Pathogenesis-related (PR) proteins are proteins produced in plants in the event of a pathogen attack.[1] They are induced as part of systemic acquired resistance. Infections activate genes that produce PR proteins. Some of these proteins are antimicrobial, attacking molecules in the cell wall of a bacterium or fungus. Others may function as signals that spread “news” of the infection to nearby cells. Infections also stimulate the cross-linking of molecules in the cell wall and the deposition of lignin, responses that set up a local barricade that slows spread of the pathogen to other parts of the plant.[2]
Salicylic acid plays a role in the resistance to pathogens by inducing the production of pathogenesis-related proteins.[3] Many proteins found in wine are grape pathogen-related proteins.[4] Those include thaumatin-like proteins and chitinases.
Many pathogenesis-related protein families also coincide with groups of human allergens, even though the allergy may have nothing to do with the defense function of the proteins.[5] Grouping these proteins by their sequence features allows for finding potential allergenic proteins from sequenced plant genomes, a field of study dubbed "allergenomics".[6]
17allergens
was invoked but never defined (see the help page).