Anti-plant Defense Response Strategies Mediated by the Secondary Symbiont

Bacterial symbionts are omnipresent in insects, particularly aphids, and often exert important effects on the host ecology; however, examples of symbionts that mediate herbivore-plant interactions remain limited. Here, three clones with identical genetic backgrounds were established: a Hamiltonella defensa-free clone, H. defensa-infected clone and H. defensa-cured clone. H. defensa infection was found to increase the fitness of Sitobion miscanthi by increasing the total number of offspring and decreasing the age of first reproduction. Furthermore, gene expression studies and phytohormone measurement showed that feeding by the Hamiltonella-infected clone suppressed the salicylic acid (SA)- a…