HDA6 is redox-sensitive and required for heat-stress tolerance A. Dard 2022

Histone deacetylases (HDAs) play an important role in plant adaptation to environmental changes by modulating gene expression. In animals, some HDAs are regulated by oxidation-reduction (redox) modifications, and we hypothesize that plant HDAs may be regulated during stresses known to generate cellular oxidation. During my thesis, I discovered that KO mutants of HDA6 (a plant HDA) are extremely sensitive to heat stress (37°C). My RNA-seq analysis shows a marked deviation in gene expression in the mutant at 37°C. Moreover, I detected a redox modification of HDA6, under oxidative conditions, affecting its oligomerization state. Furthermore, I found that HDA6 co-localizes with the cytosolic stress granule marker protein PAB2 at 37°C in a redox-dependent manner, suggesting that HDA6 is part of stress-granule complexes. Finally, my work highlights the emerging link between redox signaling and histone acetylation in response to heat stress.