Study of primary transcriptional changes induced by EDS1/PAD4 in Arabidopsis using an estradiol-inducible system. Arabidopsis thaliana

Arabidopsis Enhanced Disease Susceptibility 1 (EDS1) and its direct partner Phytoalexin Deficient 4 (PAD4) are required for both basal resistance against virulent pathogens and innate immune responses mediated by all tested TIR (Toll-Interleukin-1 Receptors) type nucleotide-binding/leucine-rich-repeat (NLR) receptors. Using transgenic Arabidopsis plants in Col-0 eds1-2 pad4-1 background conditionally expressing PAD4 and constitutively expressing EDS1 (ED-P4E1), an EDS1/PAD4 immune response can be triggered by estradiol treatment and can induce expression of defense-related genes and lead to enhanced basal resistance. In order to capture primary transcriptional changes in response to EDS1/PAD4, we performed RNA-seq gene expression analysis in ED-P4E1 plants after estradiol or mock treatment at three time points: 6, 12 and 24 h. Overall design: We used transgenic Arabidopsis plants expressing PAD4 under the control of an estradiol-inducible promoter and EDS1 driven by CaMV 35S promoter in an eds1-2 pad4-1 mutant background (named ED-P4E1). The ED-P4E1 plants were grown at 22ºC for 4 weeks, and then were spray-treated with either 10 uM estradiol plus 0.01% silwet-L77 or 0.2% DMSO (in water) plus 0.01% silwet-L77 as mock control. Samples were collected at 6, 12 and 24h after treatment. For each condition, three replicates were obtained.