Potato (Solanum tuberosum) is the third most important crop in terms of human consumption. Hence understanding regulatory mechanisms controlling tuber initiation is significant not only from a theoretical but also practical point of view. Tuberization of S. tuberosum is a complex morphogenic process regulated by both, environmental conditions and inner plant status. Environmental conditions regulating the onset of tuberization have been known for a long time, but the molecular basis of tuber initiation has only recently been discovered, in particular using wild subspecies S. tuberosum subsp. andigena. BELL transcription factors are among the important components of the regulatory signalling network. The aim of this study was to modulate balance between the BELL transcription factors that induce and repress tuberization towards strengthening of tuber induction using two cultivars of Solanum tuberosum subsp. tuberosum, cv. Kamýk, resp. cv. Korela. To achieve this, transgenic lines carrying construct containing a part of coding sequence StBEL11, resp. StBEL29 in antisense orientation (AS) under control of constitutive promoters and lines carrying complete sequences of StBEL5 and StPTB6 genes under control of their native promoters were derived. We used the StBEL11 and StBEL29 AS constructs with the aim to...

Plants are exposed to the stress of the environment throughout their entire live. They therefore had to develop sophisticated mechanisms to avoid or tolerate stress. In some plants, repeated exposure to stress increases tolerance, which is known as stress memory. The aim of this study is to assess stress memory in terms of oxidative stress level. Content of malondialdehyde (MDA), reactive oxygen species (ROS) and the electrolyte leakage were chosen as markers of oxidative stress. Fresh weight, plant height and water content were also evaluated. The level of oxidative stress was assessed in several genotypes of Solanum tuberosum subspecies, Andigena and Tuberosum. In vitro culture did not work well for the evaluation of stress memory, ex vitro partially did. The content of MDA in 66B was significantly lower than in cv. Lada (Tuberosum) in root (in vitro) and shoot (ex vitro) in control groups as well as during water shortage. Treatment of acclimation-inducing cold before the stress-inducing cold had a variable effect on growth and electrolyte leakage according to the culture conditions. In vitro, the effect on electrolyte leakage in roots of cv. Lada was positive, in leaves of 66B (Andigena) it was negative. In ex vitro, a positive effect was found on electrolyte leakage in 66B leaves, but at the...

[EN] Eggplant (Solanum melongena L.) is one of the vegetables with highest content in phenolic compounds, giving eggplant a high antioxidant power and other bioactive beneficial health properties. This means that there is a growing demand among consumers concerned about a healthy diet. However, despite being a crop with a great economic importance worldwide, it is one of the least-studied Solanaceae (much less than tomato, pepper and potato), so it is necessary to carry out studies that contribute to the genetic improvement of eggplant to the commercial level so that the genetic diversity is increased and that is adapted to the demands of producers and consumers. The work carried out in this Thesis aims to obtain relevant information for the breeding programmes of eggplant through the study of genetic diversity and development and use of tools for the morphological characterization as well as increasing genetic diversity in élite germplasm for the development of programs aimed at obtaining high-value hybrids. For achieving this objective, commercial eggplant (semi-larga) black type, as well as other types, origins and varieties of local material are used. In the first part of the Thesis, we rely on the study of genetic diversity in S. melongena and the application of new tools to perform accurate morphological characterization and improve the process of selection of the breeding programs. This diversity studies have been conducted in three centres of origin side in different regions (Spain, Sri Lanka and China), in local materials of eggplant with different typologies, and new phenomic tools have been used for the morphological characterization of the fruit of the eggplant. In the second part of this work, we deal with the development of plant material to increase the genetic base of eggplant cultivars and with the implementation of various programmes for genetic improvement. For this we plan and develop different breeding programs according to different objectives, including the implementation of a programme of improvement of a local variety with protected geographical indication (IGP), and increasing the diversity and new "elite" material of black type eggplant through a program of genetic improvement. In summary, our work that shows that the study of the genetic diversity and the use of phenomics tools for morphological characterization, as well as the development of new plant material, is very useful for obtaining new varieties of eggplant as well as scientific and technical information of interest to other researchers and breeders. We have also found that "public-private research" interaction allows a synergistic collaboration in obtaining plant material and information of interest for vegetables breeding. / [ES] La berenjena (Solanum melongena L.) es una de las hortalizas más ricas en compuestos fenólicos, lo cual le confiere un alto poder antioxidante y otras propiedades bioactivas beneficiosas para la salud. Ello hace que haya una demanda creciente entre consumidores preocupados por una dieta saludable. Sin embargo, a pesar de ser un cultivo con una gran importancia económica a nivel mundial, es una de las solanáceas menos estudiadas (mucho menos que tomate, pimiento y patata), por lo que es necesario realizar estudios que contribuyan a la mejora genética de la berenjena a nivel comercial de forma que amplíen la diversidad genética y que permitan adaptarse a las demandas de productores y consumidores. El trabajo realizado en esta Tesis pretende obtener información relevante para los programas de mejora genética de berenjena mediante el estudio de la diversidad genética y el desarrollo y uso de herramientas para la caracterización morfológica, así como el aumento de la diversidad genética en el germoplasma élite de los programas de desarrollo de híbridos de alto valor. Para ello se utiliza material vegetal tanto de la berenjena comercial tipo negra (semi-larga), como material de otros tipos, orígenes y variedades locales. En una primera parte de la Tesis, nos basamos en el estudio de diversidad genética en S. melongena y en la aplicación de nuevas herramientas para realizar una caracterización morfológica precisa y mejorar el proceso de selección en los programas de mejora. Para ello se han realizado estudios de diversidad en tres centros de origen secundarios de distintas regiones (España, Sri Lanka y China), en materiales locales de berenjena con distintas tipologías, y se han utilizado nuevas herramientas fenómicas para la caracterización morfológica del fruto de la berenjena. Como segunda parte de este trabajo, abordamos el desarrollo de material vegetal para el incremento de la base genética de los cultivares de berenjena e implementación de distintos programas de mejora genética. Para ello se plantean y ejecutan diferentes programas de mejora según los objetivos explícitos, incluyendo la realización de un programa de mejora para una variedad local con Indicación Geográfica Protegida (IGP), e incrementando la diversidad y la obtención de nuevos materiales de élite de berenjena tipo negra mediante un programa de mejora genética. En definitiva, nos encontramos con un trabajo que muestra que el estudio de la diversidad genética y el desarrollo y utilización de herramientas fenómicas para la caracterización morfológica, además de la obtención de material vegetal nuevo, es de gran utilidad para el desarrollo de nuevas variedades de berenjena, así como para obtener información científico-técnica de interés para otros investigadores y mejoradores. También hemos constatado que la interacción "investigación pública-privada" permite una colaboración sinérgica en la obtención de material vegetal e información de interés en la mejora de hortícolas. / [CA] L'albergina (Solanum melongena L.) és una de les hortalisses més riques en compostos fenòlics, el que li confereix un alt poder antioxidant i altres propietats bioactives beneficioses per a la salut. Aquest fet fa que hi haja una demanda creixent entre els consumidors preocupats per una dieta saludable. No obstant això, a pesar de ser un cultiu amb una gran importància econòmica a nivell mundial, és una de les solanàcies menys estudiades (molt menys que tomaca, pimentó i creïlla) , per la qual cosa és necessari realitzar estudis que contribuïsquen a la millora genètica de l'albergina a nivell comercial de manera que amplien la diversitat genètica i que permeten adaptar-se a les demandes de productors i consumidors. El treball realitzat en esta Tesi pretén obtindre informació rellevant per als programes de millora genètica d'albergina per mitjà de l'estudi de la diversitat genètica i el desenvolupament i ús de ferramentes per a la caracterització morfològica, així com l'augment de la diversitat genètica en el germoplasma elit dels programes de desenvolupament d'híbrids d'alt valor. Per a això s'utilitza material vegetal tant de l'albergina comercial de tipus negra (semi-llarga), com material d'altres tipus, orígens i varietats locals. En una primera part de la Tesi, ens basem en l'estudi de diversitat genètica en S. melongena i en l'aplicació de noves ferramentes per a realitzar una caracterització morfològica precisa i millorar el procés de selecció en els programes de millora. Per a això s'han realitzat estudis de diversitat en tres centres d'origen secundaris de distintes regions (Espanya, Sri Lanka i Xina), en materials locals d'albergina amb distintes tipologies, i s'han utilitzat noves ferramentes fenòmiques per a la caracterització morfològica del fruit de l'albergina. Com a segona part d'este treball, abordem el desenvolupament de material vegetal per a l'increment de la base genètica dels cultivars d'albergina i implementació de distints programes de millora genètica. Per a això es plantegen i executen diferents programes de millora segons els objectius explícits, incloent la realització d'un programa de millora per a una varietat local amb Indicació Geogràfica Protegida (IGP), i incrementant la diversitat i l'obtenció de nous materials d'elit d'albergina tipus negra per mitjà d'un programa de millora genètica. En definitiva, ens trobem amb un treball que mostra que l'estudi de la diversitat genètica i el desenvolupament i utilització de ferramentes fenómiques per a la caracterització morfològica, a més de l'obtenció de material vegetal nou, és de gran utilitat per al desenvolupament de noves varietats d'albergina, així com per a obtindre informació cientificotècnica d'interés per a altres investigadors i milloradors. També hem constatat que la interacció "investigació pública-privada" permet una col·laboració sinèrgica en l'obtenció de material vegetal i informació d'interés en la millora d'hortícoles. / Hurtado Ricart, M. (2016). Mejora genética de la berenjena (S. melongena L.) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61386 / TESIS

No description available.

Fruits and flowers house microbial communities that are unique from the rest of the plant. While a great deal is known about a handful of symbiotic microbes associated with roots and leaves, the microbial communities of fruits and flowers have received considerably less attention. Fruits are reproductive tissues that house, protect, and facilitate the dispersal of seeds, and thus they are directly tied to plant reproductive success. Fruit and flower microbial communities may, therefore, also impact plant fitness. This dissertation examines how fruit bacterial communities, as determined using the 16S rRNA gene marker, are shaped across spatial and environmental gradients and the role of pollinators in shaping floral bacterial communities among natural populations of Solanum carolinense. There have been limited studies on how spatial distance influences bacterial communities found in and on fruit tissue and the role of pollinators in shaping floral bacterial communities. The first study addresses how bacterial communities in fruit change across similar environmental conditions at fine spatial scales (2 to 450 m). Overall, no differences were found in observed richness or bacterial community composition. Next, the role that generalist pollinators might play in shaping these communities was tested using pollinator exclusion cages. Here we found that generalist pollinators do not play a large role in shaping floral bacterial communities in Solanum carolinense. Comparing bacterial community diversity between caged and uncaged flowers, via PCoA we found no significant clustering of samples. In contrast, significant clustering was detected between flowers and bee pollen baskets. Together these results suggested that environmental factors may be more important in shaping floral bacterial communities. To test this, we sampled 9 populations along a 337 km latitudinal transect and again used the 16S rRNA gene to characterize bacterial communities. We did not identify a significant correlation between distance and bacterial community composition in either the total nor endophytic community in the fruit. Results from these studies suggest that while there is some evidence for environmental effects shaping fruit and flower communities, other factors such as host selection (e.g., secondary compounds in fruit) also likely play an important role in shaping bacterial communities. / Doctor of Philosophy / Fruit and flowers are directly tied to plant reproduction, yet little is known about the bacterial communities associated with these important organs, especially compared to other plant tissues. This dissertation aims to address gaps in our knowledge regarding how spatial distance and pollinators influence fruit and floral bacterial communities. Specifically, how does bacterial community composition (what bacteria taxa are present or not and how abundant the bacterial taxa are) change based on spatial distance. Studies were conducted at both fine (under 0.5 km) and broad (337 km) scales to determine if a pattern was observed between increasing distance and how distinct the bacterial community composition is. There was no significant correlation between spatial distance and bacterial community composition at fine spatial distances, however there were high levels of dissimilarity in the bacterial communities sampled across fine spatial scales. This led to the investigation of pollinators, which directly interact with flowers and may act as a source of bacterial community transmission in the flower and fruit bacterial communities as they move around the landscape. To address the role that pollinators play in shaping bacterial communities in the fruits an exclusion cage study was used to prevent pollinators from interacting with a subset of flowers. Pollen baskets (pollen that was collected by the pollinator and is found on the legs of pollinator) were also collected from pollinators to determine what bacteria may be present on the pollinator. Pollen baskets may also represent what bacteria may have been picked up by the pollinator at the site. It was observed that caged and uncaged samples were similar to one another, which suggest that pollinators were not adding new bacteria nor changing the bacterial composition in the flowers. Yet, the pollen baskets (from the pollinator) were unique from the caged and uncaged floral samples. To further investigate what factors may be at play in shaping the fruit bacterial community the transect was expanded to 337 km to determine if there was an observable relationship between spatial distance and bacterial community composition. The relationship between spatial distance and bacterial community composition was not significant in either the endophytic (internal bacterial community) or the total fruit bacterial community (which represented external and internal bacterial communities). Similar to the fine spatial scale study, there were high levels of dissimilarity in the bacterial community that was observed across sites. Results from these studies may suggest that there are other factors that play a larger role in shaping bacterial communities in fruit and flower tissue. These could include the host plant and the production of secondary compounds, which in some cases can act as antimicrobial compounds, and enhance or inhibit the growth of specific bacterial taxa. Environmental factors such as wind and rainfall may have influenced the bacterial community composition. It is likely that environmental factors play a role in shaping floral and fruit bacterial communities. However, it is still unclear what factors shape fruit and floral bacterial communities are. This study provides the foundation for future studies to address additional factors that shape fruit and flower bacterial communities.

No description available.

Thesis(Ph.D. Agriculture (Soil Science)) -- University of Limpopo, 2020 / Due to high incidents of drought in the semi-arid regions of Limpopo Province, South Africa, the potential feasibility of using treated wastewater for irrigating vegetable crops had been researched and developed under the best practices of Natuurboerdery farming system. The investigation aimed at the development of soil and plant health management strategies for crops irrigated with treated wastewater that could ameliorate the ever-increasing demand for fresh irrigation water in the Province. Seven specific objectives, reduced to three overall objectives under Natuurboedery farming system were intended to investigate (1) the chemical and biological quality of treated wastewater used in irrigation with respect to disposal points and sampling period, (2) the responses of soil physico-chemical properties, heavy metal distribution and biological-soil-health indicators to irrigation with treated wastewater under field conditions and (3) the partitioning of cations and heavy metals in root, stem and leaf tissues of onion, tomato and a selected weed plant irrigated with treated wastewater. In each objective, unless otherwise stated, treatment effects were described at the probability level of 5%. In Objective 1, relative to the borehole water, treated wastewater had lower concentration of Ca, Mg, K, Na, Cl, HCO3 - , SO4 - , Zn, Cr and Pb, with temporal and spatial tendencies in accumulation of certain elements. In contrast, the treated wastewater had higher loads of pathogenic microbes that included bacteria (Escherichia coli, Salmonella spp., Shigella spp. and Vibrio spp.), protozoa (Entamoeba histolytica) and two helminths (Schistosoma mansoni; Ascaris lumbricoides), with temporal and spatial tendencies. In Objective 2, Al and Cr tended to be high in deeper soil layers (60-100 cm), whereas most essential nutrient elements and essential heavy metals (Cu, Fe, Mn, Ni, Zn, As, Cr and Pb) were contained in the upper soil levels (0-40 cm). The upper soil levels were also characterised by having substantial attributes of root health, namely, soil organic carbon, active carbon and potentially mineralisable nitrogen. In Objective 3, root, stem and leaf tissues of horseweed (Conyza canadensis L.), onion (Allium cepa L.) and tomato (Solanum lycopersicum L.) plants had different accumulation abilities for different metals, except for As. Contrary to the expectation, the onion bulb contained less test cations and heavy metals. In conclusion, in terms of chemical component at the time of sampling, as depicted from the water and soil samples, the treated wastewater was suitable for irrigation. However, in terms of pathogenic microbes, the treated wastewater was not suitable for irrigating crops intended for human consumption due to significantly higher loads than the permissible standards. Amongst all observed challenges, the reduction of pathogenic microbes should be given priority since it contravened existing national and international standards for using treated wastewater for in irrigation of crops intended for human consumption. / National Research Foundation (NRF)

Tomato is an important food crop and a model for fleshy fruit development. The process of fruit ripening involves changes in chemical composition and in particular the accumulation of sugars, organic, amino acids and carotenes. The research described in this thesis aimed to identify key regulatory aspects associated with the accumulation of the major acids in tomato fruit by analysis of introgression lines resulting from a cross between a cultivated variety, Solanum lycopersicum, and a wild progenitor species, Solanum pennellii. Line 2-5 showed increases in citrate, malate, aspartate and glutamate in fruit grown under greenhouse conditions. The genetic differences between line 2-5, its overlapping lines, sub-introgression lines and the recurrent parent were used to link the metabolite phenotypes to smaller chromosomal regions. This analysis suggested multiple epistatic loci control fruit metabolite accumulation. Investigation of the biochemical differences between line 2-5 and the recurrent parent revealed that organic and amino acid accumulation did not dependent upon increased TCA cycle capacity. Regulation at the metabolic level was identified for citrate accumulation with changes in cytosolic aconitase in line 2-5. As these metabolites accumulate in the vacuole, tonoplast transport was investigated. Correlation of ATPase-dependent malate influx with altered malate content suggested malate tonoplast transport plays a role in malate accumulation and highlights the importance of vacuolar storage and transport in the regulation of organic and amino acid accumulation.

No description available.

The main purpose of the master thesis project is to investigate the influence of selected serine protease inhibitors (SPI) on the catalytic action of the serine proteases chymotrypsin and trypsin, in a conjugated and non-conjugated state. The inhibitors included for this study were extracted from Solanum tuberosum, i.e.common potato. The purification method included in this study consist of crude extraction by mixer, followed by a salt-out procedure with ammonium sulphate. Further purification steps were cation exchange chromatography and, finally, gel filtration to obtain SPI of high purity. The purified sample was then characterized by SDS-page and kinetic activity measurement of trypsin and chymotrypsin action on synthetic substrate derivate, N-Benzoyl-DL-arginine-4-nitroanilide hydrochloride (BAPA) and N-Succinyl-L-phenylalanine-p-nitroaniline (SFpNA) respectively. The characterization showed inhibitory inactivation of both pancreatic proteases. This would indicate successful extraction of SPI. To investigate inhibitory action in a conjugated state, either enzyme or inhibitor was immobilized onto aluminium oxide membranes. Then two different experimental setups were tested, called experiment 1 and 2. In experiment 1, the inhibitor was immobilized and the interaction was monitored from a retention shift of enzyme flow-through compared to a blank column, using detection at 280 nm of the enzyme. In experiment 2 the enzyme was instead immobilized and a mixture of inhibitor and substrate was circulated with monitoring of the catalytic activity. The main goal was thus to measure the effects on the kinetics in the conjugated state compared to enzyme and inhibitor in the free state. The result from both experiment 1 and 2 did not yield consistent and reliable result so the discussed method should be regarded as preliminary results. The study also includes investigation of inhibitor-enzyme interaction as revealed by molecular mass data to determine complex formation. This part was conducted with static light scattering analysis to determine the stoichiometry for the interaction between pancreas proteases and the inhibitor. Results from light scattering showed promising indication of many-to-one interaction between enzyme and inhibitor, which have been seen by previous studies. It should be considered a preliminary result as complex formation does not exclude aggregation of enzymes or inhibitor in the solution.