Trichoderma asperellum T1 mediated antifungal activity and induced defense response against leaf spot fungi in lettuce (Lactuca sativa L.)

Publication date: April 2019Source: Physiological and Molecular Plant Pathology, Volume 106Author(s): Burhanah Baiyee, Shin-ichi Ito, Anurag SunpapaoAbstractLeaf spot, caused by Corynespora cassiicola and Curvularia aeria, is a major disease of lettuce that results in the reduction of the quality and the quantity of lettuce production. Primary in vitro examination revealed that Trichoderma sp. T1 inhibited the mycelial growth of C. cassiicola and C. aeria by 83.79% and 85.71%, respectively, in dual culture assays. Gel diffusion showed cell-free culture filtrate of Trichoderma sp. T1 inhibited C. cassiicola and C. aeria by 50.38% and 53.97%, respectively. Based on the ITS gene sequence, an effective T1 isolate was identified as Trichoderma asperellum. Treatments of lettuce plants with spore suspension of T. asperellum T1 induced defense-related enzymes such as peroxidase and polyphenol oxidase, and the cell wall degrading enzymes β-1,3-glucanase and chitinase in the plants. The activities of β-1,3-glucanase, chitinase, peroxidase and polyphenol oxidase were higher at 24 and 48 h after treatment with spore suspension of T. asperellum T1 than in the control group. Crude extract from inoculated lettuce caused morphology changes in fungal mycelia. In addition, reduction of disease severity was observed in lettuce pretreated with T. asperellum T1. The obtained results suggest that T. asperellum T1 efficiently controlled leaf spot and induced defense responses in lettuce.
Source: Physiological and Molecular Plant Pathology - Category: Molecular Biology Source Type: research