Multisensory integration predated land plant colonization

The transition from aquatic to terrestrial environments required complex multisensory systems that enabled plants to perceive and integrate a broader range of environmental cues, such as light intensity and temperature. However, it remains unclear whether this ability was a pre-adaptation or an innovation during early plant terrestrialization.

Here, we show that the aquatic streptophyte ancestor of land plants could integrate light and temperature through a complex regulatory network. A conserved regulatory nexus, comprising phytochromes and transcription factors, was active in the last common ancestor of land plants, allowing the first terrestrial colonizers to adapt and flourish on the harsh terrestrial surface of our planet. Thus, we propose that the multisensory integration that enables extant plants to achieve perceptual disambiguation and fine-tune growth in various ecological niches was a pre-adaptation encoded in the genomes of ancestral land plants.