Genome-wide characterization and expression analysis of aquaporins in salt cress (Eutrema salsugineum).

Weiguo Qian,Jiawen Li,Rui Luo,Xiaomin Yang,Qiuying Pang,Xiufeng Yan

doi:10.7717/peerj.7664

Abstract

Aquaporins (AQPs) serve as water channel proteins and belong to major intrinsic proteins (MIPs) family, functioning in rapidly and selectively transporting water and other small solutes across biological membranes. Importantly, AQPs have been shown to play a critical role in abiotic stress response pathways of plants. As a species closely related to Arabidopsis thaliana, Eutrema salsugineum has been proposed as a model for studying salt resistance in plants. Here we surveyed 35 full-length AQP genes in E. salsugineum, which could be grouped into four subfamilies including 12 plasma membrane intrinsic proteins (PIPs), 11 tonoplast intrinsic proteins (TIPs), nine NOD-like intrinsic proteins (NIPs), and three small basic intrinsic proteins (SIPs) by phylogenetic analysis. EsAQPs were comprised of 237–323 amino acids, with a theoretical molecular weight (MW) of 24.31–31.80 kDa and an isoelectric point (pI) value of 4.73–10.49. Functional prediction based on the NPA motif, aromatic/arginine (ar/R) selectivity filter, Froger’s position and specificity-determining position suggested quite differences in substrate specificities of EsAQPs. EsAQPs exhibited global expressions in all organs as shown by gene expression profiles and should be play important roles in response to salt, cold and drought stresses. This study provides comprehensive bioinformation on AQPs in E. salsugineum, which would be helpful for gene function analysis for further studies.

Highlights

Water is the most abundant molecule in living cells, forming the basic medium in which all biochemical reactions take place (Dev & Herbert, 2018)
Based on the phylogenetic analysis, we found that the identified EsAQPs have very high similarity with AtAQPs which can be grouped into four subfamilies, including 12 plasma membrane intrinsic proteins (PIPs), 11 tonoplast intrinsic proteins (TIPs), nine NOD-like intrinsic proteins (NIPs) and three small basic intrinsic proteins (SIPs)
The EsPIP subfamily was further divided into two classes, the EsTIP subfamily into five classes, the EsNIP subfamily into seven classes (1 EsNIP1s, 1 EsNIP2s, 1 EsNIP3s, three EsNIP4s, one EsNIP5s, one EsNIP6s and one EsNIP7s), and the EsSIP subfamily into two classes

Summary

Introduction

Water is the most abundant molecule in living cells, forming the basic medium in which all biochemical reactions take place (Dev & Herbert, 2018). Aquaporins (AQPs) belong to the major intrinsic proteins (MIPs) superfamily, which could selectively transport water molecules across the cell membrane. AQPs can transport many small molecules, such as glycerol, urea, carbon dioxide (CO2), silicon, boron, ammonia (NH3) and hydrogen peroxide (H2O2) (Biela et al, 1999; Gerbeau et al, 1999; Uehlein et al, 2003; Ma et al, 2006; Takano et al, 2006; Loqué et al, 2005; Dynowski et al, 2008). AQP was first discovered in animals and subsequently found in almost all living organisms (Gomes et al, 2009). There are 35 AQPs in Arabidopsis thaliana, 33 in Oryza sativa, 40 in Sorghum bicolor, 72 in Glycine

Methods

Results

Discussion

Conclusion