The nutritional value of seeds is explained by the accumulation of proteins, starches, and oils during plant development and maturation, which has allowed their sustained use as a food base. Understanding the mechanisms that enable seeds to remain viable in adverse conditions has become a relevant field of study in plant biology.
Plant adaptation and extreme dehydration Researcher Alejandra Covarrubias Robles from the Institute of Biotechnology (IBt) at the National Autonomous University of Mexico studies the adaptive characteristics that allow seeds to keep the embryo alive even when they are practically dehydrated for prolonged periods. This phenomenon is characteristic of spermatophytes, plants that, upon completing their development, can lose more than 90% of their accumulated water without compromising the embryo's viability, a condition incompatible with the survival of animal tissues.
The vitreous state and embryo protection One of the key processes identified in the dry seed is the formation of a solid, vitreous state, a physical condition similar to glass that contributes to the structural and functional stability of the embryo. This state is achieved during the final stages of water loss and is essential for prolonged conservation. Water, an indispensable element for life, is functionally replaced by specialized molecular components that prevent irreversible damage during dehydration.
LEA proteins: flexibility and multiple functions Proteins known as LEA (Late Embryogenesis Abundant) accumulate significantly in dry seeds and also in the roots and leaves of plants subjected to drought stress. In vitro studies show that these proteins can keep other dehydration-sensitive proteins active, which opens the possibility of using them to preserve embryos, cells, or proteins under water stress or freezing conditions. These properties suggest potential applications in both plant breeding to select more resistant and durable seeds, and in biotechnology and medicine.
Seeds as biological time capsules Seeds can remain in a dormant state for long periods, resisting fires, frosts, prolonged droughts, and even transit through the digestive tract of animals. These studies are mainly carried out on Arabidopsis thaliana, a model plant widely used in plant biology. Complementarily, bean seeds are analyzed, in which drought-induced genes associated with LEA protein production have been identified.
Biological implications and potential applications LEA proteins are not restricted to the plant kingdom. These proteins were originally described by researcher Leon Dure III in cotton seeds. Unlike globular proteins, LEA proteins are structurally disordered, which gives them conformational flexibility and the ability to adopt different structures depending on the environment, allowing them to perform more than one protective function.
Experimental evidence and study models The research team has demonstrated that by modifying or deleting genes that encode LEA proteins, seeds show lower viability, accelerated aging, and loss of nutritional value. This capacity was decisive for plants with seeds to dominate the terrestrial flora and colonize almost all ecosystems. These findings were disseminated by Alejandra Covarrubias Robles and Inti A. Arroyo Mozo in the article "Secretos de las semillas," published in the magazine "¿cómo ves?", which exposes the central role of seeds as key biological structures in the history of the planet and humanity.
