THE ROLE OF RETROGRADE SIGNALS DURING PLANT STRESS RESPONSES

STRAND, Å; BLANCO, N.E.; WHELAN, J.

Parana

Congreso; 54th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2018

SAIB

Cells can sense changes in the environment by external cues that affect different receptors on the cell surface. Exposure to stress also inhibits metabolic activities and causes severe constraints on cellular energy homeostasis. Recovery of energy homeostasis by restoring respiration and photosynthesis is therefore essential for stress acclimation and plant productivity during stress. Organelles play crucial roles as stress sensors in the cell and communicate their status through so-called retrograde signals to regulate nuclear gene expression. Thus, the stress signalling response is not linear but rather a complex integration of signalling networks originating in different cellular compartments. The Mediator kinase module subunit CDKE1/CDK8 was identified through a screen for mutants that did not respond correctly to retrograde signals triggered by oxidative stress. The cdke/cdk8 mutant demonstrated a genome-uncoupled phenotype in response to retrograde signals originating in both mitochondria and plastids. As a consequence the mutant showed severely impaired ability to recover energy metabolism following exposure to stress. CDKE1 is potentially a central nuclear component integrating mitochondrial and plastid retrograde signals playing a role in regulating energy metabolism during the response to stress