Assessment of 3 Tac-I/Beta, an Antimicrobial Peptide Source, in the Control of PseudomonasPlant Pathogens | Biomed Grid

Diseases caused by Pseudomonas syringae and other species of Pseudomonas cause severe losses in different fruit crops worldwide. Antimicrobial peptides (AMPs) are small and consist of a variety of proteins that act on the lipid bilayer of the bacterial membrane that is produced by multicellular organisms. The product, 3 Tac-I/Beta, is a biopesticide that bases its action on three Trichoderma strains (T. viride strain T-26, T. harzianum strain T-22, and T. longibrachiatum strain T-397), its total concentration is >25 x 103 c.f.u. g-1, which is authorized in Chile to control different fungal diseases in fruit and vegetable crops. However, the reduction of bacterial stone canker disease has suggested a possible AMPs mode of action associated with 3 Tac-I/Beta. In this study we used Transmission Electronic Microscopy (TEM) to assess the possible AMP activity of this product on the bacterial membrane of Pseudomonas syringae pv. syringae (Pss). The effect of two filtered solutions of 3 Tac-I/Beta (commercial and concentrated) on the population of this bacterium was assessed by using in vitro tests.