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Background and Aims: Wet processed alfalfa-based products can provide high-quality concentrated protein, also contain nutrients and phytochemicals. Agronomic fortification can increase selenium (Se) incorporation into green biomass. For this reason, the aim was to investigate how different forms of Se are incorporated into the green biomass of multiple-harvest alfalfa and how they affect the chemical quality of the processed product candidates. Methods: In this research, alfalfa was enriched with three forms of selenium at different concentrations [selenate (Se(VI)); selenite (Se(IV)); and red elemental Se (Se0)]. The fortified green biomass was fractionated into leaf protein concentrate (LPC), fiber and phytoserum, and changes in selenium content and speciation, protein and phytochemical composition were determined. Results: Total Se content in alfalfa fractions drastically reduced within the four consecutive harvests, particularly for Se(VI) and Se(IV) forms, and significantly varied according to the Se treatments. Selenomethionine (SeMet) was the predominant organic Se species in LPC (35.7–246.0 µg g −1 DW) and fiber (9.0- 47.7 µg g −1 DW) fractions. Se-fortification induced considerable changes in the crude protein of LPC, which varied between 29—45 (m/m)%. Phytochemical composition markedly varied among Se-treatments. Besides several flavonoids, aglycones and glycosyl derivatives, apigenin glucuronide, and apigenin were the most abundant with a concentration up to 170.85 µg g −1 DW. Medicagenic acid concentration was below 1.86 µg g −1 DW in LPC. Conclusions: Se-enhanced alfalfa green biomass could provide functional products, such as LPC, for human and animal consumption with enhanced nutritional value, including Se, protein, and phytochemical contents. [ABSTRACT FROM AUTHOR]

The present study evaluates the green biomass of Jerusalem artichoke (JA) as an alternative green protein. A leaf protein concentrate (LPC) was prepared from leafy shoots using biotechnological methods. Seven clones were compared to assess the importance of the genetic basis of JA, and alfalfa served as the control. The LPC content of JA was an average 39 g kg−1 of fresh biomass, while that of alfalfa was 32 g kg−1. The JA can produce up to 936 kg of protein ha−1 year−1 without fertilization under rainfed conditions. The crude protein content of the LPC varied from 24.2 to 31.4 m/m%, depending on clones and harvesting time, which was comparable to that of alfalfa LPC (~ 32.3%). The amino acid profile of the LPC of JA, particularly of the essential amino acids, was similar to alfalfa and soybean. In addition, our results confirmed that the polyunsaturated fatty acid (PUFA) content varied between 64 and 68% in the LPC fraction, regardless of the clone that was used, with linoleic acid and linolenic acid being the predominant PUFAs. In addition, unlike alfalfa, the content of arachidonic acid was 0.5% in the JA LPC. The tuber yield was significantly reduced because of the repeated harvesting of the shoot parts; however, the tubers obtained were sufficient to regenerate the plantation in the subsequent year, thus ensuring the renewable ability and sustainability of the green biomass of JA. [ABSTRACT FROM AUTHOR]

The response of giant reed (Arundo donax L.) to selenium (Se), added as selenate, was studied. The development, stress response, uptake, translocation, and accumulation of Se were documented in three giant reed ecotypes STM (Hungary), BL (USA), and ESP (Spain), representing different climatic zones. Plantlets regenerated from sterile tissue cultures were grown under greenhouse conditions in sand supplemented with 0, 2.5, 5, and 10 mg Se kg−1 added as sodium selenate. Total Se content was measured in different plant parts using hydride generation atomic fluorescence spectroscopy. All plants developed normally in the 0-5.0 mg Se kg−1 concentration range regardless of ecotype, but no growth occurred at 10.0 mg Se kg−1. There were no signs of chlorosis or necrosis, and the photosynthetic machinery was not affected as evidenced by no marked differences in the structure of thylakoid membranes. There was no change in the maximum quantum yield of photosystem II (Fv/Fm ratio) in the three ecotypes under Se stress, except for a significant negative effect in the ESP ecotype in the 5.0 mg Se kg−1 treatment. Glutathione peroxidase (GPx) activity increased as the Se concentration increased in the growth medium. GPx activity was higher in the shoot system than the root system in all Se treatments. All ecotypes showed great capacity of take up, translocate and accumulate selenium in their stem and leaf. Relative Se accumulation is best described as leaf ˃˃ stem ˃ root. The ESP ecotype accumulated 1783 μg g−1 in leaf, followed by BL with 1769 μg g−1, and STM with 1606 μg g−1 in the 5.0 mg Se kg−1 treatment. All ecotypes showed high values of translocation and bioaccumulation factors, particularly the ESP ecotype (10.1 and 689, respectively, at the highest tolerated Se supplementation level). Based on these findings, Arundo donax has been identified as the first monocot hyperaccumulator of selenium, because Se concentration in the leaves of all three ecotypes, and also in the stem of the ESP ecotype, is higher than 0.1% (dry weight basis) under the conditions tested. Tolerance up to 5.0 mg Se kg−1 and the Se hyperaccumulation capacity make giant reed a promising tool for Se phytoremediation. [ABSTRACT FROM AUTHOR]

Aims: Distribution of selenium (Se) in soils around the world is not identical and many soils are classified as Se-poor soils. Therefore, Se fortification of crops grown on these soils is crucial, where increasing Se intake by human - below toxic threshold - is vital for better health. The recent work aims to investigate the possible use of Se to alleviate the detrimental effects of soil salinity on lettuce and enhance its growth, yield quality and Se enrichment. Methods: Field experiments were conducted during two successive seasons (2016 and 2017) in salt-affected soil (EC 4.49 dS m, pH 8.65) using four concentrations of Se (0, 50, 75 and 100 ppm) by three different application methods. Antioxidant capacity, ion leakage, Se content in plant and soil, yield and vegetative parameters of lettuce were measured. Results: The results showed that Se addition mitigated the detrimental effect of salinity on lettuce growth and its development. Se application (100 ppm) increased also the head weight, leaf area, leaves dry weight and chlorophyll content by 46.4, 66.4, 61.8 and 31.5%, respectively, compared to control plants. Likewise, catalase (CAT) and ascorbate peroxidase (APX) activities increased by 108.8 and 123.6%, respectively, as a result for using 100 ppm of Se. Otherwise, Se (100 ppm) reduced the electrolyte leakage from lettuce leaves by 68.4% against control. The positive effect of Se (100 ppm) on lettuce under salinity was fully verified with data of total yield which increased by 42.1% over control. Foliar application increased Se content in lettuce without exceeding the toxic level and residual Se in soil was the lowest among other treatments. Conclusion: The present work reports that in salt-affected soils spraying lettuce with Se (100 ppm) improves its growth, antioxidant capacity, Se fortification and yield quality. [ABSTRACT FROM AUTHOR]

During the past 10 years, exploiting engineered nanoparticles in agricultural sector has been rapidly increased. Nanoparticles are used to increase the productivity of different crops particularly under biotic and abiotic stresses. This study aims to test the ability of nanosilica (NS) to ameliorate the detrimental impact of Na with different concentrations on the seed germination and the growth of common bean seedlings. Five doses of Na have been prepared from NaCl, i.e., 1000, 2000, 3000, 4000, and 5000 mg L, and distilled water was applied as a control. Seeds and seedlings were treated with three different NS concentrations (100, 200, and 300 mg L). The results proved that Na concentrations had detrimental effects on all measured parameters. However, treating seeds and seedlings with NS improved their growth and resulted in higher values for all measurements. For instance, the addition of 300 mg L NS leads to an increase of the final germination percentage, vigor index, and germination speed for seeds irrigated with 5000 mg Na L by 19.7, 80.7, and 22.6%, respectively. Although common bean seedlings could not grow at the highest level of Na, fortification seedlings with NS helped them to grow well under 5000 mg L of Na. An increase of 11.1 and 23.1% has been measured for shoot and root lengths after treating seedlings with 300 mg L NS under irrigation with 5000 mg Na L solutions, and also at the same treatment, shoot and root dry masses are enhanced by 110.9 and 328.0%, respectively. These results proved the importance of using NS to relieve the detrimental effects of Na-derived salinity. This finding could be reinforced by low Na content which was measured in plant tissues after treating seedlings with 300 mg L of NS. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a naturally occurring metalloid element which occurs nearly in all environments. Se is considered as a finite and non-renewable resource on the Earth. The common sources of Se in earth's crust occur in association with sulfide minerals such as metal selenide, whereas it is rarely found in elemental form (Se). While there is no evidence of Se need for higher plants, several reports show that when Se added at low concentrations, Se exerts beneficial effects on plant growth. Se may act as quasi-essential micronutrient through altering different physiological and biochemical traits. Thus, plants vary considerably in their physiological and biochemical response to Se. This review focusses on the physiological importance of Se forms as well as different Se fertilizers for higher plants, especially plant growth, uptake, transport, and metabolism. [ABSTRACT FROM AUTHOR]

Global climate changes can alter the suitable geographical range of different crops, leading to possible changes in cropping pattern and its extent in some regions. For example, temperature changes can interact very closely with changes in availability of water and soil nutrients, and crop growth cycle. The consequences of the biophysical impacts of climate changes will be influenced by the human responses to these impacts. There is a strong link between soils and human health, and these soils per se are controlled by climate changes. The human health is very close to both selenium (Se) element and climate changes. It is estimated that about 37-40 % of the total Se emissions to the atmosphere are due to the anthropogenic activities. Those anthropogenic activities, which are sources of Se, include coal and oil combustion, mining activities, the utilization of rock phosphates as a fertilizer and the application of sewage sludge to agricultural land. It was thought that selenium was a toxicant for a long time due to inadequate analytical data. In the recent past, Se has become very important in environmental biogeochemistry because of its influence on human health. Although Se is an essential nutrient for animals and humans, it is also toxic at high doses. Furthermore, the range between Se deficiency, lower than 40 μg day, and toxicity, higher than 400 μg day, is narrow. Selenium deficiency has been linked to several human diseases including multiple sclerosis, muscular dystrophy, heart disease, immune system, cancer and reproductive disorders. On the other hand, Se toxicity can lead to hair and nail loss and disruption of the nervous and digestive systems in animals and humans. Despite the obvious connections between Se element and human health under climate changes, there has not been a great amount of research done in this area. So, more and more studies should be carried out to enhance and protect human health. Therefore, this article reviews the biological and economic dimensions of the effects of Se element on human health under climate changes. [ABSTRACT FROM AUTHOR]