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 Application Improves Salt Tolerance of Alfalfa (Medicago sativa L.) by Enhancing Antioxidant Capacity

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 220 ◽  
Author(s):  
Huifang Cen ◽  
Tingting Wang ◽  
Huayue Liu ◽  
Danyang Tian ◽  
Yunwei Zhang
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Medicago Sativa ◽  
Salt Resistance ◽  
Primary Role ◽  
Waterlogging Tolerance ◽  
Alfalfa Seed ◽  
Mda Content ◽  
Medicago Sativa L

Alfalfa (Medicago sativa L.) is an important and widely cultivated forage grass. The productivity and forage quality of alfalfa are severely affected by salt stress. Melatonin is a bioactive molecule with versatile physiological functions and plays important roles in response to various biotic and abiotic stresses. Melatonin has been proven efficient in improving alfalfa drought and waterlogging tolerance in recent studies. In our reports, we applied melatonin exogenously to explore the effects of melatonin on alfalfa growth and salt resistance. The results demonstrated that melatonin application promoted alfalfa seed germination and seedling growth, and reduced oxidative damage under salt stress. Further application research found that melatonin alleviated salt injury in alfalfa plants under salt stress. The electrolyte leakage, malondialdehyde (MDA) content and H2O2 content were significantly reduced, and the activities of catalase (CAT), peroxidase (POD), and Cu/Zn superoxide dismutase (Cu/Zn-SOD) were increased with melatonin pretreatment compared to control plants under salt stress with the upregulation of genes related to melatonin and antioxidant enzymes biosynthesis. Melatonin was also involved in reducing Na+ accumulation in alfalfa plants. Our study indicates that melatonin plays a primary role as an antioxidant in scavenging H2O2 and enhancing activities of antioxidant enzymes to improve the salt tolerance of alfalfa plants.

scholarly journals Induction of tolerance to salt stress in soursop seedlings using hydrogen peroxide

2019 ◽  
Vol 10 (4) ◽  
pp. 484-490 ◽  
Author(s):  
André Alisson Rodrigues Da Silva ◽  
Geovani Soares De Lima ◽  
Carlos Alberto Vieira de Azevedo ◽  
Luana Lucas De Sá Almeida Veloso ◽  
Jessica Dayanne Capitulino ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Peroxide ◽  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Gas Exchange ◽  
Irrigation Water ◽  
Water Salinity ◽  
Exogenous Application ◽  
Induction Of Tolerance

The exogenous use of hydrogen peroxide is an alternative in the acclimatization of plants to salt stress due to the greater activity of antioxidant enzymes. In this perspective, this study aimed to evaluate the gas exchange and the growth of soursop seedlings under salt stress using hydrogen peroxide. The study was conducted under greenhouse conditions. The treatments were distributed in randomized blocks, in a 5 x 2 factorial arrangement, related to five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) and two concentrations of hydrogen peroxide - H2O2 (0 and 20 μM), with four replicates and two plants per plot. The effects of the treatments were evaluated by the variables of gas exchange and growth. The increase in water salinity negatively affected the gas exchange and the growth of the soursop seedlings. The gas exchange and growth variables presented deleterious effects caused by the salinity of the irrigation water, mitigated by the exogenous application of hydrogen peroxide at the concentration of 20 μM. The exogenous use of hydrogen peroxide at the concentration of 20 μM can be used to induce salt tolerance in soursop seedlings.

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 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 Changes in Leaf Structural and Functional Characteristics when Changing Planting Density at Different Growth Stages Alters Cotton Lint Yield under a New Planting Model

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 859 ◽  
Author(s):  
Aziz Khan ◽  
Jie Zheng ◽  
Daniel Kean Yuen Tan ◽  
Ahmad Khan ◽  
Kashif Akhtar ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Gas Exchange ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
High Density ◽  
Lint Yield ◽  
Planting Density ◽  
Cotton Lint ◽  
Cotton Lint Yield

Manipulation of planting density and choice of variety are effective management components in any cropping system that aims to enhance the balance between environmental resource availability and crop requirements. One-time fertilization at first flower with a medium plant stand under late sowing has not yet been attempted. To fill this knowledge gap, changes in leaf structural (stomatal density, stomatal length, stomata width, stomatal pore perimeter, and leaf thickness), leaf gas exchange, and chlorophyll fluorescence attributes of different cotton varieties were made in order to change the planting densities to improve lint yield under a new planting model. A two-year field evaluation was carried out on cotton varieties—V1 (Zhongmian-16) and V2 (J-4B)—to examine the effect of changing the planting density (D1, low, 3 × 104; D2, moderate, 6 × 104; and D3, dense, 9 × 104) on cotton lint yield, leaf structure, chlorophyll fluorescence, and leaf gas exchange attribute responses. Across these varieties, J-4B had higher lint yield compared with Zhongmian-16 in both years. Plants at high density had depressed leaf structural traits, net photosynthetic rate, stomatal conductance, intercellular CO2 uptake, quenching (qP), actual quantum yield of photosystem II (ΦPSII), and maximum quantum yield of PSII (Fv/Fm) in both years. Crops at moderate density had improved leaf gas exchange traits, stomatal density, number of stomata, pore perimeter, length, and width, as well as increased qP, ΦPSII, and Fv/Fm compared with low- and high-density plants. Improvement in leaf structural and functional traits contributed to 15.9%–10.7% and 12.3%–10.5% more boll m−2, with 20.6%–13.4% and 28.9%–24.1% higher lint yield averaged across both years, respectively, under moderate planting density compared with low and high density. In conclusion, the data underscore the importance of proper agronomic methods for cotton production, and that J-4B and Zhongmian-16 varieties, grown under moderate and lower densities, could be a promising option based on improved lint yield in subtropical regions.

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

scholarly journals Effect of fungal infection on leaf gas-exchange and chlorophyll fluorescence in Quercus ilex

2001 ◽  
Vol 58 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Bouchra El Omari ◽  
Isabel Fleck ◽  
Xavier Aranda ◽  
Asumpci� Moret ◽  
Mart� Nadal
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Fungal Infection ◽  
Quercus Ilex ◽  
Leaf Gas Exchange
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