Downstream signaling induced by several plant Toll/interleukin-1 receptor (TIR)-containing immune proteins is stable at elevated temperature

Plant immunity and in particular immune responses induced by nucleotide-binding leucine-rich repeat receptors (NLRs) are often dampened above the optimal plant’s growth range, but the underlying molecular mechanisms remains elusive. N-terminal Toll/interleukin-1 receptor (TIR) domains are self-sufficient to trigger immune signaling.

We showed that conditional activation of two well characterized TIR-containing NLRs (TNLs) or their corresponding TIR domains alone induce the same signaling route at permissive temperature (EDS1/RNLs requirement and activation of the salicylic acid sector) in Arabidopsis.

Yet, this signaling pathway is maintained under elevated temperature (30°C) when induced by TIRs-only, but not full-length TNLs. This work underlines the need to further study how NLRs are impacted by an increase of temperature, which is particularly important to improve the resilience of plant disease resistance in a warming climate.