LEA Proteins

Late embryogenesis abundant proteins, or LEA proteins, are a group of diverse proteins commonly found in plants, bacteria, and some invertebrates. They are found during the later stages of development in seeds or embryos, hence the E in their name. They can also be found as a response to stress in other tissues. LEA Proteins are Intrinsically Disordered Proteins (IDPs); these types of proteins do not have a stable 3D structure and can change shape, aiding them in their primary function: to give cells a tolerance to water loss, freezing, salinity, and  other abiotic stresses. 

As IDPs, LEA proteins are able to form viscous layers between other macromolecules and when water is scarce, molecules are forced together. This viscous layer made of the LEA proteins keeps macromolecules from denaturing and prevents sensitive enzymes and structural proteins from clustering together. They can also interact with lipid bilayers, preventing fusion and leakage during the abrupt phase changes that occur during dessication, or water loss. Essentially acting as sponges that maintain stable lipid spacing. LEA proteins are also hydrophilic and charged. This acts against certain structure destroying substances by binding to soluble ions that can reach toxic levels within a cell. Along with ion sequestration, LEA proteins also maintain a level of hydration in a cell because they always have a shell of water surrounding them, even in dry conditions or during desiccation, preserving the hydrogen shells of other critical components of the cell. As LEA proteins dehydrate, they undergo a transformation, adopting secondary structures and giving themselves shape. This disorder-to-order transformation is key to LEA proteins’ protective capabilities during desiccation.

Going back to LEA protein’s role in abiotic stress responses, these responses don’t happen just in embryonic stages of development, but also have been observed in adult vegetative tissue. LEA proteins have a lot of diversity between plants due to duplication and mutations. This allows them to have genes that activate under different conditions and do different things. Some of these are activated via abiotic stress. The stresses produced by the environment cause a build up of Abscisic Acid, which activates Abscisic Acid Response Element. These bind to the promoter that causes the LEA proteins to be produced via gene transcription.

Despite decades of research, a single, universal mechanism for LEA protein function remains elusive. The functionality of LEA proteins is most likely context-dependent, involving numerous complex elements during gene transcription, taking into account life stage, stress and other molecular behaviors.

References:

Tunnacliffe, Alan, et al. “Lea Proteins: Versatility of Form and Function.” SpringerLink, Springer Berlin Heidelberg, 1 Jan. 1970, link.springer.com/chapter/10.1007/978-3-642-12422-8_6. 

Vogel, Johannes, et al. “New Generation of Resistant Sugar Beet Varieties for Advanced Integrated Management of Cercospora Leaf Spot in Central Europe.” Frontiers, Frontiers, 19 Oct. 2025, www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00222/full. 

Yenmiş, Melodi, et al. “Skin Structure, Coloration, and Habitat Utilization in Typical and Melanistic Morphs of the Grass Snake (Natrix Natrix) - the Science of Nature.” SpringerLink, Springer Berlin Heidelberg, 4 Apr. 2022, link.springer.com/article/10.1007/s00114-022-01794-w. 

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