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University of Agricultural Sciences, Bengaluru
University of Agricultural Sciences Bangalore, a premier institution of agricultural education and research in the country, began as a small agricultural research farm in 1899 on 30 acres of land donated by Her Excellency Maharani Kempa Nanjammanni Vani Vilasa Sannidhiyavaru, the Regent of Mysore and appointed Dr. Lehmann, German Scientist to initiate research on soil crop response with a Laboratory in the Directorate of Agriculture. Later under the initiative of the Dewan of Mysore Sir M. Vishweshwaraiah, the Mysore Agriculture Residential School was established in 1913 at Hebbal which offered Licentiate in Agriculture and later offered a diploma programme in agriculture during 1920. The School was upgraded to Agriculture Collegein 1946 which offered four year degree programs in Agriculture. The Government of Mysore headed by Sri. S. Nijalingappa, the then Chief Minister, established the University of Agricultural Sciences on the pattern of Land Grant College system of USA and the University of Agricultural Sciences Act No. 22 was passed in Legislative Assembly in 1963. Dr. Zakir Hussain, the Vice President of India inaugurated the University on 21st August 1964.
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ThesisItem Open Access OVEREXPRESSION OF ZINC TRANSPORTER GENE IN TOMATO (Lycopersicon esculentum, Mill.)(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2009-07-10) BASAVARAJESHWARI R., MATHAPATI; SHANKAR, A GZinc deficiency causes reduction in plant productivity. Zinc is not only essential for plants but also for humans is a micronutrient of exceptional biologic and public health importance. Zinc deficiency in soil also leads to deficiency in human beings through plants. Zinc deficiency in humans can be addressed through dietary diversification, mineral supplementation, food fortification and biofortification (increasing mineral concentrations in edible parts of the crop). For a long and sustainable approach biofortification is considered to be the best. In this regard attempt was made to biofortify tomato with zinc. Tomato is consumed by everyone and also everyday. As tomato can also be consumed raw, nutrient loss due to cooking can be minimised hence tomato was found to be an ideal plant for biofortification. In this study expression analysis of zinc transporters in leaves of tomato plants treated at different levels of zinc showed LeZIP1, LeZIP3, LeZIP5 and LeZIP6 as low zinc responsive zinc transporter genes and LeZIP2 as a high zinc responsive one. Estimation of zinc content in leaves and roots of these zinc treated plants showed significant increase in zinc content of zinc deprived plants upon providing moderate zinc. Zinc content in leaves and roots increased with the increase in the external zinc application. Thus different zinc contents in plant parts could be attributed to differential expression of zinc transporter genes. From the expression analysis of zinc transporter genes, LeZIP1 a low zinc responsive gene, was found to be closely related to OsZIP1. OsZIP1 known to be a high affinity zinc transporter was subcloned in gateway destination vector and overexpressed in tomato to increase the zinc nutrition through transgenic approach.ThesisItem Open Access VACUOLAR SODIUM COMPARTMENTATION AND SALT TOLERANCE: DEVELOPMENT OF RICE TRANSGENICS FOR THE Na+ TRANSPORTER GENE NHX1(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2009-07-10) SUSHMA M, AWAJI; SASHIDHAR, V RSalinity is one of the major environmental factors limiting plant growth and its productivity worldwide. To maintain growth and productivity plants must adapt to stress conditions and exercise specific tolerance mechanisms. In plants Na+/H+ antiporters which catalyze the exchange of Na+ for H+ are localized on both plasma and vacuolar membranes, removing Na+ from cytosol or compartmentalizing it in vacuoles for maintenance of a low Na+ concentration. In the present study, analysis of T1 transgenic rice plants overexpressing NHX1 to select putative transformants was done. To screen putative T1 plants for salt tolerance, a Stringent Salt Screening Test (SSST) was followed at two levels. At seed level, root and shoot growth of T1 putative transformants was used as a selection criterion. At plant level, extent of chlorosis was used at selection criteria. Some of the transgenics showed significantly higher root and shoot growth and lesser or no chlorotic symptoms compared to wild type. To confirm the presence of gene in putative T1 transgenic plants, PCR, Southern analysis and RT-PCR analysis were followed using genomic DNA. The results showed that all the selected seedlings from the SSST were PCR positives. And four selected lines were positive for southern and RT-PCR analysis. Physiological studies such as chlorophyll estimation and membrane permeability tests were also conducted to assess their levels of tolerance at T1 generation. Some of the T1 transformants showed lower percent reduction in chlorophyll content and less membrane leakage after NaCl treatment compared to wild type. These results clearly demonstrate that transgenic rice plants overexpressing PgNHX1, a vacuolar antiporter have better salt-tolerance. This could have been mediated by compartmentation of excess Na+ from cytosol into the vacuole and there by reducing the toxic effects of Na+ in the cell.ThesisItem Open Access CHEMICAL PROFILING FOR RESVERATROL AND COUMARIN FROM THE PLANT SPECIES OF WESTERN GHAT, INDIA(University of Agricultural Sciences, Bangalore, 2009-07-15) VIJAYA, R. CHITNIS; UMA SHAANKER), R.Resveratrol and coumarin are important class of plant secondary metabolites. In recent years these biomolecules have came prominent as potential clinical therapeutic candidates, thus reliable methods for there rapid and sensitive detection are of paramount importance. Accordingly this study examines alternate sources for resveratrol and coumarin from Indian bioresources. In this study three sampling strategies were adopted for collection of plant species, namely phylogenetic/taxonomic relatedness to species already reported to contain the metabolite, prior Indigenous Traditional Knowledge (ITK) and a random collection. For selected species GIS based distribution maps were developed. Eleven species of Polygonum collected from the Western Ghats and north east India were analysed for reserveratol. Among these, promising leads were observed in two species. There was a significant difference among the species in their resveratrol content. Three hundred and ten plant species were screened for coumarin. Four species namely, Mentha piperita (Labiateae), Lavandula bipinnata (Labiateae), Melilotous parviflora (Fabaceae) and Cinnamomum camphora (Lauraceae), were found promising. The coumarin content ranged from 0.2 - 2.9 mg/g (dry weight). A comparative analysis of the different plant collection strategies indicates that the phylogenetic/taxonomic relatedness based search was most promising. The bioactivity of coumarin in selected species was evaluated by trypsin inhibition and ESR inhibition in vitro assays.ThesisItem Open Access Relevance of intrinsic tolerance at cellular level in enhancing the advantage of inherent drought tolerance traits in rice (Oryza sativa..L)(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2009-07-10) NARAYANASWAMY, B R; SHESHSHAYEE, M SSustaining rice production and saving water are the most important challenges in contemporary agricultural research. Though selection for yield was the major criterion, further crop improvement through this strategy, especially for water limited conditions would be insufficient. Instead, a trait based approach is being increasingly adopted. Improved maintenance of water relations through better extraction of water from deeper soil profiles, efficiency of its use for biomass production, maintenance of higher spikelet fertility under water limited conditions are the most important traits that deserve exploitation. An investigation was initiated with a hypothesis that a genotype with higher intrinsic stress tolerance at cellular level would maintain better spikelet fertility under moisture stress conditions. And superior intrinsic tolerance combined with better root traits would help sustain rice productivity under aerobic conditions. A novel temperature induction response (TIR) technique was standardized to assess the genetic variability in intrinsic tolerance. The recovery in growth in the induced seedlings was compared with the non-induced seedlings to assess the intrinsic tolerance. A set of 194 diverse germplasm accessions of rice was screened using this technique and a significant variability was noticed. Based on the variability in root and WUE traits, a few selected contrasting lines were subjected to moisture stress during the period 5 days before anthesis and 10 days after anthesis. A significant increase in spikelet sterility was noticed among the accessions under stress with a significant genetic variability. The genotypes were classified based on differences in root traits and intrinsic tolerance. The results clearly demonstrated that the spikelet fertility was higher under stress in genotypes that possessed either higher root traits or superior intrinsic tolerance. It was observed that the spikelet fertility was higher even under stress in genotypes that had the combined advantage of root traits and intrinsic tolerance to stress at cellular level. Genotypes such as JBT 36/14, AC 39016, AC 35310, Doddabatta , AC 35006, AC 39000 and RASI have b identified as promising lines that can be considered as trait donor parents while transfering relevant traits into a single genetic background.ThesisItem Open Access IDENTIFICATION AND VALIDATION OF HIGH WATER USE EFFICIENT AND BETTER ROOT TYPE SUNFLOWER (Helianthus annuus L.) INBREDS AND PARENTAL LINES FOR IMPROVED DROUGHT TOLERANCE(University of Agricultural Sciences, Bangalore, 2009-07-15) SHASHIDHARA, K. N.; Mohan Raju, B.Among the several traits associated with drought tolerance, roots, water use efficiency and intrinsic tolerance at cellular level found to have some practical relevance under water limited conditions. Hence in the present study, one hundred and twenty lines of sunflower comprising parents and inbreds were evaluated in root structures for some of the relevant physiological traits associated with drought tolerance. Accordingly, a wide and significant genetic variability was found in several traits such as total leaf area, specific leaf area, root length, root volume, root dry weight, total dry matter and water use efficiency measured through carbon isotope discrimination approach. Existence of such a wide genetic variability in sunflower lines enabled to identify highly contrasting lines for roots, WUE and TDM and accordingly, a good number of lines with different drought tolerance traits have been identified. In order to check the consistency of traits and to test the relevance of roots under water limited condition, a subset of sunflower lines from contrasting groups were again evaluated in root structures by imposing moisture stress during active vegetative phase. The results of the study revealed that, even with a small subset of sunflower lines, a significant genetic variability in several of the physiological traits associated with drought tolerance was found both under control and stress condition to indicate that the material is diverse. A strong and significant correlation was also found for various traits such as total leaf area, root dry weight, TDM and ∆13C between 1st and 2nd experiment to indicate that the traits are consistent and heritable. Further, the high root types performed well over low root types under moisture stress condition to indicate that roots are important for imparting drought tolerance in sunflower. Overall, the existence of wide genetic variability and presence trait donor parents in sunflower will certainly help in sunflower improvement programme.ThesisItem Open Access FUNCTIONAL VALIDATION OF DROUGHT STRESS RESPONSIVE GENES BY POST TRANSCRIPTIONAL GENE SILENCING APPROACH(University of Agricultural Sciences GKVK, Bangalore, 2009-07-02) NIYA CELINE, V. J.; NATARAJA KARABA, N.Drought is one of the major environmental stresses that limit crop productivity worldwide. Naturally, plants have evolved several adaptive mechanisms, which involve complex signalling network leading to the altered expression of several stress-relatedgenes. Though several genes, which are known to be induced under drought, have been identified, the functional relevance of only a few has been validated. One of the major emphases now is to evaluate the function of the genes discovered. Amongst various functional genomic approaches Post Transcriptional Gene Silencing (PTGS) techniques is gaining popularity. In the present study, PTGS using Virus induced gene silencing (VIGS) was used to evaluate the function of abiotic stress responsive genes. A few genes namely, Thioredoxin-h, Universal-stress-protein, Shine, Cytochrome-P450, Phosphoinositide specific phospholipase-C, MAP kinase like protein, ABC- transporter like protein, Serine/Threonine protein kinase like protein, were selected from cDNA library developed from stress adapted crops (finger millet and ground nut), and the relevance of these genes was examined by PTGS using TRV-based VIGS in model plant Nicotiana benthamiana. VIGS constructs were developed for the selected genes from N. benthamiana partial cDNA fragments. All VIGS vectors were mobilised into Agrobacterium for PTGS by Agro-infiltration assay. Agro-infiltrated plants were maintained under controlled environment for efficient silencing. The extent of downregulation of endogenous transcripts was analysed by semi-quantitative RT-PCR, and results indicated significant down-regulation of target genes. Since there was no observable phenotype under drought stress at whole plant level, the stress effects were assessed in leaf discs. Photosynthetic rate measured at whole plant level did not shown any significant difference. However, in leaf disc assay, under osmotic and salinity stress, sensitive phenotype was noticed in silenced plants. There was increase in membrane damage and reduction in chlorophyll content under stress in silenced plants indicating relevance of the genes selected in imparting stress tolerance.ThesisItem Unknown Role of jaggery on 14C-glyphosate and 14C-2,4-D entry, translocation and herbicide efficacy in control of Oxalis latifolia, Cyperus rotundus and Eicchornia crassipes(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2009-07-10) SHWETA, B; DEVENDRA, RCyperus rotundus and Oxalis latifolia are world’s worst weeds which reproduce through their predominant underground plant parts called tubers/bulbs, while Eicchornia crassipes is an aquatic weed having high transpiration rate effecting fish industry. Jaggery was added to herbicides which significantly increased the evaporation time of the herbicide droplet but it did not substantially altered the spread of the droplet. Senescence was induced through pretreatment of glyphosate, as senescence enhances translocation of nutrients to other plant parts. Translocation of radiolabelled 14CGlyphosate and 14C-2,4-D herbicides into the plant parts i.e. dormant and non-dormant tubers of Cyperus rotundus and bulbs of Oxalis latifolia was more along with jaggery and in senescent plant when compared to non-senescent plants. The studies of increase in concentration of herbicide in drop or more drop density per fed spot in Eicchornia crassipes showed that much of the herbicide remained as dried out residue and was locked up in plants, less than 1% moved to water after 10 days of feeding. Half-life of both the herbicides in fresh water or pond water infected with Eicchornia crassipes was about 9 days. Biomass reduction assay revealed that, addition of jaggery to glyphosate substantially reduced the total biomass and dormant tuber weight and non-dormant tuber weight compared to control in Cyperus rotundus and Oxalis latifolia. Senescence followed by herbicide application substantially reduced sprouting ability of tubers as reflected by reduced number of shoots produced per tuber both by non-dormant and dormant tubers in Cyperus rotundus. The bioassay experiment suggests that glyphosate is more effective than 2,4-D in controlling Cyperus rotundus and Oxalis latifolia.ThesisItem Open Access TARGETING THE VACUOLAR TRANSPORTER GENES INVOLVED IN ION HOMEOSTASIS AND SALT TOLERANCE: DEVELOPING TRANSGENIC RICE PLANTS OVEREXPRESSING V-ATPASE AVP1 GENE IN RICE(University of Agricultural Sciences GKVK, Bangalore, 2009-07-15) PRASHANTKUMAR, S. HANJAGI.; SASHIDHAR, V. R.Salt stress affects plant growth and development in many different ways. To maintain growth and productivity plants must adapt to stress conditions and exercise specific tolerance mechanisms. In plants H+-PPase proton pumps which drive the activity of Na+/H+ antiporters are localized on vacuolar membranes, actively generating proton gradient which in turn drives Na+/H+ antiporters which compartmentalize Na+ into the vacuoles for maintenance of a low Na+ concentration. In the present study, AVP1, a vacuolar H+-PPase gene from Arabidopsis thaliana was overexpressed in rice (var-Vikas) by Agrobacterium mediated In Planta transformation technique. To screen putative T1 plants for salt tolerance, stringent salt screening test was followed and root and shoot growth of T1 putative transformants was used as a selection criterion. Some of the transgenics showed significantly higher root and shoot growth compared to wild type. To confirm the presence of gene in putative T1 transgenic plants, PCR based approach was followed using genomic DNA. The results showed that 100% of the selected seedlings from the stringent salt screening test were PCR positives. Physiological studies such as chlorophyll estimation, membrane integrity, cell viability tests were also conducted to assess their levels of tolerance at T1 generation. Some of the T1 transformants showed lower percent reduction in chlorophyll content, higher cell viability after NaCl treatment compared to wild type. These results clearly demonstrate that transgenic rice plants overexpressing AVP1, a vacuolar H+ proton pump have better salt-tolerance. This could have been mediated by the proton gradient generated by AVP1, which drives Na+/H+ antiporter which carries out compartmentation of excess Na+ from cytosol into the vacuole and there by reducing the toxic effects of Na+ in the cell.ThesisItem Open Access STACKING REGULATORY GENES FOR IMPROVING ABIOTIC STRESS TOLERANCE IN PLANTS(University of Agricultural Sciences GKVK, Bangalore, 2009-08-12) SHAILESH, K. S.; NATARAJA KARABA, N.Plant growth and productivity is severely affected due to the occurrence of various environmental stresses. These stresses cause reduction in yield up to 50% in most of the major crops, thereby threatening the sustainability of agriculture. Plants evolved various stress tolerant mechanisms by coordinated expression of stress-responsive genes under stressful conditions. Abiotic stress tolerance can be improved by activating coordinated expression of stress genes by various approaches. One of the options would be to stack stress genes which encode specific regulatory or functional proteins. From this context, in the present study, transgenic groundnut (Arachis hypogaea) plants over expressing multiple abiotic stress regulatory genes were developed through a bacteriophage (λ) based site specific recombination system called Multisite gateway cloning technology. Three gene cassette including G Box binding factor (stress responsive transcription factor, EcGBF1), 5-Enolpyruvylshikimate- 3-phosphate synthase (EPSPS) gene imparting Glyphosate resistance and DNA unwinding enzyme PDH45 driven by individual promoter and terminator were put together into a single destination vector system for developing a multigene expression system. The multigene expression system was further mobilized into crop plant groundnut via Agrobacterium mediated gene transfer technique. A novel method was developed and standardized to transform groundnut using cotyledonary nodes. Molecular characterisation of the putative transgenics confirmed the integration of all the three gene cassettes in putative transgenic lines. The pattern of expression of transgenes was tested by RT-PCR analysis. The putative lines were also evaluated for their resistance to herbicide, glyphosate and all the transformed lines showed tolerance to the herbicide. The transgenic lines overexpressing the stress genes (EcGBF1 and PDH45) showed improved tolerance to methyl viologen induced oxidative stress compared to the wild type plants. The results indicate that multigene integration and expression is possible, and stress tolerance can be improved by gene stacking approach.