Genome-wide identification and expression analysis of aquaporin family in Canavalia rosea and their roles in the adaptation to saline-alkaline soils and drought stress

Abstract

Background Canavalia rosea (Sw.) DC. (bay bean) is an extremophile halophyte that is widely distributed in coastal areas of the tropics and subtropics. Seawater and drought tolerance in this species may be facilitated by aquaporins (AQPs), channel proteins that transport water and small molecules across cell membranes and thereby maintain cellular water homeostasis in the face of abiotic stress. In C. rosea, AQP diversity, protein features, and their biological functions are still largely unknown. Results We describe the action of AQPs in C. rosea using evolutionary analyses coupled with promoter and expression analyses. A total of 37 AQPs were identified in the C. rosea genome and classified into five subgroups: 11 plasma membrane intrinsic proteins, 10 tonoplast intrinsic proteins, 11 Nod26-like intrinsic proteins, 4 small and basic intrinsic proteins, and 1 X-intrinsic protein. Analysis of RNA-Seq data and targeted qPCR revealed organ-specific expression of aquaporin genes and the involvement of some AQP members in adaptation of C. rosea to extreme coral reef environments. We also analyzed C. rosea sequences for phylogeny reconstruction, protein modeling, cellular localizations, and promoter analysis. Furthermore, one of PIP1 gene, CrPIP1;5, was identified as functional using a yeast expression system and transgenic overexpression in Arabidopsis. Conclusions Our results indicate that AQPs play an important role in C. rosea responses to saline-alkaline soils and drought stress. These findings not only increase our understanding of the role AQPs play in mediating C. rosea adaptation to extreme environments, but also improve our knowledge of plant aquaporin evolution more generally.

Genome-Wide Characterization of the Aquaporin Gene Family in Radish and Functional Analysis of RsPIP2-6 Involved in Salt Stress

“…Subsequently, the expression of seven RsPIP genes was upregulated under salt exposure, indicating that they might play a crucial role in the response to salt stress. Similar results were also observed in soybean (Zhou et al, 2014), Arabidopsis (Feng et al, 2018), and Canavalia rosea (Lin et al, 2021). The distribution of RsAQP in linkage groups showed tandem duplicated pairs, such as RsPIP2-1, RsPIP2-2, RsPIP2-3, and RsPIP2-4, on the R6 chromosome, which might have been caused by gene duplication during evolution.…”

Integration of QTL Mapping and Whole Genome Sequencing Identifies Candidate Genes for Alkalinity Tolerance in Rice (Oryza sativa)

“…As these genes have not been implicated in alkalinity tolerance, we selected four genes from the 10.18 QTL region for expression analysis under alkaline stress ( Figure 5 ). Several studies showed that overexpression of aquaporin genes has a negative impact on salt and alkaline stress [ 43 , 44 ]. These findings further corroborate the downregulation of LOC_Os10g34000 in the tolerant cultivar used in this study.…”

Genome-wide identification, expression analysis, and potential roles under low-temperature stress of bHLH gene family in Prunus sibirica

“…Due to the degeneracy of the code, sites within codons were defined as synonymous substitutions (Ks) when they did not result in an amino acid change, and as a non-synonymous substitutions (Ka) when they did ( Harouaka et al., 2016 ). Generally, Ka/Ks >1 indicates positive selection, Ka/Ks =1 indicates neutral selection, and Ka/Ks <1 indicates purified selection ( Lin et al., 2021 ). Based on the Ka/Ks ratio, all PsbHLH pairs were subjected to purifying selection.…”