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ThesisItem Open Access Effect of salicylic acid on antioxidant defense system on berseem (Trifolium alexandrinum L.) against cold stress(Punjab Agricultural University, Ludhiana, 2017) Harpreet Kaur; Goyal, MeenakshiThe objective of this study was to evaluate the effectiveness of salicylic acid (SA) pretreatment on antioxidant system in berseem under cold stress. Berseem seeds were (var. BL42 and BL-10) primed with water (control) and different concentrations of SA (25, 50, 75, 100 and 125 µg/ml) for 4 hours. Soaked seeds were germinated on moist filter papers in petri plates at 25°C in two different sets. After germination of three days one set of petri plates was exposed to cold stress (5°C) for five days and other set was remained at 25°C. Physiological and biochemical parameters were observed in root and shoot samples after seven days of germination. Higher vigor index was obtained at 50 and 75 µg/ml of SA pretreatment. SA pretreatment enhanced root and shoot length, fresh weight uptill 100 µg/ml and then decreased at 125 µg/ml of SA. Pretreatment with 50 and 75 µg/ml of SA showed higher increase in antioxidant enzyme (CAT, APX, GR, GPX and SOD) activities. SA pretreatment of 50 to 100 µg/ml concentrations resulted in upregulation of non-enzymatic antioxidants under both normal and cold conditions. Biochemical metabolites such as total protein, proline and total phenol were differentially affected by different salicylic acid treatments under cold stress. SA alleviated the adverse effect of cold stress by decreasing lipid peroxidation and H2O2 content in berseem seedlings. So SA pretreatment ameliorated the cold stress in berseem by upregulating enzymatic antioxidants, non-enzymatic antioxidants and biochemical metabolites.ThesisItem Restricted Influence of calcium and salicylic acid on antioxidative enzymes and quality of stored radish and carrot(Punjab Agricultural University, Ludhiana, 2017) Jomika Devi; Bhatia, SurekhaEffect of post harvest treatments with calcium chloride and salicylic acid on physiological and biochemical parameters in relation to activities of antioxidative enzymes were investigated in radish and carrot. Carrot of variety Punjab Carrot Red and radish of variety Punjab Safed Mooli 2 were harvested, washed and treated with CaCl2 (1, 1.5 and 2%) or SA ( 1, 1.5 and 2mM). Treated as well as untreated carrot and radish were placed in open trays and stored under ambient and refrigerated conditions. Irrespective of treatments and environmental conditions, a gradual decline in weight, colour, texture and carotenoid content with simultaneous enhancement in total soluble solids, total antioxidant activity and ascorbic acid content was found with increase in storage period in both radish and carrot whereas titrable acidity and total phenolics first increased reaching to its maximum and declined thereafter. In carrot, the activities of antioxidative enzymes i.e. CAT, SOD, GR and DHAR and in radish activities of enzymes CAT, GR, POX and MDHAR first increased to maximum followed by decline at the latter stages under both the storage conditions. Activities of POX and MDHAR in carrot and activities SOD and DHAR in radish showed a gradual enhancement throughout the storage period under ambient as well as refrigerated conditions. Changes in physiological, biochemical quality parameters and activities of enzymes during storage were high under ambient conditions as compared to refrigerated conditions. Treatment of carrot and radish with CaCl2 and SA slowed down the changes in biochemical and physiological quality parameters and enhanced the rate of increase in activities of antioxidative enzymes as compared to untreated carrot and radish under both the storage conditions. Effectiveness of different treatments in maintaining the biochemical quality parameters was in order of 1.5mM SA> 1.5% CaCl2> 1mM SA> 2mM SA. However treatment of carrot and radish with 1% and 2% CaCl2 were not much effective. Among all the treatments, 1.5mM SA under refrigerated condition maintained the quality parameters to greater extent and can be used to enhance the shelf life of carrot and radish.ThesisItem Restricted Evaluation of rice genotypes for nutritional components and lipase activity in bran(Punjab Agricultural University, Ludhiana, 2017) Rajinder Kaur; Sharma, NeerjaTo achieve the objective of the evaluation of rice genotypes for nutritional components and lipase activity in bran, sixteen rice genotypes including ten non-basmatis and six basmatis were used in the present study. Significant variation in ash (5.29-14.43%), crude protein (11.38-20.25%), crude fat (16.43-21.88%) and crude fibre (3.24- 14.01%) was observed in bran from rice genotypes under evaluation. The bound phenolic content (BPC) was 39.19 percent higher than free phenolic content (FPC), while significant variation was seen in total phenolic content (TPC, 11.59-28.73 mg g-1 DW), flavonoid (0.17-2.32 mg g-1 DW) and o- dihydroxyphenol (0.023-0.112 mg g-1 DW) content. Compared to non- basmatis, bran from basmati varieties showed about 14% higher anthocyanin content. Significant variations were observed in the content of proanthocyanidins (0.86-7.75 mg g-1 DW), phytate (21.6-36.7 mg g-1 DW), tocopherols (0.11-0.31 mg g-1 DW) and free amino acids (3.38-12.20 mg g-1 DW). Bran from rice genotypes under evaluation showed a high DPPH free radical scavenging activity (72.46-92.59%). Wide variations in reducing power (1.06-2.47 mg g-1 DW), metal chelating power (13.61-94.36 %), free radical ABTS.+ scavenging activity (0.54-1.31 mM g-1 DW), and ferric reducing ability power (8.31-20.15 µM Fe(II)g-1DW) of rice bran extracts were seen. Accumulation of free fatty acids after 48 hours of storage ranged from 0.36-1.20 mM g-1 DW. Wide differences in endogenous rice bran lipase activity (0.49-2.77 µmoles of pNP produced min-1 mg-1protein) were observed. This knowledge about on the variations in phytochemical components, antioxidant potential and lipase activity among rice bran from different genotypes would enable the breeders to produce rice genotypes with improved phytochemical levels, high antioxidant potential and low lipase activity.ThesisItem Restricted Defense mechanism in chickpea (Cicer arientinum L.) against Ascochyta blight(Punjab Agricultural University, Ludhiana, 2017) Khushpreet Kaur; Grewal, Satvir KaurThe present investigation was carried out on ten chickpea genotypes namely ILWC 115, C. juncea 182, ILWC 292, L 552, PBG 7, GLK 14313, HC5, GLK-08-104, GLK 12021, C. pinnatum 212 sown separately in control and sick plots infested with Ascochyta rabiei, to study the response of enzymatic antioxidants, non-enzymatic antioxidants and signalling molecules in leaves at different four stages of infestation i.e. S0 (pre-inoculatory) stage, S1 stage (7 days after infestation), S2 stage (20 days after infestation), S3 stage (30 days after infestation). The chickpea genotypes were characterized as resistant (PBG7, GLK08-104, GLK1433, ILWC292, C. juncea 182), moderately resistant (HC5), susceptible (GLK 14313, L 552, C. pinnatum 212) and highly susceptible (ILWC115) genotypes on the basis of disease severity scale. The timely upregulation and more intensity of defensive enzymes such as SOD, APX-GR followed by CAT and POD and the enzymes involved in phenylpropanoid pathway such as PAL, TAL, PPO as compared to susceptible genotypes might be responsible for resistance to ascochyta blight in resistant genotypes. The higher accumulation of H2O2, total phenols and proline in resistant genotypes and higher MDA content in susceptible genotypes also contribute to their differential tolerance behaviour towards infestation. Higher radical scavenging activities such as NO radical scavenging activity, OH free radical scavenging activity, superoxide anion radical scavenging activity and FRAP mediates the ascochyta blight tolerance in PBG7, HC5, GLK08-104,GLK12021, ILWC292, C. juncea 182 chickpea resistant genotypes as compared to GLK14313, L552, ILWC115, C. pinnatum 212 susceptible chickpea genotypes. The upregulation of defensive enzymes at later stages of infestation in GLK14313, L552, C. pinnatum 212 and their lower activities in ILWC115 might be responsible for their susceptible behaviour indicating that the time and intensity of induced defensive mechanism is an important contributing factor towards disease tolerance.ThesisItem Open Access Cellulase production using agricultural biomass for paddy straw saccharifaction(Punjab Agricultural University, Ludhiana, 2017) Singla, Diksha; Taggar, Monica SachdevaSix different plant based agricultural residues were used for Cellulase production required for paddy straw saccharifaction. The study revealed that soybean pod husk, as a lignocellulosic residue, could be used as a supplement with paddy straw for maximizing cellulase production and saccharifaction of straw.ThesisItem Open Access Exploring potential of plant ribosome inactivating proteins (RIPs) in combating leaf curl and fungal foliar diseases of cotton(Punjab Agricultural University, Ludhiana, 2017) Brar, Gundeep Kaur; Sangha, Manjeet KaurRibosome inactivating proteins (RIPs) are N-glycosydases, which catalyse the depurination of conserved single adenine (A4034) in yeast ribosomal RNA, leading to cell death. They are endowed with antimicrobial activities against bacteria, fungi and viruses in plants and animals. Cotton leaf curl disease (CLCuD) transmitted by whitefly (Bemisia tabaci) affects cotton production in northern India. In the present study, RIPs were purified by ion exchange chromatography (SP and CM sepharose) from the seeds of seven crops viz. Momordica charantia, Momordica balsmina, Spinacia oleracea, Phaseolus vulgaris, Cucurbita moschata, Zea mays and Hordeum vulgare. RIPs purified from M. balsmina and M. charantia showed maximum per cent recovery of 12.8 and 11.06 respectively. They also depicted maximum RIP activity on yeast ribosomal RNA by qualitative depurination assay. Depurination assay was carried out on ribosomes isolated from yeast. Both purified RIPs gave a single homogenous band on PAGE and SDS-PAGE of 28kDa. They registered a pI value of 10 on isoelectric focusing, showing them to be highly basic. Secondary structure determination of balsmina and charantia RIPs by CD spectroscopy revealed the presence of both alpha helices (23.5% and 32.8%) and beta sheets (24.6% and 43.6%). The RIPs also exhibited superoxide dismutase and chitinase activity. The purified balsmin RIP @0.250 mg/ml and charantia RIP @0.250 mg/ml and @0.500 mg/ml were sprayed on two cotton cultivars LH2076 and F1378, before and after whitefly infestation. Disease incidence was recorded after 28 and 40 days of RIP treatment. The disease incidence was found to be lower (20%-60%) in plants sprayed with RIPs as compared to their respective controls (100%). The latency or absence of virus was verified by PCR analysis using coat protein and beta DNA primers. The results correlated with disease incidence data. Charantia and balsmina RIPs also exhibited antifungal activity against Alternaria alternata and Myrothecium roridum. Inhibition of fungal growth by balsmin RIP @0.250 mg/ml on both fungi varied from 60.09% and 55.10% respectively, where as with charantia RIP 78.8% and 56.2% inhibition respectively was observed. Charantia RIP at 0.500 mg/ml inhibited the mycelial growth to 87.41% and 75.39% respectively. The spore germination inhibition studies revealed an EC50 value of 0.2 mg/ml for both the RIPs. Catalase, peroxidase, total sugars, reducing sugars, proteins, proline and total antioxidant activity increased in RIPs treated plants, highest increase was recorded in plants treated with charantia @0.500 mg/ml, thus depicting the role of RIPs in systemic acquired resistance (SAR). Therefore, the study depicts the antiviral and antifungal activity of RIPs purified from Momordica charantia and Momordica balsmina along with their role in SAR.ThesisItem Open Access Re-established desiccation tolerance as a mechanism of stress tolerance in wheat(Punjab Agricultural University, Ludhiana, 2017) Satinder Kour; Zhawar, Vikramjit KaurRe-established desiccation tolerance (Re-DT) is a mechanism of extreme level of tolerance for almost complete water loss. It was found higher in wheat cultivar PBW 644 (drought tolerant) than PBW 343 (drought susceptible). Higher level of Re-DT in PBW 644 was related to higher reduction of water level so to arrest metabolic activity to avoid increases of ROS and oxidative toxicity, induction of special antioxidants like aldehyde dehydrogenase for detoxification and effective recycling of ascorbate under desiccation. This type of response in PBW 644 helped this plant to revive with higher survival upon rehydration. Contrary to it, PBW 343 showed higher water content, metabolic activity, ROS and oxidative toxicity under desiccation, though it induced antioxidant enzymes but failed to induce effective detoxification system (aldehyde dehydrogenase) and ascorbate recycling, therefore produced poor survival upon rehydration. Re-DT was ABA-regulated mechanism of cross tolerance. It involved ABA/ROS/NO-pathways for induction of antioxidant activity under desiccation and subsequent rehydration. It was improved by ABA and stress factors like water deficit stress, salt stress and heat stress. Ten wheat cultivars were screened for Re-DT and other related features. Four cultivars (HD 3086, PBW 725, PBW 658, PBW 677) showed a clear difference from six cultivars (gladius, kirchauff, HD 2967, BWL 5200, BWL 5202, PBW 723) for having higher level of Re-DT. Seeds of these four cultivars also showed higher dormancy, ABA sensitivity, less level of ROS/nitric oxides in embryos at 0 and 90 days of after-ripening. Laboratory testing of abiotic (osmotic, salt and heat) stress tolerance at seedlings stage found higher increase of root length and root to shoot length ratios by these four cultivars compared to other six. Therefore, this study indicated the presence of relatively higher level of vegetative stress tolerance in HD 3086, PBW 725, PBW 658, PBW 677compared to other six cultivars.ThesisItem Restricted Nitric oxide or hydrogen peroxide as regulators of antioxidant response under ABA and water stress in wheat cultivars(Punjab Agricultural University, Ludhiana, 2017) Tanotra, Suchita; Zhawar, Vikramjit KaurHydrogen peroxide (H2O2) and nitric oxide (NO) signallings were studied under ABA and under water deficit stress using H2O2/NO producers and scavengers in shoots and roots of two wheat cultivars contrasting in drought tolerance. PBW 644 (drought tolerant cultivar) showed higher activities of antioxidant enzymes (catalase, glutathione reductase, superoxide dismutase monodehydroascorbate reductase) and invertases (cell wall bound and soluble), higher levels of ascorbate, ascorbate to dehydroascorbate ratio, proline, sucrose under control, ABA supply and water deficit conditions as compared to PBW 343 (drought susceptible cultivar). Under these conditions, H2O2/NO-signalling were found to upregulate these parameters in both cultivars but regulations were higher in PBW 644. H2O2 and NO-signallings did not differ from each other rather appear to produce almost similar regulations under these conditions. PBW 644 also showed improved root growth (primary root, lateral root and number of axile roots) under water deficit stress, this was related to the presence of endogenous ROS-signalling, however this feature was not shown by PBW 343.ThesisItem Open Access Biochemical basis of salt tolerance in wheat landrace derivatives and Gly II transformed lines(Punjab Agricultural University, Ludhiana, 2017) Lovenpreet Kaur; Asthir, BavitaThe present investigation was aimed to study the effect of salt stress (150 mM and 250 mM NaCl) on antioxidant defence system in Gly II transformed lines alongwith check PBW 621 and Kharchia lines raised hydroponically. Various biochemical and morpho-physiological parameters were recorded in salt tolerant (Kharchia 65, Kharchia local), Gly II transformed lines (G-2-2, G-3-4, G-1-13) and PBW 621 (non transgenic) genotypes of wheat grown under laboratory conditions. Growth parameters recorded at 15 days after germination revealed better performance of Kharchia 65 and G-1-13 as compared to other genotypes. Salinity stress enhanced activities of superoxide dismutase, glyoxalase II (Gly II), glutathione reductase (GR), guaiacol peroxidase (GPX), glutathione s transferase (GST) in all genotypes. Apparently, increase in Na+ and decrease in K+ was recorded in leaves of all the genotypes except in Kharchia 65 where Na+ accumulation was lesser. The contents of glutathione increased in all genotypes while ascorbic acid was highest in G-1-13 and Kharchia 65 genotypes. Soluble sugar content increased maximum in G-3-4 and Kharchia 65. The higher concentration of H2O2 and electrolyte leakage was recorded in PBW 621 (check). Gly II transformed lines exhibited superior salt tolerance over PBW 621 by accumulating higher content of glutathione with increasing levels of GR, GPX and Gly II activities. The upregulation of antioxidant defence system and less accumulation of Na+ ions, H2O2 and TBARS content in gly II transformed lines and Kharchia lines might have played role in salinity tolerance.
