AUTHOR=Agbessenou Ayaovi , Akutse Komivi S. , Yusuf Abdullahi A. , Khamis Fathiya M. 

TITLE=The Endophyte Trichoderma asperellum M2RT4 Induces the Systemic Release of Methyl Salicylate and (Z)-jasmone in Tomato Plant Affecting Host Location and Herbivory of Tuta absoluta

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.860309

DOI=10.3389/fpls.2022.860309

ISSN=1664-462X

ABSTRACT=<p>The use of endophytic fungi has dramatically increased plant performance through the enhancement of plant protection against abiotic and biotic stressors. We previously demonstrated that the endophytic fungus <italic>Trichoderma asperellum</italic> M2RT4 improves tomato defenses against the tomato leafminer <italic>Tuta absoluta</italic> through the reduction of oviposition, leafmining, pupation, and adult emergence. However, the underlying mechanism by which the presence of this endophytic fungus within tomato host plant affects <italic>T. absoluta</italic> host selection and life-history traits is unknown. We tested the behavioral responses of <italic>T. absoluta</italic> in Y-tube olfactometer bioassays and found that females preferred non-inoculated tomato plants against those inoculated by endophytes. Additionally, <italic>T. absoluta</italic> females were not attracted to non-inoculated infested nor to inoculated-infested tomato plants. Chemical analysis revealed the emission of methyl salicylate in inoculated tomato plant and an increase in the amounts of monoterpenes emitted from non-inoculated infested plants. Additionally, we found that upon herbivory, <italic>T. asperellum</italic> M2RT4 modulates tomato plant chemistry through the production of (<italic>Z</italic>)-jasmone thus activating both salicylic and jasmonic acid defense pathways. Further, <italic>T. absoluta</italic> females were attracted to monoterpernes including α-pinene, 2-carene, and β-phellandrene but repelled by methyl salicylate. Methyl salicylate could therefore be considered as a good semiochemical-based candidate for sustainable <italic>T. absoluta</italic> management using a “push-pull” approach. However, in dose-response bioassays, females of <italic>T. absoluta</italic> did not show any preference to the four component-blend (α-pinene, 2-carene, β-phellandrene, and methyl salicylate). (<italic>Z</italic>)-jasmone-treated tomato leaflets significantly reduced the leafmining activity of the pest at the concentration of 10 ng/μL and causing the highest larval mortality rate (83%) with the shortest LT<sub>50</sub> (1.73 days) 7 days post-treatment. <italic>T. asperellum</italic> M2RT4 effect on herbivore performance was then (<italic>Z</italic>)-jasmone-mediated. These findings expand our understanding of how the endophytic fungus <italic>T. asperellum</italic> M2RT4 could mediate chemical interactions between <italic>T. absoluta</italic> and its host plant which are potentially important for development of environmentally friendly <italic>T. absoluta</italic> management programs.</p>