A UNIGE team has discovered the mechanisms by which the seed decides to remain in «hibernation» or to trigger its germination depending on the outside temperature.
Germination is a crucial stage in the life of a plant as it will leave the stage of seed resistant to various environmental constraints (climatic conditions, absence of nutritive elements, etc.) to become a seedling much more vulnerable. The survival of the young plant depends on the timing of this transition. It is therefore essential that this stage be finely controlled. A Swiss team, led by scientists from the University of Geneva (UNIGE), has discovered the internal thermometer of seeds that can delay or even block germination if temperatures are too high for the future seedling. This work could help optimize plant growth in a context of global warming. These results can be read in the journal Nature Communications.
Newly formed seeds are dormant: they are unable to germinate. After a few days (or even months, depending on the species), the seeds awaken and acquire the ability to germinate during the favorable season for seedling growth and new seed production. However, non-dormant seeds can still decide their fate. For example, a non-dormant seed that is suddenly subjected to excessively high temperatures (>28°C) can block germination. This mechanism of repression by temperature (thermo-inhibition) allows a very fine regulation. A variation of only 1 to 2°C can indeed delay the germination of a seed population and thus increase the chances of survival of future seedlings.
Read more at Université de Genève
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