Genome-Wide Identification and Expression Analysis of the NHX (Sodium/Hydrogen Antiporter) Gene Family in Cotton

et al. 2020

IJMS

The CPA (cation proton antiporter) family plays an essential role during plant stress tolerance by regulating ionic and pH homeostasis of the cell. Radish fleshy roots are susceptible to abiotic stress during growth and development, especially salt stress. To date, CPA family genes have not yet been identified in radish and the biological functions remain unclear. In this study, 60 CPA candidate genes in radish were identified on the whole genome level, which were divided into three subfamilies including the Na+/H+ exchanger (NHX), K+ efflux antiporter (KEA), and cation/H+ exchanger (CHX) families. In total, 58 of the 60 RsCPA genes were localized to the nine chromosomes. RNA-seq. data showed that 60 RsCPA genes had various expression levels in the leaves, roots, cortex, cambium, and xylem at different development stages, as well as under different abiotic stresses. RT–qPCR analysis indicated that all nine RsNHXs genes showed up regulated trends after 250 mM NaCl exposure at 3, 6, 12, and 24h. The RsCPA31 (RsNHX1) gene, which might be the most important members of the RsNHX subfamily, exhibited obvious increased expression levels during 24h salt stress treatment. Heterologous over-and inhibited-expression of RsNHX1 in Arabidopsis showed that RsNHX1 had a positive function in salt tolerance. Furthermore, a turnip yellow mosaic virus (TYMV)-induced gene silence (VIGS) system was firstly used to functionally characterize the candidate gene in radish, which showed that plant with the silence of endogenous RsNHX1 was more susceptible to the salt stress. According to our results we provide insights into the complexity of the RsCPA gene family and a valuable resource to explore the potential functions of RsCPA genes in radish.

Section: Evolutionary Characterization Of the Rscpa Familysupporting

confidence: 83%

Genome-Wide Identification and Functional Characterization of the Cation Proton Antiporter (CPA) Family Related to Salt Stress Response in Radish (Raphanus sativus L.)

Wang

Ying

et al. 2020

IJMS

Section: Discussionmentioning

confidence: 99%

“…The CaNHX gene was found to contain up to 9 genes in different varieties of pepper. So far, NHX genes have been identified in many species, with the most identified in Gossypium hirsutum and G. barbadense (23 GhNHX and 24 GbNHX, respectively) (Fu et al, 2020). However, in subcellular localization, NHX genes can be classified into three subgroups according to their subcellular localization according to previous reports which were divided into three categories, namely Vac-Class, Endo-class, and PMclass, among which VAC-class is located in Vacuole, Endo-class in Endoretinal Reticulum, and PM-class in Plasma membrane (Wu et al, 2019).…”

Section: Nhx Gene Family In Peppermentioning

confidence: 99%

“…AtNHX3 was detected in roots, while AtNHX4 and AtNHX6 mRNA were only detected by RT-PCR ( Yokoi et al, 2002 ). To date, NHX genes of several plant species have been identified, such as Vitis vinifera (6 VvNHX genes) ( Ayadi et al, 2020 ), Medicago truncatula ( MtNHX1 - MtNHX8 ) ( Sandhu et al, 2018 ), Populus trichocarpa ( PtNHX1 - PtNHX8 ) ( Tian et al, 2017 ), Populus euphratica ( PeNHX1 - PeNHX6 ) ( Ye et al, 2009 ), Gossypium hirsutum ( GhNHX1 - GhNHX23 ) ( Fu et al, 2020 ), Morus alba ( MaNHX1 - MaNHX7 ) ( Cao et al, 2016 ), and Beta vulgaris ( BvNHX1 - BvNHX5 ) ( Wu et al, 2019 ). This study performed different bioinformatic analyses of CaNHX genes in cultivated and wild peppers, and the CaNHX gene family of pepper was identified at the genome level, providing a theoretical basis for analyzing the function of the gene under salt stress.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Characterization and Expression Analysis of the Na+/H+ Exchanger Gene Family in Capsicum annuum L.

Luo

Luo³

et al. 2021

Front. Genet.

The Na+/H+ exchangers (NHXs) are a class of transporters involved in ion balance during plant growth and abiotic stress. We performed systematic bioinformatic identification and expression-characteristic analysis of CaNHX genes in pepper to provide a theoretical basis for pepper breeding and practical production. At the whole-genome level, the members of the CaNHX gene family of cultivated and wild pepper were systematically identified using bioinformatics methods. Sequence alignment and phylogenetic tree construction were performed using MEGA X software, and the gene functional domain, conserved motif, and gene structure were analyzed and visualized. At the same time, the co-expression network of CaNHX genes was analyzed, and salt-stress analysis and fluorescence quantitative verification of the Zunla-1 cultivar under stress conditions were performed. A total of 9 CaNHX genes were identified, which have typical functional domains of the Na+/H+ exchanger gene. The physical and chemical properties of the protein showed that the protein was hydrophilic, with a size of 503–1146 amino acids. Analysis of the gene structure showed that Chr08 was the most localized chromosome, with 8–24 exons. Cis-acting element analysis showed that it mainly contains cis-acting elements such as light response, salicylic acid response, defense, and stress response. Transcriptom and co-expression network analysis showed that under stress, the co-expressed genes of CaNHX genes in roots and leaves were more obvious than those in the control group, including ABA, IAA, and salt. The transcriptome and co-expression were verified by qRT-PCR. In this study, the CaNHX genes were identified at the genome level of pepper, which provides a theoretical foundation for improving the stress resistance, production, development, and utilization of pepper in genetic breeding.

“…NHX Family 2.2.1. Plasma-Membrane-Located Family Members, Function and the Effect of Their Expression Level Changes on the Cytosolic pH Amongst eight NHXs (Na + /H + exchanger) in Arabidopsis [54,55], only two genes (AtNHX7 and AtNHX8) are located in the plasma membrane [56][57][58][59]. Homologues of the AtNHX7 widely exist in plants such as wheat, maize, and tomato [60][61][62]; however, no protein homologous to AtNHX8 has been found in the sequenced genomes of cereals [63].…”

Section: Regulation By Extracellular/cytosolic Phmentioning

confidence: 99%

Regulation of Cytosolic pH: The Contributions of Plant Plasma Membrane H+-ATPases and Multiple Transporters

Zhou¹,

Hao

2021

IJMS

Cytosolic pH homeostasis is a precondition for the normal growth and stress responses in plants, and H+ flux across the plasma membrane is essential for cytoplasmic pH control. Hence, this review focuses on seven types of proteins that possess direct H+ transport activity, namely, H+-ATPase, NHX, CHX, AMT, NRT, PHT, and KT/HAK/KUP, to summarize their plasma-membrane-located family members, the effect of corresponding gene knockout and/or overexpression on cytosolic pH, the H+ transport pathway, and their functional regulation by the extracellular/cytosolic pH. In general, H+-ATPases mediate H+ extrusion, whereas most members of other six proteins mediate H+ influx, thus contributing to cytosolic pH homeostasis by directly modulating H+ flux across the plasma membrane. The fact that some AMTs/NRTs mediate H+-coupled substrate influx, whereas other intra-family members facilitate H+-uncoupled substrate transport, demonstrates that not all plasma membrane transporters possess H+-coupled substrate transport mechanisms, and using the transport mechanism of a protein to represent the case of the entire family is not suitable. The transport activity of these proteins is regulated by extracellular and/or cytosolic pH, with different structural bases for H+ transfer among these seven types of proteins. Notably, intra-family members possess distinct pH regulatory characterization and underlying residues for H+ transfer. This review is anticipated to facilitate the understanding of the molecular basis for cytosolic pH homeostasis. Despite this progress, the strategy of their cooperation for cytosolic pH homeostasis needs further investigation.