On growth and flow: hydraulic aspects of aboveground meristems

Summary Water is essential for plant growth under both normal and stress conditions. Aboveground, two key meristems control plant development: the shoot apical meristem and the vascular cambium. Here, stem cell maintenance and cell differentiation are affected by hydraulic fluctuations across seasons, days, or even hours. Water fluxes, turgor pressure, osmotic gradients, and tissue mechanics are integrated by molecular signals to provide a robust control of meristematic activity. Despite this fundamental connection, our understanding of how meristems sense and respond to hydraulic changes is only beginning to emerge. Thus, integrating insights from research on plant stress and development opens exciting avenues to study meristem plasticity.