Analysis of Clonostachys rosea-induced resistance to grey mould disease and identification of the key proteins induced in tomato fruit

• C. rosea induced tomato fruits resistance to gray mold most significantly.
• Biocontrol mechanism of C. rosea against B.cinerea in fruit is further clarified.
• The mechanism relies on changes of signal molecules and protective enzymes.
• ATP synthase CF1 alpha subunit is the abundant protein in C. rosea–treated fruit.

Tomato grey mould disease, which is caused by Botrytis cinerea, is a serious threat to tomato postharvest handling and storage. Clonostachys rosea is an effective antagonistic fungus to B. cinerea and can prevent this disease in tomatoes. To elucidate the mechanism of C. rosea-induced resistance in tomato, fruit were subjected to four treatments: spraying with B. cinerea, spraying with C. rosea, inoculation with C. rosea after spraying with B. cinerea, and inoculation with B. cinerea after spraying with C. rosea. Compared to the control (water), increases in indole acetic acid (IAA), salicylic acid (SA) and NO levels and enhanced phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities were observed, whereas catalase (CAT) activity and abscisic acid (ABA) levels decreased, particularly in the B. cinerea-plus-C. rosea- and C. rosea-plus-B. cinerea-treated fruit. We identified 22 proteins differentially expressed in the treated fruit compared to the control fruit using two-dimensional electrophoresis (2-DE) and mass spectrometry. ATP synthase CF1 alpha subunit was identified as an abundant protein in fruit sprayed with C. rosea. This study advances our understanding of C. rosea biocontrol mechanisms in tomato fruit.