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

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.

Exploiting genetic and genomic resources to enhance productivity and abiotic stress adaptation of underutilized pulses

“…Recently discovered putative candidate genes and QTL associated with agronomically useful traits are, respectively, summarized in Tables 6, 7. The examples include pod/seed, pod fiber and pod shattering traits in African yard long bean or moth bean (Yundaeng et al, 2019;Garcia-Oliveira et al, 2020;Watcharatpong et al, 2020); seed weight and seed size in rice bean ; photoperiod-induced flowering in adzuki and lablab beans (Imoto et al, 2022;Krishna et al, 2022); relative water content, root traits (volume, weight, and length), chlorophyll content and biochemical pathways genes associated with abiotic stress adaptation in adzuki bean, Bambara groundnut, horse Gram, and moth bean (Katoch and Chahota et al, 2021;Tayade et al, 2022b;Choudhary et al, 2022;Meena et al, 2022;Odesola et al, 2023) or salt stress tolerance in grass pea (Alsamman et al, 2023); genes involved with unique nutritive values of moth bean seed (Suranjika et al, 2022); and anthocyanin contents in winged bean pod and seed (Chankaew et al, 2022).…”

Genome-wide analysis of key gene families in RNA silencing and their responses to biotic and drought stresses in adzuki bean

“…Bean common mosaic virus (BCMV) is one of the most damaging viruses infecting legume plants with worldwide distribution and has been reported in adzuki bean in China with serious symptoms [ 10 , 11 ]. For abiotic stress, drought is one of the most devastating environmental stresses that restricts the root and shoot growth and the final productivity [ 12 ].…”