Genome-Wide Identification of Aquaporin Genes in Adzuki Bean (Vigna angularis) and Expression Analysis under Drought Stress

Rupesh Tayade; Varnika Rana; Mohammad Shafiqul; Rizwana Begum Syed Nabi; Gaurav Raturi; Hena Dhar; Vandana Thakral; Yoonha Kim

doi:10.3390/ijms232416189

Genome-Wide Identification of Aquaporin Genes in Adzuki Bean (Vigna angularis) and Expression Analysis under Drought Stress

Int J Mol Sci. 2022 Dec 19;23(24):16189. doi: 10.3390/ijms232416189.

Authors

Rupesh Tayade¹, Varnika Rana², Mohammad Shafiqul¹, Rizwana Begum Syed Nabi³, Gaurav Raturi², Hena Dhar², Vandana Thakral², Yoonha Kim¹

Affiliations

¹ Department of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea.
² National Agri-Food Biotechnology Institute (NABI), Mohali 140306, India.
³ Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Miryang 50424, Republic of Korea.

Abstract

The adzuki bean Vigna angularis (Wild.) is an important leguminous crop cultivated mainly for food purposes in Asian countries; it represents a source of carbohydrates, digestible proteins, minerals, and vitamins. Aquaporins (AQPs) are crucial membrane proteins involved in the transmembrane diffusion of water and small solutes in all living organisms, including plants. In this study, we used the whole genome sequence of the adzuki bean for in silico analysis to comprehensively identify 40 Vigna angularis aquaporin (VaAQP) genes and reveal how these plants react to drought stress. VaAQPs were compared with AQPs from other closely-related leguminous plants, and the results showed that mustard (Brassica rapa) (59), barrel medic (Medicago truncatula) (46), soybean (Glycine max) (66), and common bean (Phaseolus vulgaris L.) (41) had more AQP genes. Phylogenetic analysis revealed that forty VaAQPs belong to five subfamilies, with the VaPIPs (fifteen) subfamily the largest, followed by the VaNIPs (ten), VaTIPs (ten), VaSIPs (three), and VaXIPs (two) subfamilies. Furthermore, all AQP subcellular locations were found at the plasma membrane, and intron-exon analysis revealed a relationship between the intron number and gene expression, duplication, evolution, and diversity. Among the six motifs identified, motifs one, two, five, and six were prevalent in VaTIP, VaNIP, VaPIP, and VaXIP, while motifs one, three, and four were not observed in VaPIP1-3 and VaPIP1-4. Under drought stress, two of the VaAQPs (VaPIP2-1 and VaPIP2-5) showed significantly higher expression in the root tissue while the other two genes (VaPIP1-1 and VaPIP1-7) displayed variable expression in leaf tissue. This finding revealed that the selected VaAQPs might have unique molecular functions linked with the uptake of water under drought stress or in the exertion of osmoregulation to transport particular substrates rather than water to protect plants from drought. This study presents the first thorough investigation of VaAQPs in adzuki beans, and it reveals the transport mechanisms and related physiological processes that may be utilized for the development of drought-tolerant adzuki bean cultivars.

Keywords: adzuki bean; aquaporin gene; drought; gene structure; genome-wide identification; phylogeny.

MeSH terms

Aquaporins* / genetics
Aquaporins* / metabolism
Droughts
Phaseolus* / genetics
Phaseolus* / metabolism
Phylogeny
Vigna* / genetics
Vigna* / metabolism
Water / metabolism

Substances

Aquaporins
Water

Grants and funding

This research work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2021R1I1A3040280).