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20202
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Subject: Biochemistry × End date: 2020 × Start date: 2020 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of brassinolide on morpho-physiological and biochemical parameters under drought stress in Indian mustard
    (CCSHAU, Hisar, 2020-02) Naveen; Kumari, Nisha
    The present experiment was conducted in Oilseed Research Area during Rabi 2018-19 with two Indian mustard varieties viz. drought-tolerant (RH-725) and drought-sensitive (RH-749) to find the efficiency of brassinolide in two concentrations of 10 ppm and 20 ppm sprayed at 42 and 52 days after sowing. The experiment was laid out in RBD design with three replications. Results revealed that: The activities of antioxidative enzyme (SOD, CAT and POX) increase in both the varieties but this increase was more pronounced in RH-725 with 20 ppm concentration of brassinolide spray. The concentration of non-enzymatic antioxidants (carotenoid, ascorbic acid and proline) also increase significantly in RH-725 as compared to RH-749 at 20 ppm spray of brassinolide. The oxidative stress indicators (hydrogen peroxide, malondialdehyde and electrolyte leakage) decrease to a significant level under brassinolide spray in tolerant variety at 50 % flowering. The exogenous application of brassinolide improved the physiological framework in the leaves of RH-725 at 50 % flowering. The yield and yield attributing characters such as plant height (cm), number of primary branches/plant, main shoot length (cm), number of siliquae on main shoot, number of seeds/siliqua, siliqua length (cm), seed yield/plant (g) were significantly increased among the treatments as well as varieties. Due to spraying of brassinolide the percentage of increase in seed yield ranged from 11.84 % in RH-725 and 5.77 % in RH-749 at 10 ppm concentration over control. In view of the present findings, the higher concentration of non-enzymatic antioxidants, higher activity of antioxidative enzymes and improved physiological parameters and maximum yield was found in RH-725 i.e. drought-tolerant at 20 ppm concentration of brassinolide spray.
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    ThesisItemOpen Access
    Biochemical studies on fatty acid esterase isolated from pearl millet and wheat flours
    (CCSHAU, Hisar, 2020) Nisha; Chugh, L. K
    The present investigation was conducted on pearl millet cv. HC 20 and wheat cv. WH 1105. Pearl millet fatty acid esterase (PM-FAE) and wheat fatty acid esterase (WH-FAE) were partially purified from by ammonium sulphate fractionation (30-60 % saturation) followed by dialysis by 3.03 and 7.75 folds with specific activity of 15.35 and 22.5 units/mg protein and recovery of 57and 56 % of the activity, respectively. PM-FAE and WH-FAE, both exhibited optimum pH of 8.0. Optimum temperature for PM-FAE (40oC) was lower than WH-FAE (45oC). WH-FAE was comparatively more stable at high temperature (70OC). Km value of PM-FAE (0.129 μM p-NPB) was lower than that of WH-FAE (0.28 μM p-NPB). Km values of PM-FAE for p-NPB and NPO were about 50 % lower compared to that of WH-FAE. Affinity of PM-FAE and WH-FAE for NPD was approximately equal. Ascorbic acid and palmitoyl ascorbate inhibited both FAEs in a concentration dependent manner. After 5 days of storage, reduction of 73 % in total buildup of fat acidity (FA), 84% reduction in rate of increase in FA, 55 % inhibition of in vitro activity of FAE, 52 % inhibition in situ activity of FAE and 50 % inhibition of activity of lipoxygenase (LOX) in 0.58 % ascorbic acid-fortified flour compared to unfortified flour were observed. Inhibitory effect of ascorbic acid fortification on in vitro activity of FAE, in situ activity of FAE and LOX increased with fortified concentration of ascorbic acid whereas rate of increase in FA was almost unaffected. Inhibition of LOX (62-69 %) in 0.84 % ascorbic acid-fortified flour was comparable to that (68-74 %) of blanched grain flour (BGF) throughout storage period. It was concluded that comparatively higher activity of PM-FAE in flour, lower Km value for its substrates and lower optimum temperature might be responsible for faster in situ hydrolysis of lipids and hence poor shelf life of pearl millet flour than wheat flour. Indirect fortification of flour by ascorbic acid treatment of pearl millet grains was effective in negatively modulating activities of FAE and LOX in flour for arresting not only in situ hydrolysis but also enzymatic oxidation of lipids.