cutina

Cutina is a term used in plant science to describe the polymeric component of the plant cuticle, commonly referred to in English as cutin. It forms the non-wax, polyester matrix that underlies the outer surface of aerial parts and is deposited by epidermal cells during cuticle formation. In many contexts, cutin and cutina are used interchangeably, with cutina reflecting historical or language-based usage in some botanical literature.

The cutin network is composed of long-chain hydroxy fatty acids, typically C16 and C18 derivatives, which bear hydroxyl and sometimes epoxy groups. These monomers are linked by ester bonds to create a cross-linked, water-insoluble polymer that helps seal the epidermis. The cuticle is often accompanied by epicuticular waxes that overlay the cutin layer, forming a composite barrier against water loss and environmental challenges.

Functions of cutina include reducing transpiration, providing a physical barrier to pathogens, and contributing to the mechanical strength of the plant surface. Biogenesis involves lipid synthesis in the epidermal cells, trafficking to the cell wall, and enzymatic polymerization to form the adhesive, protective matrix.

Composition and thickness vary among species and environmental conditions, reflecting adaptations to different climates. Cutin can be analyzed by depolymerization to identify monomer composition, typically using methods such as methanolysis followed by gas chromatography–mass spectrometry.

See also: plant cuticle, epicuticular wax, suberin.