scholarly journals Nano-Formulations of Copper Species Coated with Sulfated Polysaccharide Extracts and Assessment of Their Phytotoxicity on Wheat (Triticum aestivum L.) Seedlings in Seed Germination, Foliar and Soil Applications

2020 ◽  
Vol 10 (18) ◽  
pp. 6302
Author(s):  
Hanaa L. Essa ◽  
Mohamed S. Abdelfattah ◽  
Alaa S. Marzouk ◽  
Hania A. Guirguis ◽  
Mayyada M. H. El-Sayed

Copper nanoparticles were synthesized via a bioreduction using sulfated polysaccharides (SPs) extracted from Avicennia marina mangrove leaves and their phytotoxicity effect on wheat (Triticum aestivum L.) seedlings was assessed. As analyzed by high-performance liquid chromatography (HPLC), SPs extract constituted mainly 49.3% glucose, 24.6% galactose and 20.5% glucouronic acid by mol. A nanoformulation of ultrafine Cu2O/Cu(OH)2 nanoparticles coated with SPs (Cu NPs) was prepared with an average particle size of 2.11 ± 0.64 nm and a slightly negatively-charged zeta potential of 11 ± 0.46 mV. Applying high concentrations of Cu NPs on wheat seeds inhibited the respective shoot and root relative growth percentages, yielding 13.22 ± 9.91 and 36.72 ± 18.51% at 0.06 mg/mL of the nanoformulation. Comparable values were obtained when the seeds were subjected to 0.06 mg/L of SPs extract applied in the free form. In a foliar application, 0.06 mg/mL of Cu NPs reduced the respective total chlorophyll and carotenoids contents by 17.4% and 24.3% relative to the control while the treatment with SPs reduced them by slightly higher values of 27.9% and 32.6%, respectively, after 14 days of application. Therefore, Cu NPs show a comparable inhibition effect to that of the free SPs extract but offer the additional advantages of nanoformulations. In soil applications, however, Cu NPs stimulated the growth of wheat seedlings in contrary to SPs and increased the total chlorophyll and carotenoids by 49.76% and 70%, respectively. This gives an additional merit to the nanoformulation that can potentially be used as an effective biostimulant in soil.

2020 ◽  
Vol 10 (5) ◽  
pp. 166-169
Author(s):  
Ye.V. Syvoded ◽  
O.V. Kolesnichenko ◽  
S.M. Hrysiuk

The study presents variability in the qualitative composition and quantitative indicators of secondary mycelium metabolites of the fungus Diaporthe (Phomopsis) helianthi Munt.-Cvet. et al., the most harmful plant pest of Helianthus annuus L. Toxicity of secondary metabolites of D. helianthi was analyzed by determining the average length of seedling shoots of Triticum aestivum L. test object grown on fungus filtrates of different cultivation dates. The maximum toxic effect of D. helianthi was recorded during the germination of Triticum aestivum L. seedlings on a 17-day filtrate of pure mycelium culture of the fungus. The mean length of wheat seedlings in this variant of the experiment decreased by 3.5 times compared with the control and 3.3 times compared with the filtrate of the culture medium of 7 days of cultivation. High-performance liquid chromatography (HPLC) identified secondary metabolites of D. helianthi as fomosin, fomopsolides, cytosporones, and xanthones. There was a redistribution of secondary metabolites due to increase in number of cytosporones, decrease in content of fomopsolides, and termination of xanthone synthesis with increasing time of cultivation of fomopsis mycelium, under conditions of relatively stable indicators of fomosin content.


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.


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.


2021 ◽  
Vol 1034 ◽  
pp. 35-42
Author(s):  
Shubhajit Das ◽  
M. Chandrasekaran ◽  
Sutanu Samanta

The present work investigates the mechanical characterization of aluminium alloy (AA) 6061 based hybrid nanometal matrix composites (MMCs) fabricated using conventional stir casting process. Two compositions viz., AA6061+1.5 wt.% B4C+0.5 wt.% SiC (Hybrid A) and AA6061+1.5 wt.% B4C+1.5 wt.% SiC (Hybrid B) was prepared and its mechanical properties such as microhardness, tensile, compressive, flexural and impact strength were investigated to compare with unreinforced AA6061. SiC and B4C ceramic particles (purity 99.89%) of average particle size of 50 nm were used as reinforcements. Significant enhancement in microhardness of 30.2% and 31.02% for hybrid A and B are observed respectively. The ultimate tensile strength (UTS) increased by 10.72% and 16.55% for hybrid A and B respectively. Improved interaction because of the enhanced surface to volume ratio at the interface resulted in improvement of mechanical properties. Field emission scanning electron microscopy (FESEM) of the fractured surface shows brittle fracture because of the incorporation of the ceramic reinforcements in the matrix material. The developed AA6061/SiC/B­4C hybrid nanocomposites show improved mechanical properties for high-performance structural applications.


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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