Seed Dispersal: Deciding when to move

Dandelion seeds respond to wet weather by closing their plumes, which reduces dispersal when wind conditions are poor.
  1. Lauren Sullivan  Is a corresponding author
  1. Department of Plant Biology, Michigan State University, United States
  2. Ecology, Evolution, and Behavior Program, Michigan State University, United States
  3. W. K. Kellogg Biological Station, Michigan State University, United States

When you think about plants spreading their seeds, you may conjure an image of dandelion seeds being carried away by the wind. In fact, if you have ever blown on a dandelion to make a wish, you may have helped a plant disperse its seeds to new habitats where it can reproduce more easily. Understanding how far seeds travel is important for predicting whether plant species will be able to keep pace with climate change and migrate to places with the right conditions for them to continue to grow (Corlett and Westcott, 2013).

As plants cannot move themselves to a new location, they rely on vectors to disperse their seeds away from them (Clobert et al., 2012). Some plants depend on non-living parts of an ecosystem to move their seeds: the dandelion, for instance, depends on the wind while seeds of other species may be carried by flowing water. Plants can also exploit the active movement of animals. For example, seeds can be consumed by animals or stuck to their fur or feathers, and thus be dispersed over large distances as animals often migrate when foraging for food or searching for a mate (Vittoz and Engler, 2007).

It is largely believed that plants that rely on non-living mechanisms are mostly passive in how their seeds are dispersed and have no control over where their seeds will eventually land. Now, in eLife, Naomi Nakayama and colleagues – including Madeleine Seale as first author – report new findings that turn this assumption on its head (Seale et al., 2022a). The team (who are based the University of Edinburgh and various institutes in the United Kingdom and The Netherlands) found that dandelion seeds can sense the environment and modify their shape to alter their own dispersal depending on the weather.

To understand how dandelion seeds move under both dry and wet conditions, Seale et al. placed individual seeds in a wind tunnel at different levels of humidity. In agreement with previous studies, they found that the hairs dandelion seeds use to travel via the wind are more spread out in dry environments, resulting in an open plume structure (Figure 1A). This configuration creates an air vortex ring above the plume that allows the seed to remain in the air for longer periods of time (Cummins et al., 2018). However, under humid conditions, such as in wet weather, the plume structure closes due to the swelling of cells on the flowering portion of the dandelion, also known as the seed head (Seale et al., 2022b; Figure 1B). The wind tunnel experiments by Seale et al. showed that when the seed has a closed structure, the vortex ring shrinks and moves closer to the plume. This changes the aerodynamics of the seed and causes it to fall faster, thus limiting how far it can travel by wind (Figure 1A and B).

Dandelion seeds change their shape in wet conditions, which alters their overall movement.

(A) Dandelion seeds can travel longer distances under dry conditions by opening their plumes. This configuration creates large vortices of air (represented by arrows) that help the seed stay aloft for longer, allowing it to travel further away from the plant. (B) Under wet conditions seeds change their shape to a closed state which only generates small vortices of air that cannot move seeds as far. However, the closed shape makes it harder for seeds to detach from the head of the dandelion, increasing the chance that seeds only disperse when conditions are more favorable (e.g., when it is dryer and windier). (C) The ability of seeds to morph (change shape between closed and open) leads to a larger proportion moving long distances under dry conditions compared to seeds that are always open (left yellow bar) and seeds that cannot morph under wet conditions (blue bar).

Seale et al. then investigated how humid conditions altered the chance that a seed would be released by placing whole seed heads in the wind tunnel. This revealed that those with a closed plume structure were much less likely to detach under wet conditions. In contrast, when conditions were dry, more dandelion seeds with open plumes dislodged from the seed head, particularly at high horizontal wind speeds which have been shown to increase seed detachment (Greene, 2005). These findings suggest that under humid, wet conditions (when wind speeds are typically lower) seed dispersal is initiated much less frequently. Seeds are then more likely to detach under dry conditions, which according to previous work leads to wind updrafts that pull the seeds high into the atmosphere, causing them to disperse over longer distances (Tackenberg et al., 2003).

Finally, Seale et al. explored how their wind tunnel results scaled up to affect how dandelion seeds disperse in the real world. The team used a simulation model that accounts for realistic wind, temperature and humidity dynamics (Soons et al., 2004) incorporated from local sources in Scotland. They found that under dry conditions, a greater percentage of seeds that were able to morph between open and closed plumes traveled longer distances than seeds that remained open (Figure 1C). In addition, if seeds had a closed plume, they were more likely to remain on the plant when conditions were not good for movement, i.e. when wind speed is low and/or there is high humidity.

The results of this study suggest that seeds can, in fact, sense their environment and that this environmental sensing allows plants to maximize their dispersal under variable conditions. This interdisciplinary work serves as a model for answering questions related to passive seed dispersal and showcases the power in connecting cellular mechanisms to aerodynamics and the ecological consequences of dispersal. Further studies could address whether other plant species can sense the humidity of their environment and morph accordingly so they only spread when weather conditions are best for moving long distances. This could influence their ability to adapt to changing wind patterns and increasingly warming temperatures caused by climate change (Kling and Ackerly, 2020).


Article and author information

Author details

  1. Lauren Sullivan

    Lauren Sullivan is in the Department of Plant Biology, and the Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, United States; and the W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, United States

    For correspondence
    Competing interests
    No competing interests declared
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4198-3483

Publication history

  1. Version of Record published: January 31, 2023 (version 1)


© 2023, Sullivan

This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.


  • 764
    Page views
  • 43
  • 0

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Lauren Sullivan
Seed Dispersal: Deciding when to move
eLife 12:e85477.
  1. Further reading

Further reading

    1. Physics of Living Systems
    Celine Bellegarda, Guillaume Zavard ... Claire Wyart
    Research Article

    The Reissner fiber (RF) is an acellular thread positioned in the midline of the central canal that aggregates thanks to the beating of numerous cilia from ependymal radial glial cells (ERGs) generating flow in the central canal of the spinal cord. RF together with cerebrospinal fluid (CSF)-contacting neurons (CSF-cNs) form an axial sensory system detecting curvature. How RF, CSF-cNs and the multitude of motile cilia from ERGs interact in vivo appears critical for maintenance of RF and sensory functions of CSF-cNs to keep a straight body axis, but is not well-understood. Using in vivo imaging in larval zebrafish, we show that RF is under tension and resonates dorsoventrally. Focal RF ablations trigger retraction and relaxation of the fiber’s cut ends, with larger retraction speeds for rostral ablations. We built a mechanical model that estimates RF stress diffusion coefficient D at 5 mm2/s and reveals that tension builds up rostrally along the fiber. After RF ablation, spontaneous CSF-cN activity decreased and ciliary motility changed, suggesting physical interactions between RF and cilia projecting into the central canal. We observed that motile cilia were caudally-tilted and frequently interacted with RF. We propose that the numerous ependymal motile monocilia contribute to RF's heterogenous tension via weak interactions. Our work demonstrates that under tension, the Reissner fiber dynamically interacts with motile cilia generating CSF flow and spinal sensory neurons.

    1. Cell Biology
    2. Physics of Living Systems
    Xarxa Quiroga, Nikhil Walani ... Pere Roca-Cusachs
    Research Article

    As cells migrate and experience forces from their surroundings, they constantly undergo mechanical deformations which reshape their plasma membrane (PM). To maintain homeostasis, cells need to detect and restore such changes, not only in terms of overall PM area and tension as previously described, but also in terms of local, nano-scale topography. Here we describe a novel phenomenon, by which cells sense and restore mechanically induced PM nano-scale deformations. We show that cell stretch and subsequent compression reshape the PM in a way that generates local membrane evaginations in the 100 nm scale. These evaginations are recognized by I-BAR proteins, which triggers a burst of actin polymerization mediated by Rac1 and Arp2/3. The actin polymerization burst subsequently re-flattens the evagination, completing the mechanochemical feedback loop. Our results demonstrate a new mechanosensing mechanism for PM shape homeostasis, with potential applicability in different physiological scenarios.