Mycorrhiza-induced resistance as a hub for plant immunity against pathogens and pests

Abstract

Plants have developed an immune system that allows them to cope with harmful organisms. This resistance can be stimulated through the use of beneficial organisms such as Arbuscular Mycorrhizal Fungi. Understanding the mechanisms that are part of this mycorrhiza-induced resistance (MIR) may give rise to a wide range of possible environment-friendly agricultural practices. In this doctoral thesis, the effectiveness of MIR in two different pathosystems has been studied: tomato plants against the necrotrophic fungi Botrytis cinerea and citrus plants against the herbivore insect Tetranychus urticae. On the one hand, the implication of the hormone peptide systemin in B. cinerea perception was confirmed in mycorrhizal plants. Furthermore, the overall response that occurs in mycorrhizal tomato plants upon Botrytis cinerea infection was assessed through transcriptomic, proteomic, phosphoproteomic, and metabolomic approaches. On the other hand, a comparative study of MIR mechanisms against spider mites in two citrus genotypes with different levels of basal resistance was performed.