The mycotoxin patulin inhibits respiration of higher plant cells

Abstract

The mycotoxin patulin inhibits germination of apple pollen in vitro, and the growth of cultured soybean cell suspensions. Patulin inhibits pollen respiration by 50%. In soybean cultures both salicylhydroxamic acid (SHAM), an inhibitor of the cyanide-insensitive mitochondrial electron transport which is alternative to cytochrome electron transport, and patulin inhibit respiration 50–60%. In contrast KCN stimulates soybean cell respiration. Patulin and SHAM appear to compete for the same site(s) of inhibition since patulin is not as inhibitory when respiration is previously inhibited by SHAM. Patulin inhibits the entry of phenylalanine and threonine into soybean cells. Phenylalanine transport appears to be energy coupled since it is inhibited by the uncoupler 2,4-dinitrophenol (DNP) and by a combination of the respiratory inhibitors KCN plus SHAM.