Aluminum (Al) is one of the most abundant elements of the Earth's crust. Acidic soils (pH <5.0) comprise about 40% of the world arable land, and under these conditions, Al is in the form of Al 3+ , which is toxic to most plants. In the presence of Al, there are reduction in the gas exchange parameters and leaf hydration, which m ay be directly related to the decrease in root water transport. Aquaporins are integral prote ins of the plasma membrane that facilitate water transport and they can contribute to more tha n 50% of the root hydraulic conductivity by transmembrane pathway. Therefore, a decrease in aquaporin abundance in the roots may lead to lower water transport up to the leaf. In a 90-day study, we cultivated 'Rangpur' lime plants ( Citrus limonia ) in nutrient solution with Al. At six time points, we measured gas exchange, water potential ( Ψ w), relative water content (RWC) in the leaves and we also assessed the expression of three aquaporin genes in the roots, PIP1-1 , PIP1-2 and PIP2 . We confirm lower leaf hydration by a reduction in RWC and Ψ w, as well as decreased CO 2 ( A ) assimilation, stomatal conductance ( gs ), transpiration ( E ), and estimated hydraulic conductivity from the root to the leaf ( K L ) in plants exposed to Al. In addition, plants submitted to Al presented an attenuation in the tra nscriptional profile of PIP1-1 and PIP2 , and an increase in the expression of PIP1-2 , of which only PIP1-1 presented a correlation with A and gs in the Al treatment. Our data suggests that the at tenuation in the transcriptional profile of PIP1-1 is associated with the low leaf hydration observed in ‘Rangpur’lime plants exposed to Al.