Abstract: Recent studies have documented plant responses to climate change extensively, particularly to single-stress exposures. However, critical factors for stress survival, such as sexual differentiation, are not often considered. The dioicous Marchantia polymorpha stands as an evolutionary milestone, potentially preserving ancestral traits from the early colonizers. In this study, we employed proteomic analyses complemented with physiological monitoring to investigate combined heat and drought responses in Tak-1 (male) and Tak-2 (female) accessions of this liverwort. Additionally, targeted transcriptomics was conducted using different natural populations from contrasting environments. Our findings revealed sex-biased dynamics among natural accessions, particularly evident under control conditions and during early stress responses. Although Tak-2 exhibited greater diversity than Tak-1 under control conditions, male accession demonstrated distinct and more rapid stress sensing and signaling. These differences in stress response appeared to be strongly related to sex-specific plasticity influenced by geoclimatic origin. Furthermore, we established distinct protein gene ages and genomic distribution trends, underscoring the importance of protein diversification over time. This study provides an evolutionary perspective on sexual divergence and stress emergence employing a systems biology approach, which allowed for the establishment of global and sex-specific interaction networks in the stress response.

Key words: abiotic stress, land adaptation, liverwort, sex‐biased response, systems biology