PROTON ATPASE TRANSLOCATION CONTROL 1-mediated H + -ATPase translocation boosts plant growth under drought by optimizing root and leaf functions.

Optimizing leaf photosynthesis and root water and mineral uptake in crops during drought is crucial for enhancing agricultural productivity under climate change. Although plasma membrane H ⁺ -ATPase plays a key role in plant physiological processes, its overexpression alone does not consistently improve growth. While PROTON ATPASE TRANSLOCATION CONTROL 1 (PATROL1) regulates H ⁺ -ATPase translocation in response to various environmental stimuli in leaves, its function in roots remains largely unknown. Here, we show that H ⁺ -ATPase was coimmunoprecipitated with PATROL1 in roots of Arabidopsis thaliana. Under hyperosmotic stress, PATROL1 overexpression line had significantly greater root length and lateral root numbers than wild type (WT) and knockout lines. Micrografting between WT and PATROL1 knockout or overexpression lines showed that PATROL1 is indispensable in both shoots and roots, indicating that root uptake and leaf photosynthesis are simultaneous limiting factors for plant growth under soil water deficit. Compared with the WT, PATROL1 overexpression in whole plants resulted in a 41% increase in shoot dry weight and a 43% increase in shoot nitrogen content under drought conditions. These findings highlight the potential of H ⁺ -ATPase regulation in both roots and shoots as a new strategy to improve plant productivity, particularly under drought conditions.