Hydroxyproline is a protein amino acid not encoded in the DNA, that is, it is part of the plant’s proteins, but it has no codon associated to it. It is mainly found in animal tissues, yet it is a component of some glycoproteins found in the cell wall. It shares properties with its proline precursor, and according to scientific literature, there is a connection between overcoming abiotic stress situations with the application of exogenous hydroxyproline.