Activation of postharvest BTH treatment on phenylpropanoid pathway and pathogenesis- related proteins accumulation in apple fruit

The effect of benzothiadiazole( BTH) dipping on phenylpropanoid pathway and accumulation of pathogenesis- related proteins in apple fruit was investigated in this paper.Apple fruit( cv.Guoguang) were dipped in 100 mg / L BTH for 10 min to study the effect of BTH on key enzymes activities,metabolites accumulation in phenylpropanoid pathway and production of pathogenesis- related proteins( PRs). The results indicated that BTH treatment significantly increased the activities of phenylalanine ammonia- lyase( PAL) and 4- coumaric acid-coenzyme A ligase( 4CL),and the content of total phenolic compounds,flavonoids and lignin.The activities of β-1,3- glucanase( GLU),chitinase( CHT) and peroxidase( POD) were also induced by BTH treatment. These results suggest that postharvest BTH treatment induced disease resistance in apple fruit by activating phenylpropanoid pathway and promoted the accumulation of PRs.