Genome-wide identification and characterization of aquaporins in mangrove plant Kandelia obovata and its role in response to intertidal environment.

Aquaporins (AQPs) play important roles in plant growth, development and tolerance to environmental stresses. To understand the role of AQPs in mangrove plant Kandelia obovata, which has the ability to acquire water from seawater, we identified 34 AQPs in the K. obovata genome and analyzed their structural features. Phylogenetic analysis revealed that KoAQPs are homologous to AQPs of Populus and Arabidopsis, which are evolutionarily conserved. Key amino acid residues was used to assess water-transport ability. Analysis of cis-acting elements in the promoters indicated that KoAQPs may be stress- and hormone-responsive. Subcellular localization of KoAQPs in yeast showed most KoAQPs function in the membrane system. Those transgenic yeast with increased cell volume showed that some KoAQPs have significant water-transport activity, and the substrate sensitivity assay indicate that some KoAQPs can transport H2O2. The transcriptome data were used to analyze the expression patterns of KoAQPs in roots, stems, leaves, flowers and developing fruits of K. obovata. In addition, RT-qPCR analyses combined transcriptome data showed that KoAQPs have complex responses to environmental factors including salinity, flooding and cold. Collectively, KoAQPs contribute to water and solute transport during growth and development of K. obovata, as well as adaptation to the coastal intertidal environment. This article is protected by copyright. All rights reserved.