E.; Choi, G.; Yamaguchi, S. Interaction of light and hormone signals in germinating seeds. Plant Mol. Biol. 2009, 69, 463–472.
  5. Arana, M.V.; Sánchez-Lamas, M.; Strasser, B.; Ibarra, S.E.; Cerdán, P.D.; Botto, J.F.; Sánchez, R.A. Functional diversity of phytochrome family in the control of light and gibberellin-mediated germination in Arabidopsis. Plant Cell Environ. 2014, 37, 2014–2023.
  6. Liwen Yang; Shuangrong Liu; Rongcheng Lin; The role of light in regulating seed dormancy and germination. Journal of Integrative Plant Biology 2020, 62, 1310-1326, 10.1111/jipb.13001.
  7. Riefler, M.; Novak, O.; Strnad, M.; Schmülling, T. Arabidopsis cytokinin receptor mutants reveal functions in shoot growth, leaf senescence, seed size, germination, root development, and cytokinin metabolism. Plant Cell 2006, 18, 40–54.
  8. Liu, P.-P.; Montgomery, T.A.; Fahlgren, N.; Kasschau, K.D.; Nonogaki, H.; Carrington, J.C. Repression of AUXIN RESPONSE FACTOR10 by microRNA160 is critical for seed germination and post-germination stages. Plant J. 2007, 52, 133–146.
  9. Linkies, A.; Leubner-Metzger, G. Beyond gibberellins and abscisic acid: How ethylene and jasmonates control seed germination. Plant Cell Rep. 2012, 31, 253–270.
  10. Miransari, M.; Smith, D.L. Plant hormones and seed germination. Environ. Exp. Bot. 2014, 99, 110–121.
  11. Steber, C.M.; McCourt, P. A role for brassinosteroids in germination in Arabidopsis. Plant Physiol. 2001, 125, 763–769.
  12. Xuan Zhao; Liru Dou; Zhizhong Gong; Xiangfeng Wang; Tonglin Mao; BES 1 hinders ABSCISIC ACID INSENSITIVE 5 and promotes seed germination in Arabidopsis. New Phytologist 2018, 221, 908-918, 10.1111/nph.15437.
  13. Arc, E.; Sechet, J.; Corbineau, F.; Rajjou, L.; Marion-Poll, A. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination. Front. Plant Sci. 2013, 4, 63.
  14. Corbineau, F.; Xia, Q.; Bailly, C.; El-Maarouf-Bouteau, H. Ethylene, a key factor in the regulation of seed dormancy. Front. Plant Sci. 2014, 5, 539.
  15. Sun, M.; Tuan, P.A.; Izydorczyk, M.S.; Ayele, B.T. Ethylene regulates post-germination seedling growth in wheat through spatial and temporal modulation of ABA/GA balance. J. Exp. Bot. 2020, 71, 1985–2004.
  16. Beaudoin, N.; Serizet, C.; Gosti, F.; Giraudat, J. Interactions between abscisic acid and ethylene signaling cascades. Plant Cell 2000, 12, 1103–1115.
  17. Chiwocha, S.D.S.; Cutler, A.J.; Abrams, S.R.; Ambrose, S.J.; Yang, J.; Ross, A.R.S.; Kermode, A.R. The etr1-2 mutation in Arabidopsis thaliana affects the abscisic acid, auxin, cytokinin and gibberellin metabolic pathways during maintenance of seed dormancy, moist-chilling and germination. Plant J. 2005, 42, 35–48.
  18. Cheng, W.-H.; Chiang, M.-H.; Hwang, S.-G.; Lin, P.-C. Antagonism between abscisic acid and ethylene in Arabidopsis acts in parallel with the reciprocal regulation of their metabolism and signaling pathways. Plant Mol. Biol. 2009, 71, 61–80.
  19. Karen M. Leon-Kloosterziel; Marta Alvarez Gil; Gerda J. Ruijs; Steven E. Jacobsen; Neil E. Olszewski; Steven H. Schwartz; Jan A.D. Zeevaart; Maarten Koornneef; Isolation and characterization of abscisic acid-deficient Arabidopsis mutants at two new loci. The Plant Journal 1996, 10, 655-661, 10.1046/j.1365-313x.1996.10040655.x.
  20. Xiaoying Li; Tiantian Chen; Yu Li; Zhi Wang; Hong Cao; Fengying Chen; Yong Li; Wim J. J. Soppe; Wenlong Li; Yong-Xiu Liu; et al. ETR1/RDO3 Regulates Seed Dormancy by Relieving the Inhibitory Effect of the ERF12-TPL Complex on DELAY OF GERMINATION1 Expression. The Plant Cell 2019, 31, 832-847, 10.1105/tpc.18.00449.
  21. Anton J. M. Peeters; Hetty Blankestijn-De Vries; Corrie Hanhart; Karen M. Léon-Kloosterziel; Jan A. D. Zeevaart; Maarten Koornneef; Characterization of mutants with reduced seed dormancy at two novel rdo loci and a further characterization of rdo1 and rdo2 in Arabidopsis. Physiologia Plantarum 2002, 115, 604-612, 10.1034/j.1399-3054.2002.1150415.x.
  22. Leónie Bentsink; Jemma Jowett; Corrie J. Hanhart; Maarten Koornneef; Cloning of DOG1, a quantitative trait locus controlling seed dormancy in Arabidopsis. Proceedings of the National Academy of Sciences 2006, 103, 17042-17047, 10.1073/pnas.0607877103.
  23. Dekkers, B.J.W.; He, H.; Hanson, J.; Willems, L.A.J.; Jamar, D.C.L.; Cueff, G.; Rajjou, L.; Hilhorst, H.W.M.; Bentsink, L. The Arabidopsis DELAY OF GERMINATION 1 gene affects ABSCISIC ACID INSENSITIVE 5 (ABI5) expression and genetically interacts with ABI3 during Arabidopsis seed development. Plant J. 2016, 85, 451–465.
  24. Carrillo-Barral, N.; Rodríguez-Gacio, M.D.C.; Matilla, A.J. Delay of Germination-1 (DOG1): A Key to Understanding Seed Dormancy. Plants 2020, 9, 480.
  25. Zhen Yang; Lining Tian; Marysia Latoszek-Green; Daniel Brown; Keqiang Wu; Arabidopsis ERF4 is a transcriptional repressor capable of modulating ethylene and abscisic acid responses. Plant Molecular Biology 2005, 58, 585-596, 10.1007/s11103-005-7294-5.
  26. Ohta, M.; Matsui, K.; Hiratsu, K.; Shinshi, H.; Ohme-Takagi, M. Repression domains of class II ERF transcriptional repressors share an essential motif for active repression. Plant Cell 2001, 13, 1959–1968.
  27. Hiratsu, K.; Mitsuda, N.; Matsui, K.; Ohme-Takagi, M. Identification of the minimal repression domain of SUPERMAN shows that the DLELRL hexapeptide is both necessary and sufficient for repression of transcription in Arabidopsis. Biochem. Biophys. Res. Commun. 2004, 321, 172–178.
  28. Szemenyei, H.; Hannon, M.; Long, J.A. TOPLESS mediates auxin-dependent transcriptional repression during Arabidopsis embryogenesis. Science 2008, 319, 1384–1386.
  29. Rebecca L. Wilson; Arkadipta Bakshi; Brad M. Binder; Loss of the ETR1 ethylene receptor reduces the inhibitory effect of far-red light and darkness on seed germination of Arabidopsis thaliana. Frontiers in Plant Science 2014, 5, 433, 10.3389/fpls.2014.00433.
  30. West, M.A.L.; Harada, J.J. Embryogenesis in Higher Plants: An Overview. Plant. Cell 1993, 5, 1361–1369.
  31. Gutiérrez, R.A.; Lejay, L.V.; Dean, A.; Chiaromonte, F.; Shasha, D.E.; Coruzzi, G.M. Qualitative network models and genome-wide expression data define carbon/nitrogen-responsive molecular machines in Arabidopsis. Genome Biol. 2007, 8, R7.
  32. Maia, J.; Dekkers, B.J.W.; Provart, N.J.; Ligterink, W.; Hilhorst, H.W.M. The re-establishment of desiccation tolerance in germinated Arabidopsis thaliana seeds and its associated transcriptome. PLoS ONE 2011, 6, e29123.
  33. Maia, J.; Dekkers, B.J.W.; Dolle, M.J.; Ligterink, W.; Hilhorst, H.W.M. Abscisic acid (ABA) sensitivity regulates desiccation tolerance in germinated Arabidopsis seeds. New Phytol. 2014, 203, 81–93.
  34. Jendrisak, J. The use of alpha-amanitin to inhibit in vivo RNA synthesis and germination in wheat embryos. J. Biol. Chem. 1980, 255, 8529–8533.
  35. Schultz, C.; Small, J.G. Inhibition of lettuce seed germination by cycloheximide and chloramphenicol is alleviated by kinetin and oxygen. Plant. Physiol. 1991, 97, 836–838.
  36. Rajjou, L.; Gallardo, K.; Debeaujon, I.; Vandekerckhove, J.; Job, C.; Job, D. The effect of alpha-amanitin on the Arabidopsis seed proteome highlights the distinct roles of stored and neosynthesized mRNAs during germination. Plant. Physiol. 2004, 134, 1598–1613.
  37. He, D.; Han, C.; Yao, J.; Shen, S.; Yang, P. Constructing the metabolic and regulatory pathways in germinating rice seeds through proteomic approach. Proteomics 2011, 11, 2693–2713.
  38. Sano, N.; Permana, H.; Kumada, R.; Shinozaki, Y.; Tanabata, T.; Yamada, T.; Hirasawa, T.; Kanekatsu, M. Proteomic analysis of embryonic proteins synthesized from long-lived mRNAs during germination of rice seeds. Plant. Cell Physiol. 2012, 53, 687–698.
  39. Liu, S.-J.; Xu, H.-H.; Wang, W.-Q.; Li, N.; Wang, W.-P.; Lu, Z.; Møller, I.M.; Song, S.-Q. Identification of embryo proteins associated with seed germination and seedling establishment in germinating rice seeds. J. Plant. Physiol. 2016, 196–197, 79–92.
  40. Sano, N.; Takebayashi, Y.; To, A.; Mhiri, C.; Rajjou, L.C.; Nakagami, H.; Kanekatsu, M. Shotgun Proteomic Analysis Highlights the Roles of Long-Lived mRNAs and De Novo Transcribed mRNAs in Rice Seeds upon Imbibition. Plant. Cell Physiol. 2019, 60, 2584–2596.
  41. Dure, L.; Water, L. Long-lived messenger RNA: Evidence from cotton seed germination. Science 1965, 147, 410–412.
  42. Ihle, J.N.; Dure, L.S. The Temporal Separation of Transcription and Translation and its Control in Cotton Embryogenesis and Germination. In Plant Growth Substances 1970; Carr, D.J., Ed.; Springer: Berlin/Heidelberg, Germany, 1972; pp. 216–221. ISBN 978-3-642-65406-0.
  43. Nakabayashi, K.; Okamoto, M.; Koshiba, T.; Kamiya, Y.; Nambara, E. Genome-wide profiling of stored mRNA in Arabidopsis thaliana seed germination: Epigenetic and genetic regulation of transcription in seed. Plant. J. 2005, 41, 697–709.
  44. Kimura, M.; Nambara, E. Stored and neosynthesized mRNA in Arabidopsis seeds: Effects of cycloheximide and controlled deterioration treatment on the resumption of transcription during imbibition. Plant. Mol. Biol. 2010, 73, 119–129.
  45. Bazin, J.; Langlade, N.; Vincourt, P.; Arribat, S.; Balzergue, S.; El-Maarouf-Bouteau, H.; Bailly, C. Targeted mRNA oxidation regulates sunflower seed dormancy alleviation during dry after-ripening. Plant. Cell 2011, 23, 2196–2208.
  46. Naoto Sano; Loïc Rajjou; Helen M. North; Lost in Translation: Physiological Roles of Stored mRNAs in Seed Germination. Plants 2020, 9, 347, 10.3390/plants9030347.
  47. Katharine A. Howell; Reena Narsai; Adam Carroll; Aneta Ivanova; Marc Lohse; Björn Usadel; A. Harvey Millar; James Whelan; Mapping Metabolic and Transcript Temporal Switches during Germination in Rice Highlights Specific Transcription Factors and the Role of RNA Instability in the Germination Process. Plant Physiology 2008, 149, 961-980, 10.1104/pp.108.129874.
  48. Marc Galland; Romain Huguet; Erwann Arc; Gwendal Cueff; Dominique Job; Loïc Rajjou; Dynamic Proteomics Emphasizes the Importance of Selective mRNA Translation and Protein Turnover duringArabidopsisSeed Germination. Molecular & Cellular Proteomics 2013, 13, 252-268, 10.1074/mcp.m113.032227.
  49. Bing Bai; Alessia Peviani; Sjors Van Der Horst; Magdalena Gamm; ‎berend Snel; Leónie Bentsink; Johannes Hanson; Extensive translational regulation during seed germination revealed by polysomal profiling. New Phytologist 2016, 214, 233-244, 10.1111/nph.14355.
More
Information
Subjects: Plant Sciences
Contributor MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
View Times: 428
Revisions: 2 times (View History)
Update Date: 19 Jan 2021
1000/1000
Video Production Service