Work

Regulatory Divergence in Wound-Responsive Gene Expression between Domesticated and Wild Tomato

Year: 2018

Type: article

Abstract: ABSTRACT Background The evolution of cis- and trans- regulatory components of transcription is central to how stress response and tolerance differ across species. However, it remains largely unknown how divergence in TF binding specificity and cis -regulatory sites contribute to the divergence of stress-responsive gene expression between wild and domesticated species. Results Using tomato as model, we analyzed the transcriptional profile of wound-responsive genes in wild Solanum pennellii and domesticated S. lycopersicum . We found that extensive expression divergence of wound-responsive genes is associated with speciation. To assess the degree of trans-regulatory divergence between these two species, 342 and 267 putative cis- regulatory elements (pCREs) in S. lycopersicum and S. pennellii , respectively, were identified that were predictive of wound-induced gene expression. We found that 35-66% of pCREs were conserved across species, suggesting that the remaining proportion (34-65%) of pCREs are species specific. This finding indicates a substantially higher degree of trans-regulatory divergence between these two plant species, which diverged ∼3-7 million years ago, compared to that observed in mouse and human, which diverged ∼100 million years ago. In addition, differences in pCRE sites were significantly associated with differences in wound-responsive gene expression between wild and domesticated tomato orthologs, suggesting the presence of substantial cis -regulatory divergence. Conclusions Our study provides new insights into the mechanistic basis of how the transcriptional response to wounding is regulated and, importantly, the contribution of cis- and trans- regulatory components to variation in wound-responsive gene expression during species domestication.

Source: The Plant Cell

DOI: 10.1105/tpc.18.00194