Effect of 24-epibrassinolide on localization of ABA, AZP, and dehydrins in wheat plant roots during dehydration

Biomics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 329-336
Author(s):  
A.R. Lubyanova ◽  
F.M. Shakirova ◽  
M.V. Bezrukova

We studied the immunohistochemical localization of abscisic acid (ABA), wheat germ agglutinin (WGA) and dehydrins in the roots of wheat seedlings (Triticum aestivum L.) during 24-epibrassinolide-pretreatment (EB-pretreatment) and PEG-induced dehydration. It was found coimmunolocalization of ABA, WGA and dehydrins in the cells of central cylinder of basal part untreated and EB-pretreated roots of wheat seedlings under normal conditions and under osmotic stress. Such mutual localization ABA and protective proteins, WGA and dehydrins, indicates the possible effect of their distribution in the tissues of EB-pretreated wheat roots during dehydration on the apoplastic barrier functioning, which apparently contributes to decrease the water loss under dehydration. Perhaps, the significant localization of ABA and wheat lectin in the metaxylem region enhances EB-induced transport of ABA and WGA from roots to shoots under stress. It can be assumed that brassinosteroids can serve as intermediates in the realization of the protective effect of WGA and wheat dehydrins during water deficit.

1994 ◽  
Vol 21 (1) ◽  
pp. 85 ◽  
Author(s):  
MLD Lima ◽  
L Copeland

Investigations have been carried out on morphological changes induced by aluminium ions in roots of wheat seedlings (Triticum aestivum L. cv. Vulcan). Lesions were evident on the surface of the roots after 4-8 h of exposure, and within 24 h there was increased vacuolation, loss of turgor, and severe cytoplasmic disorganisation in epidermal and peripheral cap cells. The central cap and cortical layers were also severely damaged by aluminium, but changes in the meristematic cells became evident only after more prolonged exposure of roots to aluminium. Mobilisation of starch in amyloplasts of peripheral and central cap cells of aluminium-stressed roots was particularly noticeable, and this was accompanied by an increase in the amount of extractable activity of starch-degrading enzymes. The possibility that the mobilisation of starch is linked to a coincident increase in fermentative metabolism in Al-stressed wheat roots is considered.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1127
Author(s):  
Nazir Ahmed ◽  
Mingyuan Zhu ◽  
Qiuxia Li ◽  
Xilei Wang ◽  
Jiachi Wan ◽  
...  

Droughts represent one of the main challenges that climate change imposes on crop production. As a globally cultivated staple crop, wheat (Triticum aestivum L.) is prone to drought environments. Therefore, improvement in drought tolerance represents a growing concern to ensure food security, especially for wheat. In this perspective, the application of Phyto-phillic exogenous materials such as glycine-betaine (GB) has been attracting attention, particularly in stress-related studies. Since roots procure the water and nutrients for plants, any improvements in their response and capacity against drought stress could induce stress tolerance in plants. However, the knowledge about the changes in root architecture, defense mechanism, hormonal metabolism, and downstream signaling, in response to GB-mediated root priming, is still limited. Therefore, we designed the present study to investigate the role of GB-mediated root priming in improving the water stress tolerance in wheat (cv. Jimai-22) under in-vitro conditions. The roots of twelve days old wheat seedlings were treated with Hoagland’s solution (GB-0), 50 mM GB (GB-1), and 100 mM GB (GB-2) for 48 h and subjected to well-watered (WW) and water-stress (WS) conditions. The osmotic stress substantially impaired shoot/root growth, dry matter accumulation, and increased malondialdehyde (MDA) and hydrogen-peroxide (H2O2) production in the roots of wheat seedlings. However, GB-mediated root priming improved the redox homeostasis of wheat roots by boosting the activities of SOD and POD and triggering the significantly higher accumulation of abscisic acid (ABA) and salicylic acid (SA) in the roots of GB-primed plants. Consequently, it modified the root architecture system and improved plant growth, dry matter accumulation, and water-stress tolerance of wheat seedlings. Moreover, GB-mediated root priming increased root sensitivity to water stress and induced overexpression of stress-responsive genes involved in ABA metabolism (TaNECD1, TaABA’OH2), their downstream signal transduction (TaPP2C, TaSNRK2.8), and activation of different transcriptional factors (TabZIP60, TaAREB3, TaWRKY2, TaERF3, and TaMYB3) that are associated with plant metabolite accumulation and detoxification of ROS under water stress conditions. Overall, our results demonstrated that GB-priming improved the physiological and biochemical attributes of wheat plants under WS conditions by improving the drought perception capacity of wheat roots, ultimately enhancing the water stress tolerance. Thus, the GB-priming of roots could help to enhance the water-stress tolerance of economically important crops (i.e., wheat).


2021 ◽  
pp. 1-14
Author(s):  
Álvaro Luís Pasquetti Berghetti ◽  
Maisa Didone Wohlenberg ◽  
Juliete Araújo da Silva ◽  
Lucas Antônio Telles Rodrigues ◽  
Qamar Sarfaraz ◽  
...  

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Wedad A. Kasim ◽  
Mohamed E. H. Osman ◽  
Mohamed N. Omar ◽  
Samar Salama

Abstract Background The effectiveness of two PGPB; Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 was investigated in enhancing the drought tolerance of wheat (Triticum aestivum L.) seedlings cultivar Gemiza9. The inoculated or uninoculated grains were sown in unsterilized sandy soil and watered normally untill the 8th day. Drought stress was initiated by completely withholding water for 7 days (until wilting). Samples were collected after 15 days from sowing to evaluate some growth criteria, damage and defense indicators and to analyze the roots’ protein pattern. Results The results showed that inoculating wheat seedlings with these strains significantly diminished the inhibitory effects of drought stress on the relative water content of roots, shoots and leaves; area of leaves; contents of pigments (chlorophyll a and b) and ascorbic acid; and on the protein patterns of roots. Moreover, the bacterial inoculation notably reduced the drought-induced damage indicated by lower leakage of electrolytes and less accumulation of Malondialdehyde and hydrogen peroxide, surprisingly with less enhanced production of proline and activities of catalase and peroxidase than their uninoculated counterparts. Under normal conditions, inoculating wheat plants with these PGPB resulted in significantly promoted growth and elevated contents of pigments and altered protein patterns of roots. Conclusion Overall, we can say that both Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 were able to deactivate the growth inhibition in wheat seedlings to some extent, while maintaining a certain level of efficient protection against damage under drought stress.


Author(s):  
Shailja Dubey ◽  
Renu Bist ◽  
Shrilekha Misra

Objective: Ethyl methano sulphonate (Ems), a chemical mutagen is widely used to induce a large number of functional variation in wheat plant. The objective of present study was to determine the activity of enzymatic antioxidants and Lipid peroxidation (LPO) after EMS exposure in a wheat plant in M1, M2 and M3 generation of Triticum aestivum L. var. HD 2894.Methods: Presoaked seeds were treated with EMS for 6 hour with different concentration like 0%, 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. Some biochemical parameter such as Catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and Lipid peroxidation (LPO) were studied.Results: Our result showed that EMS affects enzymatic and oxidative parameters in all generation. CAT, GR, APX and LPO activity was found to be reduced in m1 generation as compared to control. A simultaneous elevation was recorded in the concentration of ems compared to control treated plants after given the exposure of ems in m2 and m3 generation. Data analysis of antioxidant and LPO during the m2 generation showed that the effect of the mutagen on the activity of antioxidant and LPO did not cease in the m1 but continued to affect the m2 generation. Analysis of m3 generation showed stability in the activity of antioxidant and LPO from m2 to m3 generation.Conclusion: Lethal dose of ems was determined by the activity of antioxidant under laboratory condition. In this experiment, quantitative determination was applied as a regular procedure. The data analysis showed the activity of antioxidant, LPO and doses of ems concentration in m1, m2 and m3 generation. Variability observed on the basis of mean and standard deviation. On the whole, differences between concentrations and treatment time of Ems significantly affect the activity of antioxidant and LPO in all generation. 


1972 ◽  
Vol 20 (1) ◽  
pp. 49 ◽  
Author(s):  
JW Patrick

The courses of the various vascular bundles in the nodes of the main tiller of Triticum aestivum L. have been reconstructed from anatomical observations of con- secutive serial transverse sections. Of the bundles entering a node (n) from its attached leaf, the first-formed and largest, the median, passes directly through the node to the second node below (n-2), where it bifurcates and fuses with other strands. These continue to node n- 3 before fusing completely with the nodal plexus. The next six bundles to form (laterals) establish some links with bundles from higher leaves in the node of entry, much more extensive connections in node n- 1, and fuse completely with the nodal plexus in node n-2. The next four lateral bundles to differentiate are more extensively linked in node n and fuse completely with the nodal plexus in node n - I . The remaining 16-20 bundles from the leaf (intermediates) follow much the same course but develop more extensive connections with other bundles. The extensive plexus which develops in each node ensures vascular connections between most bundles. The significance of these in transport is briefly discussed.


2012 ◽  
Vol 58 (No. 12) ◽  
pp. 534-539 ◽  
Author(s):  
G.Q. Wu ◽  
L.N. Zhang ◽  
Y.Y. Wang

 To investigate the responses of growth and antioxidant enzymes to osmotic stress in two different wheat cultivars, one drought tolerant (Heshangtou, HST) and the other drought sensitive (Longchun 15, LC15), 15-day-old wheat seedlings were exposed to osmotic stress of –0.25, –0.50, and –0.75 MPa for 2 days. It is found that osmotic stress decreased shoot length in both wheat cultivars, whereas to a lesser degree in HST than in LC15. The contents of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) of shoot in both wheat cultivars were increased by osmotic stress. It is clear that MDA contents increased less in the more drought tolerant cultivar HST than in drought sensitive one LC15. On the contrary, POD and CAT activities increased more in HST than LC15 under osmotic stress. As the activity of SOD, however, no significant differences were found between HST and LC15. These results suggest that wheat cultivar HST has higher activities of antioxidant enzymes such as POD and CAT to cope with oxidative damage caused by osmotic stress compared to sensitive LC15.  


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