ITQB:PGR-PhD Theses
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- How diel-regulated responses are modulated by environmental cues in rice:Publication . Andrade, Luís Carlos Lopes"Rice is the third largest food crop and is a staple for more than half of the world’s population. Considering the importance of rice in the diet and culture of so many people, it is paramount to secure the future of rice cultivation by developing varieties capable of growing and achieving high yields in diverse geographical regions under different climates. Major factors limiting the location and duration of rice production are temperature and photoperiod (daytime duration).(...)"
- Investigate the role of the transcription factor FBH1 mediating the Circadian Clock regulation of C4 photosynthesisPublication . Gonçalves, Ivan Sandro Batista Guerreiro" Engineering C4 photosynthesis into rice, a C3 plant, is predicted to increase yield by 50%. We must understand how C4 photosynthesis is regulated, in particular how the C3 transcriptional machinery regulates C4 photosynthetic genes. In C4 plants, Phosphoenolpyruvate Carboxylase (PEPC) is crucial for the high assimilation of CO2 by Rubisco. Identification and characterization of C3 transcription factors (TF) that regulate C4PEPC expression, is an important step for installing a functional C4 photosynthetic pathway in rice. OsFBH1 has been shown to regulate two C4PEPC promoters, making it a very interesting TF to study. In arabidopsis, FBH1 regulates and is regulated by CCA1, a key component of the circadian oscillator. If this interaction is conserved in rice, OsFBH1 might be the link between circadian clock and C4 photosynthesis. In this study, we intended to investigate the reciprocal regulation of OsFBH1 and OsCCA1. Performing a time course experiment using OsCCA1 knockout lines, we observed an impairment in the expression of OsFBH1, demonstrating its regulation by OsCCA1.(...)"
- Unveiling the Setaria viridis PEPC1 promoter regulatory network in RicePublication . Carvalho, PedroMore people to feed, reduced arable area, and more extreme environ mental conditions creates constraints never seen before in agricultural systems. In order to feed the increasing world population, plant yield improvement needs to be achieved. Photosynthesis, a process that is tightly related to plant yield, is limited by the efficiency of Rubisco. This enzyme, responsible for the carbon fixation that ulti mately leads to the production of photoassimilates, is limited by its dual role, working as a carboxylase and an oxygenase. When it works as an oxygenase, it produces 2-phosphoglycolate, which needs to be recycled through a process called photorespiration, leading to CO2 and energy losses. To overcome photorespiration, some plants have evolved carbon concentrating mechanisms that allow the increase of CO2 concentration around Rubisco, thus reducing its oxygenase activity. One such mechanisms is C4 photosynthesis. In most C4 plants, two carboxylation reactions take place in two different cell types, mesophyll and bundle sheath.
- Transcriptional regulatory mechanisms controlling key genes involved in C4 photosynthesis in maizePublication . Borba, Ana Rita Andrade"Global food security is under threat due to global warming and population growth. This alarming scenario could however be mitigated by increasing crop yield potential through photosynthesis improvement. Although plants performing the C3-type of photosynthesis (e.g. rice and wheat) are the most abundant and well-characterised in terms of their biology, biochemistry, and physiology, C4 plants (e.g. maize and sugarcane) are generally more efficient than C3 in capturing carbon dioxide (CO2) and producing biomass in high-temperature and drought conditions.(...)"
- Understanding the transcriptional network regulating ZmPEPC1 gene expressionPublication . Gorska, Alicja MartaHuman population is growing fast and this will lead to an extremely high demand for food, feed, and energy. Therefore, to guarantee future food security, we definitely need to improve crop yield. Given that C4 photosynthesis is much more efficient than C3 photosynthesis, and therefore correlated with higher plant productivity, one strategy to improve crop yield is to transfer C4 photosynthetic traits into C3 crops, such as rice. However, this strategy requires a deep understanding of the transcriptional C4 gene regulation, so far poorly understood. In most C4 plants, the C4 metabolism is associated with a specific leaf anatomy (Kranz anatomy) and compartmentalization of the photosynthetic reactions into two leaf cell types, mesophyll (M) and bundle sheath (BS), which is based on a tightly regulated cell-specific gene expression.(...)
- The rice Phytochrome-Interacting Factor 14 – a regulator of cold, jasmonic acid and light related genesPublication . Cordeiro, André Miguel Henriques"Rice (Oryza sativa L.) is the staple food for more than half of the world population, and it is very sensitive to adverse environmental conditions. It is also very important for Portugal, which is the biggest rice consumer in Europe with a consumption of 14.8 kg/capita/year. Nowadays, due to climate changes and competition with other crops, the arable land for rice is decreasing. To overcome this and feed the growing world population, keeping the prices affordable, it is estimated that rice yield needs to grow 1.0–1.2% annually beyond 2020. Therefore, it is urgent to develop rice with higher grain yield and more resistant to adverse environmental conditions.(...)"
- Regulation of the OsNHX1 Gene Expression: Identification and Characterization of Novel Transcription FactorsPublication . Almeida, Diego MeloFor half of the world´s population, rice is life. This cereal crop is considered an important staple food worldwide, and more than three billion people count on it for 50-80% of their daily calorie intake. Soil salinity is a major environmental constraint to crop production, resulting in considerable yield losses around the globe every year. According to the Food and Agriculture Organization (FAO), in 2008 over 6% of world's total land and over 20% of irrigated land were affected by high levels of salt. Irrigated land is only 15% of cultivated land, but it produces one third of the world’s food, raising awareness about salinity as a serious problem for crop productivity. Rice like as most crops is very sensitive to salt, showing salt stress symptoms and reduced yield at relatively low soil salinity levels (≈ 40 mM NaCl). Among the agronomically important cereals, rice shows the highest sensitivity to salt. However, some degree of genotype tolerance for salt stress is available in rice germplasm. To cope with salt stress conditions, plants evolved several and diverse response mechanisms. One of these mechanisms is tissue tolerance, in which high salt concentration is found in leaves but is compartmentalized, especially in the vacuole, reducing the deleterious effect of Na+ in the cytosol and driving water uptake to cells. Cation/H+ antiporters mediate the transport of Na+ into the vacuole.(...)