Organelle Remote Control of Alternative Splicing Through TOR

Light makes the difference between life and death for plants, it is their source of energy and also a regulator of plant growth and adaptations to the environment. In plants, light regulates gene expression at various levels including alternative splicing. Chloroplasts are a key part in this process sensing light and providing retrograde signals which modulate alternative splicing in the leaves but also in the roots. We show here that sugars are the mobile signals responsible for the alternative splicing changes in the roots. We provide evidence for the involvement of mitochondria and the activation of TOR kinase in this light signaling pathway. Furthermore, translation activation seems to be of most relevance in order to properly adjust the alternative splicing patterns in response to light/dark transitions and might be a common node for cross-regulation by different pathways.