Parasitismo vegetal e transporte de metais: narrativas complementares da evolução e inovação molecular em plantas

Abstract

The evolution of land plants has been driven by the reuse, modification and specialization of ancestral molecular pathways that enabled the colonization of terrestrial environments and the diversification of both autotrophic and heterotrophic forms. This thesis integrates two major evolutionary axes: the emergence and diversification of plant parasitism, and the evolution of systems for metal acquisition and homeostasis. The first axis examines the haustorium, the key organ of parasitic plants, focusing on the mobility of long non-coding RNAs at the parasitehost interface, the co-option of defense and signaling pathways typical of non-parasitic plants, and the role of PRR-RLK receptors in the perception of molecules that trigger haustorium development. Together, these processes illustrate how biotic pressures shaped regulatory circuits capable of sustaining highly specialized parasitic lifestyles. The second axis investigates the strategies for iron uptake and the structural evolution of metal transporters, highlighting the convergent emergence of mechanisms for ferrous iron acquisition and the functional diversification of the HMA family. The synthesis of these themes reveals that mechanisms underlying signal perception, defense, mineral nutrition, and interspecies communication emerge from shared evolutionary principles shaped by convergence, co-option, modularity, and structural plasticity. Overall, the results presented here elucidate how ancestral molecular pathways were remodeled throughout plant evolution to generate distinct adaptive solutions.