Overview:

“The main goal of our research is to comprehensively understand how plants respond to pest attacks, not only by studying the induction of defence mechanisms but also by evaluating the potential fitness costs associated with these responses. Expanding our knowledge in this area allows us to explore strategies and compounds that enhance pest resistance without compromising crop yield”.

To fulfil this objective, we have established two main lines of research:

Research lines:

1. Dissection of the molecular mechanisms underlying plant responses to pest attacks
   

In our group, we use different approaches to identify and characterize genes and pathways involved in plant response to pests. To this end, we use the Arabidopsis thaliana–Tetranychus urticae model system, as well as other plant and phytophagous species, to study the specificity of the molecular mechanisms. So far, we have identified key genes and pathways involved in plant defence against the spider mite at various levels of the plant defence response (Figure 1).

FIGURE 1 | Summary of plant response to spider mite characterization. Modified from Santamaría et al., 2018.

Induced defences have evolved from constitutive defences as a cost-saving strategy. However, the activation of defence responses often entails a fitness cost. Assessing these costs can help in designing pest control strategies that enhance resistance without compromising fitness. Our results show that, in general, the implementation of defences against pests leads to a reduction in growth, photosynthesis, and reproduction (see Figure 2A). In addition, we are interested in the study of the effect of the different parameters surrounding plant herbivore interaction in the final cost (see Figure 2B). In the specific case of the Arabidopsis–spider mite interaction, we have observed that defence activation results in decreased seed production and reduced seed viability during storage (Garcia et al., 2024).

Understanding the molecular mechanisms that regulate the defence–growth trade-off is key to designing pest control strategies that enhance resistance without compromising the plant’s overall fitness. In our laboratory, we combine different molecular approaches to investigate this regulation (see Figure 3). In the Arabidopsis-spider mite interaction, integrating fitness parameter studies with transcriptomic and hormonomic analyses has enabled us to propose a model for the regulation of the defence-growth trade-off. This model reveals a finely tuned regulatory mechanism that allows the plant to adapt to stress and survive, albeit with a fitness cost (Garcia et al., 2024).

2. Exploration of strategies and compounds that enhance plant resistance to pests without incurring fitness costs

Various strategies have been proposed to enhance resistance without compromising fitness. Among these, our laboratory focuses on seed defence priming (SDP) and the identification and application of cell wall-derived damage-associated molecular patterns (DAMPs).

Plants have developed the capacity to respond to previous stimuli by enhancing the activation of inducible defences upon later infestation or herbivore attack. This physiological process, known as defence priming, triggers a minor part of the plant defence response and enables prompter or more effective reactions against future biotic or abiotic stresses. However, although primed plants theoretically endure fewer costs in relation to the direct activation of defences, the physiological alterations while shifting the plant to the alert are bound to cause some allocation and/or ecological costs. Under this scenario, our objective is to identify priming agents that produce higher resistance, minimizing the penalty in plant fitness and to unveil the molecular basis of how these priming treatments modulate the defence-growth trade-off established upon the infestation (see Figure 4). Besides our Arabidopsis-spider mite working model, we will extend our analyses to the related crop Brassica rapa and the herbivorous insect Pieris brassicae. As an example, we just validated the potential of the application of MeJA to the Arabidopsis seeds in defence against both spider mite and Pieris. The molecular mechanism behind were pest specific (Talavera-Mateo et al., 2025).

FIGURE 4 | Simplified scheme of the potential effect of “priming” over the plant defence-growth trade-off. The plant cell wall has traditionally been regarded as a physical barrier against infestation by pests and pathogens. In recent years, the scientific community studying plant–pathogen interactions has highlighted the role of cell wall-derived compounds in triggering defence activation and their potential application in pest control. However, this aspect has been less explored in plant–pest interactions. In our group, we aim to investigate the role of the cell wall in defence against pests, considering not only the enhancement of defence responses but also the impact on plant fitness.

The plant cell wall has traditionally been regarded as a physical barrier against infestation by pests and pathogens. In recent years, the scientific community studying plant-pathogen interactions have highlighted the role of cell wall-derived compounds in triggering defence activation and their potential application in pathogen control. However, this aspect has been less explored in plant–pest interactions. In our group, we aim to investigate the role of the cell wall in the defence-growth trade-off that occurs in plants upon pest infestation, and to identify cell wall-derived DAMPs that could potentially be used in pest management strategies (see Figure 5).

FIGURE 5 | Schematic overview of pattern-triggered immunity (PTI) in plants upon pest infestation. Cell wall degrading enzymes (CWDEs) secreted by herbivory disrupt CW integrity, releasing damage-associated molecular patterns (DAMPs). The defence response is activated by the recognition of these DAMPs, as well as herbivore-associated molecular patterns (HAMPs), by pattern recognition receptors complexes (PRRs and co-PRRs). Elicitor binding to PRRs leads to a series of signalling events, such as membrane depolarization (Vm), activation of Ca2+-channels and influx of Ca2+ into the cytosol, burst of reactive oxygen species (ROS) via activation of RBOHD, membrane depolarization and activation of the mitogen-activated protein kinases (MAPK) cascade. MAPK and Ca2+-dependent kinase (CDPK) cascades trigger transcriptional reprogramming, activating phytohormone (SA, JA, ET) signalling, transcription regulatory factors and synthesis of defensive compounds. 

In addition to these main research lines, we collaborate with private companies in the search for plant-derived metabolites or by-products with potential activity in pest defence.