Water uptake and transport are important for plant growth and development. The presence of aquaporins (AQPs) accelerates water transport at certain location and cells for the transmembrane water diffusion. Aquaporins are known as water channels as well as other small solutes channels, such as H2O2, CO2 and NH3. In roots, water passes through a series of cells, including epidermis, exodermis, cortical, endodermis and finally reaching xylem vessels for long distance transport. Three water pathways are included in this process, i.e., apoplastic pathway that water going through cell wall, symplastic pathway that water going through the plasmodesmata, and transmembrane pathway that water going through cell membrane. The transmembrane transport pathway, controlled by AQPs, makes water transport more flexible under unfavorable environment conditions. We measured water transport in maize root cells by cell pressure probe and compared cell hydraulic conductivity (Lpc) in wild type (WT) and AQP overexpression maize plants. Lpc was higher in the overexpression plants than in WT. In leaves, stomata are fine-tuned micropores presenting on leaf epidermis. The stomatal opening and closure are controlled by guard cell turgor pressure, which depending on osmolytes and water accumulation in guard cells. It is shown that AQPs play important roles in stomatal movements by affecting solutes transport and signaling pathways that inducing stomatal movements. Here, we found that stomatal closure was enhanced by AQP overexpression in maize under water deficit, and possible by regulating the transport of H2O and H2O2.