Every cloud has a silver lining: how abiotic stresses affect gene expression in plant pathogen-interactions

The current context of environmental and climate changes deeply influences the outcome of plantpathogen interactions. Indeed, nowadays it is clear that abiotic stresses strongly affect biotic interactions at various levels. For instance, physiological parameters such as plant architecture and tissue organization along with primary and specialized metabolism are affected by environmental constraints, thus making the plant a more or less worthy host for a given pathogen. Moreover, abiotic stresses can affect the timely expression of plant defense and pathogen virulence. Indeed, several studies have shown that variations in temperature, water and mineral nutrient availability impact plant defense gene expression. Virulence gene expression, known to be crucial for disease outbreak, is also affected by environmental conditions, potentially modifying existing pathosystems and paving the way for emerging pathogens. The present review summarizes the current knowledge on the impact of abiotic stress on biotic interactions at the transcriptional level in both the plant and the pathogen side of the interaction. We performed a meta-data analysis of four different combinations of abiotic and biotic stresses. 197 modulated genes were common to all four combinations, with a strong defenserelated GO term enrichment. We also describe the multistress-specific responses of selected defenserelated genes.