Abstract:

The effect of protein elicitor from the nonhost Trichothecium roseum on black rot of apricot fruits and its possible
induction mechanisms were studied. The inductive effect and its time-dependent manner of the protein elicitor in apricot
fruits inoculated with Alternaria alternate at different times after treatment were studied. The effect of selected optimum
concentration of protein elicitor on reactive oxygen species (ROS) and resistance-related enzymes in apricot fruit tissue
were also evaluated. The lesion development of wound-inoculated apricot fruits were significantly reduced by protein elicitor
treatment(P < 0.05), and at 72 h after treatment with 14.4 μg/mL protein elicitorthe best induction effect on apricot fruits was
observed. The rate of superoxide anion (O2
- ·) production and the content of hydrogen peroxide (H2O2) in fruit tissue reached the
peak at 48 and 72 h, respectively. The activities of superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO),
β-1,3-glucanase (GLU) and chitinase (CHT) in apricot fruit tissue treated with the protein elicitor were also increased. The protein
elicitor treatment could significantly increase the disease resistance of apricot fruit tissue, and the possible mechanism might be due
to the outburst of ROS and the improved activities of resistance-related enzymes. So protein elicitor from Trichothecium roseum
may be a potential resistance inducer and can be further applied to postharvest diseases control.

Key words: Trichothecium roseum, protein elicitor, apricot fruit, reactive oxygen species, induced disease resistance, Alternaria rot