Amidst the growing challenges of climate change, crops face threats from rising temperatures and prolonged droughts, leading to reduced photosynthetic efficiency and the need for rapid stress acclimation. In this PhD project we will investigate the role of the nucleotide guanosine tetraphosphate (ppGpp) signalling pathway, a known regulator of plastid function and photosynthesis. Recent preliminary work from our and other labs indicate that ppGpp plays a pivotal role in plant stress acclimation, and we have indications that perturbation of ppGpp signalling affects plant responses to heat stress. This research aims to explore how ppGpp is involved in plant acclimation to heat and drought stress. Using a combination of physiological evaluations, biochemical techniques, transcriptomics, and biosensors this study will investigate the modulation of ppGpp levels under stress conditions, its impact on plastid genome expression, and its intersection with other signalling pathways. The ultimate goal is to enhance our understanding of ppGpp's role in plant acclimation, offering insights for improving crop resilience in a climate-challenged world.