Identification and Functional Analysis of Two Purple Acid Phosphatases AtPAP17 and AtPAP26 Involved in Salt Tolerance in Arabidopsis thaliana Plant

Tolerance to salinity is a complex genetic trait including numerous physiological processes, such as metabolic pathways and gene networks; thereby, identification of genes indirectly affecting, as well as those directly influencing, is of utmost importance. In this study, we identified and elucidated the functional characterization of AtPAP17 and AtPAP26 genes, as two novel purple acid phosphatases associated with high-salt tolerance in NaCl-stressed conditions. Here, the overexpression of both genes enhanced the expression level of AtSOS1, AtSOS2, AtSOS3, AtHKT1, AtVPV1, and AtNHX1 genes, involving in the K+/Na+ homeostasis pathway. The improved expression of the genes led to facilitating intracellular Na+ homeostasis and decreasing the ion-specific damages occurred in overexpressed genotypes (OEs). An increase in potassium content and K+/Na+ ratio was observed in OE17 and OE26 genotypes as well; however, lower content of sodium accumulated in these plants at 150 mM NaCl. The overexpression of these two genes resulted in the upregulation of the activity of the catalase, guaiacol peroxidase, and ascorbate peroxidase. Consequently, the overexpressed plants showed the lower levels of hydrogen peroxide where the lowest amount of lipid peroxidation occurred in these lines. Besides the oxidation resistance, the boost of the osmotic regulation through the increased proline and glycine-betaine coupled with a higher content of pigments and carbohydrates resulted in significantly enhancing biomass production and yield in the OEs under 150 mM NaCl. High-salt stress was also responsible for a sharp induction on the expression of both PAP17 and PAP26 genes. Our results support the hypothesis that these two phosphatases are involved in plant responses to salt stress by APase activity and/or non-APase activity thereof. The overexpression of PAP17 and PAP26 could result in increasing the intracellular APase activity in both OEs, which exhibited significant increases in the total phosphate and free Pi content compared to the wild-type plants. Opposite results witnessed in mutant genotypes (Mu17, Mu26, and DM), associating with the loss of AtPAP17 and AtPAP26 functions, clearly confirmed the role of these two genes in salt tolerance. Hence, these genes can be used as candidate genes in molecular breeding approaches to improve the salinity tolerance of crop plants.

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Characterization of Interactions between the Soybean Salt-Stress Responsive Membrane-Intrinsic Proteins GmPIP1 and GmPIP2

Agronomy ◽

10.3390/agronomy11071312 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1312

Author(s):

Jia Liu ◽

Weicong Qi ◽

Haiying Lu ◽

Hongbo Shao ◽

Dayong Zhang

Keyword(s):

Plasma Membrane ◽

Salt Stress ◽

Salt Tolerance ◽

Expression Profiles ◽

Expression Patterns ◽

Gene Expression Profiles ◽

Early Gene ◽

Plant Responses ◽

Constitutive Overexpression ◽

Important Trait

Salt tolerance is an important trait in soybean cultivation and breeding. Plant responses to salt stress include physiological and biochemical changes that affect the movement of water across the plasma membrane. Plasma membrane intrinsic proteins (PIPs) localize to the plasma membrane and regulate the water and solutes flow. In this study, quantitative real-time PCR and yeast two-hybridization were engaged to analyze the early gene expression profiles and interactions of a set of soybean PIPs (GmPIPs) in response to salt stress. A total of 20 GmPIPs-encoding genes had varied expression profiles after salt stress. Among them, 13 genes exhibited a downregulated expression pattern, including GmPIP1;6, the constitutive overexpression of which could improve soybean salt tolerance, and its close homologs GmPIP1;7 and 1;5. Three genes showed upregulated patterns, including the GmPIP1;6 close homolog GmPIP1;4, when four genes with earlier increased and then decreased expression patterns. GmPIP1;5 and GmPIP1;6 could both physically interact strongly with GmPIP2;2, GmPIP2;4, GmPIP2;6, GmPIP2;8, GmPIP2;9, GmPIP2;11, and GmPIP2;13. Definite interactions between GmPIP1;6 and GmPIP1;7 were detected and GmPIP2;9 performed homo-interaction. The interactions of GmPIP1;5 with GmPIP2;11 and 2;13, GmPIP1;6 with GmPIP2;9, 2;11 and GmPIP2;13, and GmPIP2;9 with itself were strengthened upon salt stress rather than osmotic stress. Taken together, we inferred that GmPIP1 type and GmPIP2 type could associate with each other to synergistically function in the plant cell; a salt-stress environment could promote part of their interactions. This result provided new clues to further understand the soybean PIP–isoform interactions, which lead to potentially functional homo- and heterotetramers for salt tolerance.

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The full-length transcriptome of Spartina alterniflora reveals the complexity of high salt tolerance in monocotyledonous halophyte

10.1101/680819 ◽

2019 ◽

Cited By ~ 2

Author(s):

Wenbin Ye ◽

Taotao Wang ◽

Wei Wei ◽

Shuaitong Lou ◽

Faxiu Lan ◽

...

Keyword(s):

Gene Expression ◽

Salt Stress ◽

Alternative Splicing ◽

Salt Tolerance ◽

Protein Kinases ◽

Spartina Alterniflora ◽

High Salt ◽

Full Length ◽

Salt Tolerant ◽

High Salt Tolerance

ABSTRACTSpartina alterniflora (Spartina) is the only halophyte in the salt marsh. However, the molecular basis of its high salt tolerance remains elusive. In this study, we used PacBio full-length single molecule long-read sequencing and RNA-seq to elucidate the transcriptome dynamics of high salt tolerance in Spartina by salt-gradient experiments (0, 350, 500 and 800 mM NaCl). We systematically analyzed the gene expression diversity and deciphered possible roles of ion transporters, protein kinases and photosynthesis in salt tolerance. Moreover, the co-expression network analysis revealed several hub genes in salt stress regulatory networks, including protein kinases such as SaOST1, SaCIPK10 and three SaLRRs. Furthermore, high salt stress affected the gene expression of photosynthesis through down-regulation at the transcription level and alternative splicing at the post-transcriptional level. In addition, overexpression of two Spartina salt-tolerant genes SaHSP70-I and SaAF2 in Arabidopsis significantly promoted the salt tolerance of transgenic lines. Finally, we built the SAPacBio website for visualizing the full-length transcriptome sequences, transcription factors, ncRNAs, salt-tolerant genes, and alternative splicing events in Spartina. Overall, this study sheds light on the high salt tolerance mechanisms of monocotyledonous-halophyte and demonstrates the potential of Spartina genes for engineering salt-tolerant plants.

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RsSOS1 Responding to Salt Stress Might Be Involved in Regulating Salt Tolerance by Maintaining Na+ Homeostasis in Radish (Raphanus sativus L.)

Horticulturae ◽

10.3390/horticulturae7110458 ◽

2021 ◽

Vol 7 (11) ◽

pp. 458

Author(s):

Wanting Zhang ◽

Jingxue Li ◽

Junhui Dong ◽

Yan Wang ◽

Liang Xu ◽

...

Keyword(s):

Plasma Membrane ◽

Salt Stress ◽

Salt Tolerance ◽

Functional Characterization ◽

Vital Role ◽

Salt Stress Response ◽

Reading Frame ◽

Yield And Quality

Radish is a kind of moderately salt-sensitive vegetable. Salt stress seriously decreases the yield and quality of radish. The plasma membrane Na+/H+ antiporter protein Salt Overly Sensitive 1 (SOS1) plays a crucial role in protecting plant cells against salt stress, but the biological function of the RsSOS1 gene in radish remains to be elucidated. In this study, the RsSOS1 gene was isolated from radish genotype ‘NAU-TR17’, and contains an open reading frame of 3414 bp encoding 1137 amino acids. Phylogenetic analysis showed that RsSOS1 had a high homology with BnSOS1, and clustered together with Arabidopsis plasma membrane Na+/H+ antiporter (AtNHX7). The result of subcellular localization indicated that the RsSOS1 was localized in the plasma membrane. Furthermore, RsSOS1 was strongly induced in roots of radish under 150 mmol/L NaCl treatment, and its expression level in salt-tolerant genotypes was significantly higher than that in salt-sensitive ones. In addition, overexpression of RsSOS1 in Arabidopsis could significantly improve the salt tolerance of transgenic plants. Meanwhile, the transformation of RsSOS1△999 could rescue Na+ efflux function of AXT3 yeast. In summary, the plasma membrane Na+/H+ antiporter RsSOS1 plays a vital role in regulating salt-tolerance of radish by controlling Na+ homeostasis. These results provided useful information for further functional characterization of RsSOS1 and facilitate clarifying the molecular mechanism underlying salt stress response in radish.

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Combined Transcriptomic and Metabolomic Analysis Reveals the Role of Phenylpropanoid Biosynthesis Pathway in the Salt Tolerance Process of Sophora alopecuroides

International Journal of Molecular Sciences ◽

10.3390/ijms22052399 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2399

Author(s):

Youcheng Zhu ◽

Qingyu Wang ◽

Ying Wang ◽

Yang Xu ◽

Jingwen Li ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Agricultural Development ◽

Plant Responses ◽

Biosynthesis Pathway ◽

Metabolomic Analysis ◽

Flavonoid Synthesis ◽

Sophora Alopecuroides ◽

Significant Gene ◽

Phenylpropanoid Biosynthesis

Salt stress is the main abiotic stress that limits crop yield and agricultural development. Therefore, it is imperative to study the effects of salt stress on plants and the mechanisms through which plants respond to salt stress. In this study, we used transcriptomics and metabolomics to explore the effects of salt stress on Sophora alopecuroides. We found that salt stress incurred significant gene expression and metabolite changes at 0, 4, 24, 48, and 72 h. The integrated transcriptomic and metabolomic analysis revealed that the differentially expressed genes (DEGs) and differential metabolites (DMs) obtained in the phenylpropanoid biosynthesis pathway were significantly correlated under salt stress. Of these, 28 DEGs and seven DMs were involved in lignin synthesis and 23 DEGs and seven DMs were involved in flavonoid synthesis. Under salt stress, the expression of genes and metabolites related to lignin and flavonoid synthesis changed significantly. Lignin and flavonoids may participate in the removal of reactive oxygen species (ROS) in the root tissue of S. alopecuroides and reduced the damage caused under salt stress. Our research provides new ideas and genetic resources to study the mechanism of plant responses to salt stress and further improve the salt tolerance of plants.

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De novo transcriptome sequencing and analysis of genes related to salt stress response in Glehnia littoralis

PeerJ ◽

10.7717/peerj.5681 ◽

2018 ◽

Vol 6 ◽

pp. e5681 ◽

Cited By ~ 6

Author(s):

Li Li ◽

Mimi Li ◽

Xiwu Qi ◽

Xingli Tang ◽

Yifeng Zhou

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Rna Sequencing ◽

Gene Networks ◽

Molecular Mechanisms ◽

De Novo ◽

Biosynthetic Pathways ◽

Salt Stress Response ◽

Glehnia Littoralis ◽

Plant Signal Transduction

Soil salinity is one of the major environmental stresses affecting plant growth, development, and reproduction. Salt stress also affects the accumulation of some secondary metabolites in plants. Glehnia littoralis is an endangered medicinal halophyte that grows in coastal habitats. Peeled and dried Glehnia littoralis roots, named Radix Glehniae, have been used traditionally as a Chinese herbal medicine. Although Glehnia littoralis has great ecological and commercial value, salt-related mechanisms in Glehnia littoralis remain largely unknown. In this study, we analysed the transcriptome of Glehnia littoralis in response to salt stress by RNA-sequencing to identify potential salt tolerance gene networks. After de novo assembly, we obtained 105,875 unigenes, of which 75,559 were annotated in public databases. We identified 10,335 differentially expressed genes (DEGs; false discovery rate <0.05 and |log2 fold-change| ≥ 1) between NaCl treatment (GL2) and control (GL1), with 5,018 upregulated and 5,317 downregulated DEGs. To further this investigation, we performed Gene Ontology (GO) analysis and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. DEGs involved in secondary metabolite biosynthetic pathways, plant signal transduction pathways, and transcription factors in response to salt stress were analysed. In addition, we tested the gene expression of 15 unigenes by quantitative real-time PCR (qRT-PCR) to confirm the RNA-sequencing results. Our findings represent a large-scale assessment of the Glehnia littoralis gene resource, and provide useful information for exploring its molecular mechanisms of salt tolerance. Moreover, genes enriched in metabolic pathways could be used to investigate potential biosynthetic pathways of active compounds by Glehnia littoralis.

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PvB3s: Genome-wide and Transcriptome-wide Identification and Analysis Reveals the B3 Family Regulate Auxin to Resist Salt Stress at the Sprout Stage in Common Bean(P. Vulgaris L. ) .

10.21203/rs.3.rs-36056/v1 ◽

2020 ◽

Author(s):

Qi Zhang ◽

Wei-jia Li ◽

Wen-jing Zhang ◽

Zhen-gong Yin ◽

Yu-xin Wang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Common Bean ◽

Dna Sequences ◽

Functional Characterization ◽

Pcr Analysis ◽

Genome Wide ◽

Genes Expression ◽

Intron Structure ◽

Auxin Content

Abstract Background: B3 gene family is a transcription factor family unique to plants, which play an important role in plant growth and development by binding specific DNA sequences. However, data on the B3 genes in the common bean and participate in many abiotic stresses especially salt stress are limited. Result: A total of encoding 100 proteins were identified in common bean. Phylogenetic analysis showed that PvB3s were classified into 4 subgroups, and these clusters were supported by several group-specific features, including exon/intron structure, MEME motifs, and predicted binding site structure. Collinearity analysis showed the connection of PvB3s in the same species and different species. The genes expression pattern showed that PvB3s expressed with a tissue-specific manner during sprout stage. Through RNA-seq and qRT-PCR analysis, it was found that there were differences in expression in extreme materials under salt stress. The determination of auxin content and the analysis of PvB3s expression in the enriched pathway showed that PvB3s would respond to auxin to enhance salt tolerance in common bean sprouting stage. Conclusion: The results provided useful and rich resources of PvB3s for the functional characterization and understanding of B3 transcription factors (TFs) in common bean, which further provides insights that PvB3s may respond to auxin to enhance salt tolerance of common bean.

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Salt Tolerance Mechanism of the Rhizosphere Bacterium JZ-GX1 and Its Effects on Tomato Seed Germination and Seedling Growth

Frontiers in Microbiology ◽

10.3389/fmicb.2021.657238 ◽

2021 ◽

Vol 12 ◽

Author(s):

Pu-Sheng Li ◽

Wei-Liang Kong ◽

Xiao-Qin Wu

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Seedling Growth ◽

Salt Concentration ◽

High Salt ◽

Stem Length ◽

Tolerance Mechanism ◽

Rhizosphere Bacterium ◽

Moderately Halophilic Bacterium ◽

Growth Promoting

Salinity is one of the strongest abiotic factors in nature and has harmful effects on plants and microorganisms. In recent years, the degree of soil salinization has become an increasingly serious problem, and the use of plant growth-promoting rhizobacteria has become an option to improve the stress resistance of plants. In the present study, the salt tolerance mechanism of the rhizosphere bacterium Rahnella aquatilis JZ-GX1 was investigated through scanning electron microscopy observations and analysis of growth characteristics, compatible solutes, ion distribution and gene expression. In addition, the effect of JZ-GX1 on plant germination and seedling growth was preliminarily assessed through germination experiments. R. aquatilis JZ-GX1 was tolerant to 0–9% NaCl and grew well at 3%. Strain JZ-GX1 promotes salt tolerance by stimulating the production of exopolysaccharides, and can secrete 60.6983 mg/L of exopolysaccharides under the high salt concentration of 9%. Furthermore, the accumulation of the compatible solute trehalose in cells as the NaCl concentration increased was shown to be the primary mechanism of resistance to high salt concentrations in JZ-GX1. Strain JZ-GX1 could still produce indole-3-acetic acid (IAA) and siderophores and dissolve inorganic phosphorus under salt stress, characteristics that promote the ability of plants to resist salt stress. When the salt concentration was 100 mmol/L, strain JZ-GX1 significantly improved the germination rate, germination potential, fresh weight, primary root length and stem length of tomato seeds by 10.52, 125.56, 50.00, 218.18, and 144.64%, respectively. Therefore, R. aquatilis JZ-GX1 is a moderately halophilic bacterium with good growth-promoting function that has potential for future development as a microbial agent and use in saline-alkali land resources.

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A Review on Plant Responses to Salt Stress and Their Mechanisms of Salt Resistance

Horticulturae ◽

10.3390/horticulturae7060132 ◽

2021 ◽

Vol 7 (6) ◽

pp. 132

Author(s):

Shanhu Hao ◽

Yiran Wang ◽

Yunxiu Yan ◽

Yuhang Liu ◽

Jingyao Wang ◽

...

Keyword(s):

Salt Stress ◽

Protein Kinase ◽

Salt Tolerance ◽

Ion Homeostasis ◽

Soil Salinization ◽

Mitogen Activated Protein Kinase ◽

Practical Significance ◽

Plant Responses ◽

Ros Scavenging ◽

Physiological Mechanisms

Nowadays, crop insufficiency resulting from soil salinization is threatening the world. On the basis that soil salinization has become a worldwide problem, studying the mechanisms of plant salt tolerance is of great theoretical and practical significance to improve crop yield, to cultivate new salt-tolerant varieties, and to make full use of saline land. Based on previous studies, this paper reviews the damage of salt stress to plants, including suppression of photosynthesis, disturbance of ion homeostasis, and membrane peroxidation. We have also summarized the physiological mechanisms of salt tolerance, including reactive oxygen species (ROS) scavenging and osmotic adjustment. Four main stress-related signaling pathways, salt overly sensitive (SOS) pathway, calcium-dependent protein kinase (CDPK) pathway, mitogen-activated protein kinase (MAPKs) pathway, and abscisic acid (ABA) pathway, are included. We have also enumerated some salt stress-responsive genes that correspond to physiological mechanisms. In the end, we have outlined the present approaches and techniques to improve salt tolerance of plants. All in all, we reviewed those aspects above, in the hope of providing valuable background knowledge for the future cultivation of agricultural and forestry plants.

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Isolation and Functional Characterization of a Salt-Responsive Calmodulin-Like Gene MpCML40 from Semi-Mangrove Millettia pinnata

International Journal of Molecular Sciences ◽

10.3390/ijms22073475 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3475

Author(s):

Yi Zhang ◽

Jianzi Huang ◽

Qiongzhao Hou ◽

Yujuan Liu ◽

Jun Wang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Transgenic Plants ◽

Heterologous Expression ◽

Germination Rate ◽

Functional Characterization ◽

Normal Growth ◽

Growth Conditions ◽

Yeast Cells ◽

Millettia Pinnata

Salt stress is a major increasing threat to global agriculture. Pongamia (Millettia pinnata), a semi-mangrove, is a good model to study the molecular mechanism of plant adaptation to the saline environment. Calcium signaling pathways play critical roles in the model plants such as Arabidopsis in responding to salt stress, but little is known about their function in Pongamia. Here, we have isolated and characterized a salt-responsive MpCML40, a calmodulin-like (CML) gene from Pongamia. MpCML40 protein has 140 amino acids and is homologous with Arabidopsis AtCML40. MpCML40 contains four EF-hand motifs and a bipartite NLS (Nuclear Localization Signal) and localizes both at the plasma membrane and in the nucleus. MpCML40 was highly induced after salt treatment, especially in Pongamia roots. Heterologous expression of MpCML40 in yeast cells improved their salt tolerance. The 35S::MpCML40 transgenic Arabidopsis highly enhanced seed germination rate and root length under salt and osmotic stresses. The transgenic plants had a higher level of proline and a lower level of MDA (malondialdehyde) under normal and stress conditions, which suggested that heterologous expression of MpCML40 contributed to proline accumulation to improve salt tolerance and protect plants from the ROS (reactive oxygen species) destructive effects. Furthermore, we did not observe any measurable discrepancies in the development and growth between the transgenic plants and wild-type plants under normal growth conditions. Our results suggest that MpCML40 is an important positive regulator in response to salt stress and of potential application in producing salt-tolerant crops.

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Improved salt tolerance in transgenic tobacco by over-expression of poplar NAC13 gene

10.7287/peerj.preprints.27861 ◽

2019 ◽

Author(s):

Xuemei Zhang ◽

Zihan Cheng ◽

Kai Zhao ◽

Renhua Li ◽

Boru Zhou ◽

...

Keyword(s):

Transcription Factor ◽

Salt Stress ◽

Salt Tolerance ◽

Transgenic Tobacco ◽

Stress Responses ◽

Gene Networks ◽

Molecular Mechanisms ◽

Physiological Characterization ◽

Protein Functions ◽

Forest Genetic

Background: NACs are one of the major transcription factor families in plants which play an important role in plant growth and development, as well as in adverse stress responses. Methods: In this study, we cloned a salt-inducible NAC transcription factor gene (NAC13) from a poplar variety 84K, followed by transforming it into both tobacco and Arabidopsis. Results: Stable expression analysis of 35S::NAC13-GFP fusion protein in Arabidopsis indicated that NAC13 was localized to the nucleus. We also obtained five transgenic tobacco lines. Evidence from morphological and physiological characterization and salt treatment analyses indicated that the transgenic tobacco enhanced salt tolerance, suggesting that NAC13 gene may function as a positive regulator in tobacco responses to salt stress. Furthermore, evidence from yeast two-hybrid screening demonstrated that NAC13 protein functions as a transcriptional activator, with an activation domain located in the C-terminal region. Discussion: NAC13 gene plays an important role in response to salt stress in tobacco. Future studies are needed to shed light on molecular mechanisms of gene regulation and gene networks related to NAC13 gene in response to salt stress, which will provide a valuable theoretical basis for forest genetic breeding and resistant breeding.

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