Seed dormancy is adopted by plants to optimize their reproductive strategy. The DOG1 (DELAY OF GERMINATION 1) gene is the main QTL controlling this trait in Arabidopsis (Bentsink et al., 2006) and therefore is extensively regulated. This includes the alternative polyadenylation (APA) of DOG1 mRNA (Cyrek et al., 2016) and an antisense transcript, asDOG1, which in cis suppresses DOG1 expression during seed maturation (Fedak et al., 2016). As with many antisense transcripts (Mellor et al., 2016; Rosa et al., 2016), asDOG1 originates from close to the transcription termination site of the sense gene. This raises the question of how this proximity affects antisense promoter activity.

Transcription terminators are DNA elements located at the 3' end of genes that ensure efficient cleavage of nascent RNA generating the 3' end of mRNA, as well as facilitating disengagement of elongating DNA-dependent RNA polymerase II. Surprisingly, terminators are also a potent source of antisense transcription. We have recently described an Arabidopsis antisense transcript originating from the 3' end of a master regulator of Arabidopsis thaliana seed dormancy DOG1. In this review, we discuss the broader implications of our discovery in light of recent developments in yeast and Arabidopsis. We show that, surprisingly, the key features of terminators that give rise to antisense transcription are preserved between Arabidopsis and yeast, suggesting a conserved mechanism. We also compare our discovery to known antisense-based regulatory mechanisms, highlighting the link between antisense-based gene expression regulation and major developmental transitions in plants.