ROS AND SIGNALLING

ROS are, not only in plants, but also in animal cells, important signalling molecules. ROS (in particular H₂O₂) may:

• influence cell proliferation and cell death (either apoptosis or necrosis).

• influence gene expression. Many transcription factors contain cysteine residues that can be affected by ROS.

• directly activate a number of signalling pathways.

Signalling pathways that are targeted by ROS:

• activation of kinases
• inactivation of phosphatases

Reversible protein phosphorylation is the key biochemical event in many cell signalling pathways.

See more later on regulation of gene expression in the chapter Antioxidant defence - Endogenous.