Warm temperature and mild drought remodel transcriptome and alter Arabidopsis responses to mite herbivory

In the context of climate change, increased temperature and decreased water availability are expected to have profound effects on plant-herbivore interactions. To gain further insight into this issue, this work focuses on the dissection of the response of the Arabidopsis thaliana plant to the mite pest Tetranychus urticae under environmental conditions that resemble climate change. Phenotypical and molecular changes were analyzed in plants grown under mild drought and/or warm temperatures. When the transcriptome results were compared in standard and altered climate conditions, a large number of genes were found to be differentially expressed. Mite infestations in these plants showed that basal alterations conditioned the subsequent response of the plant to a specific biotic stressor. Warm temperatures favored mite performance and decreased jasmonic acid accumulation. Reduced plant damage in mild drought conditions was correlated with a higher jasmonic acid accumulation and the up-regulation of many genes involved in the production of defensive compounds. In conclusion, the use of ambient conditions that resemble climate change highlighted the drastic alterations in gene expression that may occur in nature. Understanding how these changes affect specific plant-herbivore interactions is crucial to determining how global warming will affect crop production in the future.