Na+ Transporter SvHKT1;1 from a Halophytic Turf Grass Is Specifically Upregulated by High Na+ Concentration and Regulates Shoot Na+ Concentration

We characterized an Na+ transporter SvHKT1;1 from a halophytic turf grass, Sporobolus virginicus. SvHKT1;1 mediated inward and outward Na+ transport in Xenopus laevis oocytes and did not complement K+ transporter-defective mutant yeast. SvHKT1;1 did not complement athkt1;1 mutant Arabidopsis, suggesting its distinguishable function from other typical HKT1 transporters. The transcript was abundant in the shoots compared with the roots in S. virginicus and was upregulated by severe salt stress (500 mM NaCl), but not by lower stress. SvHKT1;1-expressing Arabidopsis lines showed higher shoot Na+ concentrations and lower salt tolerance than wild type (WT) plants under nonstress and salt stress conditions and showed higher Na+ uptake rate in roots at the early stage of salt treatment. These results suggested that constitutive expression of SvHKT1;1 enhanced Na+ uptake in root epidermal cells, followed by increased Na+ transport to shoots, which led to reduced salt tolerance. However, Na+ concentrations in phloem sap of the SvHKT1;1 lines were higher than those in WT plants under salt stress. Based on this result, together with the induction of the SvHKT1;1 transcription under high salinity stress, it was suggested that SvHKT1;1 plays a role in preventing excess shoot Na+ accumulation in S. virginicus.

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AtKATANIN1 Modulates Microtubule Depolymerization and Reorganization in Response to Salt Stress in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms21010138 ◽

2019 ◽

Vol 21 (1) ◽

pp. 138

Author(s):

Jie Yang ◽

Bang An ◽

Hongli Luo ◽

Chaozu He ◽

Qiannan Wang

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Early Stage ◽

Microscopic Analysis ◽

Microtubule Depolymerization ◽

Phenotypic Analysis ◽

Microtubule Organization ◽

Knock Out ◽

Microtubule Disruption ◽

Mutant Cells

The microtubule cytoskeleton is a dynamic system that plays vital roles in fundamental cellular processes and in responses to environmental stumili. Salt stress induced depolymerization and reorganization of microtubules are believed to function in the promotion of survival in Arabidopsis. Microtubule-severing enzyme ATKATANIN1 (AtKTN1) is recognized as a MAP that help to maintain organized microtubule structure. To date, whether AtKTN1 is involved in response to salt stress in Arabidopsis remains unknown. Here, our phenotypic analysis showed that the overexpression of AtKTN1 decreased tolerance to salt stress, whereas the knock-out of AtKTN1 increased salt tolerance in the early stage but decreased salt tolerance in the later stage. Microscopic analysis revealed that microtubule organization and dynamics are distorted in both overexpression and mutant cells which, in turn, resulted in an abnormal disassembly and reorganization under salt stress. Moreover, qRT analysis revealed that stress-responsive genes were down-regulated in overexpression and mutant cells compared to WT cells under salt stress. Taken together, our results indicated roles of AtKTN1 in modulating microtubule organization, salt-stress induced microtubule disruption and recovery, and its involvement in stress-related signaling pathways.

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Ectopic Overexpression of Barley PIP2;4 Confers Salt Tolerance in Arabidopsis

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v4i4.16254 ◽

2017 ◽

Vol 4 (4) ◽

pp. 498-512

Author(s):

Jayeeta Mitra ◽

Jay Prakash Awasthi ◽

Sanjib Kumar Panda

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Molecular Mechanisms ◽

Dominant Role ◽

Constitutive Expression ◽

Crop Plant ◽

Nacl Concentration ◽

Abiotic Stress Condition ◽

Plant Salt Tolerance ◽

Dose Dependent

In the present study HvPIP2;4 was overexpressed in Arabidopsis thaliana to engineer enhanced salt tolerance. Barley Aquaporin was selected since barley shows fairly good tolerance to drought, salt stress and low temperature compared to many other crops including rice, and it was thought that analysis of barley aquaporin will provide a good insight into the molecular mechanisms involved in transport of water & their efficacy during abiotic stress condition. Arabidopsis line expressing HvPIP2;4 from annual crop plant Hordeum vulgare (Barley) under the control of constitutive promoter was used to analyze the expression of HvPIP2; 4 and its efficacy during salt stress when NaCl concentration gradually increased. The pattern of expression of HvPIP2; 4 were found to be NaCl dose dependent during salt stress. The constitutive expression of HvPIP2;4 enhanced salt stress tolerance in Arabidopsis. HvPIP2;4 played a dominant role in improving plant salt tolerance. It may be very well presumed that overexpression of HvPIP2;4 in crop plant might benefit them by enhancing their salt tolerance capacity.Int J Appl Sci Biotechnol, Vol 4(4): 498-512

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Downregulation of high-affinity potassium and sodium symporter gene, EcHKT1;1, in Eucalyptus roots enhances salt tolerance

10.22541/au.161750552.29310677/v1 ◽

2021 ◽

Author(s):

BALASUBRAMANIAN Aiyar ◽

Selvakesavan Rajendran kamalabai ◽

Shamili Krishnaraj ◽

Sandhya M C ◽

Usha Jayachandran ◽

...

Keyword(s):

Salt Tolerance ◽

Tree Species ◽

External Medium ◽

Major Gene ◽

In Planta ◽

Na Transport ◽

High Affinity ◽

Na Uptake ◽

Transgenic Plantlets

Engineering for restricted root Na+ uptake could potentially enhance salt tolerance in Eucalyptus. High-affinity K+ transporters (HKTs) have been implicated in Na+ uptake from the external medium as in the case of TaHKT2;1 or in the unloading of Na+ from xylem like in AtHKT1;1. To rapidly determine the in planta role of EcHKT1:1, composite transgenics in which EcHKT1:1 was specifically downregulated via RNAi in the roots were generated. Compared to the controls that failed to survive at 350 mM NaCl, 33 % of the composite transgenic plantlets generated using the EcHKT1;1 silencing construct were able to tolerate up to 400 mM NaCl. In these composite transgenics, EcHKT1;1 downregulation ranged from 37 % to 74 %. The average shoot to root ratio of sodium was 4.9 folds lower than the controls indicating restricted translocation of Na+ to the shoots. Relative expression analysis in the leaves of two non-transgenic genotypes contrasting for their salt tolerance also showed downregulated EcHKT1;1 expression in the tolerant clone. The study thus determined that EcHKT1;1 is a major gene determining Na+ transport from the roots to shoots. This study also demonstrated the utility of the composite transgenic approach for screening genes conferring salt tolerance in tree species.

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Ascorbic Acid Modulation by ABI4 Transcriptional Repression of VTC2 in The Salt Tolerance of Arabidopsis

10.21203/rs.3.rs-116368/v1 ◽

2020 ◽

Author(s):

Xiamusiya Kakan ◽

Yanwen Yu ◽

Shenghui Li ◽

Xiaoying Li ◽

Rongfeng Huang ◽

...

Keyword(s):

Ascorbic Acid ◽

Salt Stress ◽

Salt Tolerance ◽

Stress Responses ◽

Transcriptional Repression ◽

Early Stage ◽

Stress Sensitivity ◽

Loss Of Function ◽

Ros Scavenging ◽

Plant Salt Tolerance

Abstract Background:Abscisic acid (ABA) plays an important role in plant abiotic stress responses, and ABA INSENSITIVE 4 (ABI4) is a pivotal transcription factor in the ABA signaling pathway. In Arabidopsis, ABI4 negatively regulates salt tolerance; however, the mechanism through which ABI4 regulates plant salt tolerance is poorly understood. Our previous study showed that ABI4 directly binds to the promoter of the VITAMIN C DEFECTIVE 2 (VTC2) gene, inhibiting the transcription of VTC2 and ascorbic acid (AsA) biosynthesis.Results: In the present study, we found that treatment with exogenous AsA could alleviate salt stress sensitivity of ABI4-overexpressing transgenic plants. The decreased AsA content and increased reactive oxygen species (ROS) levels in ABI4-overexpressing seedlings under salt treatment indicated that AsA-promoted ROS scavenging was related to ABI4-mediated salt tolerance. Gene expression analysis showed that ABI4 was induced at the early stage of salt stress, giving rise to reduced VTC2 expression. Accordingly, the abundance of the VTC2 protein decreased under the same salt stress conditions, and was absent in the ABI4 loss-of-function mutants, suggesting that the transcriptional inhibition of ABI4 on VTC2 resulted in the attenuation of VTC2 function. In addition, other encoding genes in the AsA biosynthesis and recycling pathways showed different responses to salt stress, demonstrating that AsA homeostasis is complicated under salinity stress. Conclusions: This study elucidates the negative modulation of ABI4 in salt stress tolerance through the regulation of AsA biosynthesis and ROS accumulation in plants.

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The long non-coding RNA lncRNA973 is involved in cotton response to salt stress

BMC Plant Biology ◽

10.1186/s12870-019-2088-0 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 7

Author(s):

Xiaopei Zhang ◽

Jie Dong ◽

Fenni Deng ◽

Wei Wang ◽

Yingying Cheng ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Transgenic Plants ◽

Germination Rate ◽

Stress Conditions ◽

Virus Induced Gene Silencing ◽

Wild Type ◽

Rna Molecules ◽

Regulatory Processes ◽

Reduced Salt

Abstract Background Long non-coding (lnc) RNAs are a class of functional RNA molecules greater than 200 nucleotides in length, and lncRNAs play important roles in various biological regulatory processes and response to the biotic and abiotic stresses. LncRNAs associated with salt stress in cotton have been identified through RNA sequencing, but the function of lncRNAs has not been reported. We previously identified salt stress-related lncRNAs in cotton (Gossypium spp.), and discovered the salt-related lncRNA-lncRNA973. Results In this study, we identified the expression level, localization, function, and preliminary mechanism of action of lncRNA973. LncRNA973, which was localized in the nucleus, was expressed at a low level under nonstress conditions but can be significantly increased by salt treatments. Here lncRNA973 was transformed into Arabidopsis and overexpressed. Along with the increased expression compared with wild type under salt stress conditions in transgenic plants, the seed germination rate, fresh weights and root lengths of the transgenic plants increased. We also knocked down the expression of lncRNA973 using virus-induced gene silencing technology. The lncRNA973 knockdown plants wilted, and the leaves became yellowed and dropped under salt-stress conditions, indicating that the tolerance to salt stress had decreased compared with wild type. LncRNA973 may be involved in the regulation of reactive oxygen species-scavenging genes, transcription factors and genes involved in salt stress-related processes in response to cotton salt stress. Conclusions LncRNA973 was localized in the nucleus and its expression was increased by salt treatment. The lncRNA973-overexpression lines had increased salt tolerance compared with the wild type, while the lncRNA973 knockdown plants had reduced salt tolerance. LncRNA973 regulated cotton responses to salt stress by modulating the expression of a series of salt stress-related genes. The data provides a basis for further studies on the mechanisms of lncRNA973-associated responses to salt stress in cotton.

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Ascorbic acid modulation by ABI4 transcriptional repression of VTC2 in the salt tolerance of Arabidopsis

BMC Plant Biology ◽

10.1186/s12870-021-02882-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xiamusiya Kakan ◽

Yanwen Yu ◽

Shenghui Li ◽

Xiaoying Li ◽

Rongfeng Huang ◽

...

Keyword(s):

Ascorbic Acid ◽

Salt Stress ◽

Salt Tolerance ◽

Stress Responses ◽

Transcriptional Repression ◽

Early Stage ◽

Stress Sensitivity ◽

Loss Of Function ◽

Ros Scavenging ◽

Plant Salt Tolerance

Abstract Background Abscisic acid (ABA) plays an important role in plant abiotic stress responses, and ABA INSENSITIVE 4 (ABI4) is a pivotal transcription factor in the ABA signaling pathway. In Arabidopsis, ABI4 negatively regulates salt tolerance; however, the mechanism through which ABI4 regulates plant salt tolerance is poorly understood. Our previous study showed that ABI4 directly binds to the promoter of the VITAMIN C DEFECTIVE 2 (VTC2) gene, inhibiting the transcription of VTC2 and ascorbic acid (AsA) biosynthesis. Results In the present study, we found that treatment with exogenous AsA could alleviate salt stress sensitivity of ABI4-overexpressing transgenic plants. The decreased AsA content and increased reactive oxygen species (ROS) levels in ABI4-overexpressing seedlings under salt treatment indicated that AsA-promoted ROS scavenging was related to ABI4-mediated salt tolerance. Gene expression analysis showed that ABI4 was induced at the early stage of salt stress, giving rise to reduced VTC2 expression. Accordingly, the abundance of the VTC2 protein decreased under the same salt stress conditions, and was absent in the ABI4 loss-of-function mutants, suggesting that the transcriptional inhibition of ABI4 on VTC2 resulted in the attenuation of VTC2 function. In addition, other encoding genes in the AsA biosynthesis and recycling pathways showed different responses to salt stress, demonstrating that AsA homeostasis is complicated under salinity stress. Conclusions This study elucidates the negative modulation of ABI4 in salt stress tolerance through the regulation of AsA biosynthesis and ROS accumulation in plants.

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Salt tolerance of Glycyrrhiza inflata seedlings in Xinjiang and its ion response to salt stress

Chinese Journal of Plant Ecology ◽

10.3724/sp.j.1258.2013.00088 ◽

2014 ◽

Vol 37 (9) ◽

pp. 839-850 ◽

Cited By ~ 3

Author(s):

Jia-Hui LU ◽

Xin LÜ ◽

Yong-Chao LIANG ◽

Hai-Rong LIN

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Glycyrrhiza Inflata

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Genetic Potential for Salt Tolerance During Germination in Lycopersicon Species

HortScience ◽

10.21273/hortsci.32.2.296 ◽

1997 ◽

Vol 32 (2) ◽

pp. 296-300 ◽

Cited By ~ 46

Author(s):

M.R. Foolad ◽

G.Y. Lin

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Genotypic Variation ◽

Control Treatment ◽

Molar Ratio ◽

Wild Accession ◽

Salt Tolerant ◽

Plant Introductions ◽

Genetic Potential ◽

Stress Levels

Seed of 42 wild accessions (Plant Introductions) of Lycopersicon pimpinellifolium Jusl., 11 cultigens (cultivated accessions) of L. esculentum Mill., and three control genotypes [LA716 (a salt-tolerant wild accession of L. pennellii Corr.), PI 174263 (a salt-tolerant cultigen), and UCT5 (a salt-sensitive breeding line)] were evaluated for germination in either 0 mm (control) or 100 mm synthetic sea salt (SSS, Na+/Ca2+ molar ratio equal to 5). Germination time increased in response to salt-stress in all genotypes, however, genotypic variation was observed. One accession of L. pimpinellifolium, LA1578, germinated as rapidly as LA716, and both germinated more rapidly than any other genotype under salt-stress. Ten accessions of L. pimpinellifolium germinated more rapidly than PI 174263 and 35 accessions germinated more rapidly than UCT5 under salt-stress. The results indicate a strong genetic potential for salt tolerance during germination within L. pimpinellifolium. Across genotypes, germination under salt-stress was positively correlated (r = 0.62, P < 0.01) with germination in the control treatment. The stability of germination response at diverse salt-stress levels was determined by evaluating germination of a subset of wild, cultivated accessions and the three control genotypes at 75, 150, and 200 mm SSS. Seeds that germinated rapidly at 75 mm also germinated rapidly at 150 mm salt. A strong correlation (r = 0.90, P < 0.01) existed between the speed of germination at these two salt-stress levels. At 200 mm salt, most accessions (76%) did not reach 50% germination by 38 days, demonstrating limited genetic potential within Lycopersicon for salt tolerance during germination at this high salinity.

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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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Comprehensive transcriptome and metabolome profiling reveal metabolic mechanisms of Nitraria sibirica Pall. to salt stress

Scientific Reports ◽

10.1038/s41598-021-92317-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Huanyong Li ◽

Xiaoqian Tang ◽

Xiuyan Yang ◽

Huaxin Zhang

Keyword(s):

Salt Stress ◽

Amino Acid ◽

Salt Tolerance ◽

Metabolic Pathways ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Sulfur Metabolism ◽

Enrichment Analysis ◽

Extracellular Region ◽

Nitraria Sibirica

AbstractNitraria sibirica Pall., a typical halophyte that can survive under extreme drought conditions and in saline-alkali environments, exhibits strong salt tolerance and environmental adaptability. Understanding the mechanism of molecular and physiological metabolic response to salt stress of plant will better promote the cultivation and use of halophytes. To explore the mechanism of molecular and physiological metabolic of N. sibirica response to salt stress, two-month-old seedlings were treated with 0, 100, and 400 mM NaCl. The results showed that the differentially expressed genes between 100 and 400 mmol L−1 NaCl and unsalted treatment showed significant enrichment in GO terms such as binding, cell wall, extemal encapsulating structure, extracellular region and nucleotide binding. KEGG enrichment analysis found that NaCl treatment had a significant effect on the metabolic pathways in N. sibirica leaves, which mainly including plant-pathogen interaction, amino acid metabolism of the beta alanine, arginine, proline and glycine metabolism, carbon metabolism of glycolysis, gluconeogenesis, galactose, starch and sucrose metabolism, plant hormone signal transduction and spliceosome. Metabolomics analysis found that the differential metabolites between the unsalted treatment and the NaCl treatment are mainly amino acids (proline, aspartic acid, methionine, etc.), organic acids (oxaloacetic acid, fumaric acid, nicotinic acid, etc.) and polyhydric alcohols (inositol, ribitol, etc.), etc. KEGG annotation and enrichment analysis showed that 100 mmol L−1 NaCl treatment had a greater effect on the sulfur metabolism, cysteine and methionine metabolism in N. sibirica leaves, while various amino acid metabolism, TCA cycle, photosynthetic carbon fixation and sulfur metabolism and other metabolic pathways have been significantly affected by 400 mmol L−1 NaCl treatment. Correlation analysis of differential genes in transcriptome and differential metabolites in metabolome have found that the genes of AMY2, BAM1, GPAT3, ASP1, CML38 and RPL4 and the metabolites of L-cysteine, proline, 4-aminobutyric acid and oxaloacetate played an important role in N. sibirica salt tolerance control. This is a further improvement of the salt tolerance mechanism of N. sibirica, and it will provide a theoretical basis and technical support for treatment of saline-alkali soil and the cultivation of halophytes.

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