Main conclusion PATOL1 contributes to increasing biomass not only by effective stomatal movement but also by root meristematic activity. Abstract PATROL1 (PROTON ATPase TRANSLOCATION CONTROL 1), a protein with a MUN domain, is involved in the intercellular trafficking of AHA1 H + -ATPase to the plasma membrane in guard cells. This allows for larger stomatal opening and more efficient photosynthesis, leading to increased biomas...