Global climate change is a reality, day-to-day impacting our capacity to ensure food security worldwide. The timely reprogramming of gene expression in response to internal and external cues is essential for plant development and acclimation, especially in harsh environmental conditions. Understanding how plants do this is essential to design the next generation of stress-resistant crops. Recently, mRNA chemical (i.e epitranscriptomic) modifications were shown to play a key role in this process. In contrast, tRNA chemical modifications, although critical for optimal function of the translational apparatus, and much more diverse and quantitatively important compared to mRNAs modifications, were until recently considered as mainly static chemical decorations. The main objective of this project is, using several genome-wide approaches followed by functional validations, to test the hypothesis that plant tRNA epitranscriptomic marks can vary between different developmental stages and stress conditions and that these variations are not only passive consequences of different cellular conditions but can fine-tune translation to adapt plant responses to internal and external cues. It also aims at identifying the most critical tRNA marks needed to efficiency translate key developmental and stress responsive genes and to provide mechanistic evidence that proper codon decoding is central to this regulatory network. The project will attempt to establish tRNA epitranscriptomic variations as a new layer of plant gene regulation important for development and stress responses. It also aims at reveling direct links between tRNA marks, tRNA steady state levels, mRNAs translation efficiency and protein production at genome-wide level. This project will identify critical developmental and stress-responsive genes whose expression is affected by the loss of key tRNA marks. It will also reveal new gene targets for improving plant growth and its capacity to survive abiotic stresses.