Orientador: Marcelo Andreotti / Resumo: Os sistemas integrados de produção agropecuária são alternativas viáveis para recuperação de áreas degradadas, rotação de culturas e produção de palhada com efeitos sobre as propriedades físicas, químicas e biológicas do solo. Esta pesquisa objetivou, em um LATOSSOLO VERMELHO distrófico, avaliar o desempenho produtivo da soja em sucessão ao capim Marandu, que foi submetido à três manejos: adubado com 50 kg ha-1 de N (Ureia) a cada corte antecessor, simulando o pastejo (0,30 m de altura), totalizando 4 cortes com intervalo de um para o outro de aproximadamente 30 dias, ou com pulverização foliar a cada corte com Azospirillum brasilense, e numa condição sem adubação nitrogenada e sem pulverização com Azospirillum após cada corte (controle), e em duas condições de semeadura da soja, com sementes inoculadas apenas com Bradyrhizobium japonicum ou co-inoculada com Azospirillum brasilense. A pesquisa constituiu-se de dois experimentos (um em área de sequeiro e outro em área irrigada por aspersão – pivô central) e foi realizada no ano agrícola 2016/2017 na Fazenda de Ensino, Pesquisa e Extensão (FEPE), localizada no município de Selvíria-MS. A cultura anterior ao experimento, em ambas as áreas, foi a Urochloa brizantha cv Marandu advinda do consórcio com milho, onde após a colheita do milho, o capim permaneceu na área até a semeadura da soja BMX POTÊNCIA RR. O delineamento experimental foi o de blocos casualizados, com quatro repetições, em esquema fatorial 3 x 2, constituídos do cul... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Crop livestock are viable alternatives for the recovery of degraded areas, crop rotation and straw production with effects on the physical, chemical and biological properties of the soil. The aim of the research in a dystrophic RED LATOSOLO, was to evaluate the productive performance of soybean in succession to the Marandu grass, which was submitted to three treatments: fertilized with 50 kg ha-1 of N (Urea) to each predecessor cut, simulating grazing (0,30 m high), totaling 4 cuts with interval from one to another of approximately 30 days, or with leaf spraying at each cut with Azospirillum brasilense, and in a condition without nitrogen fertilization and without spraying with Azospirillum after each cut (control), and under two conditions of soybean sowing, inoculated only with Bradyrhizobium or co-inoculated with Azospirillum brasilense. The research consisted of two experiments (one in the dry area and the other in a overhead irrigation area - central pivot) and was carried out in the agricultural year 2016/2017 at the Fazenda de Ensino, Pesquisa e Extensão (FEPE), located in the municipality of Selvíria-MS. The culture before the experiment, in both areas, was Urochloa brizantha cv. Marandu from the maize consortium, and after maize harvesting, the grass remained in the area until sowing of soybean BMX POTÊNCIA RR. The experimental design was a randomized complete block design, with four replications, in a 3 x 2 factorial scheme, consisting of the soybean crop in success... (Complete abstract click electronic access below) / Mestre

Submitted by Osvaldo Araujo (osvaldo.araujo.agro@gmail.com) on 2018-03-27T18:26:29Z No. of bitstreams: 1 Arauj Junior_o_ilha (3).pdf: 1043962 bytes, checksum: dce6e72d8aff0d848771cdd45f1576d6 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-03-27T19:27:27Z (GMT) No. of bitstreams: 1 araujojunior_o_me_ilha.pdf: 1043962 bytes, checksum: dce6e72d8aff0d848771cdd45f1576d6 (MD5) / Made available in DSpace on 2018-03-27T19:27:27Z (GMT). No. of bitstreams: 1 araujojunior_o_me_ilha.pdf: 1043962 bytes, checksum: dce6e72d8aff0d848771cdd45f1576d6 (MD5) Previous issue date: 2018-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os sistemas integrados de produção agropecuária são alternativas viáveis para recuperação de áreas degradadas, rotação de culturas e produção de palhada com efeitos sobre as propriedades físicas, químicas e biológicas do solo. Esta pesquisa objetivou, em um LATOSSOLO VERMELHO distrófico, avaliar o desempenho produtivo da soja em sucessão ao capim Marandu, que foi submetido à três manejos: adubado com 50 kg ha-1 de N (Ureia) a cada corte antecessor, simulando o pastejo (0,30 m de altura), totalizando 4 cortes com intervalo de um para o outro de aproximadamente 30 dias, ou com pulverização foliar a cada corte com Azospirillum brasilense, e numa condição sem adubação nitrogenada e sem pulverização com Azospirillum após cada corte (controle), e em duas condições de semeadura da soja, com sementes inoculadas apenas com Bradyrhizobium japonicum ou co-inoculada com Azospirillum brasilense. A pesquisa constituiu-se de dois experimentos (um em área de sequeiro e outro em área irrigada por aspersão – pivô central) e foi realizada no ano agrícola 2016/2017 na Fazenda de Ensino, Pesquisa e Extensão (FEPE), localizada no município de Selvíria-MS. A cultura anterior ao experimento, em ambas as áreas, foi a Urochloa brizantha cv Marandu advinda do consórcio com milho, onde após a colheita do milho, o capim permaneceu na área até a semeadura da soja BMX POTÊNCIA RR. O delineamento experimental foi o de blocos casualizados, com quatro repetições, em esquema fatorial 3 x 2, constituídos do cultivo da soja em sucessão ao capim-marandu submetido à três manejos e em duas condições de semeadura da soja, inoculada apenas com Bradyrhizobium ou co-inoculada com A. brasilense. A co-inoculação via semente de Bradyrhizobium e Azospirillum não incrementou o crescimento, os componentes da produção e produtividade da soja sob Sistema Plantio Direto (SPD), independentemente se em área de sequeiro ou irrigada. Em ambos os manejos, sequeiro e irrigado, a pulverização foliar de A. brasilense no capim Marandu é viável para o SIPA promovendo produção de forragem satisfatória em relação à adubação nitrogenada, bem como este residual de A. brasilense no solo, resultante da aplicação foliar no capim Marandu antecessor à soja, aumentou a massa de nódulos da soja, mostrando ser uma alternativa viável para potencializar a fixação biológica de N2, principalmente em condições de sequeiro. / Crop livestock are viable alternatives for the recovery of degraded areas, crop rotation and straw production with effects on the physical, chemical and biological properties of the soil. The aim of the research in a dystrophic RED LATOSOLO, was to evaluate the productive performance of soybean in succession to the Marandu grass, which was submitted to three treatments: fertilized with 50 kg ha-1 of N (Urea) to each predecessor cut, simulating grazing (0,30 m high), totaling 4 cuts with interval from one to another of approximately 30 days, or with leaf spraying at each cut with Azospirillum brasilense, and in a condition without nitrogen fertilization and without spraying with Azospirillum after each cut (control), and under two conditions of soybean sowing, inoculated only with Bradyrhizobium or co-inoculated with Azospirillum brasilense. The research consisted of two experiments (one in the dry area and the other in a overhead irrigation area - central pivot) and was carried out in the agricultural year 2016/2017 at the Fazenda de Ensino, Pesquisa e Extensão (FEPE), located in the municipality of Selvíria-MS. The culture before the experiment, in both areas, was Urochloa brizantha cv. Marandu from the maize consortium, and after maize harvesting, the grass remained in the area until sowing of soybean BMX POTÊNCIA RR. The experimental design was a randomized complete block design, with four replications, in a 3 x 2 factorial scheme, consisting of the soybean crop in succession to the Marandu grass submitted to three treatments and in two sowing conditions of soybean, inoculated only with Bradyrhizobium or co-inoculated with A.brasilense. The co-inoculation of Bradyrhizobium and Azospirillum in the seeds did not increase the growth, the components of the production and productivity of the soybeans under no-tillage system, irrespective of dry or irrigated areas. In both dry and irrigated managements, the A. brasilense leaf spray in the Marandu grass is viable for the SIPA promoting satisfactory forage production in relation to the nitrogen fertilization, as well as this residual of A. brasilense in the soil, resulting from the foliar application in the Marandu grass predecessor to soybean, increased the nodule mass of the soybean, proving to be a viable alternative to potentiate the biological N2 fixation, mainly in dry conditions.

Made available in DSpace on 2014-08-20T14:38:46Z (GMT). No. of bitstreams: 1 dissertacao_manuela_zardin_de_pellegrini.pdf: 867365 bytes, checksum: 0d6793294ffa9bf2c92471e5c33514d9 (MD5) Previous issue date: 2012-08-24 / The research evaluated the incidence of mastitis sheep and its relation to pain and behavioral variables in Corriedale herd, handled on native pasture in Rio Grande do Sul. The results were collected in two reviews. The first stage was conducted in December 2010 to determine the incidence of mastitis in multiparous ewes after weaning their lambs. The sheep were submittedto clinical examination and palpation of the udder and classified as scale change in consistency of the udder. No cases of clinical mastitis, but 25% of the herd had chronic mastitis. In the second stage, held in September 2011, was observed behavioral variables in two environments: pen and paddock. Two sheep were evaluated postpartum, which showing udderalteredconsistencyandnormal, respectively.The sheep with udderalteredconsistencyshowed alert behavior pen and paddock. The sheep with normal udder showed higher gregarious behavior and vocalised more often for her lamb. The presence ofnodulesin the udderalteredmaternal-filial behavior the sheep.The indicators of pain were not observed. The clinical mastitis is not a problem in the extensive breeding of sheep, but the presence of chronic mastitis indicates trauma or inflammation without prior treatment. / A pesquisa avaliou a incidência da mastite ovina e sua relação com variáveis de dor e comportamentais, em rebanho Corriedale, manejado em campo nativo no Rio Grande do Sul. Os resultados foram coletados em duas avaliações. A primeira etapa foi realizada em dezembro de 2010, para verificar a incidência da mastite em ovelhas multíparas após o desmame dos seus cordeiros. As ovelhas foram submetidas ao exame clínico e palpação do úbere e classificadas conforme escala de alteração da consistência do úbere. Não houve casos de mastite clínica, porém 25% do rebanho apresentou mastite crônica. Na segunda etapa, realizada em setembro de 2011, foi observado as variáveis comportamentais em dois ambientes: mangueira (curral) e piquete. Duas ovelhas foram avaliadas no pós-parto, as quaisapresentaram consistência de úbere alterado e úbere normal, respectivamente. A ovelha com alteração no úbere mostrou comportamento alerta no curral e piquete. A ovelha com úbere normal apresentou maior comportamento gregário e vocalizou mais vezes para seu cordeiro. A presença de nodulações no úbere alterou o comportamento materno-filial. Os indicadores de dor não foram observados. A mastite clínica não é um problema na criação extensiva de ovinos, contudo a presença de mastite crônica indica trauma ou inflamação prévia sem tratamento.

The aim of this study was to describe the laryngeal anatomy, perceptual, acoustic and aerodynamic vocal characteristics of school-aged children with and without ADHD. The predisposition that children with ADHD have for laryngeal injuries are recurrent in nature and are more often than not overlooked as laryngitis. Previous studies have reported varied results on the prevalence rates of paediatric VFN within the school-aged ADHD population. A static, two-group comparison was used in the study to investigate the clinical, perceptual, acoustic and aerodynamic vocal characteristics of children between 7 and 9 years old with and without ADHD. The study replicated the protocol as executed by Barona-Lleo and Fernandez (2016) with additions. The Multidimensional Voice Program (MDVP) and the Voice Range Profile (VRP) as additions to the assessment of vocal parameters were used with which comparable dysphonia severity index (DSI) scores were calculated. Once-off clinical, perceptual, acoustic and aerodynamic voice assessments were conducted on 20 age-gender matched participants. The difference in assessment results between the vocal characteristics of children without a history of ADHD (control group) and those of children with ADHD (ADHD group) was then investigated and described. Forty five percent (n=9) of the total sample population had laryngeal pathology. Comparable parent reported etiological voice symptoms and vocal habits were seen across both groups. Both groups performed similarly across both perceptual and aerodynamic voice assessments. Acoustically, the control group achieved significantly higher producible pitches than the ADHD group (p=0.028) and were found to have more dysphonic DSI scores than their ADHD group peers (p=0.034). Prepubertal, school-aged children with or without ADHD may have similar vocal characteristics than previously thought. This variation in school-aged children warrants further research into larger sample sizes with this population with a special focus on the effect that CNS stimulants may have on the voice. / Dissertation (MCommunication Pathology)--University of Pretoria, 2019. / Speech-Language Pathology and Audiology / MCommunication Pathology / Unrestricted

Actinorhizal plants are in symbiosis with the nitrogen-fixating soil bacterium Frankia, which forms nodules in the plant root. However, several studies also report other endophytic bacteria appearing in the nodules, but their function and interaction with the host plant or Frankia is not yet understood. This thesis used a bioinformatic approach to investigate the metagenomes of eighteen actinorhizal nodule samples to find out which bacteria are present, how the microbiomes differed from each other, and if the genomes of non-Frankia inhabitants could give indications of any functions. The results showed that the bacterial composition, richness, and diversity differed among the samples, especially between the samples sequenced from the field versus those primarily cultivated in a greenhouse. All samples had a substantial number of sequencing reads belonging to potential endophytes, such as strains of Enterobacteria, Pseudomonas, Streptomyces, Micromonospora, Mycobacteria and Pseudonocardia. There seemed to be a common microbial community shared among the plants on a family level, since no significant difference was found in the core microbiomes between the field and greenhouse groups. Some sequences found in the metagenomes were annotated as potential functions of the fellow travellers, such as antibiotic synthesis, proteins involved in regulating abiotic stresses, but also probable plant damaging compounds rather associated with pathogens than symbionts.

It is not known whether seed inoculated soybean intercropping can increase the number of nodules, nitrogen uptake and yield of the subsequent main crop, soybean. For this reason, the soybean intercropping approach, sole or mixed cropping with buckwheat, was adopted to examine the influence of inoculation and intercropping of soybean and buckwheat on the subsequent main crop, soybean. Field trials were conducted from 2016 to 2019 in Germany and Poland. For this purpose, soils on which soybeans had not been grown in the past were selected as experimental plots and laid out in a split-plot design. It was surprising that even without inoculation a nodule growth could be documented. However, intercrop inoculation resulted in an average of 12 times more nodules per plant at four out of five sites. In addition, a 43% higher number of nodules was found on the lateral roots of the main soybean crop when intercropping with inoculated soybean occurred. The influence of the intercrop on the main crop soybean also depended on their growth in late summer and autumn. Further, there was a medium relationship (R = 0.7) between the number of nodules in the intercrop soybean and the nitrogen content of the soybean grain in the main crop. In terms of soybean grain yield, a single inoculation of the intermediate soybean crop contributed an average of 5% higher yield and inoculation of both the intercrops, and the main crop improved yield by 15%.

Object detection on natural images has become a single-stage end-to-end process thanks to recent breakthroughs on deep neural networks. By contrast, automated pulmonary nodule detection is usually a three steps method: lung segmentation, generation of nodule candidates and false positive reduction. This project tackles the nodule detection problem with a single stage modelusing a deep neural network. Pulmonary nodules have unique shapes and characteristics which are not present outside of the lungs. We expect the model to capture these characteristics and to only focus on elements inside the lungs when working on raw CT scans (without the segmentation). Nodules are small, distributed and infrequent. We show that a well trained deep neural network can spot relevantfeatures and keep a low number of region proposals without any extra preprocessing or post-processing. Due to the visual nature of the task, we designed a three-dimensional convolutional neural network with residual connections. It was inspired by the region proposal network of the Faster R-CNN detection framework. The evaluation is performed on the LUNA16 dataset. The final score is 0.826 which is the average sensitivity at 0.125, 0.25, 0.5, 1, 2, 4, and 8 false positives per scan. It can be considered as an average score compared to other submissions to the challenge. However, the solution described here was trained end-to-end and has fewer trainable parameters. / Objektdetektering i naturliga bilder har reducerates till en enstegs process tack vare genombrott i djupa neurala nätverk. Automatisk detektering av pulmonella nodulärer är vanligtvis ett trestegsproblem: segmentering av lunga, generering av nodulärkandidater och reducering av falska positiva utfall. Det här projektet tar sig an nodulärdetektering med en enstegsmodell med hjälp av ett djupt neuralt nätverk. Pulmonella nodulärer har unika karaktärsdrag som inte finns utanför lungorna. Modellen förväntas fånga dessa drag och enbart fokusera på element inuti lungorna när den arbetar med datortomografibilder. Nodulärer är små och glest föredelade. Vi visar att ett vältränat nätverk kan finna relevanta särdrag samt föreslå ett lågt antal intresseregioner utan extra för- eller efter- behandling. På grund av den visuella karaktären av det här problemet så designade vi ett tredimensionellt s.k. convolutional neural network med residualkopplingar. Projektet inspirerades av Faster R-CNN, ett nätverk som utmärker sig i sin förmåga att detektera intresseregioner. Nätverket utvärderades på ett dataset vid namn LUNA16. Det slutgiltiga nätverket testade 0.826, vilket är genomsnittlig sensitivitet vid 0.125, 0.25, 0.5, 1, 2, 4, och 8 falska positiva per utvärdering. Detta kan anses vara genomsnittligt jämfört med andra deltagande i tävlingen, men lösningen som föreslås här är en enstegslösning som utför detektering från början till slut och har färre träningsbara parametrar. / La détection d’objets sur les images naturelles est devenue au fil du temps un processus réalisé de bout en bout en une seule étape grâce aux évolutions récentes des architectures de neurones artificiels profonds. En revanche, la détection automatique de nodules pulmonaires est généralement un processus en trois étapes : la segmentation des poumons (pré-traitement), la génération de zones d’intérêt (modèle) et la réduction des faux positifs (post-traitement). Ce projet s’attaque à la détection des nodules pulmonaires en une seule étape avec un réseau profond de neurones artificiels. Les nodules pulmonaires ont des formes et des structures uniques qui ne sont pas présentes en dehors de cet organe. Nous nous attendons à ce qu’un modèle soit capable de capturer ces caractéristiques et de se focaliser uniquement sur les éléments à l’intérieur des poumons alors même qu’il reçoit des images brutes (sans segmentation des poumons). Les nodules sont petits, peu fréquents et répartis aléatoirement. Nous montrons qu’un modèle correctement entraîné peut repérer les éléments caractéristiques des nodules et générer peu de localisations sans pré-traitement ni post-traitement. Du fait de la nature visuelle de la tâche, nous avons développé un réseau neuronal convolutif tridimensionnel. L’architecture utilisée est inspirée du méta-algorithme de détection Faster R-CNN. L’évaluation est réalisée avec le jeu de données du challenge LUNA16. Le score final est de 0.826 qui représente la sensibilité moyenne pour les valeurs de 0.125, 0.25, 0.5, 1, 2, 4 et 8 faux positifs par scanner. Il peut être considéré comme un score moyen comparé aux autres contributions du challenge. Cependant, la solution décrite montre la faisabilité d’un modèle en une seule étape, entraîné de bout en bout. Le réseau comporte moins de paramètres que la majorité des solutions.

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Thesis (PhD(Agric) (Plant Biotechnology))--University of Stellenbosch, 2010. / Includes bibliography. / ENGLISH ABSTRACT: Salinity is one of the major limiting abiotic stresses on legume plant yield, leading to early senescence of root nodules. This occurs because of accumulation of reactive oxygen species (ROS) in plant cells under salinity stress. Concurrent with the increase in cellular reactive oxygen species levels is the increase in cellular antioxidants and corresponding antioxidant enzymes. This feature is observed mostly in the shoots and roots of more tolerant genotypes compared to the susceptible genotypes. It is accepted that the mechanism of plant tolerance to stress is dependent upon the response of the antioxidant systems. Most studies carried out on shoot tissues suggest that scavenging of ROS by the plant antioxidant system is modulated by nitric oxide (NO). However, the pathways by which NO mediates such antioxidant responses are not fully understood. For legumes, salinity stress has adverse effects on yield and this is in part due to inhibition of nitrogen fixation in the root nodules of the legumes, which causes severe nitrogen starvation in nitrogen-deficient soils. Nodules are specialized organs comprising of both the rhizobia and the plant tissue, hence the physiological aspects may vary from the findings from the leaves. It was therefore deemed necessary to establish the role of NO on the nodule antioxidant system in the absence and presence of salinity stress. For the purposes of this study, the effect of both exogenously applied NO and endogenous NO on superoxide dismutase, glutathione peroxidase and glutathione content was determined. The studies involved the use of nitric oxide donors like sodium nitroprusside (SNP) and diethylenetriamine/nitric oxide adduct (DETA/NO), their respective fixed controls potassium ferricyanide and diethylenetriamine (DETA), plus a nitric oxide synthase inhibitor (to inhibit nitric oxide production by the enzyme nitric oxide synthase) on nodulated roots. The data obtained in this work points out specifically at roles played by nitric oxide in regulating superoxide dismutases, glutathione peroxidase and glutathione during salinity stress and proposes a link between nitric oxide-mediated changes in these antioxidant systems and salinity stress tolerance. Both the exogenously applied and endogenous nitric oxide increases the enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione reductase (GR). However, there is both time dependency and nitric oxide concentration dependency on the enzyme activities. The total SOD enzyme activity increases upon nitric oxide exposure and with time of exposure. The individual SOD isoforms identified and studied in the root nodules all contribute to this increase in SOD activity upon nitric oxide treatment except for MnSOD I. This increase in activity is regulated at transcriptional level as the RT-PCR results targeting the individual isoforms reveals an increase in transcript levels after 6 hours of nitric oxide treatment. However, the CuZn SOD I isoform transcripts are reduced upon nitric oxide treatment. A similar response was also observed in GPX enzyme activity in which nitric oxide increased the GPX activity above all the controls. The GR enzyme activity exhibits an opposite response because the activity decreases with time of exposure to NO and concentration of NO. In order to determine the effect of NO under saline conditions, an experiment was set up that involved incubation of nodulated roots in solutions containing 150 mM NaCl. The stressed nodules exhibited generally higher levels of enzyme activities than the non-stressed nodules. Furthermore, exposure to nitric oxide donor in combination with NaCl induced even higher activities of SOD and GPX than NaCl or nitric oxide donor alone. There were also higher levels of reduced glutathione and total glutathione recorded under stress compared to optimal conditions. Nitric oxide increased the concentration of these forms of glutathione, suggesting an improved redox status based on the GSH/GSSG ratios under salinity stress in the presence of nitric oxide. Attenuation of nitric oxide synthesis with L-Nω-Nitroarginine methyl ester (L-NAME) reverses all the recorded effects of nitric oxide on antioxidant enzymes and glutathione pool. This was observed in salinity stressed nodules and non-stressed nodules. This work further establishes that NO plays a pivotal role in modulating the enzymatic activities through a pathway that is mediated by guanosine 3,5-cyclic monophosphate (cGMP). The experiment involving the inhibition of soluble guanylyl cyclase (sCG) (an enzyme that catalyzes the biosynthesis of cGMP), cell-permeable cGMP anaologue and L-NAME revealed that GPx activity is modulated through a cGMP-dependent pathway and NO is positioned up-stream of cGMP in the pathway leading to improved GPX activity. Cyclic GMP also modulates the GPX activity in a concentration dependent manner. NO improves the redox status of the cell under both saline conditions and non-saline conditions and this effect is modulated through a cGMP-dependent pathway. It is thus rational to conclude that; in the root nodules of legumes, like in other plant tissues, the increased accumulation of antioxidants and the increased activity of their corresponding enzymes, as modulated through the cGMP-dependent pathway by nitric oxide, confer root nodule tolerance to salinity. This concept directly points out at an attractive strategy for developing legumes that are genetically improved for enhanced root nodule tolerance to salinity; via differential regulation of antioxidants and antioxidant enzyme genes in the root nodules under abiotic stress. Towards attaining the goal for such genetic improvement, experiments involving construction of an abiotic stress-responsive and nodule-specific chimeric promoter were carried out. By fusing the 5-untranslated (5-UTR) region of the LEA gene that contains an abiotic stress-responsive cis-acting element (from theGmPM9 promoter) to the nodulin N23 promoter bearing the highly functional cluster of motifs for nodule specificity, the candidate nodule specific promoter that is abiotic stress responsive (ASREF/NSP) was constructed. The construct harbouring this ASREF/NSP chimeric promoter was fused to the -glucuronidase (GUS) reporter gene so as to study the functionality of the promoter in Medigaco truncatula plants. The construct was delivered into the Medicago plants through Agrobacterium rhyzogenes mediated transformation to produce composite Medicago plants. The transgenic roots have been cultured for futher manipulation and to confirm the functionality of the promoter. Furthermore several strategies can be deployed via the use of this chimeric promoter so as to enhance the nodular antioxidant system. This would involve either gene regulator-chimeric promoter fusion or the use of a single gene approach. As part of this work, the MtNOA gene homologous to AtNOAs, has been cloned from Medicago trancatula and put as ASREF/NSP fusion in a binary vector pBINPLUS and delivered into Medicago trancatula for nodule-specific and abiotic stress-induced nitric oxide synthesis. Since there is no plant NOS identified to date, the possibility of the use of a regulatory gene in this aspect is still limited. There are other options involving the use of the chimeric promoter with the individual genes encoding the antioxidant enzyme genes such as genes encoding SOD, GPX and the glutathione synthatase to enhance the plant antioxidant system during abiotic stress. / AFRIKAANSE OPSOMMMING: Geen opsomming was ingedien met die tesis