Plant sexual reproduction in a warming world

Sexual reproduction is the most heat-sensitive phase of the plant life cycle; however, studies of reproductive failure under heat stress have primarily focused on individual organs. Here, we propose a conceptual framework in which heat stress causes a system-level breakdown of male and female gametophyte development, shared metabolic and proteostatic support networks, and pollen–pistil interaction. This combined collapse within a narrow temperature window cannot be predicted from individual organs or gametophytes. Heat also remodels epigenetic makeup, generating stress memory, though its transmission across generations remains unresolved. We highlight that techniques such as single-cell omics, AI-driven phenotyping, and genome editing can provide valuable mechanistic insights to support the development of predictive, actionable breeding strategies for heat-resilient crops.