BMC Genom. 21, 396 (2020).

Extreme climate-related events threaten food security. The predicted continued increase in frequency and severity of drought, a major contributor to crop losses, highlights the need to better understand plant drought responses as a first step in improving crop resilience.

Caitlin Simopoulos, Mitchell MacLeod and colleagues at McMaster University, Canada, investigated drought response in Eutrema salsugineum, a salt-tolerant extremophyte species closely related to cruciferous crops. Previous research comparing drought response in two ecotypes (races) of E. salsugineum, revealed that while the ecotypes responses were physically similar under a single drought treatment, they differed when the stress was repeated. Here, comparative transcriptomics was undertaken to clarify gene expression differences between the two ecotypes during a two-stage drought treatment. The study revealed extensive drought-related reprogramming that vastly differed between the ecotypes.

These works highlight the importance of understanding how organisms respond to successive (as opposed to single) stress events, and underscore how these responses can be driven by genetic diversity that is apparent even at the sub-species level.