ЕФЕКТИ НА ИЗЛИШЪКА НА Cu ВЪРХУ РАСТЕЖА И ФОТОСИНТЕЗАТА НА ЕЧЕМИЧНИ РАСТЕНИЯ. ВРЪЗКА СЪС СКРИНИНГ ТЕСТ ЗА ТОЛЕРАНТНОСТ КЪМ Cu

Twenty-day-old barley (Hordeum vulgare L. cv. Ribeka) plants grown as sand culture were exposed to Cu treatment (0, 10, 15 and 20 mg Cu kg-1 sand) for ten days. The effects of excess Cu on both growth and photosynthetic performance were studied in order to identify the most sensitive probes implicating a further development of screening test for Cu tolerance within barley genotypes. The results obtained indicated that stomata conductance and photosynthetic electron transport linked to PSII+OEC exhibited the highest sensitivity to excess Cu, followed by plant dry weigh accumulation, leaf area formation, net photosynthetic rate, photosynthetic electron transport linked to PSI and PSII-OEC. It was concluded that leaf gas exchange parameters, plant dry weight accumulation and leaf area formation present an effective plant test system for screening for barley genotypes with higher Cu tolerance.Двадесетдневни ечемични (Hordeum vulgare L. сорт Ribeka ) растения, отглеждани като пясъчна култура, са подложени на третиране с Cu (0, 10, 15 and 20 mg Cu kg-1 пясък) в продължение на 10 дни. Проучени са ефектите на излишъка на Cu върху растежа и фотосинтетичната активност на растенията с цел да се определят най-чувствителните индикатори във връзка с понататъшното разработване на тест за скрининг на толерантни към Cu ечемични генотипове. Получените резултати показват, че с най-висока чувствителност към Cu са устичната проводимост, фотосинтетичния електронен транспорт свързан с PSII+OEC, следвани от натрупването на суха маса в растенията, формирането на листната площ, нето скоростта на фотосинтезата, фотосинтетичния електронен транспорт свързан с PSI и PSIIOEC. Заключава се, че листният газообмен, натрупването на суха маса и формирането на листна площ представляват ефективна растителна система за скрининг за ечемични генотипове с по-висока толерантност към Cu

ЕФЕКТИ НА ИЗЛИШЪКА НА Cu ВЪРХУ РАСТЕЖА И ФОТОСИНТЕЗАТА НА ЕЧЕМИЧНИ РАСТЕНИЯ. ВРЪЗКА СЪС СКРИНИНГ ТЕСТ ЗА ТОЛЕРАНТНОСТ КЪМ Cu

Twenty-day-old barley (Hordeum vulgare L. cv. Ribeka) plants grown as sand culture were exposed to Cu treatment (0, 10, 15 and 20 mg Cu kg-1 sand) for ten days. The effects of excess Cu on both growth and photosynthetic performance were studied in order to identify the most sensitive probes implicating a further development of screening test for Cu tolerance within barley genotypes. The results obtained indicated that stomata conductance and photosynthetic electron transport linked to PSII+OEC exhibited the highest sensitivity to excess Cu, followed by plant dry weigh accumulation, leaf area formation, net photosynthetic rate, photosynthetic electron transport linked to PSI and PSII-OEC. It was concluded that leaf gas exchange parameters, plant dry weight accumulation and leaf area formation present an effective plant test system for screening for barley genotypes with higher Cu tolerance.Двадесетдневни ечемични (Hordeum vulgare L. сорт Ribeka ) растения, отглеждани като пясъчна култура, са подложени на третиране с Cu (0, 10, 15 and 20 mg Cu kg-1 пясък) в продължение на 10 дни. Проучени са ефектите на излишъка на Cu върху растежа и фотосинтетичната активност на растенията с цел да се определят най-чувствителните индикатори във връзка с понататъшното разработване на тест за скрининг на толерантни към Cu ечемични генотипове. Получените резултати показват, че с най-висока чувствителност към Cu са устичната проводимост, фотосинтетичния електронен транспорт свързан с PSII+OEC, следвани от натрупването на суха маса в растенията, формирането на листната площ, нето скоростта на фотосинтезата, фотосинтетичния електронен транспорт свързан с PSI и PSIIOEC. Заключава се, че листният газообмен, натрупването на суха маса и формирането на листна площ представляват ефективна растителна система за скрининг за ечемични генотипове с по-висока толерантност към Cu

Mineral Monitorization in Different Tissues of Solanum tuberosum L. during Calcium Biofortification Process

Calcium is one of the 16 essential elements for plants, being required as Ca2+ and being involved in several fundamental processes (namely, in the stability and integrity of the cell wall, the development of plant tissue, cell division, and in stress responses). Moreover, Ca plays an important role in potato production. In this context, this study aimed to monitor the culture development (in situ and using an unmanned aerial vehicle (UAV)) and the mineral content of four essential elements (Ca, P, K, and S) in different organs of Solanum tuberosum L. (roots, stems, leaves, and tubers) during a calcium biofortification process, carried out with two types of solutions (CaCl2 and Ca- EDTA) with two concentrations (12 and 24 kg ha1). The calcium content generally increased in the S. tuberosum L. organs of both varieties and showed, after the last foliar application, an increase in Ca content that varied between 5.7–95.6% and 20.7–33%, for the Picasso and Agria varieties, respectively. The patterns of accumulation in both varieties during the biofortification process were different between the variety and mineral element. Regarding the quality analysis carried out during the development of the tubers, only the Agria variety was suitable for industrial processing after the last foliar applicationinfo:eu-repo/semantics/publishedVersio

The tolerance of eucalyptus globulus to soil contamination with arsenic

UID/FIS/04559/2020The contamination of abandoned mining areas is a problem worldwide that needs urgent attention. Phytoremediation emerges as a successful method to extract different contaminants from the soil. In this context, Eucalyptus globulus plants growing in soils artificial contaminated with arsenic (As) were used to access its phytoremediation capabilities. The effects of As on photosynthetic performance were monitored through different physiological parameters, whereas the uptake and translocation of As and the putative effects on calcium, iron, potassium, and zinc levels on plants were evaluated by X-ray fluorescence analysis. Root system is the major accumulator organ, while the translocation to the above-ground organs is poor. In the end of the experiment, the root biomass of plants treated with 200 μg As mL−1 is 27% and 49.7% lower than equivalent biomass from plants treated with 100 μg As mL−1 and control plants, respectively. Each plant can accumulate 8.19 and 8.91 mg As after a 6-month period, when submitted to 100 As and 200 As, respectively. It seems to exist an antagonistic effect of As on Zn root uptake by E. globulus. In general, the tested concentrations do not influence negatively plant metabolism, indicating that this species is suitable for plantation in contaminated areas.publishersversionpublishe

Elemental composition of algae-based supplements by energy dispersive X-ray fluorescence

The aim of this study is to evaluate the elemental composition of fifteen algae-based supplements commonly sold in the Portuguese market, by energy dispersive X-ray fluorescence. Despite the fact that the majority of Kelp samples were a good source of iodine, the levels observed might well contribute to an excess in the human body, which can cause dysfunction of the thyroid gland. Furthermore, the presence of lead in Sea spaghetti, Arame, Hijiki and Wakame caused a considerable risk to public health vis a vis possible ingestion of a high daily dose. Regarding arsenic, great variability was observed in all the samples with concentrations equal to or above 60 μg/g in the case of Arame, KelpJ and Hijiki. Although algae mainly accumulate organic arsenic, some also contain high levels of its inorganic form, as is commonly pointed out for Hijiki. Thus, regular ingestion of these supplements must also take into account the mentioned facts. There is no doubt that these supplements are also good sources of other nutrients, but the lack of accurate regulations and control should alert consumers to avoid indiscriminate use of these types of productsinfo:eu-repo/semantics/publishedVersio

Transcriptomic leaf profiling reveals differential responses of the two most traded coffee species to elevated [co2]

PTDC/ASP-AGR/31257/2017 UIDB/00239/2020 UIDP/04035/2020 UID/AGR/04129/2020 UIDB/04551/2020 CRA-RED-00053-16As atmospheric [CO2] continues to rise to unprecedented levels, understanding its impact on plants is imperative to improve crop performance and sustainability under future climate conditions. In this context, transcriptional changes promoted by elevated CO2 (eCO2) were studied in genotypes from the two major traded coffee species: the allopolyploid Coffea arabica (Icatu) and its diploid parent, C. canephora (CL153). While Icatu expressed more genes than CL153, a higher number of differentially expressed genes were found in CL153 as a response to eCO2. Although many genes were found to be commonly expressed by the two genotypes under eCO2, unique genes and pathways differed between them, with CL153 showing more enriched GO terms and metabolic pathways than Icatu. Divergent functional categories and significantly enriched pathways were found in these genotypes, which altogether supports contrasting responses to eCO2. A considerable number of genes linked to coffee physiological and biochemical responses were found to be affected by eCO2 with the significant upregulation of photosynthetic, antioxidant, and lipidic genes. This supports the absence of photosynthesis down-regulation and, therefore, the maintenance of increased photosynthetic potential promoted by eCO2 in these coffee genotypes.publishersversionpublishe

Enrichment of Grapes with Zinc-Efficiency of Foliar Fertilization with ZnSO4 and ZnO and Implications on Winemaking

Grapes and wine are widely consumed in the world, yet their mineral content can be influenced by many factors such as the mineral composition of soils, viticulture practices and environmental conditions. In this context, considering the importance of Zn in the human physiology, the enrichment of Moscatel and Castelão grapes (white and red variety, respectively) with this nutrient prompted this study; further assessment of tissue deposition and some implications for wine production. Using two foliar fertilizers (ZnO or ZnSO4, at 150, 450 and 900 g ha1), decreases in net photosynthesis and stomatal conductance occurred in both varieties, suggesting that the physiological threshold of Zn toxicity was reached without visible symptoms. Following foliar spraying with both fertilizers, the content of Zn in leaves of the Castelão and Moscatel varieties showed higher values in all treatments relative to the control. Moreover, in grapes this tendency occurred only in Castelão. Concerning Cu, Fe, Ca, K, S and P, some significant differences also happened in leaves and grapes among treatments. At harvest, the indexes of Zn enrichment in grapes increased between 2.14- and 8.38-fold and between 1.02- and 1.44-fold in Castelão and Moscatel varieties, respectively. Zinc in the dried skin of Castelão only increased with ZnO and ZnSO4 sprayed at 900 g ha1 (ca. 2.71- and 1.5-fold relative to the control, respectively), but in Moscatel a clear accumulation trend could not be found. The dry weight of grapes ranged (in %) between 16 and 23 (but did not vary significantly among treatments of each variety or in each treatment between varieties), and total soluble solids (e.g., mainly soluble sugars and proteins) and color parameters showed some significant variations. Through winemaking, the contents of Zn increased in both varieties (1.34- and 3.57-fold, in Castelão and Moscatel, respectively) and in all treatments, although non-significantly in Castelão. It is concluded that, to increase the contents of Zn in grapes without reaching the threshold of toxicity ZnO or ZnSO4 can be used for foliar spraying of Castelão and Moscatel varieties until 900 g ha1 and that winemaking augments the level of this nutrientinfo:eu-repo/semantics/publishedVersio

Zinc Biofortification in Vitis vinifera: Implications for Quality and Wine Production

Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO4 at concentrations of 150, 450, and 900 g ha1 during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO4-450 g ha1). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO4, without significantly affecting the physicochemical characteristics of grapesinfo:eu-repo/semantics/publishedVersio

Alterações climáticas nas Bacias do Sado e Tejo e seus efeitos na produtividade de arroz

SFRH/BD/121892/2016A agricultura é fortemente dependente das condições meteorológicas. As alterações climáticas podem modificar padrões de precipitação levando à ocorrência de fenómenos extremos como secas e cheias. As culturas irrigadas, como é o caso do arroz, podem ser afectadas por escassez de água devido à ocorrência de extensos períodos de secas ou até mesmo cheias. Em Portugal, importantes áreas de produção orizícola estão localizadas nas bacias do Tejo e do Sado. A análise da precipitação de estações meteorológicas desde 1931/32 até 2016/17 na bacia do Sado e 1909/10 até 2016/17 na bacia do Tejo evidenciam variações similares na distribuição anual da precipitação. Desde o início dos registos até 1949/50 foi observado um período seco, seguido de um húmido desde 1950/51 até 1994/95. Um período instável e seco foi observado desde 1995/96 até à actualidade com um decréscimo no padrão de precipitação e uma maior oscilação relativamente à tendência que se vinha verificando. Em contrapartida, em períodos húmidos, o regime de precipitações é mais regular e com menos episódios muito húmidos e muito secos. Para avaliar os efeitos do regime de distribuição anual da precipitação foi estudada a produtividade de dois canteiros de arroz no intervalo de 10 e 11 anos, não tendo sido observada qualquer correlação com a precipitação porque esta depende de muitos outros factores, tais como as técnicas agrícolas utilizadas ou variedades cultivadas.publishersversionpublishe

Effect of high [CO2] and temperature on the photosynthetic enzymes and electron transport of Coffea Arabica L..

It is expected that future climate changes and global warming conditions will limit the coffee crop yields. However, the real effects of enhanced air [CO2] and temperature on this plant remain completely unknown. Therefore, this work studied the impact of such environmental changes on the photosynthetic machinery of Coffea arabica L. cv. Icatu. Plants were grown for 1 year under controlled conditions (temperature, RH, irradiance, photoperiod), at 380 or 700 ?L CO2 L-1 air, without nutrient, water and root space limitations, and then subjected to temperature increase (0.5ºC/day) to 42/34ºC. Thylakoid electron transport involving PSI and II, and enzyme activities (RuBisCO and RuB5PK) were assessed at 25/20ºC, 31/25ºC, 37/30ºC and 42/34ºC.The results showed a marginal impact until 37 ºC irrespective of [CO2] conditions, configuring a clear tolerance to supra-optimal temperatures. Also, a higher metabolic performance was observed in the plants under high [CO2]. Only at 42 ºC the tolerance limit was exceeded, as shown by significant impacts in all parameters, particularly in enzymes, but under elevated [CO2] a better performance was preserved regarding the photosystems functioning. Our findings showed that the elevated [CO2] allowed maintenance of higher metabolic activity and seemed to some extent mitigate the heat impact at the photosystems level, what is quite relevant in a context of predict global warming scenarios. This work was supported by Portuguese funds from Fundação para a Ciência e a Tecnologia, through the project PTDC/AGR-PRO/3386/2012