scholarly journals Exogenous Melatonin Improves Salt Tolerance by Mitigating Osmotic, Ion, and Oxidative Stresses in Maize Seedlings

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 663 ◽  
Author(s):  
Jianhong Ren ◽  
Jun Ye ◽  
Lina Yin ◽  
Gouxia Li ◽  
Xiping Deng ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Antioxidant Activities ◽  
Term Treatment ◽  
Plant Tolerance ◽  
Short Term Treatment ◽  
Exogenous Melatonin ◽  
Positive Effects ◽  
Oxidative Stresses

Melatonin has been confirmed extensively for the positive effects on increasing plant tolerance to various abiotic stresses. However, the roles of melatonin in mediating different stresses still need to be explored in different plants species and growth periods. To investigate the role of melatonin in mitigating salt stress, maize (Zea mays L.) seedlings growing in hydroponic solution were treated with 100 mM NaCl combined with or without 1 μM melatonin. Melatonin application had no effects on maize growth under normal condition, while it moderately alleviated the NaCl-induced inhibition of plant growth. The leaf area, biomass, and photosynthesis of melatonin-treated plants were higher than that of without melatonin under NaCl treatment. The osmotic potential was lower, and the osmolyte contents (including sucrose and fructose) were higher in melatonin-treated plants. Meanwhile, the decreases in Na+ content and increases in K+/Na+ ratio were found in shoots of melatonin-applied plant under salt stress. Moreover, both enzymatic and nonenzymatic antioxidant activities were significantly increased in leaves with melatonin application under salt treatment. These results clearly indicate that the exogenous melatonin-enhanced salt tolerance under short-term treatment could be ascribed to three aspects, including osmotic adjustment, ion balance, and alleviation of salt-induced oxidative stress.

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 Overexpression of Peroxidase Gene GsPRX9 Confers Salt Tolerance in Soybean

2019 ◽  
Vol 20 (15) ◽  
pp. 3745 ◽  
Author(s):  
Ting Jin ◽  
Yangyang Sun ◽  
Ranran Zhao ◽  
Zhong Shan ◽  
Junyi Gai ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Glycine Soja ◽  
Primary Root ◽  
Wild Soybean ◽  
Plant Tolerance ◽  
Salt Tolerant ◽  
Fresh Weight ◽  
Peroxidase Gene

Peroxidases play prominent roles in antioxidant responses and stress tolerance in plants; however, their functions in soybean tolerance to salt stress remain unclear. Here, we investigated the role of a peroxidase gene from the wild soybean (Glycine soja), GsPRX9, in soybean tolerance to salt stress. GsPRX9 gene expression was induced by salt treatment in the roots of both salt-tolerant and -sensitive soybean varieties, and its relative expression level in the roots of salt-tolerant soybean varieties showed a significantly higher increase than in salt-sensitive varieties after NaCl treatment, suggesting its possible role in soybean response to salt stress. GsPRX9-overexpressing yeast (strains of INVSc1 and G19) grew better than the control under salt and H2O2 stress, and GsPRX9-overexpressing soybean composite plants showed higher shoot fresh weight and leaf relative water content than control plants after NaCl treatment. Moreover, the GsPRX9-overexpressing soybean hairy roots had higher root fresh weight, primary root length, activities of peroxidase and superoxide dismutase, and glutathione level, but lower H2O2 content than those in control roots under salt stress. These findings suggest that the overexpression of the GsPRX9 gene enhanced the salt tolerance and antioxidant response in soybean. This study would provide new insights into the role of peroxidase in plant tolerance to salt stress.

scholarly journals Exogenous melatonin improves the salt tolerance of cotton by removing active oxygen and protecting photosynthetic organs

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dan Jiang ◽  
Bin Lu ◽  
Liantao Liu ◽  
Wenjing Duan ◽  
Yanjun Meng ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Oxidative Damage ◽  
Photosynthetic Capacity ◽  
Photochemical Efficiency ◽  
Photochemical Quenching ◽  
Plant Tolerance ◽  
Signal Molecule ◽  
Ion Balance ◽  
Photosynthetic System

Abstract Background As damage to the ecological environment continues to increase amid unreasonable amounts of irrigation, soil salinization has become a major challenge to agricultural development. Melatonin (MT) is a pleiotropic signal molecule and indole hormone, which alleviates the damage of abiotic stress to plants. MT has been confirmed to eliminate reactive oxygen species (ROS) by improving the antioxidant system and reducing oxidative damage under adversity. However, the mechanism by which exogenous MT mediates salt tolerance by regulating the photosynthetic capacity and ion balance of cotton seedlings still remains unknown. In this study, the regulatory effects of MT on the photosynthetic system, osmotic modulators, chloroplast, and anatomical structure of cotton seedlings were determined under 0–500 μM MT treatments with salt stress induced by treatment with 150 mM NaCl. Results Salt stress reduces the chlorophyll content, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, PSII photochemical efficiency, PSII actual photochemical quantum yield, the apparent electron transfer efficiency, stomata opening, and biomass. In addition, it increases non-photochemical quenching. All of these responses were effectively alleviated by exogenous treatment with MT. Exogenous MT reduces oxidative damage and lipid peroxidation by reducing salt-induced ROS and protects the plasma membrane from oxidative toxicity. MT also reduces the osmotic pressure by reducing the salt-induced accumulation of Na+ and increasing the contents of K+ and proline. Exogenous MT can facilitate stomatal opening and protect the integrity of cotton chloroplast grana lamella structure and mitochondria under salt stress, protect the photosynthetic system of plants, and improve their biomass. An anatomical analysis of leaves and stems showed that MT can improve xylem and phloem and other properties and aides in the transportation of water, inorganic salts, and organic substances. Therefore, the application of MT attenuates salt-induced stress damage to plants. Treatment with exogenous MT positively increased the salt tolerance of cotton seedlings by improving their photosynthetic capacity, stomatal characteristics, ion balance, osmotic substance biosynthetic pathways, and chloroplast and anatomical structures (xylem vessels and phloem vessels). Conclusions Our study attributes help to protect the structural stability of photosynthetic organs and increase the amount of material accumulation, thereby reducing salt-induced secondary stress. The mechanisms of MT-induced plant tolerance to salt stress provide a theoretical basis for the use of MT to alleviate salt stress caused by unreasonable irrigation, fertilization, and climate change.

scholarly journals Thymol improves salinity tolerance of tobacco by increasing the Na+ efflux and enhancing the content of NO and GSH

2021 ◽  
Author(s):  
liang xu ◽  
Jia-Qian Song ◽  
yuelin wang ◽  
Xiao-Han Liu ◽  
Xue-Li Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Root Growth ◽  
Abiotic Stresses ◽  
Nature Medicine ◽  
Oxygen Species ◽  
Plant Tolerance ◽  
Ros Accumulation ◽  
Na Efflux ◽  
The Stability

Abstract Plants have evolved a lot of strategies to improve salt tolerance to cope with salt stress. Recent studies have suggested that thymol (a nature medicine) enhances the plant tolerance against abiotic stresses, but the mechanisms are rarely known. Here, we found that thymol played an important role in maintaining root growth under salt stress. Thymol rescued root growth from salt stress via ameliorating ROS (reactive oxygen species) accumulation, lipid peroxidation, and cell death. In addition, thymol enhanced the level of NO (nitric oxide) and GSH (glutathione) to repress ROS accumulation, further protecting the stability of cell membrane. Thymol-induced Na+ efflux in roots and leaves under salt stress may depend on the upregulation of SOS1, HKT1 and NHX1. Consequently, all of these evidences suggested that thymol improved tobacco salt tolerance via enhancing NO and GSH content as well as inducing Na+ efflux.

scholarly journals Neutrophil DREAM Promotes Neutrophil Recruitment in Vascular Inflammation Via Nuclear Factor Kappa B-Dependent and Independent Mechanisms

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 435-435
Author(s):  
Tripti Kumari ◽  
Jing Li ◽  
Andrew Barazia, ◽  
Vishwanath Jha ◽  
Amber Hansch ◽  
...  
Keyword(s):  
Vascular Inflammation ◽  
Term Treatment ◽  
Neutrophil Recruitment ◽  
Neutrophil Adhesion ◽  
Short Term ◽  
Short Term Treatment ◽  
Tnf Α ◽  
Inflammatory Molecules ◽  
Β2 Integrins

Abstract The interaction between neutrophils and endothelial cells (ECs) is critical for the pathogenesis of vascular inflammation. Neutrophil recruitment to inflamed tissues is initiated by rolling on activated ECs through the interactions between P-/E-selectins and their ligands. Subsequently, activated integrins (mainly αLβ2 and αMβ2) and chemokine receptors bind to their ligands on ECs and mediate slow-rolling, adhesion, crawling, and transmigration of neutrophils. Although many neutrophil adhesion receptors have been identified, the regulation of their ligand-binding function remains not fully understood. Using real-time intravital microscopy with mice lacking downstream regulatory element antagonist modulator (DREAM) and their bone marrow chimeric mice, we demonstrated that hematopoietic cell DREAM contributes to neutrophil recruitment to sites of vascular inflammation induced by TNF-α- but not a G protein-coupled receptor ligand, MIP-2 or fMLP. Our studies using adoptive neutrophil transfers and flow chamber assays revealed that neutrophil DREAM positively regulates the neutrophil recruitment processes under TNF-α-induced inflammatory conditions. Using RNA-seq and biochemical and cell biological studies, we found that neutrophil DREAM upregulates numerous pro-inflammatory molecules and down-regulates anti-inflammatory molecules after TNF-α treatment. In particular, neutrophil DREAM repressed expression of A20, a negative regulator of NF-κB signaling, and enhanced phosphorylation of IκB kinase (IKK) in response to TNF-α, suggesting the role of neutrophil DREAM in NF-κB activity. Furthermore, we observed that DREAM deletion and IKK inhibition significantly diminishes the ligand-binding activity of β2 integrins in neutrophils after short-term treatment with TNF-α and that deletion of neutrophil DREAM does not affect the expression of other neutrophil adhesion receptors, such as PSGL-1, L-selectin, CD44, CXCR2, and CXCR4. As assessed by flow cytometry using conformation-specific reporter antibodies, knockdown of DREAM in neutrophil-like HL-60 cells decreased TNF-α-induced activation of β2 integrins. Neutrophil DREAM promoted degranulation through IKK-mediated SNAP-23 phosphorylation after short-term treatment with TNF-α, implying the role of neutrophil DREAM-IKK signaling in NF-κB-independent signaling. Using intravital microscopy with Berkeley mice (a mouse model of sickle cell disease) deficient in hematopoietic or nonhematopoietic DREAM, we demonstrated that hematopoietic cell DREAM is crucial for inducing intravascular cell-cell aggregation and vaso-occlusive events in microvessels following the TNF-α challenge. Furthermore, infusion of DREAM KO neutrophils, compared with WT neutrophils, significantly reduced neutrophil recruitment and vaso-occlusive events in TNF-α-challenged SCD mice. These results demonstrate that neutrophil DREAM positively regulates β2 integrin function and promotes neutrophil recruitment during sterile inflammation via NF-κB-dependent and independent mechanisms. Our study provides evidence that targeting DREAM might be a novel therapeutic strategy to reduce excessive neutrophil recruitment in inflammatory diseases. Disclosures No relevant conflicts of interest to declare.

scholarly journals Thymol improves salinity tolerance of tobacco by increasing the Na + efflux and enhancing the content of NO and GSH

2021 ◽  
Author(s):  
liang xu ◽  
Jia-Qian Song ◽  
yuelin wang ◽  
Xiao-Han Liu ◽  
Xue-Li Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Root Growth ◽  
Abiotic Stresses ◽  
Nature Medicine ◽  
Oxygen Species ◽  
Plant Tolerance ◽  
Ros Accumulation ◽  
Na Efflux ◽  
The Stability

Abstract Plants have evolved a lot of strategies to improve salt tolerance to cope with salt stress. Recent studies have suggested that thymol (a nature medicine) enhances the plant tolerance against abiotic stresses, but the mechanisms are rarely known. Here, we found that thymol played an important role in maintaining root growth under salt stress. Thymol rescued root growth from salt stress via ameliorating ROS (reactive oxygen species) accumulation, lipid peroxidation, and cell death. In addition, thymol enhanced the level of NO (nitric oxide) and GSH (glutathione) to repress ROS accumulation, further protecting the stability of cell membrane. Thymol-induced Na+ efflux in roots and leaves under salt stress may depend on the upregulation of SOS1, HKT1 and NHX1. Consequently, all of these evidences suggested that thymol improved tobacco salt tolerance via enhancing NO and GSH content as well as inducing Na+ efflux.

scholarly journals Role of some rhizospheric Pseudomonas on the growth and physiology of broad bean (Vicia faba) under salt stress conditions

2019 ◽  
Vol 72 (4) ◽  
Author(s):  
Boubaker Idder ◽  
Rachid Djibaoui ◽  
Hocine Abdelhakim Reguieg Yssaad ◽  
Abdelhak Djoudi
Keyword(s):  
Salt Stress ◽  
Chlorophyll Content ◽  
Vicia Faba ◽  
Broad Bean ◽  
Plant Growth Promoting Bacteria ◽  
Total Chlorophyll ◽  
Plant Tolerance ◽  
Bacterial Strains ◽  
Total Chlorophyll Content

Salt stress affects the development and growth of plants in various ways as a result of its effect on water relationships, photosynthesis, and nutrient absorption by physiological and biochemical processes. Consequently, several researchers have increasingly studied the effect of plant growth promoting bacteria (PGPR) as promoters and enhancers under saline environment. The main goals of this study were to examine the manifested response of the broad bean plant under saline conditions and to evaluate the role of some <em>Pseudomonas</em> isolates in improving plant tolerance to salt stress. Three <em>Pseudomonas</em> strains were isolated (P1 and P7 from a saline soil and P15 from a vineyard soil). These isolates were screened by salinity and used as inoculums in <em>Vicia faba</em> plants (OTONO variety) irrigated with two saline solutions (NaCl; 100 and 150 mM L<sup>−1</sup>) and one without salinity. The results show that salinity decreased the fresh weight, total chlorophyll content, and the Na<sup>+</sup>/K<sup>+</sup> ratio, but it increased proline accumulation in inoculated and noninoculated plants. The inoculation of <em>V. faba</em> plants with P1, P7, and P15 strains significantly increased the production of fresh biomass in the presence and absence of salt stress, and positively affected the accumulation of proline and the Na<sup>+</sup>/K<sup>+</sup> ratio. The inoculation with bacterial strains increased the total chlorophyll content in plants at all salt treatment levels, especially the P1 strain that showed a significant effect.

scholarly journals Exogenous melatonin improves salt stress adaptation of cotton seedlings by regulating active oxygen metabolism

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10486
Author(s):  
Dan Jiang ◽  
Bin Lu ◽  
Liantao Liu ◽  
Wenjing Duan ◽  
Li Chen ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Seedling Growth ◽  
Lipid Membrane ◽  
Soluble Sugars ◽  
Oxygen Metabolism ◽  
Membrane Lipid ◽  
Biotic And Abiotic Stress ◽  
Exogenous Melatonin ◽  
Cotton Seedling

Melatonin is a small-molecule indole hormone that plays an important role in participating in biotic and abiotic stress resistance. Melatonin has been confirmed to promote the normal development of plants under adversity stress by mediating physiological regulation mechanisms. However, the mechanisms by which exogenous melatonin mediates salt tolerance via regulation of antioxidant activity and osmosis in cotton seedlings remain largely unknown. In this study, the regulatory effects of melatonin on reactive oxygen species (ROS), the antioxidant system, and osmotic modulators of cotton seedlings were determined under 0–500 µM melatonin treatments with salt stress induced by 150 mM NaCl treatment. Cotton seedlings under salt stress exhibited an inhibition of growth, excessive hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA) accumulations in leaves, increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and elevated ascorbic acid (AsA) and glutathione (GSH) content in leaves. However, the content of osmotic regulators (i.e., soluble sugars and proteins) in leaves was reduced under salt stress. This indicates high levels of ROS were produced, and the cell membrane was damaged. Additionally, osmotic regulatory substance content was reduced, resulting in osmotic stress, which seriously affected cotton seedling growth under salt stress. However, exogenous melatonin at different concentrations reduced the contents of H2O2, O2−, and MDA in cotton leaves, increased the activity of antioxidant enzymes and the content of reductive substances (i.e., AsA and GSH), and promoted the accumulation of osmotic regulatory substances in leaves under salt stress. These results suggest that melatonin can inhibit ROS production in cotton seedlings, improve the activity of the antioxidant enzyme system, raise the content of osmotic regulation substances, reduce the level of membrane lipid peroxidation, and protect the integrity of the lipid membrane under salt stress, which reduces damage caused by salt stress to seedlings and effectively enhances inhibition of salt stress on cotton seedling growth. These results indicate that 200 µM melatonin treatment has the best effect on the growth and salt tolerance of cotton seedlings.

The role of the OsCam1-1 salt stress sensor in ABA accumulation and salt tolerance in rice

2012 ◽  
Vol 55 (3) ◽  
pp. 198-208 ◽  
Author(s):  
Sukhumaporn Saeng-ngam ◽  
Warintra Takpirom ◽  
Teerapong Buaboocha ◽  
Supachitra Chadchawan
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Sensor
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