Why Do Some Seeds Stay Dormant for Decades?
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Why do some seeds stay dormant for decades? Some seeds stay dormant for decades because dormancy is a built-in checkpoint that stops germination even when conditions look favorable. A research review defines it as “the inability of seeds to germinate in favorable conditions.” The same reviews show that dormancy is set during seed development, shaped by plant hormones, and tied to stored molecules inside the dry seed. The sources explain the mechanisms behind dormancy in general. They do not explain why one particular species keeps seeds alive for decades, and this article does not claim that they do.
Quick answer
- Dormancy is a checkpoint. One review describes it as “a developmental checkpoint that prevents mature seeds from germinating under conditions that are otherwise favorable for germination.”
- Dormancy is set during maturation. The first review says that “This stage is followed by seed maturation during which dormancy, desiccation tolerance, and seed longevity are induced.”
- Hormones control the switch. The first review states that “The requirement of GA for germination depends on the ABA concentration within seeds.”
- Stored molecules wait inside dry seeds. The second review says that “it has been demonstrated that mRNAs stored in dry seeds are selectively translated during seed germination.”
What dormancy is and why it matters
The first review explains that “This ability to remain in a quiescent state is called seed dormancy.” The review also notes that seeds can persist for long periods, stating that “Furthermore, seeds can travel for thousands of miles or wait for hundreds of years to germinate.” That is the basis for the decades-long pattern in the question.
The same review classifies dormancy by type. It says that “Dormancy can be broadly classified into 5 types of dormancies: physical, morphological, morphophysiological, physiological, and combinational dormancy.” It also states that “The most commonly studied type of dormancy is physiological dormancy.”
Dormancy is not a single switch that is either on or off in every seed. The review explains that “Dormant seeds will not surpass this stage, whereas nondormant seeds will move on to Phase III, in which water uptake is resumed and the seed coat or the testa will rupture.” This describes a stage at which dormant seeds stop, while nondormant seeds move forward into water uptake and germination.
How dormancy is set during seed development
The first review says that “The induction of dormancy is dependent on genetic factors as well as environmental factors like light, temperature, and nitrate availability that the mother plant experiences.” The conditions a plant experiences during seed formation can therefore influence how dormant its seeds become.
The maturation stage is the key period. The review states that “The maturation phase is also the critical phase wherein important traits like desiccation tolerance are established by intense moisture loss and seed dormancy and seed longevity are acquired.” This sentence links the ability to survive drying with the acquisition of dormancy and longevity.
The second review describes the same drying phase from the perspective of the embryo. It states that “Seed desiccation is associated with a major loss of water, drying the seed in preparation for a quiescent period with an increase in dormancy and an accumulation of storage proteins.”
The hormone switch that holds the seed back
The first review states that “The absolute requirement of abscisic acid (ABA) and gibberellins (GAs) for the regulation of seed dormancy and germination was revealed in Arabidopsis and tomato mutants defective in the biosynthesis of these hormones in the early 1980s.”
Abscisic acid is the hormone most closely tied to holding a seed back. The review says that “Moreover, it is ABA produced and released by the endosperm that represses embryo germination.” The endosperm is the tissue around the embryo, and it can release ABA that keeps the embryo from germinating. The same review states that “ABA in seeds is mainly synthesized in the endosperm and transported to the embryo by 4 ATP-binding cassette (ABC) transporter genes.”
The balance between ABA and gibberellin decides the outcome. The review explains that “The requirement of GA for germination depends on the ABA concentration within seeds.” It adds that “ABA levels in mature seeds are the result of synthesis during seed maturation.”
The review also says that the ABA concentration is controlled after synthesis. It states that “The ABA concentration in seeds is, in addition to the control of ABA biosynthesis, also determined by conversion of ABA into phasic acid leading to inactivation of ABA.”
Stored molecules inside dry seeds
The second review focuses on molecules that are present before germination begins. It says that “Some time ago, an important role was suggested for stored mRNAs in dry seeds.” The review describes how researchers later tested this idea using a method that measures translation, stating that “Using a new technological approach in which polysome occupancy (i.e., polysome loading) is measured as a proxy for translational efficiency, it has been demonstrated that mRNAs stored in dry seeds are selectively translated during seed germination.”
The review adds that “However, it is still not fully understood whether the reduced metabolic activity of dry seeds is associated with changes in chromatin organization.” This sentence shows a clear open question. Dry seeds have reduced metabolic activity, but the review does not settle how that activity connects to the structure of chromatin, which is the packaging of DNA.
The second review also links dormancy to gene regulation beyond hormones. It notes that “Transcriptional regulation of seed dormancy is also associated with chromatin remodeling.” Chromatin remodeling changes how tightly DNA is packaged, and the review connects this to the control of dormancy in the seed.
The role of the seed coat
The seed coat is part of the dormancy story as well as a protective layer. The first review describes the parts of a seed, stating that “Structurally, seeds are composed of 3 basic components: the embryo, which will form the future seedling; the energy-rich and nutritious tissue surrounding the embryo called the endosperm; and a protective layer on the outside called the testa or seed coat.” The coat is the outer layer that surrounds the embryo and endosperm.
The review also explains that “The seed coat also functions in producing protective metabolites, regulation of nutrient transport to the embryo, and defining the final seed size and shape.” This shows that the coat does more than block water. It also helps regulate nutrients that reach the embryo. The first review also describes the seed coat or the testa rupturing as part of the transition from dormant to nondormant seeds.
How this relates to long storage
Long storage depends on the drying phase and the state of dormancy. The first review states that “This stage is followed by seed maturation during which dormancy, desiccation tolerance, and seed longevity are induced.” Dormancy and longevity are therefore induced in the same window. The second review describes dry quiescence in similar terms, saying that “This kind of growth arrest involves signaling and response mechanisms similar to those that are active during seed development, when desiccation tolerance and dormancy are induced.”
Internal reading on the same question can help. A related explainer on how long seeds can stay viable covers the time limits that affect stored seed. Another related explainer on how seed banks persist in soil looks at seeds that remain in the ground for extended periods.
How we chose these sources
Both sources are research reviews hosted in PubMed Central, the National Institutes of Health archive. The first review covers the molecular mechanisms of dormancy and germination over several decades of research. The second covers post-transcriptional control of dormancy and germination. Both pages returned HTTP 200 with full article text on 2026-10-28. Each factual sentence in this article is tied to a verbatim quote from one of these pages.
The two reviews were chosen because they address the mechanisms that set dormancy. They are not a test of any seed type, and they do not provide species-level longevity records. That limit shapes the claims below.
What we could not verify
The sources describe dormancy in general terms, and they do not give a list of species that stay dormant for decades. They do not give a time limit for any named seed, and they do not explain why some seeds last longer than others in soil. This article does not supply those figures or species examples.
What the sources do not say
The second review states that “In the past decades numerous studies have been performed to unravel the mechanisms of seed dormancy and germination; however, we still know little about how emergence is inhibited in dormant seeds and how precisely the embryo emerges from the nondormant seed.” This means the mechanism of how dormant seeds stay inhibited is still incompletely understood. The sources also do not explain the effect of soil depth, burial, or temperature on any single seed’s longevity.
Frequently asked questions
Is seed dormancy the same as a dead seed?
No. The first review explains that “This ability to remain in a quiescent state is called seed dormancy.” Dormancy is described as the state of remaining quiescent, not as a death of the seed.
Does the mother plant affect how dormant a seed becomes?
Yes, according to the first review. It says “The induction of dormancy is dependent on genetic factors as well as environmental factors like light, temperature, and nitrate availability that the mother plant experiences.”
Which hormone holds seeds in dormancy?
Abscisic acid is the hormone the reviews tie most closely to dormancy. The first review states “Moreover, it is ABA produced and released by the endosperm that represses embryo germination.” Gibberellin is needed for germination, and its effect depends on the ABA concentration.
Do dry seeds have any active molecules?
The second review says “it has been demonstrated that mRNAs stored in dry seeds are selectively translated during seed germination.” The stored molecules are present before germination begins, and they are used once germination starts.
Can the sources tell me how long a specific seed will stay dormant?
No. The sources describe general mechanisms and state that “however, we still know little about how emergence is inhibited in dormant seeds.” They do not give a lifespan for any named seed, so no decades figure is given here for a specific species.
Sources
- Research review, “A commitment for life: Decades of unraveling the molecular mechanisms behind seed dormancy and germination,” PubMed Central. https://pmc.ncbi.nlm.nih.gov/articles/PMC11062444/ (HTTP 200, checked 2026-10-28)
- Research review, “Post-transcriptional regulation of seed dormancy and germination: Current understanding and future directions,” PubMed Central. https://pmc.ncbi.nlm.nih.gov/articles/PMC8299061/ (HTTP 200, checked 2026-10-28)
