High-resolution temporal transcriptome sequencing unravels ERF and WRKY as the master players in the regulatory networks underlying sesame responses to waterlogging and recovery

Abstract

Major crops are generally sensitive to waterlogging, but our limited understanding of the waterlogging gene regulatory network hinders the efforts to develop waterlogging-tolerant cultivars. We generated high-resolution temporal transcriptome data from root of two contrasting sesame genotypes over a 48 h period waterlogging and drainage treatments. Three distinct chronological transcriptional phases were identified, including the early-waterlogging, late-waterlogging and drainage responses. We identified 47 genes representing the core waterlogging-responsive genes. Waterlogging/drainage-induced transcriptional changes were mainly driven by ERF and WRKY transcription factors (TF). The major difference between the two genotypes resides in the early transcriptional phase. A chronological transcriptional network model predicting putative causal regulations between TFs and downstream waterlogging-responsive genes was constructed and some interactions were validated through yeast one-hybrid assay. Overall, this study unveils the architecture and dynamic regulation of the waterlogging/drainage response in a non-model crop and helps formulate new hypotheses on stress sensing, signaling and sophisticated adaptive responses.

Keywords: Gene regulatory network; Sesame; Transcription factors; Waterlogging.