Seminars

The evolution of vascular tissues was a pivotal event that enabled land plants to function as integrated systems. Beyond serving as a passive transport conduit, we propose that the vasculature acts as an active information hub that perceives systemic inputs and orchestrates developmental outputs. We identify the RNA-binding protein JULGI as a central coordinator of this process, integrating diverse physiological signals to modulate plant architecture.
 JULGI functions as a post-transcriptional regulator by specifically recognizing conserved G-rich motifs within its target RNAs. This molecular mechanism allows the vasculature to interpret metabolic status, such as sugar availability, as an instructive signal for development. Furthermore, this regulatory capacity extends spatially: vascular-derived JULGI acts non-cell-autonomously to modulate miRNA biogenesis in the leaf lamina. By binding to G-rich regions of pri-miRNAs, JULGI modulates the production of key developmental regulators, thereby harmonizing leaf patterning with vascular status.
 JULGI-mediated G-rich RNA regulation is a conserved mechanism across land plants, highlighting its fundamental role in plant terrestrialization and evolution. Collectively, our study establishes the vasculature as a sophisticated signaling center that utilizes JULGI to perceive, interpret, and translate multiple systemic inputs into developmental outcomes.