The urgency of developing thermotolerant crops is highlighted by the threat of global warming to plant survival and its detrimental impact on growth and agricultural productivity. Achieving this objective requires a deep understanding of plant responses to heat stress at the molecular level. In pursuit of this understanding, we conducted an investigation into proteome dynamics in Ara-bidopsis thaliana seedlings exposed to moderate heat stress (30°C). By employing a novel approach that integrates 15N-stable isotope labeling and the ProteinTurnover algorithm, we conducted a thorough examination of proteomic changes across various cellular fractions. Our study revealed significant alterations in the turnover rates of 571 proteins, with a median increase of 1.4-fold, in-dicating heightened protein dynamics in response to heat stress. Interestingly, soluble proteins in the roots displayed minor changes, suggesting the presence of tissue-specific adaptive mechanisms. Additionally, our analysis identified substantial turnover variations in proteins associated with redox signaling, stress response, and metabolism, highlighting the complexity of the response network. Conversely, proteins involved in carbohydrate metabolism and mitochondrial ATP syn-thesis showed minimal turnover fluctuations, underscoring their inherent stability. This compre-hensive assessment provides insights into the proteomic adaptations of Arabidopsis seedlings to moderate heat stress, elucidating the delicate balance between proteome stability and adaptability. These findings enhance our understanding of plant thermal resilience and provide valuable support for the development of crops with enhanced thermotolerance.