Cutan, a common aliphatic biopolymer in cuticles of drought-adapted plants

The aliphatic biopolymer cutan, previously only known from Agave americana and Clivia miniata, was isolated in high purity from the leaf cuticles of several drought-adapted plants. These plants have succulent leaves with thick cuticles and all but one are CAM plants. The cutan biopolymer has been identified using a chemical extraction procedure followed by pyrolysis-GC/MS. These findings shed new light on the function of this biopolymer, in particular its occurrence in drought-adapted plants. In addition, a possible explanation arises for an outstanding debate on the origin of aliphatic biopolymers in certain fossil leaves and fossil terrestrial plant deposits. We propose that the presence of cutan in the fossil record may relate to a high contribution of drought-adapted plants, such as CAM plants.