Heat stress phenotyping: A key for plant selection in a warming climate

Climate change, through rising temperatures and more frequent heat waves, threatens food security and agricultural sustainability. Heat stress is a major abiotic factor that negatively affects plant function and crop yields. Advanced phenotyping strategies are critical for developing heat-resilient crops and mitigating the impacts of climate change. This review offers an updated perspective on plant phenotyping under heat stress, providing practical guidance for researchers. It discusses key trial sites, modern phenotyping techniques, and the physiological and molecular mechanisms that plants employ in response to heat stress. Special emphasis is placed on plant plasticity and its role in adaptive responses to stress. The review further examines advanced phenotyping technologies and sensors used across various environments, both field-based and controlled, and at multiple scales, from cellular to aerial. It highlights a range of approaches, from high-tech to cost-effective solutions, aimed at enhancing accessibility. Additionally, it underscores the importance of improved data management, standardized protocols, and alignment with international best practices in heat stress phenotyping. Finally, the review presents global initiatives focused on advancing plant phenotyping for heat stress research, emphasizing the critical role of international collaboration in addressing this urgent challenge.