Tuesday Sept. 24 // Impact of elevated temperature on the plant immune system

Christian Danve M. Castroverde
Department of Biology, Wilfrid Laurier University
Website: castroverdelab.ca
Twitter: @DanveC

Climate change combined with plant diseases pose serious threats to global agriculture and food security. Because the molecular mechanisms by which environmental factors affect plant immunity and disease are poorly understood, my research program aims to address this critical knowledge gap. We have recently reported that salicylic acid (SA) production is a temperature-sensitive pathway in the plant immune system (Nature Communications 2017 vol 8:1808). SA is an important plant hormone mediating immune responses against a broad range of pathogens.
 
How elevated temperature intercepts the SA pathway is currently unclear, and strategies to counter temperature-mediated suppression of SA production are also lacking. My continued research into this central biological question has shown that elevated temperature has a profound effect on gene expression of a calmodulin-binding master transcription factor (TF) controlling various immune regulators in plants. Remarkably, constitutive gene expression of this master TF was sufficient to recover SA production and immunity at elevated temperature. Global transcriptome analyses revealed that a significant suite of defense-related target genes were downregulated at elevated temperature. My research has identified a crucial temperature-regulated component of the plant immune system.
 
The upstream mechanisms involved in temperature regulation of this master TF are unknown. Whether temperature-sensitive immunity observed in the model plant Arabidopsis thaliana occurs in other plant species is also unclear. These are important next-level questions that I am currently investigating. By integrating molecular, genetic and biochemical approaches, my research program aims to understand plant-pathogen interactions in a dynamically changing environment, in order to shed light on plant resilience mechanisms.