Abstract:

In this study, the mechanism by which the antagonistic bacterium Burkholderia contaminans B-1 induces
resistance to Botrytis cinerea in postharvest Muscat grape berry was investigated. The results showed that B. contaminans
B-1 reduced significantly the rot rate of postharvest grape berries. Compared with the control, the rot rates of the stem and
fruit treated with B. contaminans were decreased by 69.58% and 63.93%, respectively. B. contaminans B-1 could affect the
phenylpropanoid metabolic pathway, reactive oxygen species metabolic pathway, and the activities of resistance-related
enzymes. Treatment with B. contaminans B-1 enhanced the activities of phenylalanine ammonia-lyase (PAL), peroxidase
(POD), superoxide dismutase (SOD) and polyphenloxidase (PPO). B. contaminans B-1 also increased hydrogen peroxide
(H2O2) content and delayed the peak time of catalase (CAT) activity, and enhanced the activities of resistance-related
enzymes, chitinase (CHI) and β-1,3-glucanase (GLU), in grapes.

Key words: Muscat grape, biological control, induced disease resistance