RESUMO
Elevated atmospheric CO2 enhances photosynthetic rate,1 thereby increasing biomass production in plants. Nevertheless, high CO2 reduces the accumulation of essential nutrients2 such as phosphorus (P),3 which are required for photosynthetic processes and plant growth. How plants ensure enhanced growth despite meager P status remains enigmatic. In this study, we utilize genome-wide association analysis in Arabidopsis thaliana to identify a P transporter, PHT4;3, which mediates the reduction of P in chloroplasts at high CO2. Decreasing chloroplastic P fine-tunes the accumulation of a sugar-P metabolite, phytic acid, to support plant growth. Furthermore, we demonstrate that this adaptive mechanism is conserved in rice. Our results establish a mechanistic framework for sustainable food production against the backdrop of soaring CO2 levels across the world.