Synergistic Effect\nof Two Peptaibols from Biocontrol\nFungus Trichoderma longibrachiatum Strain\n40418 on CO-Induced Plant Resistance

Trichoderma longibrachiatum is a\nfilamentous fungus used as a biological control agent against different\nplant diseases. The multifunctional secondary metabolites synthesized\nby <i>Trichoderma</i>, called peptaibols, have emerged as\nkey elicitors in plant innate immunity. This study obtained a high-quality\ngenome sequence for the T. longibrachiatum strain 40418 and identified two peptaibol biosynthetic gene clusters\nusing knockout techniques. The two gene cluster products were confirmed\nas trilongin AIV a (11-residue) and trilongin BI (20-residue) using\nliquid chromatography coupled with tandem mass spectrometry. Further\ninvestigations revealed that these peptaibols induce plant resistance\nto Pseudomonas syringae pv <i>tomato</i> (<i>Pst</i>) DC3000 infection while triggering\nplant immunity and cell death. Notably, the two peptaibols exhibit\nsynergistic effects in plant-microbe signaling interactions, with\ntrilongin BI having a predominant role. Moreover, the induction of\ntomato resistance against Meloidogyne incognita showed similarly promising results.