Abstract

Aquaporins (AQPs), which serve as water channel proteins, are linked to a plethora of processes related to plant growth and development, such as water transport and the acquisition of carbon, nitrogen, or micronutrients. However, little is known about Acacia auriculiformis AQPs. In this study, we present the first transcriptome-wide identification of the AQP gene family in A. auriculiformis . The total of 21 AQP genes that were identified were divided into four sub-families (NIPs, PIPs, SIPs, and TIPs) based on a phylogenetic analysis. Functional prediction based on NPA motifs, the ar/R selectivity filter, and Froger’s positions, suggested substrate specificity for these A. auriculiformis proteins. AQPs, which were globally expressed in all organs (roots, stems, nascent and mature leaves), as shown by gene expression profiles, were responsive to three environmental cues: elevated CO 2 , salt, and drought. Heterologous expression of AaPIP1-2 in Arabidopsis thaliana played a positive role in the response to PEG-treated drought stress by maintaining relative water content and enhancing the activities of enzymes that scavenge reactive oxygen species (ROS). Reduced ROS was likely associated with an increase in the activities of ROS-scavenging enzymes, and might be linked with the up-regulated expression of AaAQP genes. This study provides comprehensive bio-information on A. auriculiformis AQPs which would be helpful for additional gene function analyses.