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2.
Plants (Basel) ; 11(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36297800

RESUMO

Aristotelia chilensis is a plant whose fruit is considered a powerful natural antioxidant. During the last years, some investigations of the fruit have been carried out, finding antioxidant properties in the juice or the phenolic fraction. The antioxidant properties of the plant are useful in the inhibition of enzymes related to diabetes such as pancreatic aldose reductase and alpha-amylase. Because many synthetic drugs used today have limitations and potentially harmful side effects, the use of naturally occurring compounds, such as flavonoids, is clinically attractive. In this study, the characterization of aqueous extracts of fruits and in vitro plants of A. chilensis was carried out based on their content of anthocyanins and total phenols, the antioxidant capacity by the antiradical activity 2,2-diphenyl-1-picrilhydrazil (DPPH), and the profile of anthocyanins and other phenolic compounds by liquid chromatography coupled to mass spectrometry (LC-MS/MS). Subsequently, the effect of these extracts on the inhibition of bovine aldose reductase and pancreatic alpha-amylase enzymes was determined. According to our results, extracts of fruits and in vitro plants of A. chilensis achieved inhibition of the bovine aldose reductase enzyme of 85.54 ± 1.86% and 75.67 ± 1.21%, respectively. Likewise, the percentage of inhibition of the pancreatic alpha-amylase enzyme for fruit extracts was 29.64 ± 0.63%, while for in vitro plant extracts it was 47.66 ± 0.66%. The antioxidant and enzymatic inhibition activity of the extracts were related to the content of anthocyanins, such as delphinidin and cyanidin glycosides as well as the phenols derived from quercetin, myricetin, and kaempferol. The results obtained allow us to suggest that the in vitro culture of plants of A. chilensis represents a viable biotechnological alternative to obtain phenolic compounds for the inhibition of aldose reductase and pancreatic alpha-amylase enzymes.

3.
Plants (Basel) ; 11(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35161399

RESUMO

In this work, we have investigated the accumulation of ryanoids in different plant parts (leaves, stems and roots) of aeroponically grown Persea indica cloned trees (one-year-old cloned individuals) and a selected mature, wild tree. We tested the insect antifeedant (against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi) and nematicidal (against Meloidogyne javanica) effects of ethanolic extracts from these different plant parts. The HPLC-MS analysis of P. indica extracts showed that mature tree (wild) leaves had two times more chemical diversity than stems. Aeroponic plants showed fewer differences in chemical diversity between leaves and stems, with the lowest diversity found in the roots. Ryanodane epiryanodol (1) was present in all the plant parts, with the mature stems (wild) containing the highest amount. The aeroponic stems also accumulated ryanoids including 1, cinnzeylanol (2) and cinnzeylanone (4). The insect Spodoptera littoralis was strongly affected by the stem extracts, while leaf extracts were moderately active. Based on predicted vs. real antifeedant values, we concluded that the ryanoid content (1 or a combination of 2, 4 and 1) explained the antifeedant effects of the stem extracts, while additional components contributed to the activity of the leaf extracts. Therefore, careful individual selection of P. indica seedlings should be carried out prior to proceeding with aeroponic cultivation in order to obtain ryanodane-rich stem or leaf extracts with strong antifeedant effects on S. littoralis.

4.
Front Plant Sci ; 12: 635491, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732277

RESUMO

Deschampsia antarctica Desv, is the most successful colonizing species of a cold continent. In recent years due to climate change, the frequency of heat waves has increased in Antarctica, registering anomalous high temperatures during the summer of 2020. However, the populations of D. antarctica are responding positively to these events, increasing in number and size throughout the Antarctic Peninsula. In this work, the physiological and biochemical responses of D. antarctica plants grown in vitro (15 ± 1°C) and plants subjected to two heat shock treatments (23 and 35°C) were evaluated. The results obtained show that D. antarctica grown in vitro is capable of tolerating heat shock treatments; without showing visible damage to its morphology, or changes in its oxidative state and photosynthetic performance. These tolerance responses are primarily mediated by the efficient role of enzymatic and non-enzymatic antioxidant systems that maintain redox balance at higher temperatures. It is postulated that these mechanisms also operate in plants under natural conditions when exposed to environmental stresses.

5.
Sci Total Environ ; 751: 141623, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32877793

RESUMO

There is a growing interest in the use of adsorbent nanoparticles to mitigate the toxic effects of pollutants in natural matrices. However, due to their small size, nanoparticles have the potential to transport and disseminate contaminants adsorbed on their surfaces into environmental compartments with greater risk to human, animal, or plant health. This potential consequence of nanoparticle application remains largely unstudied. Here, we studied the application of three adsorbents, including zeolite (Z, micrometric size), nanomagnetite (Mt), and a nanomagnetite-zeolite composite (MtZ) intended to mediate arsenic toxicity in hydroponic tomato cultures. Adsorption studies showed an arsenate adsorption sequence of MtZ (6.2 mg g-1) ≥ Mt (4.7 mg g-1) â‰« Z (0.3 mg g-1). Tomatoes grown under the Mt condition demonstrated the lowest growth rate (4.2 cm), corresponding to a 45% decrease compared to the control (7.6 cm), as well as the highest oxidative stress level (0.024 µmol g-1) as indicated by malondialdehyde (MDA) concentration, almost twice the control (0.014 µg g-1). Tomatoes grown under MtZ conditions showed a 22% decreased growth (5.9 cm) but MDA levels (0.012 µmol g-1) were comparable to the control. Together, these results suggest that Mt at the nanometric size could obstruct channels in the plant and prevent absorption of water and nutrients. Anchoring nanomaterials in larger composites of micrometer size presents a promising alternative that would retain their super-adsorbent properties while avoiding toxicity due to nanometric size.


Assuntos
Arsênio , Solanum lycopersicum , Poluentes Químicos da Água , Purificação da Água , Zeolitas , Adsorção , Arsênio/análise , Humanos , Concentração de Íons de Hidrogênio , Hidroponia , Cinética , Poluentes Químicos da Água/análise
6.
Front Microbiol ; 11: 1312, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612595

RESUMO

Xanthophyllomyces dendrorhous synthesizes astaxanthin, a carotenoid used in aquaculture. Astaxanthin is synthesized from metabolites of the mevalonate pathway, which are also precursors for sterols biosynthesis. The interruption of the CYP61 gene, which is involved in the synthesis of ergosterol (mutant CBS.cyp61 -), resulted in a phenotype that overproduces carotenoids due to the activation of the SREBP pathway. In this work, we constructed other mutants of ergosterol biosynthesis in this yeast to evaluate whether they have the same phenotype as mutant CBS.cyp61 -. By bioinformatic analysis, the ERG3 and ERG4 genes of X. dendrorhous were identified, and each gene was deleted in the wild-type strain. Mutants CBS.Δerg3 and CBS.Δerg4 did not produce ergosterol; CBS.Δerg3 primarily accumulated episterol, and CBS.Δerg4 primarily accumulated ergosta-5,7,22,24(28)-tetraenol. The transcription levels of the HMGS gene of the mevalonate pathway were evaluated by RT-qPCR, which showed a slight increase in CBS.Δerg4, but the transcription levels were still 10-fold lower than in strain CBS.cyp61 -. Both CBS.Δerg3 and CBS.Δerg4 did not overproduce carotenoids, even though they do not produce ergosterol. Thus, the results of this study indicate that the absence of ergosterol does not activate the SREBP pathway in X. dendrorhous, but rather it depends on other alterations in sterol composition.

7.
Glob Chang Biol ; 26(6): 3178-3180, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32227664

RESUMO

This summer, a heatwave across Antarctica saw temperatures soar above average. Temperatures above zero are especially significant because they accelerate ice melt. Casey Station had its highest temperature ever, reaching a maximum of 9.2°C and minimum of 2.5°C. The highest temperature in Antarctica was 20.75°C on 9 February. Here we discuss the biological implications of such extreme events.


Assuntos
Temperatura Alta , Regiões Antárticas , Congelamento , Estações do Ano , Temperatura
8.
Biol Res ; 52(1): 46, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434576

RESUMO

BACKGROUND: One of the most extreme environments on our planet is the Maritime Antarctic territory, due to its low-water availability, which restricts the development of plants. Sanionia uncinata Hedw. (Amblystegiaceae), the main colonizer of the Maritime Antarctic, has effective mechanisms to tolerate this environment. It has been described that the tolerance to desiccation is mediated by the hormone abscisic acid (ABA), antioxidants systems, accumulation of compatible solutes and proteins of the late embryogenesis abundant (LEA). However, to date, these mechanisms have not been described in S. uncinata. Therefore, in this work, we postulate that the tolerance to desiccation in the Antarctic moss S. uncinata is mediated by the accumulation of ABA, the osmolytes proline and glycine betaine, and dehydrins (an LEA class 11 proteins). To demonstrate our hypothesis, S. uncinata was subjected to desiccation for 24 h (loss in 95% of water content), and the effects on its physiological, photosynthetic, antioxidant and biochemical parameters were determined. RESULTS: Our results showed an accumulation of ABA in response to water loss, and the activation of protective responses that involves an increment in levels of proline and glycine betaine, an increment in the activity of antioxidant enzymes such as SOD, CAT, APX and POD, and the accumulation of dehydrins proteins. CONCLUSION: The results showed, suggest that S. uncinata is a  desiccation-tolerant moss, property mediated by high cellular plasticity regulated by ABA.


Assuntos
Antioxidantes/análise , Bryopsida/fisiologia , Dessecação , Fotossíntese/fisiologia , Adaptação Fisiológica , Regiões Antárticas , Bryopsida/química , Bryopsida/classificação , Fatores de Tempo
9.
Phytochemistry ; 159: 90-101, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30605853

RESUMO

The main polysaccharide of the gel present in the leaves of or Aloe vera Burm.F., (Aloe barbadensis Miller) a xerophytic crassulacean acid metabolism (CAM) plant, is an acetylated glucomannan named acemannan. This polysaccharide is responsible for the succulence of the plant, helping it to retain water. In this study we determined using polysaccharide analysis by carbohydrate gel electrophoresis (PACE) that the acemannan is a glucomannan without galactose side branches. We also investigated the expression of the gene responsible for acemannan backbone synthesis, encoding a glucomannan mannosyltransferase (GMMT, EC 2.4.1.32), since there are no previous reports on GMMT expression under water stress in general and specifically in Aloe vera. It was found by in silico analyses that the GMMT gene belongs to the cellulose synthase-like A type-9 (CSLA9) subfamily. Using RT-qPCR it was found that the expression of GMMT increased significantly in Aloe vera plants subjected to water stress. This expression correlates with an increase of endogenous ABA levels, suggesting that the gene expression could be regulated by ABA. To corroborate this hypothesis, exogenous ABA was applied to non-water-stressed plants, resulting in a significant increase of GMMT expression after 48 h of ABA treatment.


Assuntos
Ácido Abscísico/farmacologia , Aloe/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Mananas/metabolismo , Metiltransferases/genética , Estresse Fisiológico , Água/metabolismo , Aloe/enzimologia , Aloe/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Domínio Catalítico , DNA Complementar/genética , Secas , Eletroforese em Gel de Amido/métodos , Cromatografia Gasosa-Espectrometria de Massas , Metiltransferases/química , Metiltransferases/metabolismo , Homologia de Sequência de Aminoácidos
10.
Biol. Res ; 52: 46, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1019510

RESUMO

BACKGROUND: One of the most extreme environments on our planet is the Maritime Antarctic territory, due to its low-water availability, which restricts the development of plants. Sanionia uncinata Hedw. (Amblystegiaceae), the main colonizer of the Maritime Antarctic, has effective mechanisms to tolerate this environment. It has been described that the tolerance to desiccation is mediated by the hormone abscisic acid (ABA), antioxidants systems, accumulation of compatible solutes and proteins of the late embryogenesis abundant (LEA). However, to date, these mechanisms have not been described in S. uncinata. Therefore, in this work, we postulate that the tolerance to desiccation in the Antarctic moss S. uncinata is mediated by the accumulation of ABA, the osmolytes proline and glycine betaine, and dehydrins (an LEA class 11 proteins). To demonstrate our hypothesis, S. uncinata was subjected to desiccation for 24 h (loss in 95% of water content), and the effects on its physiological, photosynthetic, antioxidant and biochemical parameters were determined. RESULTS: Our results showed an accumulation of ABA in response to water loss, and the activation of protective responses that involves an increment in levels of proline and glycine betaine, an increment in the activity of antioxidant enzymes such as SOD, CAT, APX and POD, and the accumulation of dehydrins proteins. CONCLUSION: The results showed, suggest that S. uncinata is a desiccation-tolerant moss, property mediated by high cellular plasticity regulated by ABA.


Assuntos
Fotossíntese/fisiologia , Bryopsida/fisiologia , Dessecação , Antioxidantes/análise , Fatores de Tempo , Adaptação Fisiológica , Bryopsida/classificação , Bryopsida/química , Regiões Antárticas
11.
Biol Res ; 51(1): 48, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30428921

RESUMO

BACKGROUND: In field, C. quitensis is subjected to many abiotic extreme environmental conditions, such as low temperatures, high UV-B, salinity and reduced water potentials, but not metal or metalloid high concentrations in soil, however, other members of Caryophyllaceae family have tolerance to high concentrations of metals, this is the case of Silene genre. In this work, we hypothesize that C. quitensis have the same mechanisms of Silene to tolerate metals, involving accumulation and induction of antioxidant systems, sugar accumulation and the induction of thiols such as phytochelatins to tolerate. RESULTS: The results showing an effective antioxidant defensive machinery involving non-enzymatic antioxidants such as phenolics, GSH and ascorbic acid, in another hand, GSH-related oligomers (phytochelatins) and sugars was induced as a defensive mechanism. CONCLUSIONS: Colobanthus quitensis exhibits certain mechanisms to tolerate copper in vitro demonstrating its plasticity to tolerate several abiotic stress conditions.


Assuntos
Antioxidantes/fisiologia , Caryophyllaceae/metabolismo , Cobre/farmacologia , Fitoquelatinas/metabolismo , Açúcares/análise , Caryophyllaceae/química , Estresse Oxidativo/fisiologia , Fotossíntese , Açúcares/metabolismo
12.
Biol. Res ; 51: 48, 2018. graf
Artigo em Inglês | LILACS | ID: biblio-983947

RESUMO

BACKGROUND: In field, C. quitensis Is subjected to many abiotic extreme environmental conditions, such as low temperatures, high UV-B, salinity and reduced water potentials, but not metal or metalloid high concentrations in soil, however, other members of Caryophyllaceae family have tolerance to high concentrations of metals, this is the case of Silene genre. In this work, we hypothesize that C. quitensis have the same mechanisms of Silene to tolerate metals, involving accumulation and induction of antioxidant systems, sugar accumulation and the induction of thiols such as phytochelatins to tolerate. RESULTS: The results showing an effective antioxidant defensive machinery involving non-enzymatic antioxidants such as phenolics, GSH and ascorbic acid, in another hand, GSH-related oligomers (phytochelatins) and sugars was induced as a defensive mechanism. CONCLUSIONS: Colobanthus quitensis exhibits certain mechanisms to tolerate copper in vitro demonstrating its plasticity to tolerate several abiotic stress conditions.


Assuntos
Cobre/farmacologia , Caryophyllaceae/metabolismo , Açúcares/análise , Fitoquelatinas/metabolismo , Antioxidantes/fisiologia , Fotossíntese , Estresse Oxidativo/fisiologia , Caryophyllaceae/química , Açúcares/metabolismo
13.
Front Plant Sci ; 8: 921, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28620407

RESUMO

Deschampsia antarctica Desv. is one of two vascular plants that live in the Maritime Antarctic Territory and is exposed to high levels of ultraviolet-B (UVB) radiation. In this work, antioxidant physiology of D. antarctica was studied in response to UVB induced oxidative changes. Samples were collected from Antarctica and maintained in vitro culture during 2 years. Plants were sub-cultured in a hydroponic system and exposed to 21.4 kJ m-2 day-1, emulating summer Antarctic conditions. Results showed rapid and significant increases in reactive oxygen species (ROS) at 3 h, which rapidly decreased. No dramatic changes were observed in photosynthetic efficiency, chlorophyll content, and level of thiobarbituric acid reactive species (MDA). The enzymatic (superoxide dismutase, SOD and total peroxidases, POD) and non-enzymatic antioxidant activity (total phenolic) increased significantly in response to UVB treatment. These findings suggest that tolerance of D. antarctica to UVB radiation could be attributed to its ability to activate both enzymatic and non-enzymatic antioxidant systems.

14.
Front Plant Sci ; 8: 758, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28553300

RESUMO

Fungal pathogens are the cause of the most common diseases in grapevine and among them powdery mildew represents a major focus for disease management. Different strategies for introgression of resistance in grapevine are currently undertaken in breeding programs. For example, introgression of several resistance genes (R) from different sources for making it more durable and also strengthening the plant defense response. Taking this into account, we cross-pollinated P09-105/34, a grapevine plant carrying both RUN1 and REN1 pyramided loci of resistance to Erysiphe necator inherited from a pseudo-backcrossing scheme with Muscadinia rotundifolia and Vitis vinifera 'Dzhandzhal Kara,' respectively, with the susceptible commercial table grape cv. 'Crimson Seedless.' We developed RUN1REN1 resistant genotypes through conventional breeding and identified them by marker assisted selection. The characterization of defense response showed a highly effective defense mechanism against powdery mildew in these plants. Our results reveal that RUN1REN1 grapevine plants display a robust defense response against E. necator, leading to unsuccessful fungal establishment with low penetration rate and poor hypha development. This resistance mechanism includes reactive oxygen species production, callose accumulation, programmed cell death induction and mainly VvSTS36 and VvPEN1 gene activation. RUN1REN1 plants have a great potential as new table grape cultivars with durable complete resistance to E. necator, and are valuable germplasm to be included in grape breeding programs to continue pyramiding with other sources of resistance to grapevine diseases.

15.
Ann Bot ; 119(1): 27-38, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27794516

RESUMO

BACKGROUND AND AIMS: The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth, and many biotic communities inhabiting this dynamic region are responding to these well-documented climatic shifts. Yet some of the most prevalent organisms of terrestrial Antarctica, the mosses, and their responses to warming have been relatively overlooked and understudied. In this research, the impacts of 6 years of passive warming were investigated using open top chambers (OTCs), on moss communities of Fildes Peninsula, King George Island, Antarctica. METHODS: The effects of experimental passive warming on the morphology, sexual reproductive effort and stress physiology of a common dioicous Antarctic moss, Polytrichastrum alpinum ,: were tested, gaining the first species-specific mechanistic insight into moss responses to warming in the Antarctic. Additionally community analyses were conducted examining the impact of warming on overall moss percentage cover and sporophyte production in intact Antarctic moss communities. KEY RESULTS: Our results show a generally greater percentage moss cover under warming conditions as well as increased gametangia production in P. alpinum Distinct morphological and physiological shifts in P. alpinum were found under passive warming compared with those without warming: warmed mosses reduced investment in cellular stress defences, but invested more towards primary productivity and gametangia development. CONCLUSIONS: Taken together, results from this study of mosses under passive warming imply that in ice-free moss-dominated regions, continued climate warming will probably have profound impacts on moss biology and colonization along the Western Antarctic Peninsula. Such findings highlight the fundamental role that mosses will play in influencing the terrestrialization of a warming Antarctica.


Assuntos
Briófitas/fisiologia , Regiões Antárticas , Aquecimento Global , Reprodução/fisiologia , Estresse Fisiológico/fisiologia
16.
Front Plant Sci ; 7: 788, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27379111

RESUMO

White Chilean strawberries (Fragaria chiloensis) are non-climacteric fruits, with an exotic color and aroma. In order to discover genes involved in the development of these fruits, we identified a fragment of a gene encoding a late embryogenesis abundant domain protein, FcLDP1, that was expressed in early stages of fruit development, particularly in receptacles. Hormones play key roles in regulating the development of non-climacteric fruits. We show that the brassinosteroid content of the white strawberry varies during development. Additionally, FcLDP1 as well as the closest ortholog in the woodland strawberry, F. vesca (FvLDP1) possess multiple brassinosteroid, as well as abscisic acid (ABA) response motifs in the promoter region, consistent with the response of transiently expressed FcLDP1 promoter-GFP fusions to these hormones, and the rise in FcLDP1 transcript levels in white strawberry fruits treated with brassinosteroids or ABA. These findings suggest that both hormones regulate FcLDP1 expression during the development of white strawberries.

17.
Biol Res ; 49: 6, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26823072

RESUMO

BACKGROUND: Cryptogamic vegetation dominates the ice-free areas along the Antarctic Peninsula. The two mosses Sanionia uncinata and Polytrichastrum alpinum inhabit soils with contrasting water availability. Sanionia uncinata grows in soil with continuous water supply, while P. alpinum grows in sandy, non-flooded soils. Desiccation and rehydration experiments were carried out to test for differences in the rate of water loss and uptake, with non-structural carbohydrates analysed to test their role in these processes. RESULTS: Individual plants of S. uncinata lost water 60 % faster than P. alpinum; however, clumps of S. uncinata took longer to dry than those of P. alpinum (11 vs. 5 h, respectively). In contrast, rehydration took less than 10 min for both mosses. Total non-structural carbohydrate content was higher in P. alpinum than in S. uncinata, but sugar levels changed more in P. alpinum during desiccation and rehydration (60-50 %) when compared to S. uncinata. We report the presence of galactinol (a precursor of the raffinose family) for the first time in P. alpinum. Galactinol was present at higher amounts than all other non-structural sugars. CONCLUSIONS: Individual plants of S. uncinata were not able to retain water for long periods but by growing and forming carpets, this species can retain water the longest. In contrast individual P. alpinum plants required more time to lose water than S. uncinata, but as moss cushions they suffered desiccation faster than the later. On the other hand, both species rehydrated very quickly. We found that when both mosses lost 50 % of their water, carbohydrates content remained stable and the plants did not accumulate non-structural carbohydrates during the desiccation prosses as usually occurs in vascular plants. The raffinose family oligosaccarides decreased during desiccation, and increased during rehydration, suggesting they function as osmoprotectors.


Assuntos
Bryopsida/metabolismo , Metabolismo dos Carboidratos/fisiologia , Carboidratos/análise , Água/metabolismo , Análise de Variância , Regiões Antárticas , Desidratação , Dissacarídeos/análise , Células Germinativas Vegetais , Fatores de Tempo , Água/análise
18.
Biol. Res ; 49: 1-9, 2016. ilus, graf
Artigo em Inglês | LILACS | ID: lil-774433

RESUMO

BACKGROUND: Cryptogamic vegetation dominates the ice-free areas along the Antarctic Peninsula. The two mosses Sanionia uncinata and Polytrichastrum alpinum inhabit soils with contrasting water availability. Sanionia uncinata grows in soil with continuous water supply, while P. alpinum grows in sandy, non-flooded soils. Desiccation and rehydration experiments were carried out to test for differences in the rate of water loss and uptake, with non-structural carbohydrates analysed to test their role in these processes. RESULTS: Individual plants of S. uncinata lost water 60 % faster than P. alpinum; however, clumps of S. uncinata took longer to dry than those of P. alpinum (11 vs. 5 h, respectively). In contrast, rehydration took less than 10 min for both mosses. Total non-structural carbohydrate content was higher in P. alpinum than in S. uncinata, but sugar levels changed more in P. alpinum during desiccation and rehydration (60-50 %) when compared to S. uncinata. We report the presence of galactinol (a precursor of the raffinose family) for the first time in P. alpinum. Galactinol was present at higher amounts than all other non-structural sugars. CONCLUSIONS: Individual plants of S. uncinata were not able to retain water for long periods but by growing and forming carpets, this species can retain water the longest. In contrast individual P. alpinum plants required more time to lose water than S. uncinata, but as moss cushions they suffered desiccation faster than the later. On the other hand, both species rehydrated very quickly. We found that when both mosses lost 50 % of their water, carbohydrates content remained stable and the plants did not accumulate non-structural carbohydrates during the desiccation prosses as usually occurs in vascular plants. The raffinose family oligosaccarides decreased during desiccation, and increased during rehydration, suggesting they function as osmoprotectors.


Assuntos
Bryopsida/metabolismo , Metabolismo dos Carboidratos/fisiologia , Carboidratos/análise , Água/metabolismo , Análise de Variância , Regiões Antárticas , Desidratação , Dissacarídeos/análise , Células Germinativas Vegetais , Fatores de Tempo , Água/análise
19.
Molecules ; 20(4): 5698-713, 2015 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-25838172

RESUMO

Berry fruit consumption has become important in the promotion of human health, mainly due to their phenolic compounds, which have been associated with protection against different pathologies, as well as antimicrobial and other biological activities. Consequently, there has been a growing interest in identifying natural antioxidants and antimicrobials from these plants. This study aimed to characterize the phenolic chemical composition and anthocyanin profile of murta (Ugni molinae Turcz.) fruit, and to evaluate the antioxidant and antimicrobial activity of its extracts (ethanolic and methanolic). LC/MS of the ethanolic extracts showed the presence of three major compounds: caffeic acid 3-glu, quercetin-3-glu and quercetin, while in the methanolic acid extract they were cyanidin-3-glucoside, pelargonidin-3-arabinose and delphinidin-3-glucoside. The antioxidant activity of ethanolic extracts (DPPH· and ORAC assays) was higher than that of methanol acid extracts or purified anthocynins. Furthermore, the methanol acid extract showed an inhibitory activity against the bacteria E. coli and S. typhi similar to that of standard antibiotics. The results suggest that the antioxidant activity of the ethanolic extract is regulated by the high content of phenolic compounds and the fruit's characteristic color is due to the content of pelargonidin-3-arabinose and delphinidin-3-glucoside. The obtained results demonstrated the appreciable antioxidant and antibacterial activities, providing opportunities to explore murta extracts as biopreservatives.


Assuntos
Antioxidantes/isolamento & purificação , Fenóis/isolamento & purificação , Extratos Vegetais/química , Antocianinas/química , Antocianinas/isolamento & purificação , Antioxidantes/química , Antioxidantes/farmacologia , Escherichia coli/efeitos dos fármacos , Frutas/química , Glucosídeos/química , Glucosídeos/isolamento & purificação , Humanos , Myrtaceae/química , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia
20.
Bol. latinoam. Caribe plantas med. aromát ; 12(6): 603-611, nov. 2013. ilus, graf
Artigo em Inglês | LILACS | ID: lil-726594

RESUMO

Blueberry is a popular natural food product consumed worldwide. Acid soils are found throughout the world. A significant problem of acid soils is the active aluminum content, which may result toxic to plant. The present study was undertaken to assess the toxicities of Al for Blueberry (Vaccinium corymbosum L.) cultivated in vitro and treated with 100 and 200 uM Al. The effects of Al concentration on malondialdehyde (MDA) content, antioxidant activity and phenolic compounds of blueberry after 7, 14 and 21 days of treatment were established. The analysis of the MDA accumulated in the tissues of the blueberry seedlings indicates that Al concentration increases the damage caused by lipid peroxidation, for both treatments, after 14 days. The highest antioxidant activity in the extracts was observed at 200 uM Al after 14 days of treatment, being chlorogenic and ellagic acids the most significant metabolites involved in the antioxidant properties. Then, the content of Al in soil could be modulate the content of bioactive compounds in blueberry plants.


El Arándano es un popular alimento natural consumido en todo el mundo. Los suelos ácidos se encuentran en todo el mundo. Un problema significativo de suelos ácidos es el contenido de aluminio activo, que puede resultar tóxico para la planta. Este estudio se realizó para evaluar la toxicidad del aluminio en plantas de arandano, cultivadas in vitro y tratadas con 100 y 200 mM de Al. Se establecieron los del aluminio en el contenido de malodialdehido (MDA), capacidad antioxidante y contenido de compuestos fenolicos en plantulas de arandano luego de 7, 14 y 21 dias de tratamiento. El análisis del MDA acumulado en los tejidos de las plantulas de arándanos indica que la concentración de Al aumenta el daño causado medido como peroxidación de lípidos, para ambos tratamientos, después de 14 días. La actividad antioxidante más alta de los extractos se obseva a 200 mM de Al después de 14 días de tratamiento, siendo los ácidos clorogénico y elágico los metabolitos más importantes que participan en las propiedades antioxidantes. Entonces, el contenido de Al en el suelo podría modular el contenido de compuestos bioactivos en plantas de arándanos, alterando sus propiedades medicinales.


Assuntos
Antioxidantes , Alumínio/toxicidade , Mirtilos Azuis (Planta) , Compostos Fenólicos/análise , Ácido Clorogênico/análise , Ácido Elágico/análise , Cromatografia Líquida de Alta Pressão , Técnicas de Cultura , Peroxidação de Lipídeos , Plantas Medicinais , Fatores de Tempo
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