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20233
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Subject: Biochemistry × End date: 2023 × Start date: 2023 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Development, characterization and application of bionanoconjugate on terminal heat stress in wheat (Triticum aestivum L.)
    (CCSHAU, Hisar, 2023-04) Narender Mohan; Ajay Pal
    To ensure sustainable farming practices, nanotechnology in modern agriculture must address the worldwide issues of biotic and abiotic stress (Terminal Heat Stress) brought on by climate change and the population load on farms. Numerous biopolymers, including alginate, cellulose, chitin, and chitosan, have increased use in the new nanotechnology period to create new materials useful in crop growth and protection. Chitosan is the most extensively studied biomaterial in nanotechnology because it is the second most prevalent and conveniently accessible biopolymer after cellulose. Due to its unrestricted qualities, such as biocompatibility, antibacterial, biodegradability, and non-toxicity for plants, it is employed primarily as nanochitosan instead of as bulk throughout the world. Compared to pure/bulk chitosan or direct use of ionic metals, nanochitosan biopolymer has been deemed more valuable for its involvement in chelation with metal ions, such as Zn, Cu, Fe, etc. Herein we incorporated plant hormones (Salicylic acid) and metal (Zn) ions into ongoing cross linking of chitosan and TPP to create nano-composites/conjugates, leading to more pronounced and efficient effects on seed germination and screen house. The current study shows that the genotype, species, growth stage, ambient conditions, and ingredients/nutrients affect how plants react to BNCs. It is further inferred that applying BNCs with co-encapsulated SA and Zn improved the crop's resistance to stress. In combination with the slow-release capability of BNCs, it considerably improved the germination potential, antioxidant system, crop yield, and grain quality of both WH-1124 and WH-542, according to laboratory and pot studies. Additionally, we conclude that the synthesis of these BNCs may be accelerated further to assess their efficacy on other crops, which could be advantageous for the technical translation.
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    ThesisItemOpen Access
    Development, characterization and efficacy of bionanocluster of indole acetic acid and cobalt chloride on seed germination and yield in Cotton (Gossypium hirsutum L.)
    (CCSHAU, Hisar, 2023-09) Vikram Singh; Mandhania, Shiwani
    In the present investigation, Co2+ and indole-3-acetic acid were combined to create chitosan- Co2+-IAA BNCs. The mean hydrodynamic diameter, PDI value and zeta-potential of BNCs were recorded as 481.9 nm, 0.536 and +22.00 mV, respectively. Effect of seed priming with 100 ppm BNCs and four time foliar application of 100 ppm BNCs on seed germination, seedling growth, and boll drop was studied in H 1098i genotype of G. hirsutum L. Cotton seeds subjected to BNCs priming displayed higher percent germination and seed vigor index-I (92.14 %) compared to hydroprimed seeds due to elevated activities of glyoxylate cycle enzymes i.e. isocitrate lyase and malate synthase, which increased the conversion of fats to carbohydrates. Four times foliar application of 100 ppm BNCs increased leaf area, plant height, total chlorophyll content, photosynthetic rate, ACC synthase activity, indole-3-acetic acid content, boll number, boll weight ultimately increasing seed cotton yield by 20.37 %. However, ACC oxidase, cellulase, pectinase activities and boll drop significantly decreased compared to control. It is concluded that application of BNCs comprising of chitosan, IAA and Co2+ via seed priming and foliar mode is novel, economical, and environment friendly.
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    ThesisItemOpen Access
    Effect of exogenous sulphur in alleviating lead toxicity in Indian mustard [Brassica juncea (L.)]
    (CCSHAU, Hisar, 2023) Manne Hemanth Kumar; Nisha Kumari
    The Indian mustard [Brassica juncea (L.)] is one of the well-known plant for phytoextraction of heavy metals. The present study was designed to elucidate whether exogenously applied sulphur (S1; 100 ppm, S2; 200 ppm sulphur) alleviate lead (Pb)-induced (Pb1; 100 ppm, Pb2; 200 ppm and Pb3; 300 ppm Pb) stress in the leaves of Brassica juncea. Lead was applied in the form of lead nitrate five days prior to sampling and sulphur applied in the form of zinc sulphate at three days before sampling and samples were collected on 30, 60 and 90 DAS. Lead stress of 100, 200 and 300 ppm has considerably reduced plant growth as evidenced by increased H2O2 contents of 303.64, 317.39 and 238.89 % at 300 ppm of 30, 60 and 90 DAS, respectively, and they further caused the peroxidation of lipid membranes. This disruption increased more leakage of electrolytes, and created ionic imbalance. Further, alteration of chlorophyll pigment by replacing its central magnesium atom has reduced photosynthetic rate by 27.24 % at Pb3 stress, in respect to control. The redox status of the cell got altered by lead toxicity, depleting the AsA and GSH pool metabolites. Besides, GR, APX and POX antioxidative enzyme activities have shown highest increase under Pb3 stress by 51.97, 57.84 and 121.45 %, at 30, 60 and 90 DAS, respectively. In contrast, S application showed an increased AsA-GSH contents by 15.30, 9.40 and 7.89 % at S1 spray and 38.12, 23.44 and 33.40 %, respectively, at 30, 60 and 90 DAS at S2 spray. Sulphur-metabolites such as ATPS, OASTL and GST activities enhanced upon stress and resulted in further augmentation upon sulphur supplementation. Sulphur application to the Pb-stressed Brassica plants has reduced the oxidative stress by decreasing EL content by 11.69 % and MDA contents by 13.79 % at 90 DAS, respectively, in respect to Pb3-stressed plants. This decrease in oxidative stress biomarkers was due to an increase in AsA-GSH thiol pool and antioxidative enzyme enhancement under 100 and 200 ppm sulphur application to the Pb-stressed plants. Besides, S2 application to the Pb3+S2 stressed plants has increased phytochelatins by 522.47, 352.60 and 443.48 %, at 30, 60 and 90 DAS, respectively, in respect to Pb3 stress and called for PC-based detoxification of Pb. Furthermore, lead stress shown a decreased relative gene expression of BjSULT1.a gene and increased BjPb2.1, BjATPS1, BjOASTL2, BjABCC2 and BjGR1 gene expression. Moreover, S2 spray increased gene expression levels by 1.32, 1.49, 2.42 and 2.24 folds of BjSULT1.a, ABCC2, BjATPS1 and BjOASTL2, respectively, under Pb3 stress. Sulphur spray of S1 and S2 to the Pb-stressed Brassica juncea plants increased morpho-physiological parameters and yield and yield parameters. In the view of present findings, greater decrease of oxidative stress (H2O2, MDA and EL), increased enzymatic, non-enzymatic antioxidants, phytochelatins, enhanced relative gene expression levels and maximum seed yield was found under exogenous supplementation of 200 ppm sulphur and has ameliorated lead stress.