Distribution of tannins as defensive chemicals in plant resources: the potential for ingestion by mammals

Abstract

Plants contain various defensive chemicals to protect themselves from consumers. Tannins are a generic term for polyphenols that bind to proteins to form insoluble complexes and are components of astringency. Tannins can harm consumers, including reduced protein digestibility and digestive tract damage. Although tannins are widely distributed in the plant kingdom, there is limited information on tannins in plants in Japan. In the present study, 349 plant species were used in the screening analysis to characterize the distribution of tannins. Tannins were detected in 174 species (49.9%), including plants with a recorded mammalian foraging. However, the selectivity and physiological responses of mammals to tannin-containing food resources remain unknown. Further physiological studies on plant-consumer interactions, as well as detailed food habit studies on mammals, are required.