Exogenous Myo-inositol Alleviates Salt Stress by Enhancing Antioxidants and Membrane Stability via the Upregulation of Stress Responsive Genes in Chenopodium quinoa L.

Myo-inositol has gained a central position in plants due to its vital role in physiology and biochemistry. This experimental work assessed the effects of salinity stress and foliar application of myo-inositol (MYO) on growth, chlorophyll content, photosynthesis, antioxidant system, osmolyte accumulation, and gene expression in quinoa (Chenopodium quinoa L. var. Giza1). Our results show that salinity stress significantly decreased growth parameters such as plant height, fresh and dry weights of shoot and root, leaf area, number of leaves, chlorophyll content, net photosynthesis, stomatal conductance, transpiration, and Fv/Fm, with a more pronounced effect at higher NaCl concentrations. However, the exogenous application of MYO increased the growth and photosynthesis traits and alleviated the stress to a considerable extent. Salinity also significantly reduced the water potential and water use efficiency in plants under saline regime; however, exogenous application of myo-inositol coped with this issue. MYO significantly reduced the accumulation of hydrogen peroxide, superoxide, reduced lipid peroxidation, and electrolyte leakage concomitant with an increase in the membrane stability index. Exogenous application of MYO up-regulated the antioxidant enzymes' activities and the contents of ascorbate and glutathione, contributing to membrane stability and reduced oxidative damage. The damaging effects of salinity stress on quinoa were further mitigated by increased accumulation of osmolytes such as proline, glycine betaine, free amino acids, and soluble sugars in MYO-treated seedlings. The expression pattern of OSM34, NHX1, SOS1A, SOS1B, BADH, TIP2, NSY, and SDR genes increased significantly due to the application of MYO under both stressed and non-stressed conditions. Our results support the conclusion that exogenous MYO alleviates salt stress by involving antioxidants, enhancing plant growth attributes and membrane stability, and reducing oxidative damage to plants.

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Silicon ameliorates the adverse effects of salt stress on sainfoin (Onobrychis viciaefolia) seedlings

Plant Soil and Environment ◽

10.17221/665/2017-pse ◽

2017 ◽

Vol 63 (No. 12) ◽

pp. 545-551 ◽

Cited By ~ 1

Author(s):

Wu Guo-Qiang ◽

Liu Hai-Long ◽

Feng Rui-Jun ◽

Wang Chun-Mei ◽

Du Yong-Yong

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Adverse Effects ◽

Plant Growth ◽

Membrane Permeability ◽

Chlorophyll Content ◽

Salinity Stress ◽

Soluble Sugars ◽

Organic Solutes ◽

Relative Membrane Permeability

The objective of this study was to investigate whether the application of silicon (Si) ameliorates the detrimental effects of salinity stress on sainfoin (Onobrychis viciaefolia). Three-week-old seedlings were exposed to 0 and 100 mmol/L NaCl with or without 1 mmol/L Si for 7 days. The results showed that salinity stress significantly reduced plant growth, shoot chlorophyll content and root K+ concentration, but increased shoot malondialdehyde (MDA) concentration, relative membrane permeability (RMP) and Na+ concentrations of shoot and root in sainfoin compared to the control (no added Si and NaCl). However, the addition of Si significantly enhanced growth, chlorophyll content of shoot, K+ and soluble sugars accumulation in root, while it reduced shoot MDA concentration, RMP and Na+ accumulation of shoot and root in plants under salt stress. It is clear that silicon ameliorates the adverse effects of salt stress on sainfoin by limiting Na+ uptake and enhancing selectivity for K+, and by adjusting the levels of organic solutes. The present study provides physiological insights into understanding the roles of silicon in salt tolerance in sainfoin.

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Effects of Exogenous Application of Osmotic Adjustment Substances on Growth, Pigment Concentration, and Physiological Parameters of Dracaena sanderiana Sander under Different Levels of Salinity

Agronomy ◽

10.3390/agronomy10010125 ◽

2020 ◽

Vol 10 (1) ◽

pp. 125 ◽

Cited By ~ 1

Author(s):

Pedro García-Caparrós ◽

Alfonso Llanderal ◽

Elodie Hegarat ◽

María Jiménez-Lao ◽

María Teresa Lao

Keyword(s):

Osmotic Adjustment ◽

Glycine Betaine ◽

Foliar Application ◽

Stomatal Density ◽

Soluble Sugars ◽

Physiological Parameters ◽

Clear Trend ◽

Exogenous Application ◽

Mode Of Application ◽

Dracaena Sanderiana

We evaluated two osmotic adjustment substances (glycine betaine (GB) and glycine (G) and a combination of both glycine + glycine betaine (G + GB) using two modes of application; irrigation and foliar sprays with Dracaena sanderiana plants. The plants were grown in containers and subjected to two levels of NaCl concentrations (2.0 and 7.5 dS m−1) over 8 weeks. Growth, pigment concentrations, and physiological parameters were assessed at the end of the trial. The foliar application of GB resulted in most optimal plant growth and biomass production in the presence of NaCl. The chlorophyll and carotenoid concentrations showed different trends depending on the osmotic adjustment substance applied and the mode of application. Stomatal density and dimensions varied considerably with respect to the osmotic adjustment substance supplied. The concentration of soluble sugars in leaves did not show a clear trend under the different treatments assessed. The exogenous application of G resulted in the highest concentration of free proline and proteins in leaves. The antioxidant capacity in leaves increased with both osmotic adjustment substances, and both means of application, under low and high saline conditions. We concluded that the foliar application of GB can be recommended in order to achieve cost-effective growth of D. sanderiana under saline conditions.

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Seed Pretreatment and Foliar Application of Proline Regulate Morphological, Physio-Biochemical Processes and Activity of Antioxidant Enzymes in Plants of Two Cultivars of Quinoa (Chenopodium quinoa Willd.)

Plants ◽

10.3390/plants8120588 ◽

2019 ◽

Vol 8 (12) ◽

pp. 588

Author(s):

Hira Yaqoob ◽

Nudrat A. Akram ◽

Samrah Iftikhar ◽

Muhammad Ashraf ◽

Noman Khalid ◽

...

Keyword(s):

Amino Acids ◽

Hydrogen Peroxide ◽

Ascorbic Acid ◽

Free Amino ◽

Foliar Application ◽

Soluble Sugars ◽

Chenopodium Quinoa ◽

Dry Weight ◽

Total Soluble Sugars ◽

Total Free Amino Acids

In the current study, the effects of exogenously applied proline (25 and 50 mM) and low-temperature treatment were examined on the physiochemical parameters in the plants of two cultivars (V1 and V2) of quinoa (Chenopodium quinoa Willd.). The seeds were also exposed to chilling stress at 4 °C before sowing. Plants raised from the seeds treated with low temperature showed reduced plant growth and contents of chlorophyll and carotenoids, but they had significantly increased contents of malondialdehyde, proline, ascorbic acid, total free amino acids, total soluble sugars, and total phenolics, as well as the activity of the peroxidase (POD) enzyme. Cold stress applied to seeds remained almost ineffective in terms of bringing about changes in plant root, hydrogen peroxide, glycine betaine and activities of superoxide dismutase (SOD), and catalase (CAT) enzymes. The exogenous application of proline significantly increased plant growth, the contents of chlorophyll, carotenoids, proline, ascorbic acid, total free amino acids, phenolics, and total soluble sugars, as well as the activities of SOD, POD, and CAT, but it decreased malondialdehyde content. Overall, foliar application of proline was better than the seed treatment in improving root dry weight, root length, chlorophyll a, carotenoids, glycine betaine, ascorbic acid and superoxide dismutase activity, whereas seed pre-treatment with proline was effective in improving shoot dry weight, shoot length, hydrogen peroxide, malondialdehyde, and peroxidase activity in both quinoa cultivars.

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Mitigation of Salinity Stress Effects on Broad Bean Productivity Using Calcium Phosphate Nanoparticles Application

Horticulturae ◽

10.3390/horticulturae8010075 ◽

2022 ◽

Vol 8 (1) ◽

pp. 75

Author(s):

Amira K. Nasrallah ◽

Ahmed A. Kheder ◽

Maimona A. Kord ◽

Ahmed S. Fouad ◽

Mohamed M. El-Mogy ◽

...

Keyword(s):

Salt Stress ◽

Calcium Phosphate ◽

Salinity Stress ◽

Agricultural Sector ◽

Broad Bean ◽

Growth Parameters ◽

Saline Water ◽

Soluble Sugars ◽

Higher Plant ◽

Plant Yield

Water salinity is one of the major abiotic stresses, and the use of saline water for the agricultural sector will incur greater demand in the coming decades. Recently, nanoparticles (NPs) have been used for developing numerous plant fertilizers as a smart and powerful form of material with dual action that can alleviate the adverse effects of salinity and provide the plant with more efficient nutrient forms. This study evaluated the influence of calcium phosphate NPs (CaP-NPs) as a soil fertilizer application on the production and bioactive compounds of broad bean plants under salinity stress. Results showed that salinity had deleterious effects on plant yield with 55.9% reduction compared to control. On the other hand, CaP-NPs dramatically improved plant yield by 30% compared to conventional fertilizer under salinity stress. This improvement could be attributed to significantly higher enhancement in total soluble sugars, antioxidant enzymes, proline content, and total phenolics recorded use of nano-fertilizer compared to conventional use under salt stress. Additionally, nano-fertilizer reflected better mitigatory effects on plant growth parameters, photosynthetic pigments, and oxidative stress indicators (MDA and H2O2). Therefore, our results support the replacement of traditional fertilizers comprising Ca2+ or P with CaP-nano-fertilizers for higher plant productivity and sustainability under salt stress.

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Exogenous application of KNO3 elevates the salinity tolerance of Stevia rebaudiana through ion homeostasis mechanism

10.1101/657767 ◽

2019 ◽

Author(s):

Mitali Mahajan ◽

Surbhi Sharma ◽

Pawan Kumar ◽

Probir Kumar Pal

Keyword(s):

Salinity Stress ◽

Salinity Tolerance ◽

Foliar Application ◽

Ion Homeostasis ◽

Stevia Rebaudiana ◽

Exogenous Application ◽

Leaf Yield ◽

Moderate Salinity ◽

Salinity Levels ◽

Normal Water

AbstractThough relatively little is understood of adaptation, physiological and metabolic changes of Stevia rebaudiana under exposure to salinity stress, it is hypothesized that exogenous application of potassium (K+) could elevates the salinity tolerance through ions homeostasis. Thus, an experiment was conducted with twenty treatment combinations comprising four salinity levels (irrigation with normal water as control and three level of NaCl at 40, 80 and 120 mM) and five different concentrations of KNO3 (0.0, 2.5, 5.0, 7.5, and 10.0 g L−1). Dry leaf yield was not negatively affected with mild salinity (40 mM). However, the detrimental effects were observed at moderate and higher salinity levels (80 and 120 mM). The uptakes of K+, Ca2+, and N were significantly reduced at higher salinity level, whereas accumulations of Na+ and Cl− ions in plant tissues were substantially increased. Proline content in leaf was also increased significantly (P≤0.05) in response to salt stress. Among the foliar application, KNO3 at 5.0 gL−1 registered significantly (P≤0.05) higher dry leaf yield compared with control. Exogenous application of K+ under moderate salinity stress maintained ion balance in cytosol, particularly K: Na. Thus, the salinity tolerance of stevia can be elevated to some extent through exogenous application of K+.HighlightThe detrimental effects of moderate and higher salinity levels on growth and dry leaf yield of stevia were observed. However, tolerance level can be elevated through exogenous application of KNO3.

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Exogenous Nitric Oxide Reinforces Photosynthetic Efficiency, Osmolyte, Mineral Uptake, Antioxidant, Expression of Stress-Responsive Genes and Ameliorates the Effects of Salinity Stress in Wheat

Plants ◽

10.3390/plants10081693 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1693

Author(s):

Ghalia S. H. Alnusairi ◽

Yasser S. A. Mazrou ◽

Sameer H. Qari ◽

Amr A. Elkelish ◽

Mona H. Soliman ◽

...

Keyword(s):

Nitric Oxide ◽

Oxidative Damage ◽

Salinity Stress ◽

Antioxidant System ◽

Photosynthetic Efficiency ◽

Growth Parameters ◽

Soluble Sugars ◽

Mineral Elements ◽

Protective Mechanisms ◽

Concomitant Reduction

Salinity stress is one of the major environmental constraints responsible for a reduction in agricultural productivity. This study investigated the effect of exogenously applied nitric oxide (NO) (50 μM and 100 μM) in protecting wheat plants from NaCl-induced oxidative damage by modulating protective mechanisms, including osmolyte accumulation and the antioxidant system. Exogenously sourced NO proved effective in ameliorating the deleterious effects of salinity on the growth parameters studied. NO was beneficial in improving the photosynthetic efficiency, stomatal conductance, and chlorophyll content in normal and NaCl-treated wheat plants. Moreover, NO-treated plants maintained a greater accumulation of proline and soluble sugars, leading to higher relative water content maintenance. Exogenous-sourced NO at both concentrations up-regulated the antioxidant system for averting the NaCl-mediated oxidative damage on membranes. The activity of antioxidant enzymes increased the protection of membrane structural and functional integrity and photosynthetic efficiency. NO application imparted a marked effect on uptake of key mineral elements such as nitrogen (N), potassium (K), and calcium (Ca) with a concomitant reduction in the deleterious ions such as Na+. Greater K and reduced Na uptake in NO-treated plants lead to a considerable decline in the Na/K ratio. Enhancing of salt tolerance by NO was concomitant with an obvious down-regulation in the relative expression of SOS1, NHX1, AQP, and OSM-34, while D2-protein was up-regulated.

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Exogenous application of xanthine and uric acid and nucleobase-ascorbate transporter MdNAT7 expression regulate salinity tolerance in apple

BMC Plant Biology ◽

10.1186/s12870-021-02831-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Tingting Sun ◽

Tingting Pei ◽

Lulu Yang ◽

Zhijun Zhang ◽

Mingjun Li ◽

...

Keyword(s):

Uric Acid ◽

Salt Stress ◽

Salinity Stress ◽

Ion Homeostasis ◽

Oxygen Species ◽

Ros Scavenging ◽

Exogenous Application ◽

Global Agriculture ◽

Tolerance To Salinity ◽

Transgenic Apple

Abstract Background Soil salinity is a critical threat to global agriculture. In plants, the accumulation of xanthine activates xanthine dehydrogenase (XDH), which catalyses the oxidation/conversion of xanthine to uric acid to remove excess reactive oxygen species (ROS). The nucleobase-ascorbate transporter (NAT) family is also known as the nucleobase-cation symporter (NCS) or AzgA-like family. NAT is known to transport xanthine and uric acid in plants. The expression of MdNAT is influenced by salinity stress in apple. Results In this study, we discovered that exogenous application of xanthine and uric acid enhanced the resistance of apple plants to salinity stress. In addition, MdNAT7 overexpression transgenic apple plants showed enhanced xanthine and uric acid concentrations and improved tolerance to salinity stress compared with nontransgenic plants, while opposite phenotypes were observed for MdNAT7 RNAi plants. These differences were probably due to the enhancement or impairment of ROS scavenging and ion homeostasis abilities. Conclusion Our results demonstrate that xanthine and uric acid have potential uses in salt stress alleviation, and MdNAT7 can be utilized as a candidate gene to engineer resistance to salt stress in plants.

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Assessing the Adaptive Mechanisms of Two Bread Wheat (Triticum aestivum L.) Genotypes to Salinity Stress

Agronomy ◽

10.3390/agronomy11101979 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1979

Author(s):

Ulkar Ibrahimova ◽

Zarifa Suleymanova ◽

Marian Brestic ◽

Alamdar Mammadov ◽

Omar M. Ali ◽

...

Keyword(s):

Lipid Peroxidation ◽

Triticum Aestivum ◽

Salt Stress ◽

Salinity Stress ◽

Osmotic Potential ◽

Soluble Sugars ◽

Triticum Aestivum L ◽

Salt Tolerant ◽

Wheat Genotypes ◽

Tolerant Genotype

This work deals with the assessment of physiological and biochemical responses to salt stress, as well as the regulation of the expression of the K+/Na+ transporter gene-TaHKT1;5 of two Triticum aestivum L. genotypes with contrasting tolerance. According to the observations, salinity stress caused lipid peroxidation; accumulation of soluble sugars and proline; decreased osmotic potential, Fv/Fm value, and K+/Na+ ratio; and increased the activity of antioxidant enzymes in both genotypes. In the salt-tolerant genotype, the activity of enzymes, the amounts of soluble sugars and proline were higher, the osmotic potential and the lipid peroxidation were lower than in the sensitive one, and the Fv/Fm value remained unchanged. A comparison of the accumulation of Na+ and K+ ions in the roots and leaves showed that the Na+ content in the leaves is lower. The selective transport of K+ ions from roots to leaves was more efficient in the salt-tolerant genotype Mirbashir-128; consequently, the K+/Na+ ratio in the leaves and roots of this genotype was higher compared with the sensitive Fatima genotype. The semi-quantitative RT-PCR expression experiments on TaHKT1;5 indicated that this gene was not expressed in the leaf of the wheat genotypes. Under salt stress, the expression level of the TaHKT1;5 gene increased in the root tissues of the salt-sensitive genotype, while it decreased in the salt-tolerant wheat genotype. The results obtained suggest that the ion status and salt tolerance of the wheat genotypes are related to the TaHKT1;5 gene activity.

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Electron and proton transport in wheat exposed to salt stress: is the increase of the thylakoid membrane proton conductivity responsible for decreasing the photosynthetic activity in sensitive genotypes?

Photosynthesis Research ◽

10.1007/s11120-021-00853-z ◽

2021 ◽

Author(s):

Ulkar Ibrahimova ◽

Marek Zivcak ◽

Kristina Gasparovic ◽

Anshu Rastogi ◽

Suleyman I. Allakhverdiev ◽

...

Keyword(s):

Lipid Peroxidation ◽

Chlorophyll Fluorescence ◽

Chlorophyll Content ◽

Proton Conductivity ◽

Salinity Stress ◽

Electron Flow ◽

Soluble Sugars ◽

Photosynthetic Apparatus ◽

Photochemical Reactions ◽

Chlorophyll Fluorescence Parameters

AbstractEffects of salinity caused by 150 mM NaCl on primary photochemical reactions and some physiological and biochemical parameters (K+/Na+ ratio, soluble sugars, proline, MDA) have been studied in five Triticum aestivum L. genotypes with contrasting salt tolerance. It was found that 150 mM NaCl significantly decreased the photosynthetic efficiency of two sensitive genotypes. The K+/Na+ ratio decreased in all genotypes exposed to salinity stress when compared with the control. Salinity stress also caused lipid peroxidation and accumulation of soluble sugars and proline. The amounts of soluble sugars and proline were higher in tolerant genotypes than sensitive ones, and lipid peroxidation was higher in sensitive genotypes. The noninvasive measurements of photosynthesis-related parameters indicated the genotype-dependent effects of salinity stress on the photosynthetic apparatus. The significant decrease of chlorophyll content (SPAD values) or adverse effects on photosynthetic functions at the PSII level (measured by the chlorophyll fluorescence parameters) were observed in the two sensitive genotypes only. Although the information obtained by different fast noninvasive techniques were consistent, the correlation analyses identified the highest correlation of the noninvasive records with MDA, K+/Na+ ratio, and free proline content. The lower correlation levels were found for chlorophyll content (SPAD) and Fv/Fm values derived from chlorophyll fluorescence. Performance index (PIabs) derived from fast fluorescence kinetics, and F735/F685 ratio correlated well with MDA and Na+ content. The most promising were the results of linear electron flow measured by MultispeQ sensor, in which we found a highly significant correlation with all parameters assessed. Moreover, the noninvasive simultaneous measurements of chlorophyll fluorescence and electrochromic band shift using this sensor indicated the apparent proton leakage at the thylakoid membranes resulting in a high proton conductivity (gH+), present in sensitive genotypes only. The possible consequences for the photosynthetic functions and the photoprotection are discussed.

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