I have been always fascinated on capability of plants to modify the surrounding environment and the plethora of mechanisms to cope with different stresses. This interest drives my career, focusing on how plant defenses do not only interfere with plant feeders, but also mediate the interaction between other arthropod communities, and more fascinating, how the result of these interactions depend on the complexity of the system. Understanding the molecular mechanisms involved in these interactions, and the impact on arthropod communities could help to engineer new environmental friendly strategies for pest control in agro-ecosystems.
My career started in the experimental station La Mayora, from the Spanish National Research Council (currently: IHSM, Málaga, Spain). Where I studied the inheritance of resistant mechanism in tomato against the Two-Spotted Spider Mite (Tetranychus urticae), taking advantage of the natural diversity of tomato related species. I described that tomato resistance was conferred by the presence of special leaf epidermal structures called glandular trichomes. These special trichomes secrete a viscous substance called acylsugars (complex molecules containing a core of sucrose that is conjugated with fatty acid compounds). Acylsugars create a double barrier against small arthropods, as physical barrier (sort of glue) and also works as antixenotic/antibiotic compounds on several tomato pests like T. urticae; whiteflies and new invasive species like Tuta absoluta and Tetranychus evansi. We conclude that these complex traits followed a relatively easy genetic model, mainly controlled by a major gene, facilitating the introgression of this trait in commercial varieties.
On the other hand, arthropods also count with a huge biodiversity that allowed to evolved mechanisms to cope with plant defenses. One of the most interesting mechanisms is the capability of some groups to manipulate induced defenses. Defense suppression is mediated by salivary proteins (effectors) injected into the plant. These proteins induce the plant into a kind of anesthetized stage that impede the plant to react against different stresses. One line of my research is to disentangle the molecular mechanisms involved in plant defense manipulation.
Plant-defense manipulation have important ecological implications that, in principle, could cause more problems than solutions to the suppressor species. I am also interested in the behavioral mechanisms developed by suppressor species in order to protect their host plant. For instance, T. evansi makes the plant more suitable for competitors and then it has developed several mechanisms to exclude invasive species that try to colonize the same plant. For instance, it creates a dense web than impede competitors to colonize the host plant, and males interfere with the reproduction of the other mite herbivores.