PT - JOURNAL ARTICLE AU - Angélique Deleris AU - Jérôme Zervudacki AU - Agnès Yu AU - Jingyu Wang AU - Jan Drouaud AU - Lionel Navarro TI - Transcriptional control and exploitation of an immune-responsive family of retrotransposons in Arabidopsis AID - 10.1101/206813 DP - 2017 Jan 01 TA - bioRxiv PG - 206813 4099 - http://biorxiv.org/content/early/2017/10/20/206813.short 4100 - http://biorxiv.org/content/early/2017/10/20/206813.full AB - Mobilization of transposable elements (TEs) in plants has been recognized as a driving force of evolution and adaptation, in particular by providing genes with regulatory modules that impact their transcription. In this study, we employed an ATCOPIA93 Long terminal repeats (LTR) promoter-GUS fusion to show that this retrotransposon behaves like an immune-responsive gene during plant defense in Arabidopsis. We also showed that the reactivation of the endogenous ATCOPIA93 copy “EVD”, in the presence of bacterial stress, is not only negatively regulated by DNA methylation but also by Polycomb-mediated silencing -a mode of repression typically found at protein-coding and microRNA genes. Interestingly, one of the ATCOPIA93-derived soloLTRs is located upstream of the disease resistance gene RPP4 and is devoid of either DNA methylation or H3K27m3 marks. Through loss-of-function experiments, we demonstrated that this soloLTR is required for proper expression of RPP4 during plant defense, thus linking the responsiveness of ATCOPIA93 to biotic stress and the co-option of its LTR for plant immunity.