Are soluble carbohydrates ecologically relevant for salt tolerance in halophytes?

2013 ◽  
Vol 40 (9) ◽  
pp. 805 ◽  
Author(s):  
Ricardo Gil ◽  
Monica Boscaiu ◽  
Cristina Lull ◽  
Inmaculada Bautista ◽  
Antonio Lidón ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Compatible Solutes ◽  
Soluble Carbohydrates ◽  
Published Data ◽  
Ros Scavenging ◽  
Tolerance Mechanisms ◽  
Natural Habitats ◽  
Salt Stress Condition ◽  
General Response

A general response of plants to high soil salinity relies on the cellular accumulation of osmolytes, which help the plant to maintain osmotic balance under salt stress condition and/or act as ‘osmoprotectants’ with chaperon or reactive oxygen species (ROS) scavenging activities. Yet the ecological relevance of this response for the salt tolerance mechanisms of halophytes in their natural habitats remains largely unknown. In this review, we describe and discuss published data supporting the participation of compatible solutes in those mechanisms, with especial focus on soluble carbohydrates. Evidence for a functional role of carbohydrates in salt tolerance include: (i) relatively high levels of specific sugars and polyols have been detected in many halophytic taxa; (ii) an increase in salt tolerance has often been observed in parallel with increased intracellular levels of particular soluble carbohydrates, in transgenic plants overexpressing the corresponding biosynthetic enzymes; (iii) there are several examples of genes involved in carbohydrate metabolism which are induced under salt stress conditions; (iv) specific sugars or polyols have been shown to accumulate in different halophytes upon controlled salt treatments; and (v) although very few field studies on environmentally induced carbohydrate changes in halophytes exist, in general they also support the involvement of this type of osmolytes in salt stress tolerance mechanisms. We also highlight the complexities of unequivocally attributing carbohydrates a biological role in salt tolerance mechanisms of a given tolerant species. It is proposed that research on halophytes in their natural ecosystems should be intensified, correlating seasonal changes in carbohydrate contents with the degree of environmental stress affecting the plants. This could be an important complement to experiments made under more controlled (but artificial) conditions, such as laboratory set-ups.

Effects, tolerance mechanisms and management of salt stress in lucerne (Medicago sativa)

2020 ◽  
Vol 71 (5) ◽  
pp. 411 ◽  
Author(s):  
Safaa Mohammed Al-Farsi ◽  
Ahmad Nawaz ◽  
Anees-ur-Rehman ◽  
Saleem K. Nadaf ◽  
Abdullah M. Al-Sadi ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Medicago Sativa ◽  
Hormonal Regulation ◽  
Soluble Sugars ◽  
Compatible Solutes ◽  
Enzyme Activation ◽  
Plant Growth Promoting Bacteria ◽  
Dry Matter Accumulation ◽  
Tolerance Mechanisms

Lucerne (alfalfa, Medicago sativa L.) is a forage legume that is widely cultivated in arid and semi-arid regions of the world. The main aim of this review was to highlight the effects of salt stress on the performance of lucerne and to suggest different tolerance mechanisms and management strategies for improving its yield under salt stress. Salt stress significantly affects seed germination, carbon fixation, light harvesting, biological N2 fixation, mineral uptake and assimilation and dry-matter accumulation in lucerne. Accumulation of osmolytes or compatible solutes such as proline, polyamines, trehalose and soluble sugars confers salt tolerance in lucerne. Maintenance of low Na+:K+ ratios, antioxidant enzyme activation, and hormonal regulation also help lucerne to withstand salt stress. The screening of diverse genotypes on the basis of germination indices, gas exchange, biomass production, lipid peroxidation and antioxidant enzymes might be useful for breeding salt-tolerant lucerne genotypes. Novel biotechnological tools and functional genomics used to identify salt-conferring genes and quantitative trait loci will help to improve salt tolerance. Use of rhizobial and non-rhizobial plant growth-promoting bacteria, arbuscular mycorrhizal fungi, exogenous application of osmoprotectants, and seed priming with brassinolide, gibberellic acid and salicylic acid may help to improve lucerne performance in saline environments.

A Functional Alternative Oxidase Modulates Plant Salt Tolerance in Physcomitrella patens

2019 ◽  
Vol 60 (8) ◽  
pp. 1829-1841 ◽  
Author(s):  
Guochun Wu ◽  
Sha Li ◽  
Xiaochuan Li ◽  
Yunhong Liu ◽  
Shuangshuang Zhao ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Alternative Oxidase ◽  
Physcomitrella Patens ◽  
Redox Homeostasis ◽  
Respiratory Pathway ◽  
Functional Link ◽  
Salt Stress Condition ◽  
Plant Salt Tolerance

Abstract Alternative oxidase (AOX) has been reported to be involved in mitochondrial function and redox homeostasis, thus playing an essential role in plant growth as well as stress responses. However, its biological functions in nonseed plants have not been well characterized. Here, we report that AOX participates in plant salt tolerance regulation in moss Physcomitrella patens (P. patens). AOX is highly conserved and localizes to mitochondria in P. patens. We observed that PpAOX rescued the impaired cyanide (CN)-resistant alternative (Alt) respiratory pathway in Arabidopsis thaliana (Arabidopsis) aox1a mutant. PpAOX transcription and Alt respiration were induced upon salt stress in P. patens. Using homologous recombination, we generated PpAOX-overexpressing lines (PpAOX OX). PpAOX OX plants exhibited higher Alt respiration and lower total reactive oxygen species accumulation under salt stress condition. Strikingly, we observed that PpAOX OX plants displayed decreased salt tolerance. Overexpression of PpAOX disturbed redox homeostasis in chloroplasts. Meanwhile, chloroplast structure was adversely affected in PpAOX OX plants in contrast to wild-type (WT) P. patens. We found that photosynthetic activity in PpAOX OX plants was also lower compared with that in WT. Together, our work revealed that AOX participates in plant salt tolerance in P. patens and there is a functional link between mitochondria and chloroplast under challenging conditions.

scholarly journals Molecular response of canola to salt stress: insights on tolerance mechanisms

2018 ◽  
Author(s):  
Reza Shokri-Gharelo ◽  
Pouya Motie-Noparvar
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Edible Oils ◽  
Biodiesel Fuel ◽  
Molecular Response ◽  
Salt Tolerant ◽  
Tolerance Mechanisms ◽  
Brassica Napus L ◽  
Salt Response ◽  
The Many

Canola (Brassica napus L.) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as ‘salt-tolerant’, plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests where researchers should focus future studies.

Effect of Calcium on Salt Tolerance of Leaf Epidermal Cells of Ruppia maritima at High Salinity

1998 ◽  
Vol 4 (S2) ◽  
pp. 1174-1175
Author(s):  
A.D. Barnabas ◽  
R. Jagels ◽  
W.J. Przybylowicz ◽  
J. Mesjasz-Przybylowicz
Keyword(s):  
Salt Stress ◽  
Sodium Chloride ◽  
Salt Tolerance ◽  
High Salinity ◽  
Epidermal Cells ◽  
Transfer Cell ◽  
Ruppia Maritima ◽  
Terrestrial Plants ◽  
Tolerance Mechanisms ◽  
Salt Glands

Ruppia maritima L. is a submerged halophyte which occurs frequently in estuaries where sodium chloride is the dominant salt. Unlike terrestrial halophytes, R. maritima does not possess any specialised salt-secreting structures such as salt glands. Knowledge of salt tolerance mechanisms in this plant is important to our understanding of its biology. In a previous study it was shown that leaf epidermal cells of R. maritima, which possess transfer cell characteristics, are implicated in salt regulation. In the present investigation, the effect of calcium (Ca) on salt tolerance of leaf epidermal cells was studied since Ca has been found to be an important factor in resistance to salt stress in terrestrial plants.Plants were grown in artificial seawater of high salinity (33%) and at two different Ca concentrations : 400 ppm (high Ca) and 100 ppm (low Ca).

scholarly journals Transcriptomic Profiling Identifies Candidate Genes Involved in the Salt Tolerance of the Xerophyte Pugionium cornutum

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1039 ◽  
Author(s):  
Yan-Nong Cui ◽  
Fang-Zhen Wang ◽  
Cheng-Hang Yang ◽  
Jian-Zhen Yuan ◽  
Huan Guo ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Candidate Genes ◽  
Osmotic Adjustment ◽  
Assimilation Efficiency ◽  
Carbon Assimilation ◽  
Ros Scavenging ◽  
Transport Pathway ◽  
Genes Encoding ◽  
Assimilation Capacity

The xerophyte Pugionium cornutum adapts to salt stress by accumulating inorganic ions (e.g., Cl−) for osmotic adjustment and enhancing the activity of antioxidant enzymes, but the associated molecular basis remains unclear. In this study, we first found that P. cornutum could also maintain cell membrane stability due to its prominent ROS-scavenging ability and exhibits efficient carbon assimilation capacity under salt stress. Then, the candidate genes associated with the important physiological traits of the salt tolerance of P. cornutum were identified through transcriptomic analysis. The results showed that after 50 mM NaCl treatment for 6 or 24 h, multiple genes encoding proteins facilitating Cl− accumulation and NO3− homeostasis, as well as the transport of other major inorganic osmoticums, were significantly upregulated in roots and shoots, which should be favorable for enhancing osmotic adjustment capacity and maintaining the uptake and transport of nutrient elements; a large number of genes related to ROS-scavenging pathways were also significantly upregulated, which might be beneficial for mitigating salt-induced oxidative damage to the cells. Meanwhile, many genes encoding components of the photosynthetic electron transport pathway and carbon fixation enzymes were significantly upregulated in shoots, possibly resulting in high carbon assimilation efficiency in P. cornutum. Additionally, numerous salt-inducible transcription factor genes that probably regulate the abovementioned processes were found. This work lays a preliminary foundation for clarifying the molecular mechanism underlying the adaptation of xerophytes to harsh environments.

A barley mutant with improved salt tolerance through ion homeostasis and ROS scavenging under salt stress

2017 ◽  
Vol 39 (3) ◽  
Author(s):  
Davood Kiani ◽  
Hassan Soltanloo ◽  
Seyyede Sanaz Ramezanpour ◽  
Ali Asghar Nasrolahnezhad Qumi ◽  
Ahad Yamchi ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Ion Homeostasis ◽  
Ros Scavenging ◽  
Barley Mutant

scholarly journals Agronomical, Physiological and Biochemical Characterization of In Vitro Selected Eggplant Somaclonal Variants under NaCl Stress

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2544
Author(s):  
Sami Hannachi ◽  
Stefaan Werbrouck ◽  
Insaf Bahrini ◽  
Abdelmuhsin Abdelgadir ◽  
Hira Affan Siddiqui
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Normal Growth ◽  
Nacl Stress ◽  
Soluble Carbohydrates ◽  
Regenerated Plants ◽  
And Control ◽  
Physiological And Biochemical

Previously, an efficient regeneration protocol was established and applied to regenerate plants from calli lines that could grow on eggplant leaf explants after a stepwise in vitro selection for tolerance to salt stress. Plants were regenerated from calli lines that could tolerate up to 120 mM NaCl. For further in vitro and in vivo evaluation, four plants with a higher number of leaves and longer roots were selected from the 32 plants tested in vitro. The aim of this study was to confirm the stability of salt tolerance in the progeny of these four mutants (‘R18’, ‘R19’, ‘R23’ and ‘R30’). After three years of in vivo culture, we evaluated the impact of NaCl stress on agronomic, physiological and biochemical parameters compared to the parental control (‘P’). The regenerated and control plants were assessed under in vitro and in vivo conditions and were subjected to 0, 40, 80 and 160 mM of NaCl. Our results show significant variation in salinity tolerance among regenerated and control plants, indicating the superiority of four regenerants (‘R18’, ‘R19’, ‘R23’ and ‘R30’) when compared to the parental line (‘P’). In vitro germination kinetics and young seedling growth divided the lines into a sensitive and a tolerant group. ‘P’ tolerate only moderate salt stress, up to 40 mM NaCl, while the tolerance level of ‘R18’, ‘R19’, ‘R23’ and ‘R30’ was up to 80 mM NaCl. The quantum yield of PSII (ΦPSII) declined significantly in ‘P’ under salt stress. The photochemical quenching was reduced while nonphotochemical quenching rose in ‘P’ under salt stress. Interestingly, the regenerants (‘R18’, ‘R19’, ‘R23’ and ‘R30’) exhibited high apparent salt tolerance by maintaining quite stable Chl fluorescence parameters. Rising NaCl concentration led to a substantial increase in foliar proline, malondialdehyde and soluble carbohydrates accumulation in ‘P’. On the contrary, ‘R18’, ‘R19’, ‘R23’ and ‘R30’ exhibited a decline in soluble carbohydrates and a significant enhancement in starch under salinity conditions. The water status reflected by midday leaf water potential (ψl) and leaf osmotic potential (ψπ) was significantly affected in ‘P’ and was maintained a stable level in ‘R18’, ‘R19’, ‘R23’ and ‘R30’ under salt stress. The increase in foliar Na+ and Cl− content was more accentuated in parental plants than in regenerated plants. The leaf K+, Ca2+ and Mg2+ content reduction was more aggravated under salt stress in ‘P’. Under increased salt concentration, ‘R18’, ‘R19’, ‘R23’ and ‘R30’ associate lower foliar Na+ content with a higher plant tolerance index (PTI), thus maintaining a normal growth, while foliar Na+ accumulation was more pronounced in ‘P’, revealing their failure in maintaining normal growth under salinity stress. ‘R18’, ‘R19’, ‘R23’ and ‘R30’ showed an obvious salt tolerance by maintaining significantly high chlorophyll content. In ‘R18’, ‘R19’, ‘R23’ and ‘R30’, the enzyme scavenging machinery was more performant in the roots compared to the leaves. Salt stress led to a significant augmentation of catalase, ascorbate peroxidase and guaiacol peroxidase activities in the roots of ‘R18’, ‘R19’, ‘R23’ and ‘R30’. In contrast, enzyme activities were less enhanced in ‘P’, indicating lower efficiency to cope with oxidative stress than in ‘R18’, ‘R19’, ‘R23’ and ‘R30’. ACC deaminase activity was significantly higher in ‘R18’, ‘R19’, ‘R23’ and ‘R30’ than in ‘P’. The present study suggests that regenerated plants ‘R18’, ‘R19’, ‘R23’ and ‘R30’ showed an evident stability in tolerating salinity, which shows their potential to be adopted as interesting selected mutants, providing the desired salt tolerance trait in eggplant.

scholarly journals Melatonin Improves Cotton Salt Tolerance by Regulating ROS Scavenging System and Ca2 + Signal Transduction

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuexin Zhang ◽  
Yapeng Fan ◽  
Cun Rui ◽  
Hong Zhang ◽  
Nan Xu ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Signal Molecules ◽  
Protective Mechanism ◽  
Rna Seq ◽  
Ros Scavenging ◽  
Exogenous Melatonin ◽  
Endogenous Melatonin

As one of the cash crops, cotton is facing the threat of abiotic stress during its growth and development. It has been reported that melatonin is involved in plant defense against salt stress, but whether melatonin can improve cotton salt tolerance and its molecular mechanism remain unclear. We investigated the role of melatonin in cotton salt tolerance by silencing melatonin synthesis gene and exogenous melatonin application in upland cotton. In this study, applicating of melatonin can improve salt tolerance of cotton seedlings. The content of endogenous melatonin was different in cotton varieties with different salt tolerance. The inhibition of melatonin biosynthesis related genes and endogenous melatonin content in cotton resulted in the decrease of antioxidant enzyme activity, Ca2+ content and salt tolerance of cotton. To explore the protective mechanism of exogenous melatonin against salt stress by RNA-seq analysis. Melatonin played an important role in the resistance of cotton to salt stress, improved the salt tolerance of cotton by regulating antioxidant enzymes, transcription factors, plant hormones, signal molecules and Ca2+ signal transduction. This study proposed a regulatory network for melatonin to regulate cotton’s response to salt stress, which provided a theoretical basis for improving cotton’s salt tolerance.

scholarly journals Transcriptomic profiling identifies candidate genes involved in salt tolerance of the xerophyte Pugionium cornutum

2019 ◽  
Author(s):  
Yan-Nong Cui ◽  
Fang-Zhen Wang ◽  
Cheng-Hang Yang ◽  
Jian-Zhen Yuan ◽  
Huan Guo ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Candidate Genes ◽  
Molecular Mechanisms ◽  
Carbon Fixation ◽  
Assimilation Efficiency ◽  
Carbon Assimilation ◽  
Inorganic Ions ◽  
Ros Scavenging ◽  
Genes Encoding

Abstract Background: Pugionium cornutum is a xerophytic plant that primarily adapts to salt stress by accumulating inorganic ions (e.g., Cl-) for osmoregulation, improving its reactive oxygen species (ROS)-scavenging ability and maintaining high photosynthetic carbon assimilation efficiency, but the associated molecular mechanisms still remain unclear. Results: Here, we present an analysis of gene responses to salt stress based on the transcriptome of P. cornutum exposed to 50 mM NaCl treatment. The data revealed that, after NaCl treatment for 6 or 24 h, the transcript levels of multiple genes encoding proteins facilitating Cl- accumulation and NO3- homeostasis such as SLAH1, CLCg, CCC1, and NPF6.4, as well as the transport of other major inorganic osmoticums were significantly upregulated in roots and shoots, which should be favorable to enhancing osmotic adjustment capacity and maintaining the plant uptake and transport of nutrient elements; a large number of genes related to ROS-scavenging pathways were also significantly upregulated, which should be beneficial for mitigating salt-induced oxidative damage to the cell metabolism. Meanwhile, many genes encoding components of the photosynthetic electron transport and carbon fixation enzymes were significantly upregulated in shoots after salt treatment, possibly resulting in a high carbon assimilation efficiency in P. cornutum. Additionally, numerous salt-inducible transcription factor genes probably regulating the abovementioned processes were found. Conclusion: Candidate genes involved in salt tolerance of P. cornutum were identified, which lays a preliminary foundation for clarifying the molecular mechanism of the xerophytes adapting to harsh environments.

scholarly journals Foliar Application of 24-Epibrassinolide Improved Salt Stress Tolerance of Perennial Ryegrass

HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1518-1523 ◽  
Author(s):  
Shanshan Sun ◽  
Mengying An ◽  
Liebao Han ◽  
Shuxia Yin
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Tolerance ◽  
Perennial Ryegrass ◽  
Foliar Application ◽  
Soluble Sugar ◽  
Salt Stress Tolerance ◽  
Salt Stress Condition ◽  
Relative Water ◽  
Antioxidant Defense Systems

Perennial ryegrass (Lolium perenne L.) is a widely used turfgrass. In this study, the effect of exogenously applied 24-epibrassinolide (EBR) on salt stress tolerance of perennial ryegrass was investigated. The results indicated that pretreatment with four concentrations of EBR (0, 0.1, 10, 1000 nM) improved salt tolerance of perennial ryegrass. Exogenous EBR treatment decreased electrolyte leakage (EL), malondialdehyde (MDA), and H2O2 contents and enhanced the leaf relative water content (RWC), proline, soluble sugar, and soluble protein content under salt stress condition. Meanwhile, EBR reduced the accumulation of Na+ and increased K+, Ca2+, and Mg2+ contents in leaves after salt treatment. Moreover, EBR pretreatment also increased superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activity, as well as ascorbic acid (AsA) and glutathione contents. These results suggested that EBR improved salt tolerance by enhancing osmotic adjustment and antioxidant defense systems in perennial ryegrass.

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