The exponential increase in world population constitutes a global challenge to ensure food security. Paradoxically, crop quality and productivity are increasingly threatened by more frequent stress factors due to climate change and conversion of suboptimal soils into croplands. Compared to abiotic stressors, pathogens have wider impact on crop yield as they limit plant growth, interfere with post-harvest processes, and affect livestock and human health. Pathogens are responsible of 15% of global crop losses and compromise the equivalent of food for 600 million people. Therefore, deciphering features involved in plant defence is fundamental to complete our understanding about immunity and design biotechnological strategies to prepare plants for adverse environments.
There have been important limitations that precluded our capacity to elucidate mechanisms underlying immunity. First, plant immune responses have been mostly characterised upon pathogen infection in isolation, but not in combination with abiotic stressors as often occurs in nature. Second, immune responses rely on interconnections among multiple biological components and not on individual players, as traditionally addressed. Third, defence strategies characterised in model species might differ in species of agronomical interest due to interspecific barriers. To circumvent such limitations, I investigated plant immunity using sequential designs for abiotic-biotic stressors and systemic analysis in Arabidopsis and crop species.
Previous studies envisaged that metabolome reconfigurations during transient environmental changes tend to be persistent overtime. Thus, I hypothesised whether metabolite changes configured during abiotic stress conditions could act as signatures to retain “stress memory”. The overarching goal of MICROBIS was the identification of metabolic changes in Arabidopsis after exposure to abiotic stressors that enhance resilience against pathogens and set the path for translation into plants of agronomic interest. I addressed four objectives:
1. To characterise Arabidopsis immune responses under sequential stress periods reproducing natural conditions.
2. To recapitulate metabolome rewiring upon sequential stress and isolate candidate features for cross-tolerance.
3. To ascertain the biological relevance of candidate metabolites for cross-tolerance in planta.
4. To initially translate cross-tolerance mechanisms into species of agronomical interest.
The outcome of MICROBIS will contribute to design strategies that efficiently reinforce immunity against frequent pathogens in plants of agronomical interest.
