scholarly journals Serratia liquefaciens KM4 Improves Salt Stress Tolerance in Maize by Regulating Redox Potential, Ion Homeostasis, Leaf Gas Exchange and Stress-Related Gene Expression

2018 ◽  
Vol 19 (11) ◽  
pp. 3310 ◽  
Author(s):  
Mohamed El-Esawi ◽  
Ibrahim Alaraidh ◽  
Abdulaziz Alsahli ◽  
Saud Alzahrani ◽  
Hayssam Ali ◽  
...  
Keyword(s):  
Salt Stress ◽  
Gas Exchange ◽  
Plant Growth ◽  
Stress Tolerance ◽  
High Salinity ◽  
Leaf Gas Exchange ◽  
Ion Homeostasis ◽  
Stress Markers ◽  
Serratia Liquefaciens ◽  
Stress Related Genes

High salinity mitigates crop productivity and quality. Plant growth-promoting soil rhizobacteria (PGPR) improve plant growth and abiotic stress tolerance via mediating various physiological and molecular mechanisms. This study investigated the effects of the PGPR strain Serratia liquefaciens KM4 on the growth and physiological and molecular responsiveness of maize (Zea mays L.) plants under salinity stress (0, 80, and 160 mM NaCl). High salinity significantly reduced plant growth and biomass production, nutrient uptake, leaf relative water content, pigment content, leaf gas exchange attributes, and total flavonoid and phenolic contents in maize. However, osmolyte content (e.g., soluble proteins, proline, and free amino acids), oxidative stress markers, and enzymatic and non-enzymatic antioxidants levels were increased in maize under high salinity. On the other hand, Serratia liquefaciens KM4 inoculation significantly reduced oxidative stress markers, but increased the maize growth and biomass production along with better leaf gas exchange, osmoregulation, antioxidant defense systems, and nutrient uptake under salt stress. Moreover, it was found that all these improvements were accompanied with the upregulation of stress-related genes (APX, CAT, SOD, RBCS, RBCL, H+-PPase, HKT1, and NHX1), and downregulation of the key gene in ABA biosynthesis (NCED). Taken together, the results demonstrate the beneficial role of Serratia liquefaciens KM4 in improving plant growth and salt stress tolerance in maize by regulating ion homeostasis, redox potential, leaf gas exchange, and stress-related genes expression.

scholarly journals Linking exogenous foliar application of glycine betaine and stomatal characteristics with salinity stress tolerance in cotton (Gossypium hirsutum L.) seedlings

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdoul Kader Mounkaila Hamani ◽  
Shuang Li ◽  
Jinsai Chen ◽  
Abubakar Sunusi Amin ◽  
Guangshuai Wang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Plant Growth ◽  
Gossypium Hirsutum ◽  
Glycine Betaine ◽  
Leaf Gas Exchange ◽  
Nacl Stress ◽  
Stomatal Characteristics ◽  
Fluorescence Characteristics

Abstract Background Glycine betaine (GB) plays a crucial role in plants responding to abiotic stresses. Studying the physiological response of cotton seedlings to exogenous GB under salt stress provides a reference for the application of GB to improve the resistance of cotton seedlings under salt stress. The purpose of this research is to examine the impacts of foliar-applied GB on leaf stomatal structure and characteristics, gas exchange and chlorophyll fluorescence characteristics and plant growth indicators of Gossypium hirsutum L. under NaCl stress conditions. Results Under the salinity of 150 mM, the four concentrations of GB are 0, 2.5, 5, and 7.5 mM, and the control (CK) was GB-untreated non-saline. Salt stress negatively affected leaf stomata as well as gas exchange and chlorophyll fluorescence and decreased plant growth parameters of cotton seedlings. The treatment with 5 mM GB significantly increased the evolution of photosynthetic rate (Pn), transpiration rate (Tr), intracellular CO2 concentration (Ci) and stomatal conductance (gs) compared to the GB-untreated saline treatment. The Exogenous foliar-applied GB has sustainably decreased the carboxylation efficiency (Pn/Ci) and water use efficiency (WUE). The concentration of 5 mM GB leads to a significant improvement of leaf stomatal characteristics. The leaf gas exchange attributes correlated positively with stomatal density (SD), stomatal length (SL) and stomatal with (SW). Conclusion The overall results suggested that exogenous foliar supplementation with GB can effectively alleviate the damage of salt stress to cotton seedlings. The effect of applying 5 mM GB could be an optional choice for protecting cotton seedlings from NaCl stress through promoting the stomatal functions, photosynthetic activities and growth characteristics.

scholarly journals Alleviation of Salt Stress in Wheat Seedlings via Multifunctional Bacillus aryabhattai PM34: An In-Vitro Study

2021 ◽  
Vol 13 (14) ◽  
pp. 8030
Author(s):  
Shehzad Mehmood ◽  
Amir Abdullah Khan ◽  
Fuchen Shi ◽  
Muhammad Tahir ◽  
Tariq Sultan ◽  
...  
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Stress Tolerance ◽  
Bacterial Strain ◽  
Acc Deaminase ◽  
Wheat Growth ◽  
Wheat Seedlings ◽  
Pgp Traits ◽  
Bacillus Aryabhattai

Plant growth-promoting rhizobacteria play a substantial role in plant growth and development under biotic and abiotic stress conditions. However, understanding about the functional role of rhizobacterial strains for wheat growth under salt stress remains largely unknown. Here we investigated the antagonistic bacterial strain Bacillus aryabhattai PM34 inhabiting ACC deaminase and exopolysaccharide producing ability to ameliorate salinity stress in wheat seedlings under in vitro conditions. The strain PM34 was isolated from the potato rhizosphere and screened for different PGP traits comprising nitrogen fixation, potassium, zinc solubilization, indole acetic acid, siderophore, and ammonia production, along with various extracellular enzyme activities. The strain PM34 showed significant tolerance towards both abiotic stresses including salt stress (NaCl 2 M), heavy metal (nickel, 100 ppm, and cadmium, 300 ppm), heat stress (60 °C), and biotic stress through mycelial inhibition of Rhizoctonia solani (43%) and Fusarium solani (41%). The PCR detection of ituC, nifH, and acds genes coding for iturin, nitrogenase, and ACC deaminase enzyme indicated the potential of strain PM34 for plant growth promotion and stress tolerance. In the in vitro experiment, NaCl (2 M) decreased the wheat growth while the inoculation of strain PM34 enhanced the germination% (48%), root length (76%), shoot length (75%), fresh biomass (79%), and dry biomass (87%) over to un-inoculated control under 2M NaCl level. The results of experiments depicted the ability of antagonistic bacterial strain Bacillus aryabhattai PM34 to augment salt stress tolerance when inoculated to wheat plants under saline environment.

scholarly journals Down-Regulation of SlGRAS10 in Tomato Confers Abiotic Stress Tolerance

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 623
Author(s):  
Sidra Habib ◽  
Yee Yee Lwin ◽  
Ning Li
Keyword(s):  
Salt Stress ◽  
Abiotic Stress ◽  
Plant Growth ◽  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Abiotic Stress Tolerance ◽  
Functional Characterization ◽  
Flavonoid Biosynthesis ◽  
Ros Scavenging ◽  
Down Regulation

Adverse environmental factors like salt stress, drought, and extreme temperatures, cause damage to plant growth, development, and crop yield. GRAS transcription factors (TFs) have numerous functions in biological processes. Some studies have reported that the GRAS protein family plays significant functions in plant growth and development under abiotic stresses. In this study, we demonstrated the functional characterization of a tomato SlGRAS10 gene under abiotic stresses such as salt stress and drought. Down-regulation of SlGRAS10 by RNA interference (RNAi) produced dwarf plants with smaller leaves, internode lengths, and enhanced flavonoid accumulation. We studied the effects of abiotic stresses on RNAi and wild-type (WT) plants. Moreover, SlGRAS10-RNAi plants were more tolerant to abiotic stresses (salt, drought, and Abscisic acid) than the WT plants. Down-regulation of SlGRAS10 significantly enhanced the expressions of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) to reduce the effects of reactive oxygen species (ROS) such as O2− and H2O2. Malondialdehyde (MDA) and proline contents were remarkably high in SlGRAS10-RNAi plants. Furthermore, the expression levels of chlorophyll biosynthesis, flavonoid biosynthesis, and stress-related genes were also enhanced under abiotic stress conditions. Collectively, our conclusions emphasized the significant function of SlGRAS10 as a stress tolerate transcription factor in a certain variety of abiotic stress tolerance by enhancing osmotic potential, flavonoid biosynthesis, and ROS scavenging system in the tomato plant.

scholarly journals Characterization and gas exchange in accessions of Saccharum complex under salinity in the Sub-middle São Francisco, Brazil

2021 ◽  
Vol 25 (3) ◽  
pp. 163-167
Author(s):  
Welson L. Simões ◽  
Anderson R. de Oliveira ◽  
Jucicléia S. da Silva ◽  
Vinicius G. Torres Junior ◽  
Weslley O. da Silva ◽  
...  
Keyword(s):  
Salt Stress ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Saccharum Officinarum ◽  
Leaf Length ◽  
Saccharum Complex ◽  
Breeding Programs ◽  
Agricultural Yield ◽  
Semi Arid Region ◽  
Species Being

ABSTRACT Salinity is one of the factors that most limit agricultural yield in the Brazilian semi-arid region. In this context, the present study aimed to evaluate the leaf gas exchange and biometric characteristics of accessions of the Saccharum complex subjected to salt stress. The experiment was carried out in a greenhouse, installed at Embrapa Semiárido, in Petrolina, PE, Brazil. The experimental design was in randomized blocks, with the treatments represented by 19 accessions belonging to different genera/species, being 10 accessions of Saccharum officinarum (BGCN 6, BGCN 91, BGCN 104, BGCN 127, BCGN 90, BGCN 101, BGCN 102, BGCN 118, BGCN 125 and BGCN 122), two accessions of Saccharum spp. (BGCN 87 and BGCN 89), one accession of Saccharum hybridum (BGCN 88), one accession of Saccharum robustum (BGCN 94), four accessions of Erianthus arundinaceus (BGCN 117, BGCN 119, BGCN 120 and BGCN 123) and one accession of Miscanthus spp., with three repetitions. Biometric characteristics, chlorophyll index and leaf gas exchange of the accessions were evaluated when they were subjected to irrigation with salinized water (6.0 dS m-1). E. arundinaceus accessions (BGCN 120 and BGCN 123) showed the highest photosynthetic rate, transpiration rate, plant height and leaf length, indicating greater adaptability to salt stress and could be promising in breeding programs.

scholarly journals Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

2018 ◽  
Vol 70 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Mohamed Farissi ◽  
Mohammed Mouradi ◽  
Omar Farssi ◽  
Abdelaziz Bouizgaren ◽  
Cherki Ghoulam
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Membrane Potential ◽  
Salt Tolerance ◽  
Gas Exchange ◽  
Medicago Sativa ◽  
Leaf Gas Exchange ◽  
Root Cortex ◽  
Root Cortex Cells

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.

scholarly journals Melatonin: A Small Molecule but Important for Salt Stress Tolerance in Plants

2019 ◽  
Vol 20 (3) ◽  
pp. 709 ◽  
Author(s):  
Haoshuang Zhan ◽  
Xiaojun Nie ◽  
Ting Zhang ◽  
Shuang Li ◽  
Xiaoyu Wang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Stress Tolerance ◽  
Stress Responses ◽  
Ion Homeostasis ◽  
Free Radical Scavenger ◽  
Limiting Factors ◽  
Polyamine Metabolism ◽  
Antioxidant Systems ◽  
Radical Scavenger ◽  
Salt Stress Tolerance

Salt stress is one of the most serious limiting factors in worldwide agricultural production, resulting in huge annual yield loss. Since 1995, melatonin (N-acetyl-5-methoxytryptamine)—an ancient multi-functional molecule in eukaryotes and prokaryotes—has been extensively validated as a regulator of plant growth and development, as well as various stress responses, especially its crucial role in plant salt tolerance. Salt stress and exogenous melatonin lead to an increase in endogenous melatonin levels, partly via the phyto-melatonin receptor CAND2/PMTR1. Melatonin plays important roles, as a free radical scavenger and antioxidant, in the improvement of antioxidant systems under salt stress. These functions improve photosynthesis, ion homeostasis, and activate a series of downstream signals, such as hormones, nitric oxide (NO) and polyamine metabolism. Melatonin also regulates gene expression responses to salt stress. In this study, we review recent literature and summarize the regulatory roles and signaling networks involving melatonin in response to salt stress in plants. We also discuss genes and gene families involved in the melatonin-mediated salt stress tolerance.

Leaf gas exchange, chloroplastic pigments and dry matter accumulation in castor bean (Ricinus communis L) seedlings subjected to salt stress conditions

2008 ◽  
Vol 27 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Hugo Alves Pinheiro ◽  
José Vieira Silva ◽  
Laurício Endres ◽  
Vilma Marques Ferreira ◽  
Celene de Albuquerque Câmara ◽  
...  
Keyword(s):  
Salt Stress ◽  
Gas Exchange ◽  
Castor Bean ◽  
Dry Matter ◽  
Ricinus Communis ◽  
Leaf Gas Exchange ◽  
Stress Conditions ◽  
Dry Matter Accumulation ◽  
Ricinus Communis L ◽  
Chloroplastic Pigments
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