scholarly journals Differential Salt Tolerance Strategies in Three Halophytes from the Same Ecological Habitat: Augmentation of Antioxidant Enzymes and Compounds

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1100
Author(s):  
Abd El-Mageed F. M. Ghanem ◽  
Elsayed Mohamed ◽  
Ahmed M. M. A. Kasem ◽  
Abbas A. El-Ghamery

Understanding the salt tolerance mechanism in obligate halophytes provides valuable information for conservation and re-habitation of saline areas. Here, we investigated the responses of three obligate halophytes namely Arthrocnemum macrostachyum, Sarcocornia fruticosa and Salicornia europaea to salt stress (0, 100, 200, 400 and 600 mM NaCl) during their vegetative growth with regard to biomass, ions contents (Na+, K+ and Ca+2), chlorophyll contents, carotenoids, phenolic compounds, flavonoids, and superoxide dismutase, peroxidase and esterase activities. S. europaea showed the lowest biomass, root K+ content, Chl a/b ratio, and carotenoids under salinity. This reduction of biomass is concomitant with the increase in proline contents and peroxidase activity. On the other hand, the promotion of growth under low salinity and maintenance under high salinity (200 and 400 Mm NaCl) in A. Macrostachyum and S. fruticosa are accompanied by an increase in Chl a/b ratio, carotenoids, phenolics contents, and esterase activity. Proline content was decreased under high salinity (400 and 600 mM NaCl) in both species compared to S. europaea, while peroxidase showed the lowest activity in both plants under all salt levels except under 600 mM NaCl in Arthrocnemum macrostachyum compared to S. europaea. These results suggest two differential strategies; (1) the salt tolerance is due to activation of antioxidant enzymes and biosynthesis of proline in S. europaea, (2) the salt tolerance in A. macrostachyum, S. fruticosa are due to rearrangement of chlorophyll ratio and biosynthesis of antioxidant compounds (carotenoids, phenolics and flavonoids) which their cost seem to need less energy than activation of antioxidant enzymes. The differential behavior in halophytes of the same habitat confirms that the tolerance mechanism in halophytes is species-specific which provides new insight about the restoration strategy of saline areas.

2018 ◽  
Vol 19 (8) ◽  
pp. 2433 ◽  
Author(s):  
Mohamed El-Esawi ◽  
Abdullah Al-Ghamdi ◽  
Hayssam Ali ◽  
Aisha Alayafi ◽  
Jacques Witczak ◽  
...  

Pisum sativum L. (field pea) is a crop of a high nutritional value and seed oil content. The characterization of pea germplasm is important to improve yield and quality. This study aimed at using fatty acid profiling and amplified fragment length polymorphism (AFLP) markers to evaluate the variation and relationships of 25 accessions of French pea. It also aimed to conduct a marker-trait associations analysis using the crude oil content as the target trait for this analysis, and to investigate whether 5-aminolevulinic acid (ALA) could enhance salt tolerance in the pea germplasm. The percentage of crude oil of the 25 pea genotypes varied from 2.6 to 3.5%, with a mean of 3.04%. Major fatty acids in all of the accessions were linoleic acid. Moreover, the 12 AFLP markers used were polymorphic. The cluster analysis based on fatty acids data or AFLP data divided the 25 pea germplasm into two main clusters. The gene diversity of the AFLP markers varied from 0.21 to 0.58, with a mean of 0.41. Polymorphic information content (PIC) of pea germplasm varied from 0.184 to 0.416 with a mean of 0.321, and their expected heterozygosity (He) varied from 0.212 to 0.477 with a mean of 0.362. The AFLP results revealed that the Nain Ordinaire cultivar has the highest level of genetic variability, whereas Elatius 3 has the lowest level. Three AFLP markers (E-AAC/M-CAA, E-AAC/M-CAC, and E-ACA/M-CAG) were significantly associated with the crude oil content trait. The response of the Nain Ordinaire and Elatius 3 cultivars to high salinity stress was studied. High salinity (150 mM NaCl) slightly reduced the photosynthetic pigments contents in Nain Ordinaire leaves at a non-significant level, however, the pigments contents in the Elatius 3 leaves were significantly reduced by high salinity. Antioxidant enzymes (APX—ascorbate peroxidase; CAT—catalase; and POD—peroxidase) activities were significantly induced in the Nain Ordinaire cultivar, but non-significantly induced in Elatius 3 by high salinity. Priming the salt-stressed Nain Ordinaire and Elatius 3 plants with ALA significantly enhanced the pigments biosynthesis, antioxidant enzymes activities, and stress-related genes expression, as compared to the plants stressed with salt alone. In conclusion, this study is amongst the first investigations that conducted marker-trait associations in pea, and revealed a sort of correlation between the diversity level and salt tolerance.


2018 ◽  
Vol 36 ◽  
Author(s):  
Y. WANG ◽  
J. YU ◽  
B. ZHOU ◽  
S. SAPKOTA ◽  
F. WEI ◽  
...  

ABSTRACT: The effect of atrazine, mesotrione, and joint activity of atrazine plus mesotrione on pigment, lipid peroxidation, and antioxidant enzyme activity was studied. Atrazine and mesotrione treatments significantly reduced chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid concentrations, and protein content in bermudagrass (Cynodon dactylon L.) plants, whereas they significantly enhanced lipid peroxidation. The treatment of atrazine plus mesotrione caused greater phototoxic effect on bermudagrass than either herbicide alone, which was evident from the significantly decreased membrane stability noted as a function of the enhanced singlet oxygen and malondialdehyde (MDA) contents, as well as from the greater reduction in Chl a, Chl b, and carotenoid contents. Although bermudagrass activated the antioxidant enzymes catalase (CAT), peroxidase (POD), and glutathione S-transferase (GST), it was significantly injured after the herbicide treatments. Thus, results suggested that the enzymatic and non-enzymatic antioxidants of bermudagrass was overloaded after the treatment of atrazine plus mesotrione, and the reactive oxygen species (ROS) subsequently caused lipid peroxidation, pigment and protein degradation, as well as other cellular constituent damage.


2002 ◽  
Vol 53 (6) ◽  
pp. 663 ◽  
Author(s):  
C. M. Luna ◽  
M. de Luca ◽  
E. Taleisnik

In tetraploid cultivars of Rhodes grass (Chloris gayana Kunth) productivity decreases significantly under saline conditions. Two closely related clones of cv. Boma (T and S), exhibiting different degrees of salt tolerance, were compared with determine the physiological causes for such decrease. In those clones, salt tolerance was associated with differences in the proportion of dry leaves, salt gland density, Na excretion rate, and oxidative stress damage. The purpose of this paper is to evaluate whether salt tolerance and oxidative stress development in these clones are related to the activity of two antioxidant enzymes. Experiments were conducted in a greenhouse, in winter and summer, in plants treated with 0, 100, or 200 mm NaCl. In the summer, increases in oxidative damage, as determined by malondialdehyde (MDA) concentration, mirrored decreases in CO2 fixation at high salinity, especially in clone S. In clone T, salinity induced higher increases in Fe-SOD (superoxide dismutase) activity in summer-grown plants, and in ascorbate peroxidase (APX) in winter-grown plants. Oxidative stress induced by low paraquat concentration also induced an increase in Fe-SOD in leaf segments of clone T, and APX was less affected in clone T than in clone S. These results suggest that the clones differ in the control of antioxidant enzymes. Nevertheless, leaf death in winter was not related to increases in MDA, indicating that the association between salinity, leaf senescence and oxidatives stress is also influenced by other factors.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojing Xu ◽  
Yingli Zhou ◽  
Ping Mi ◽  
Baoshan Wang ◽  
Fang Yuan

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.


2016 ◽  
Vol 96 (3) ◽  
pp. 474-484 ◽  
Author(s):  
Yan-Qing Wu ◽  
Da-Qiu Zhao ◽  
Chen-Xia Han ◽  
Jun Tao

To clarify the theoretical basis of the differences in high temperature stress tolerance among herbaceous peony (Paeonia lactiflora Pall.), we investigated the heat injury index of twelve P. lactiflora cultivars. Of these, heat-tolerant ‘Zifengyu’ and moderately heat-tolerant ‘Hongyanzhenghui’ were selected to study the biochemical and molecular responses to high temperature stress. ‘Zifengyu’ had reduced malondialdehyde (MDA) content, increased soluble sugar, chlorophyll (Chl) a, Chl b, Chl a + b. and carotenoid contents, as well as elevated antioxidant enzymes activities, photosynthetic rate (Pn), transpiration rate (Tr) and relatively intact cellular structures compared with ‘Hongyanzhenghui’, especially when the temperature was the highest. Additionally, we isolated partial cDNAs of two heat shock protein genes (HSP60 and HSP90) from P. lactiflora, which were 880-bp and 1077-bp nucleotides in length, respectively. The expression levels of PlHSP60, PlHSP70 and PlHSP90 were lower in ‘Zifengyu’ than in ‘Hongyanzhenghui’ for the first three of four developmental stages examined. These results indicated that heat-tolerant P. lactiflora cultivar could effectively scavenge reactive oxygen species (ROS), protect cellular structures, reduce thermal damage and delay the death of plants by enhancing antioxidant enzymes activities and HSP expression under high temperature stress. These findings provide a theoretical basis for breeding heat-tolerant P. lactiflora cultivars.


Fine Focus ◽  
2017 ◽  
Vol 3 (2) ◽  
pp. 101-110
Author(s):  
Maedgen Q. Lindsey ◽  
Jennifer R. Huddleston

The goals of this study were to isolate microorganisms from oil well-produced water, identify the microorganisms, and test the microorganisms’ salt tolerance. Saltwater collected from two well locations producing from different zones in Jones County, Texas, was spread onto Mannitol Salt Agar (MSA). Isolates showed a 16S rDNA gene sequence identity of 99% with Idiomarina baltica and Marinobacter persicus. Salt tolerance assays indicated an optimal growth concentration of 10-12.5% NaCl for the Idiomarina isolate and a decrease in growth beyond 5% NaCl for the Marinobacter isolate. In conclusion, organisms that are phylogenetically similar to marine microorganisms are present in oil well environments, and have variable salt tolerances, which may prove useful in microbialmediated hydrocarbon bioremediation of high salinity environments.


2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .


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