Enhancement of defense responses by <i>Clonostachys rosea</i> against Botrytis <i>cinerea</i> in tomatoes

Abstract

Clonostachys rosea ( C. rosea ) is a biocontrol agent that is used to combat and prevent phytopathogenic fungi attacks because of its ability to involve many factors and diverse modes of action. The reactions of C. rosea on the control of gray mold disease in tomato leaves were investigated in this study. To investigate the reactions of C. rosea in inducing resistance to tomato plants, three treatments, including Botrytis cinerea treatment (treatment B), C. rosea treatment (treatment C), C. rosea and B. cinerea treatment (treatment C + B) and water (control), to be applied on tomato leaves were set up. Disease severity was subsequently evaluated and compared with the control. The treatment of tomato leaves with C. rosea (15 μg/ml) significantly reduced the disease index after inoculation and severity of gray mold caused by Botrytis cinerea . The results indicated that the C. rosea treatment stimulated the activity of the defense related enzymes: Peroxidases (POX), lipoxygenases (LOX) and glutathione S-transferases (GST), and the treatment C + B reduced the incidence and severity of the gray mold. Furthermore, C. rosea treatment increased the acti vity of pathogenesis related proteins PR1. There fore, our results suggest that C. rosea could enhance the resistance of tomato plants to gray mold through the activation of defense genes and via the enhancement of defense-related enzymatic activities.