Transcriptomic analysis reveals an estradiol-responsive pathway in Arabidopsis involving EDS1 and RBOHD and its modulation upon B. cinerea infection

Inducible promoters are invaluable tools in plant biology, enabling controlled modulation of gene expression while avoiding the potential negative effects of constitutive transgene activity. The XVE inducible system activated by β-estradiol is among the most widely used in plants. Although β-estradiol is generally regarded as biologically inert in plants, evidence suggests it may induce physiological changes, potentially through crosstalk with plant hormone signaling pathways. To investigate this, we performed a transcriptomic analysis of adult Arabidopsis thaliana plants at five days after β-estradiol treatment under both normal growth conditions and following infection with Botrytis cinerea. Our results show that β-estradiol induces substantial transcriptional reprogramming, affecting stress responses, immune pathways, and hormone signaling networks—including salicylic acid, jasmonic acid, ethylene, and abscisic acid. Moreover, β-estradiol treatment selectively modulates the plant's transcriptomic response to B. cinerea infection. Parallel analyses conducted in mutants lacking either the NADPH oxidase RBOHD or the immune regulator EDS1 revealed that both proteins contribute to the β-estradiol-influenced immune responses, both under basal conditions and after infection. These findings highlight the often overlooked biological effects of β-estradiol in plants and underscore the importance of accounting for its influence when employing it as an inducer in experimental studies.