scholarly journals Exogenously Applied Ascorbic Acid-Mediated Changes in Osmoprotection and Oxidative Defense System Enhanced Water Stress Tolerance in Different Cultivars of Safflower (Carthamus tinctorious L.)

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 104 ◽  
Author(s):  
Farooq ◽  
Bukhari ◽  
Akram ◽  
Ashraf ◽  
Wijaya ◽  
...  

The present study was conducted to examine the effect of exogenously applied ascorbic acid (AsA) on osmoprotectants and the oxidative defense system in four cultivars (16171, 16183, 16207 and 16246) of safflower under well-watered and water deficit conditions. Water stress (60% field capacity) significantly decreased the shoot and root fresh and dry weights, shoot and root lengths and chlorophyll contents in all four safflower cultivars, while it increased the leaf free proline, total phenolics, total soluble proteins, hydrogen peroxide content and activities of catalase, superoxide dismutase and peroxidase enzymes. Foliar-applied (100 mg L−1 and 150 mg L−1) ascorbic acid caused a marked improvement in shoot and root fresh and dry weights, plant height, chlorophyll and AsA contents as well as the activity of peroxidase (POD) enzyme particularly under water deficit conditions. It also increased the accumulation of leaf proline, total phenolics, total soluble proteins and glycine betaine (GB) content in all four cultivars. Exogenously applied AsA lowered the contents of MDA and H2O2, and the activities of CAT and SOD enzymes. Overall, exogenously applied AsA had a positive effect on the growth of safflower plants under water deficit conditions which could be related to AsA-induced enhanced osmoprotection and regulation of antioxidant defense system.

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1615
Author(s):  
Zikria Zafar ◽  
Fahad Rasheed ◽  
Ahsan Ul Haq ◽  
Faridah Hanum Ibrahim ◽  
Shazia Afzal ◽  
...  

Mitigating climate change requires the identification of tree species that can tolerate water stress with fewer negative impacts on plant productivity. Therefore, the study aimed to evaluate the water stress tolerance of young saplings of C. erectus and M. alba under three soil water deficit treatments (control, CK, 90% field capacity, FC, medium stress MS, 60% FC and high stress, HS, 30% FC) under controlled conditions. Results showed that leaf and stem dry weight decreased significantly in both species under MS and HS. However, root dry weight and root/shoot ratio increased, and total dry weight remained similar to CK under MS in C. erectus saplings. Stomatal conductance, CO2 assimilation rate decreased, and intrinsic water use efficiency increased significantly in both species under MS and HS treatments. The concentration of hydrogen peroxide, superoxide radical, malondialdehyde and electrolyte leakage increased in both the species under soil water deficit but was highest in M. alba. The concentration of antioxidative enzymes like superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase also increased in both species under MS and HS but was highest in C. erectus. Therefore, results suggest that C. erectus saplings depicted a better tolerance to MS due to an effective antioxidative enzyme system.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0254906
Author(s):  
Sidra Shafiq ◽  
Nudrat Aisha Akram ◽  
Muhammad Ashraf ◽  
Mohammad S. AL-Harbi ◽  
Bassem N. Samra

Now-a-days, plant-based extracts, as a cheap source of growth activators, are being widely used to treat plants grown under extreme climatic conditions. So, a trial was conducted to assess the response of two maize (Zea mays L.) varieties, Sadaf (drought tolerant) and Sultan (drought sensitive) to foliar-applied sugar beet extract (SBE) under varying water-deficit conditions. Different SBE (control, 1%, 2%, 3% & 4%) levels were used in this study, and plants were exposed to water-deficit [(75% and 60% of field capacity (FC)] and control (100% FC) conditions. It was observed that root and shoot dry weights (growth), total soluble proteins, RWC-relative water contents, total phenolics, chlorophyll pigments and leaf area per plant decreased under different water stress regimes. While, proline, malondialdehyde (MDA), RMP-relative membrane permeability, H2O2-hydrogen peroxide and the activities of antioxidant enzymes [CAT-catalase, POD-peroxidase and SOD-superoxide dismutase] were found to be improved in water stress affected maize plants. Exogenous application of varying levels of SBE ameliorated the negative effects of water-deficit stress by enhancing the growth attributes, photosynthetic pigments, RWC, proline, glycinebetaine (GB), activities of POD and CAT enzymes and levels of total phenolics, whereas it reduced the lipid peroxidation in both maize varieties under varying water stress levels. It was noted that 3% and 4% levels of SBE were more effective than the other levels used in enhancing the growth as well as other characteristics of the maize varieties. Overall, the sugar beet extract proved to be beneficial for improving growth and metabolism of maize plants exposed to water stress.


1970 ◽  
pp. 10-15
Author(s):  
ARUNKUMAR K

Aim of this study to screened the root morphology and root characters of different cocoa types at 100 and 50 percent field capacity under water deficit condition at seedling stage. A survey was conducted at Idukki region of Kerala and twenty seven plus trees were identified. These twenty seven plus trees were screened for water stress tolerance under glasshouse condition by gravimetric method. With respect to the performance of plus trees, root length under 50% field capacity got increased to 21.15 cm as against 20.51 cm in 100 per cent field capacity. Fresh root weight and dry root weight substantially got increased under water stress. The average root girth of 27 plus trees got increased in stressed condition from 3.70 cm to 3.88 cm. The root volume also followed the same trend (47.28 as against 45.96). The percent of nitrogen is 1.37 in 50 per cent field capacity as against 1.63 in 100 per cent field capacity. The percentage of phosphorous decreased to 0.16 under 50 per cent field capacity as against 0.37 in 100 per cent field capacity. Similarly the percentage of potassium also showed a decreasing trend (1.27 % under 100 % field capacity to 1.06 % under 50 % field capacity). In the present investigation, under water stress condition the root length, number of roots, fresh weight of root and dry weight of root tends to increase compared to the 100 per cent field capacity, indicating the morphological adaptations of roots to survive under water stress condition. Furthermore, under water stress condition, root nutrients tend to get depleted.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 469 ◽  
Author(s):  
Abdul Hameed ◽  
Nudrat Aisha Akram ◽  
Muhammad Hamzah Saleem ◽  
Muhammad Ashraf ◽  
Shakeel Ahmed ◽  
...  

The influence of seed priming with varying levels (50 and 100 mg L−1) of alpha-tocopherol (Toc) was investigated in carrot plants under water-deficit conditions. For this purpose, two cultivars of carrot, DC4 and DC90, were selected and subjected to well-watered (100% field capacity (FC)) and water-deficit stress (50% FC). After 21 days of water-deficit conditions, a significant suppression was observed in shoot and root fresh and dry weights, their lengths, chlorophyll a, b and total contents, and total soluble proteins (TSP). However, an up-regulatory effect of water stress was observed on the concentrations of glycinebetaine (GB), hydrogen peroxide (H2O2), malondialdehyde (MDA), ascorbic acid (AsA), total phenolics as well as the activities of catalase (CAT) and peroxidase (POD) enzymes. Exogenous application of alpha-tocopherol was effective in reducing the accumulation of H2O2 and MDA contents and improving all growth attributes, contents of chlorophyll, proline, GB, AsA, total phenolics, TSP, and the activities of CAT and POD enzymes. Of both carrot cultivars, cv. DC4 had better performance in terms of growth attributes, whereas the response of the two cultivars was similar in all other attributes varying water regimes. Overall, it is suggested that seed priming with 100 mg L−1 Toc was effective in improving plant growth attributes, osmoprotectants and the oxidative defense system of carrot plants under water-deficit conditions.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1316
Author(s):  
Abida Parveen ◽  
Muhammad Arslan Ashraf ◽  
Iqbal Hussain ◽  
Shagufta Perveen ◽  
Rizwan Rasheed ◽  
...  

The present work reports the assessment of the effectiveness of a foliar-spray of salicylic acid (SA) on growth attributes, biochemical characteristics, antioxidant activities and osmolytes accumulation in wheat grown under control (100% field capacity) and water stressed (60% field capacity) conditions. The total available water (TAW), calculated for a rooting depth of 1.65 m was 8.45 inches and readily available water (RAW), considering a depletion factor of 0.55, was 4.65 inches. The water contents corresponding to 100 and 60% field capacity were 5.70 and 1.66 inches, respectively. For this purpose, seeds of two wheat cultivars (Fsd-2008 and S-24) were grown in pots subjected to water stress. Water stress at 60% field capacity markedly reduced the growth attributes, photosynthetic pigments, total soluble proteins (TSP) and total phenolic contents (TPC) compared with control. However, cv. Fsd-2008 was recorded as strongly drought-tolerant and performed better compared to cv. S-24, which was moderately drought tolerant. However, water stress enhanced the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and membrane electrolyte leakage (EL) and modulated the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as accumulation of ascorbic acid (AsA), proline (Pro) and glycine betaine (GB) contents. Foliar-spray with salicylic acid (SA; 0, 3 mM and 6 mM) effectively mitigated the adverse effects of water stress on both cultivars. SA application at 6 mM enhanced the shoot and root length, as well as their fresh and dry weights, and improved photosynthetic pigments. SA foliage application further enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) and nonenzymatic antioxidants such as ascorbic acid and phenolics contents. However, foliar-spray of SA reduced MDA, H2O2 and membrane permeability in both cultivars under stress conditions. The results of the present study suggest that foliar-spray of salicylic acid was effective in increasing the tolerance of wheat plants under drought stress in terms of growth attributes, antioxidant defense mechanisms, accumulation of osmolytes, and by reducing membrane lipid peroxidation.


2012 ◽  
Vol 4 (1) ◽  
pp. 112-115 ◽  
Author(s):  
Hossein MARDANI ◽  
Hassan BAYAT ◽  
Amir Hossein SAEIDNEJAD ◽  
Ehsan Eyshi REZAIE

Impacts of various concentrations of salicylic acid (SA) on cucumber (Cucumis sativus L.) seedling characteristic were evaluated under different water stress levels by using a factorial arrangement based on completely randomized design with three replications at experimental greenhouse of Ferdowsi University of Mashhad, Iran. The studied factors included three water deficit levels (100% FC, 80% FC, and 60% FC) considered as first factor and five levels of SA concentrations (0, 0.25, 0.5, 0.75, and 1 mM) as second factor. Results showed that foliar application of SA at the highest concentration enhanced leaf area, leaf and dry weight while decreased stomatal conductance under high level of water deficit stress. Though, severe water deficit stress sharply raised the SPAD reading values. In general, exogenous SA application could develop cucumber seedling characteristic and improve water stress tolerance.


Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 627 ◽  
Author(s):  
Alaa A. Gaafar ◽  
Sami I. Ali ◽  
Mohamed A. El-Shawadfy ◽  
Zeinab A. Salama ◽  
Agnieszka Sękara ◽  
...  

One of the most vital environmental factors that restricts plant production in arid and semi-arid environments is the lack of fresh water and drought stress. Common bean (Phaseolus vulgaris L.) productivity is severely limited by abiotic stress, especially climate-related constraints. Therefore, a field experiment in split-plot design was carried out to examine the potential function of ascorbic acid (AsA) in mitigating the adverse effects of water stress on common bean. The experiment included two irrigation regimes (100% or 50% of crop evapotranspiration) and three AsA doses (0, 200, or 400 mg L−1 AsA). The results revealed that water stress reduced common bean photosynthetic pigments (chlorophyll and carotenoids), carbonic anhydrase activity, antioxidant activities (2,2-diphenyl-1-picrylhydrazyl free radical activity scavenging activity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay), growth and seed yield, while increased enzymatic antioxidants (peroxidase), secondary metabolites (phenolic, flavonoids, and tannins), malondialdehyde (MDA), and crop water productivity. In contrast, the AsA foliar spray enhanced all studied traits and the enhancement was gradual with the increasing AsA dose. The linear regression model predicted that when the AsA dose increase by 1.0 mg L−1, the seed yield is expected to increase by 0.06 g m−2. Enhanced water stress tolerance through adequate ascorbic acid application is a promising strategy to increase the tolerance and productivity of common bean under water stress. Moreover, the response of common bean to water deficit appears to be dependent on AsA dose.


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