Recurrent drought stress triggers transcriptional reprogramming and epigenetic modifications in apple seedlings

In this study, we explored the effects of recurrent drought stress on apple seedling morphology and investigated the transcriptomic and epigenetic changes in plants subjected to this treatment. Our results indicate that naïve apple seedlings can be primed upon first exposure to drought stress, and that primed plants respond differently to recurrent stress later in the season. Analyses of differentially expressed genes and differentially methylated regions further indicate that primed plants’ molecular responses differ significantly from plants exposed to drought stress for the first time.

Finally, our results suggest that following a winter period, the previously induced priming effect may be partially lost. Overall, our study demonstrates the importance of studying recurrent stress to better understand the memory-associated mechanisms leading to morphological and gene expression alterations in perennial plants.