Induction of tomato defense against pseudomonas mediated by Endophytes isolated from wild wheat
In previous work, we isolated two fungal endophytes from Triticum diccocoides and Aegilops sharonensis, two ancestors of bread wheat Triticum aestivum. The two isolates were identified as Acremonium sclerotigenum and Sarocladium implicatum, and were able to induce resistance against drought in Triticum aestivum. In this work, we tested whether these fungal endophytes were able to induce resistance in plants of different class from the ones that were isolated from the beginning. Tomato plants (Solanum lycopersicum cv. Ailsa Craig) were inoculated with Acremonium sclerotigenum or Sarocladium implicatum and inoculated with the pathogenic bacterium Pseudomonas syringae. The endophytes-inoculated plants had significantly lower symptoms of bacterial infection as well as lower levels of colony forming units per leaf compared with endophytes-free control plants. Moreover, plants inoculated with endophytes and infected with P. syringae showed an altered balance of Jasmonic acid and Salicylic acid compared with endophyte free plants. In contrast to the decrease of bacterial infection, both endophytes had no effect on infection of plants with the grey mold fungus Botrytis cinerea.
In conclusion, our results show that endophyte induced resistance is effective across plants from different species and classes. A. sclerotigenum and S. implicatum are able to induce resistance in tomato against the biotrophic bacterium P. syringae, which was associated with changes in phytohormones levels, but they did not affect infection by the necrotrophic fungus B. cinerea.