Better living through phytochemistry: “Phytoavengins” and reappraising the production-focused dichotomy for defensive phytochemicals

Abstract

Plant pathologists frequently divide defensive phytochemical specialized metabolites into two functional categories; 1) Phytoalexins that are synthesized de novo after pathogen perception, or 2) phytoanticipins that are either constitutively present or synthesized from preformed constituents. This two-category system for defensive phytochemicals based on plant-production has been widely used but reinforces misconceptions about non-phytoalexin phytochemicals. We propose that defensive phytochemicals synthesized from preformed constituents, typically as a consequence of tissue damage, should be classified separately from phytoanticipins as phytoavengins. In addition, we highlight the potential advantages of shifting towards focusing on the diverse modes-of-action and ecological contexts of defensive phytochemicals.