Salt stress vs. salt shock - the case of sugar beet and its halophytic ancestor

Here we determined the impact of salt shock and salt stress on the level of DNA methylation in selected CpG islands localized in promoters or first exons of sixteen salt-responsive genes in beets. Two subspecies differing in salt tolerance were subjected for analysis, a moderately salt-tolerant sugar beet Beta vulgaris ssp. vulgaris cv. Huzar and a halophytic beet, Beta vulgaris ssp. maritima. The CpG island methylation status was determined. All target sequences were hyper- or hypomethylated under salt shock and/or salt stress in one or both beet subspecies. It was revealed that the genomic regions analyzed were highly methylated in both, the salt treated plants and untreated controls. Methylation of the target sequences changed in a salt-dependent manner, being affected by either one or both treatments. Under both shock and stress, the hypomethylation was a predominant response in sugar beet. In Beta vulgaris ssp. maritima, the hypermethylation occurred with higher frequency than hypomethylation, especially under salt stress and in the promoter-located CpG sites. Conversely, the hypomethylation of the promoter-located CpG sites predominated in sugar beet plants subjected to salt stress. This findings suggest that DNA methylation may be involved in salt-tolerance and transcriptomic response to salinity in beets.

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The physiological and metabolic changes in sugar beet seedlings under different levels of salt stress

Journal of Plant Research ◽

10.1007/s10265-017-0964-y ◽

2017 ◽

Vol 130 (6) ◽

pp. 1079-1093 ◽

Cited By ~ 12

Author(s):

Yuguang Wang ◽

Piergiorgio Stevanato ◽

Lihua Yu ◽

Huijie Zhao ◽

Xuewei Sun ◽

...

Keyword(s):

Salt Stress ◽

Sugar Beet ◽

Metabolic Changes ◽

Different Levels

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Overexpression of a S-Adenosylmethionine Decarboxylase from Sugar Beet M14 Increased Araidopsis Salt Tolerance

International Journal of Molecular Sciences ◽

10.3390/ijms20081990 ◽

2019 ◽

Vol 20 (8) ◽

pp. 1990 ◽

Cited By ~ 5

Author(s):

Meichao Ji ◽

Kun Wang ◽

Lin Wang ◽

Sixue Chen ◽

Haiying Li ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Salt Stress ◽

Transgenic Plants ◽

Sugar Beet ◽

Stress Tolerance ◽

Membrane Damage ◽

Pcr Analysis ◽

Ros Generation ◽

Salt Stress Tolerance ◽

Adenosylmethionine Decarboxylase

Polyamines play an important role in plant growth and development, and response to abiotic stresses. Previously, differentially expressed proteins in sugar beet M14 (BvM14) under salt stress were identified by iTRAQ-based quantitative proteomics. One of the proteins was an S-adenosylmethionine decarboxylase (SAMDC), a key rate-limiting enzyme involved in the biosynthesis of polyamines. In this study, the BvM14-SAMDC gene was cloned from the sugar beet M14. The full-length BvM14-SAMDC was 1960 bp, and its ORF contained 1119 bp encoding the SAMDC of 372 amino acids. In addition, we expressed the coding sequence of BvM14-SAMDC in Escherichia coli and purified the ~40 kD BvM14-SAMDC with high enzymatic activity. Quantitative real-time PCR analysis revealed that the BvM14-SAMDC was up-regulated in the BvM14 roots and leaves under salt stress. To investigate the functions of the BvM14-SAMDC, it was constitutively expressed in Arabidopsis thaliana. The transgenic plants exhibited greater salt stress tolerance, as evidenced by longer root length and higher fresh weight and chlorophyll content than wild type (WT) under salt treatment. The levels of spermidine (Spd) and spermin (Spm) concentrations were increased in the transgenic plants as compared with the WT. Furthermore, the overexpression plants showed higher activities of antioxidant enzymes and decreased cell membrane damage. Compared with WT, they also had low expression levels of RbohD and RbohF, which are involved in reactive oxygen species (ROS) production. Together, these results suggest that the BvM14-SAMDC mediated biosynthesis of Spm and Spd contributes to plant salt stress tolerance through enhancing antioxidant enzymes and decreasing ROS generation.

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Overexpression of GSK3-like Kinase 5 (OsGSK5) in rice (Oryza sativa) enhances salinity tolerance in part via preferential carbon allocation to root starch

Functional Plant Biology ◽

10.1071/fp16424 ◽

2017 ◽

Vol 44 (7) ◽

pp. 705 ◽

Cited By ~ 7

Author(s):

Maysaya Thitisaksakul ◽

Maria C. Arias ◽

Shaoyun Dong ◽

Diane M. Beckles

Keyword(s):

Oryza Sativa ◽

Salt Stress ◽

Salinity Tolerance ◽

Carbon Allocation ◽

Oryza Sativa L ◽

Rice Seedling ◽

Shoot Biomass ◽

Salt Shock ◽

Seedling Roots ◽

Root Starch

Rice (Oryza sativa L.) is very sensitive to soil salinity. To identify endogenous mechanisms that may help rice to better survive salt stress, we studied a rice GSK3-like isoform (OsGSK5), an orthologue of a Medicago GSK3 previously shown to enhance salinity tolerance in Arabidopsis by altering carbohydrate metabolism. We wanted to determine whether OsGSK5 functions similarly in rice. OsGSK5 was cloned and sequence, expression, evolutionary and functional analyses were conducted. OsGSK5 was expressed highest in rice seedling roots and was both salt and sugar starvation inducible in this tissue. A short-term salt-shock (150 mM) activated OsGSK5, whereas moderate (50 mM) salinity over the same period repressed the transcript. OsGSK5 response to salinity was due to an ionic effect since it was unaffected by polyethylene glycol. We engineered a rice line with 3.5-fold higher OsGSK5 transcript, which better tolerated cultivation on saline soils (EC = 8 and 10 dS m–2). This line produced more panicles and leaves, and a higher shoot biomass under high salt stress than the control genotypes. Whole-plant 14C-tracing and correlative analysis of OsGSK5 transcript with eco-physiological assessments pointed to the accelerated allocation of carbon to the root and its deposition as starch, as part of the tolerance mechanism.

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Production of Sugar Beet and Maize as Energy Crops in Saline Alkali Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.2331 ◽

2013 ◽

Vol 750-752 ◽

pp. 2331-2334

Author(s):

Gui Geng ◽

Fu Qiang Song ◽

Feng Shan Yang ◽

Li Hua Yu ◽

Tie Jun Wang ◽

...

Keyword(s):

Salt Stress ◽

Sugar Beet ◽

Energy Crops ◽

Alkali Soil ◽

Growing Seasons ◽

Heavy Medium

The production of sugar beet and maize as energy crops were investigated in saline alkali soil in China during three growing seasons. A dramatically decreases of yield of grains and starch of maize was found in both medium and heavy saline-alkali soil in the three years. But there were no decreases of yield of root and sucrose of sugar beet in medium saline-alkali soil and reduction of yield of root and sucrose of sugar beet in heavy medium saline-alkali were faintly. The results indicate that sugar beet is more tolerant to salt stress and maintains higher production of sugar may be a major bioethanol crops in saline-alkali soil in China.

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Effects of salt stress on growth, inorganic ions and proline accumulation in relation to osmotic adjustment in five sugar beet cultivars

Environmental and Experimental Botany ◽

10.1016/s0098-8472(01)00109-5 ◽

2002 ◽

Vol 47 (1) ◽

pp. 39-50 ◽

Cited By ~ 298

Author(s):

Cherki Ghoulam ◽

Ahmed Foursy ◽

Khalid Fares

Keyword(s):

Salt Stress ◽

Sugar Beet ◽

Osmotic Adjustment ◽

Inorganic Ions ◽

Proline Accumulation

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Transcriptome Profiling of the Salt Stress Response in the Leaves and Roots of Halophytic Eutrema salsugineum

Frontiers in Genetics ◽

10.3389/fgene.2021.770742 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chuanshun Li ◽

Yuting Qi ◽

Chuanzhi Zhao ◽

Xingjun Wang ◽

Quan Zhang

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Soluble Sugars ◽

Lignin Biosynthesis ◽

Sugar Metabolism ◽

Transcriptome Profiling ◽

Salt Stress Response ◽

Salt Shock ◽

Eutrema Salsugineum ◽

Leaves And Roots

Eutrema salsugineum can grow in natural harsh environments; however, the underlying mechanisms for salt tolerance of Eutrema need to be further understood. Herein, the transcriptome profiling of Eutrema leaves and roots exposed to 300 mM NaCl is investigated, and the result emphasized the role of genes involved in lignin biosynthesis, autophagy, peroxisome, and sugar metabolism upon salt stress. Furthermore, the expression of the lignin biosynthesis and autophagy-related genes, as well as 16 random selected genes, was validated by qRT-PCR. Notably, the transcript abundance of a large number of lignin biosynthesis genes such as CCoAOMT, C4H, CCR, CAD, POD, and C3′H in leaves was markedly elevated by salt shock. And the examined lignin content in leaves and roots demonstrated salt stress led to lignin accumulation, which indicated the enhanced lignin level could be an important mechanism for Eutrema responding to salt stress. Additionally, the differentially expressed genes (DEGs) assigned in the autophagy pathway including Vac8, Atg8, and Atg4, as well as DEGs enriched in the peroxisome pathway such as EsPEX7, EsCAT, and EsSOD2, were markedly induced in leaves and/or roots. In sugar metabolism pathways, the transcript levels of most DEGs associated with the synthesis of sucrose, trehalose, raffinose, and xylose were significantly enhanced. Furthermore, the expression of various stress-related transcription factor genes including WRKY, AP2/ERF-ERF, NAC, bZIP, MYB, C2H2, and HSF was strikingly improved. Collectively, the increased expression of biosynthesis genes of lignin and soluble sugars, as well as the genes in the autophagy and peroxisome pathways, suggested that Eutrema encountering salt shock possibly possess a higher capacity to adjust osmotically and facilitate water transport and scavenge reactive oxidative species and oxidative proteins to cope with the salt environment. Thus, this study provides a new insight for exploring the salt tolerance mechanism of halophytic Eutrema and discovering new gene targets for the genetic improvement of crops.

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Transcriptional responses of Rosa rugosa to salt stress and salt shock

Ciência e Agrotecnologia ◽

10.1590/1413-7054202044008220 ◽

2020 ◽

Vol 44 ◽

Author(s):

Michele Valquíria dos Reis ◽

Laura Vaughn Rouhana ◽

Patrícia Duarte de Oliveira Paiva ◽

Diogo Pedrosa Correia da Silva ◽

Renato Paiva ◽

...

Keyword(s):

Salt Stress ◽

Molecular Mechanisms ◽

Expression Patterns ◽

Exposure Period ◽

Transcriptional Responses ◽

Expression Levels ◽

Salt Shock ◽

Stress Changes ◽

Stress Related Genes ◽

High Level

ABSTRACT Rugosa rugosa has high tolerance to various stresses; however, the molecular mechanisms of this behavior under adverse conditions are unclear. The objective of this study is to investigate expression patterns of stress-related genes in response to salinity stress. Changes in transcript levels of R. rugose, grown under different salt stress conditions (0, 25, 50, and 100 mM NaCl) over a long exposure period (30 days), have been investigated. In addition, the effects of salt shock stress on seedlings exposed to a high level (200 mM) of NaCl for a relatively short duration (3 h) have also been investigated. Expression levels of selected differentially expressed genes have been determined using relative reverse transcription polymerase chain reaction (RT-PCR). It has been observed that seedlings exposed to salt stress for a long duration exhibited no signs of stress in both leaves and roots. In addition, expression of NHX1 in R. rugosa increased in the presence of NaCl. Furthermore, transcripts of EXP4, GPP, NHX1, NAC, and DREB genes also increased under high levels of NaCl. In contrast, expression levels of MYB and TIR decreased during this salt shock treatment. Of particular interest is the increase in levels of transcripts of NHX1 in leaves of seedlings grown under both salt stress and salt shock conditions, thus suggesting that this gene plays an important role in salt stress tolerance in R. rugosa. These findings will support efforts in enhancing salt tolerance in roses, and perhaps in other members of the Rosaceae family.

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Genome-wide sequence identification and expression analysis of N6-methyladenosine demethylase in sugar beet (Beta vulgaris L.) under salt stress

PeerJ ◽

10.7717/peerj.12719 ◽

2022 ◽

Vol 10 ◽

pp. e12719

Author(s):

Jie Cui ◽

Junli Liu ◽

Junliang Li ◽

Dayou Cheng ◽

Cuihong Dai

Keyword(s):

Salt Stress ◽

Sugar Beet ◽

Profile Analysis ◽

Rna Modification ◽

Homologous Proteins ◽

Genome Wide ◽

Growth Development ◽

Gene Structures ◽

Almost All

In eukaryotes, N6-methyladenosine (m6A) is the most abundant and highly conserved RNA modification. In vivo, m6A demethylase dynamically regulates the m6A level by removing the m6A marker where it plays an important role in plant growth, development and response to abiotic stress. The confirmed m6A demethylases in Arabidopsis thaliana include ALKBH9B and ALKBH10B, both belonging to the ALKB family. In this study, BvALKB family members were identified in sugar beet genome-wide database, and their conserved domains, gene structures, chromosomal locations, phylogeny, conserved motifs and expression of BvALKB genes were analyzed. Almost all BvALKB proteins contained the conserved domain of 2OG-Fe II-Oxy. Phylogenetic analysis suggested that the ten proteins were clustered into five groups, each of which had similar motifs and gene structures. Three Arabidopsis m6A demethylase-homologous proteins (BvALKBH6B, BvALKBH8B and BvALKBH10B) were of particular interest in our study. Expression profile analysis showed that almost all genes were up-regulated or down-regulated to varying degrees under salt stress. More specifically, BvALKBH10B homologous to AtALKBH10B was significantly up-regulated, suggesting that the transcriptional activity of this gene is responsive to salt stress. This study provides a theoretical basis for further screening of m6A demethylase in sugar beet, and also lays a foundation for studying the role of ALKB family proteins in growth, development and response to salinity stress.

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RNA-Binding Proteins as Targets to Improve Salt Stress Tolerance in Crops

Agronomy ◽

10.3390/agronomy10020250 ◽

2020 ◽

Vol 10 (2) ◽

pp. 250 ◽

Cited By ~ 2

Author(s):

Sara Rosa Téllez ◽

Rodoldphe Kanhonou ◽

Carlos Castellote Bellés ◽

Ramón Serrano ◽

Paula Alepuz ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Sugar Beet ◽

Rna Splicing ◽

Yeast Strain ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Crop Improvement ◽

Salt Toxicity

Salt stress drastically reduce crop productivity. In order to identify genes that could improve crop salt tolerance, we randomly expressed a cDNA library of the halotolerant sugar beet in a sodium-sensitive yeast strain. We identified six sugar beet genes coding for RNA binding proteins (RBP) able to increase the yeast Na+-tolerance. Two of these genes, named Beta vulgaris Salt Tolerant 3 (BvSATO3) and BvU2AF35b, participate in RNA splicing. The other four BvSATO genes (BvSATO1, BvSATO2, BvSATO4 and BvSATO6) are putatively involved in other processes of RNA metabolism. BvU2AF35b improved the growth of a wild type yeast strain under salt stress, and also in mutant backgrounds with impaired splicing, thus confirming that splicing is a target of salt toxicity. To validate the yeast approach, we characterized BvSATO1 in sugar beet and Arabidopsis. BvSATO1 expression was repressed by salt treatment in sugar beet, suggesting that this gene could be a target of salt toxicity. Expression of BvSATO1 in Arabidopsis increased the plant salt tolerance. Our results suggest that not only RNA splicing, but RNA metabolic processes such as such as RNA stability or nonsense-mediated mRNA decay may also be affected by salt stress and could be biotechnological targets for crop improvement.

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