Descripción del proyecto
Estudio en detalle sobre cómo se protegen las plantas de los herbívoros
Las plantas se defienden de los herbívoros a través de la producción de una gran cantidad de sustancias químicas tóxicas. Con todo, los sistemas planta-herbívoro pueden llegar a estar dominados por especialistas resistentes a las defensas vegetales, lo que a su vez favorece la evolución de nuevas fitotoxinas. En el proyecto CARDEVOL, financiado con fondos europeos, se estudiarán las causas y consecuencias ecológicas, evolutivas y fisiológicas de la diversificación fitoquímica. El equipo de CARDEVOL evaluará el papel funcional de la variación natural de los mecanismos de defensa en la eficacia biológica vegetal en una especie del género «Erysimum», que presenta una amplia distribución y que ha adquirido recientemente un nuevo mecanismo de defensa basado en cardenólidos. Para investigar adaptaciones coevolutivas, en CARDEVOL también se evaluarán los mecanismos de tolerancia y resistencia de una comunidad de herbívoros especialistas no adaptados al nuevo mecanismo de defensa.
Objetivo
Plant chemical defences play a central role in mediating interactions between plants and their enemies. Phytochemical diversity may be advantageous to reduce herbivore pressure, and plants commonly produce vast numbers of chemicals. However, the diversity of functional classes of defensive chemicals is often more limited and subject to strong phylogenetic constraints. Such functional conservatism may accelerate the evolution of tolerance in specialized herbivores, resulting in plant-herbivore systems dominated by specialists resistant to host plant defences. This presents major challenges for the study of phytochemically-mediated coevolution, as most systems lack the early stages of coevolutionary interactions that are crucially important to predict evolutionary trajectories. Occasionally however, the gain of functionally novel traits allows plants to escape their coevolved herbivores. The genus Erysimum (Brassicaceae) has gained functionally novel cardenolides in addition to ancestral glucosinolate defences, allowing it to escape several glucosinolate-adapted specialists. Making use of the unique natural and emerging molecular resources in this system, CARDEVOL will comprehensively evaluate the ecological, physiological, and evolutionary consequences of novel defences for the plant and its herbivores. CARDEVOL has four main objectives: 1) to characterize the full extent of natural variation in defence of a widespread Erysimum species and to identify environmental drivers; 2) to manipulate both defences and evaluate their contributions to plant fitness in the field; 3) to evaluate tolerance and resistance mechanisms of a community of non-adapted specialist herbivores towards the new defence; and 4), to evolve herbivores under artificial selection for increased resistance. CARDEVOL thus aims at pushing the boundaries of chemical ecology and transforming the field by elucidating the causes and consequences of phytochemical diversification involving gains of function.
Ámbito científico
Programa(s)
Régimen de financiación
ERC-STG - Starting GrantInstitución de acogida
8006 Zurich
Suiza