Browsing by Author "Vasconcelos, Marta"
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- Advanced nanofertilizers for iron uptake in calcareous alkaline soilsPublication . Pinho, Simão; Santos, Carla; Rangel, Maria; Vasconcelos, Marta; Reis, Salette; Moniz, Tânia
- Assessing the nutritional and technological quality of legumesPublication . Perez, Jazmín Osorio; Santos, Carla; Pinto, Elisabete; Vasconcelos, Marta
- Avaliação do contributo da expressão genética na tolerância à desidratação em Rosa × hybrida cultivada em humidade relativa elevadaPublication . Carvalho, D. R. A.; Vasconcelos, Marta; Koning-Boucoiran, C. F. S.; Krens, F. A.; Heuvelink, E; Carvalho, S. M. P.Cultivation of cut flowers with high postharvest longevity is of extreme importance for consumer’s satisfaction. A negative water balance is indicated as the most important factor reducing longevity. This problem is more severe in plants grown at high relative air humidity (i.e. RH > 85%) mainly due to a poor stomatal functioning associated to lower abscisic acid (ABA) concentrations, leading to higher water loss. In this paper it is analysed whether a sensitive cut rose cultivar to high RH show different gene expression related to ABA metabolism when grown at moderate (60%) or high (90%) RH. RNA was isolated from fully developed leaves, harvested 180 min after the beginning of the dark period (stomatal closing stimulus) and the relative gene expression was evaluated in genes involved in: biosynthesis (AAO3 and NCED1), oxidation (CYP707A1 and CYP707A3) and conjugation (UGT75B2) of ABA. The stomatal conductivity in the dark period was 5.6-fold higher in intact plants developed at high RH compared to moderate RH-grown plants, showing the reduced closure capacity of the stomata during darkness. After 4 h of leaflet desiccation, leaflets grown at high RH showed a relative water content (RWC) 69% lower than the moderate RH-grown leaflets, validating the sensitivity of K023 to high RH during growth. At last, from the five studied genes only the expression of CYP707A3 was significantly reduced by high RH, without significant differences found in the other genes. In conclusion, the sensitivity of the genotype K023 to high RH cannot be explained by the expression of the genes evaluated in this study, using leaves harvested 180 min after the beginning of the dark period (closing stimulus). We expect that after transferring the plants to the postharvest conditions, inducing water stress, a more contrasting gene expression among RH levels will appear.
- Avaliação do contributo da expressão genética na tolerância à desidratação em Rosa × hybrida cultivada em humidade relativa elevadaPublication . Carvalho, D. R. A.; Vasconcelos, Marta; Koning-Boucoiran, C. F. S.; Krens, F. A.; Heuvelink, E; Carvalho, S. M. P.
- Benefits of pulse consumption on metabolism and health: a systematic review of randomized controlled trialsPublication . Ferreira, Helena; Vasconcelos, Marta; Gil, Ana M.; Pinto, ElisabetePulses are nutrient-dense foods that have for a long time been empirically known to have beneficial effects in human health. In the last decade, several studies have gathered evidence of the metabolic benefits of pulse intake. However, it remains unclear at what amounts these effects may be attained. This study aimed to systematically review the scientific outputs of the last two decades regarding health benefits of pulse consumption and the amounts necessary for positive outcomes to be achieved. A PubMed search including keywords [(“dietary pulses”, “pulses”, “legumes”, “grain legumes”, “bean”, “chickpea”, “pea”, “lentil”, “cowpea”, “faba bean”, “lupin”) and (“inflammation”, “inflammatory markers”, “C-reactive protein”, “blood lipids”, “cholesterol”, “cardiometabolic health”, “cardiovascular disease”, “diabetes”, “glycaemia”, “insulin”, “HOMA-IR”, “body weight”, “body fat”, “obesity”, “overweight”, “metabolome”, “metabolic profile”, “metabolomics”, “biomarkers”, “microbiome”, “microbiota”, “gut”)] was performed. Only English written papers referring to human dietary interventions, longer than one day, focusing on whole pulses intake, were included. Most of the twenty eligible publications reported improvements in blood lipid profile, blood pressure, inflammation biomarkers, as well as, in body composition, resulting from pulse daily amounts of 150 g (minimum-maximum: 54-360 g/day; cooked). Concerns regarding methodological approaches are evident and the biochemical mechanisms underlying such effects require further investigation.
- Chitosan as a biocontrol agent against the pinewood nematode (Bursaphelenchus xylophilus)Publication . Silva, M. Nunes da; Cardoso, A. R.; Ferreira, D.; Brito, M.; Pintado, M. E.; Vasconcelos, MartaThe pine wilt disease (PWD) is caused by Bursaphelenchus xylophilus and poses great environmental and economic challenges. Thus, the development of sustainable techniques for the control of this epidemic disease is of major importance. This work aimed at evaluating if the application of different molecular weight (MW) chitosans as a soil amendment could be used to control the PWD in maritime pine (Pinus pinaster, very susceptible to the disease) and stone pine (Pinus pinea, less susceptible). At the end of the experimental period (24 days after inoculation), P. pinaster and P. pinea untreated plants presented ca. 3825 100 and 70, 47 nematodes, respectively. In P. pinaster, the high-MW chitosan prompted the most drastic results, inducing a 21.9-fold reduction in nematodes numbers, whereas in P. pinea, the most effective was the low MW chitosan, which reduced nematodes numbers up to 7-fold, compared with untreated plants. P. pinea seems to be highly resistant to the disease, presenting nematode numbers up to 54.6-fold lower than P. pinaster and less severe chlorophyll loss (ca. 2-fold).
- Combined effect of elevated CO2 and Fe deficiency on common bean metabolism and mineral profilePublication . Deuchande, Teresa; Vasconcelos, MartaAims: Elevated atmospheric CO2 (eCO2) and restricted iron (Fe) supply are known to impact plant growth and nutritional quality of food crops. However, studies aimed at understanding how eCO2 will interact with Fe deficiency are scarce. Changes in the nutritional status of the common bean (Phaseolus vulgaris L.) may significantly impact the nutritional status of populations that rely heavily on this crop. Methods: To understand the combined effects of eCO2 and Fe deficiency on mechanisms relevant to plant nutrient uptake and accumulation, common bean plants were grown under Fe sufficiency (Fe+, 20 mM Fe-EDDHA) and Fe deficiency (Fe-, 0 mM Fe-EDDHA) combined with eCO2 (800 ppm) or ambient CO2 (aCO2, 400 ppm) in hydroponics until maturity. Results: Elevated CO2, besides stimulating photosynthesis and stomatal closure, highly affected plant Fe metabolism: stimulated root ferric chelate reductase (FCR) activity by 6-fold and downregulated the expression of root FRO1 and IRT1 expressions by about 4-fold. In leaves, citrate and oxalate increased, but ferritin expression decreased by 9-fold. Such changes may have determined the differences on mineral accumulation patterns particularly the lower levels of Fe in roots (62%), leaves (38%) and seeds (50%). The combination of Fe deficiency and eCO2 doubled the effect of a single factor on FCR up-regulation, balanced the internal pH of Fe deficient plants, and resulted in the lowest Fe accumulation in all plant parts. Conclusions: These results suggest that eCO2 directly affects the Fe uptake mechanism of common bean plants, decreasing plant Fe content.
- Como produzir alimentos transgénicos com maior valor nutritivoPublication . Vasconcelos, Marta
- Como produzir alimentos transgénicos com maior valor nutritivoPublication . Vasconcelos, Marta
- Como produzir alimentos transgénicos com maior valor nutritivo?Publication . Vasconcelos, Marta