Effect of 4EHP (nCBP) mutation on gene expression during heat stress responses in Arabidopsis thaliana

In this study, we show that loss of the class II eIF4E known as 4EHP (nCBP) confers enhanced basal and acquired thermotolerance and causes a mild flowering delay without major root defects. Under heat stress, 4EHP-GFP re-localizes from a diffuse cytosolic pattern to cytoplasmatic foci, where it co-localizes with canonical stress granule (SG) markers.

Transcriptomic analysis under control, acclimation and heat stress conditions reveals that 4EHP limits the accumulation of a specific subset of heat-responsive mRNAs, especially those encoding several heat shock proteins (HSPs), which remain constitutively expressed in 4ehp-1 mutant under control conditions and during heat stress. Our results indicate that 4EHP regulates chaperone production, via heat-responsive SG regulatory pathway for the corresponding mRNAs.