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1.
Foods ; 12(21)2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37959079

RESUMO

Using wounding stress to increase the bioactive phenolic content in fruits and vegetables offers a promising strategy to enhance their health benefits. When wounded, such phenolics accumulate in plants and can provide antioxidant, anti-inflammatory, and anti-obesogenic properties. This study investigates the potential of using wounding stress-treated carrots biofortified with phenolic compounds as a raw material to extract carrot juice with increased nutraceutical properties. Fresh carrots were subjected to wounding stress via slicing and then stored at 15 °C for 48 h to allow phenolic accumulation. These phenolic-enriched slices were blanched, juiced, and blended with orange juice (75:25 ratio) and 15% (w/v) broccoli sprouts before pasteurization. The pasteurized juice was characterized by its physicochemical attributes and bioactive compound content over 28 days of storage at 4 °C. Additionally, its antioxidant, anti-inflammatory, and anti-obesogenic potentials were assessed using in vitro assays, both pre- and post-storage. The results reveal that juice derived from stressed carrots (SJ) possessed 49%, 83%, and 168% elevated levels of total phenolics, chlorogenic acid, and glucosinolates, respectively, compared to the control juice (CJ) (p < 0.05). Both juices reduced lipid accumulation in 3T3-L1 cells and nitric oxide production in Raw 264.7 cells, without significant differences between them. SJ further displayed a 26.4% increase in cellular antioxidant activity. The juice's bioactive characteristics remained stable throughout storage time. In conclusion, the utilization of juice obtained from stressed carrots in a blend with orange juice and broccoli sprouts offers a promising method to produce a beverage enriched in bioactive compounds and antioxidant potential.

2.
Plants (Basel) ; 12(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37050060

RESUMO

Wounding induces phenolic biosynthesis in broccoli. However, there is scarce information about the physiological and molecular mechanisms governing this stress response. In the present study, a chemical-genetics approach was used to elucidate the role of reactive oxygen species (ROS), jasmonic acid (JA), and ethylene (ET) as stress-signaling molecules in the wound-induced phenolic biosynthesis in broccoli. Wounding activated the biosynthesis of ET and JA. Likewise, the wound-induced biosynthesis of ET and JA was regulated by ROS. JA activated primary metabolism, whereas the three signaling molecules activated phenylpropanoid metabolism. The signaling molecules inhibited the wound-induced activation of the hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) gene, which is involved in caffeoylquinic acids biosynthesis, and the main phenolics accumulated in wounded broccoli, suggesting that an alternative caffeoylquinic biosynthesis pathway is activated in the tissue due to wounding. ROS mediated the biosynthesis of most individual phenolic compounds evaluated. In conclusion, ROS, ET, and JA are essential in activating broccoli's primary and secondary metabolism, resulting in phenolic accumulation.

3.
J Plant Physiol ; 282: 153942, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36805520

RESUMO

Rubber (Hevea brasiliensis) is a latex-producing plant that often encounters mechanical wounding, as well as pathogen and pest attacks through wound sites during and after tapping. Terpenoids play an important role in the ecological interactions of many plant species, and their diversity is mainly generated by enzymes known as terpene synthases (TPS). In this study, one cDNA sequence encoding a putative terpene synthase, HbTPS20, was obtained from the bark tissues of H. brasiliensis. The encoded protein contains 610 amino acids with a putative N-terminal plastid transit peptide of approximately 70 residues. It belongs to the TPS-b subfamily. Further phylogenetic analysis showed that HbTPS20 formed a separate branch that diverged from the progenitor of all other potentially functional terpene synthases of the rubber TPS-b subfamily. The truncated HbTPS20 without the signal peptide coding sequence was successfully expressed in E. coli and in vitro enzymatic assays with geranyl diphosphate (GPP) or neryl diphosphate (NPP) as a substrate defined HbTPS20 as an active linalool synthase (HbLIS) with the ability to produce linalool as the principal product. RT-qPCR analysis showed that the highest transcript levels of HbTPS20 were found in barks, and this gene was expressed at 2.26- and 250-fold greater levels in the bark tissues of wounded and MeJA-treated plants, respectively, than in those of the control plants. This indicates that this gene may be involved in the induced stress responses of rubber.


Assuntos
Hevea , Borracha , Borracha/metabolismo , Hevea/genética , Filogenia , Casca de Planta/metabolismo , Escherichia coli , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
4.
Rev. crim ; 64(2): 77-88, 2022. ilus, tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1418088

RESUMO

El conflicto armado en Colombia se ha caracterizado por la presencia de grupos al margen de la ley, quienes utilizan las minas antipersona como unas de sus armas principales. El objetivo de esta investigación consistió en evaluar estadísticamente los casos relacionados con las víctimas de minas antipersona en Colombia entre 1990 y 2020. El proceso investigativo se generó a partir de los datos suministrados por la Oficina del Alto Comisionado para la Paz, y se empleó un análisis de correspondencia múltiple y distribución de frecuencia. Se encontró que el 60.5% de las estadísticas relacionadas con las minas antipersona se asocian a personal militar vinculado a las Fuerzas Militares, además que en el 19.7% de los incidentes con dichas armas la persona afectada pierde su vida, y también que el 10.2% de los casos reportados corresponden a menores de edad. Igualmente, se halló que en los departamentos de Antioquia, Meta, Nariño y Caquetá se presentaron el mayor número de hechos. Se concluye que el país debe dar su máximo esfuerzo para erradicar del territorio las minas que aún están sembradas, y trabajar junto con la Comunidad Internacional y los exguerrilleros reintegrados a la sociedad con el fin de promover un país libre de minas.


The armed conflict in Colombia has been characterized by the presence of illegal groups, who use landmines as one of their main weapons. The objective of this research was to statistically evaluate the cases related to landmine victims in Colombia between 1990 and 2020. The research process was generated from data provided by the Office of the High Commissioner for Peace, and a multiple correspondence and frequency distribution analysis was used. It was found that 60.5% of the statistics related to antipersonnel mines are associated with military personnel linked to the Armed Forces, and that in 19.7% of the incidents involving these weapons the affected person loses his or her life, and also that 10.2% of the reported cases correspond to minors. It was also found that the departments of Antioquia, Meta, Nariño and Caquetá had the highest number of incidents. It is concluded that the country must make its maximum effort to eradicate the mines that are still planted in the territory, and work together with the international community and the ex-guerrillas reintegrated into society in order to promote a mine-free country.


O conflito armado na Colômbia tem sido caracterizado pela presença de grupos armados ilegais, que utilizam minas terrestres como uma de suas principais armas. O objetivo desta pesquisa era avaliar estatisticamente os casos relacionados às vítimas de minas terrestres na Colômbia entre 1990 e 2020. O processo de pesquisa foi gerado a partir de dados fornecidos pelo Alto Comissariado para a Paz, e foi utilizada uma análise de correspondência múltipla e distribuição de freqüência. Constatou-se que 60,5% das estatísticas relacionadas às minas antipessoais estão associadas a militares ligados às Forças Armadas, e que em 19,7% dos incidentes envolvendo essas armas, a pessoa afetada perde a vida, e que 10,2% dos casos relatados correspondem a menores. Também foi constatado que os departamentos de Antioquia, Meta, Nariño e Caquetá tiveram o maior número de incidentes. Conclui-se que o país deve fazer o máximo para erradicar as minas que ainda estão plantadas no território e trabalhar junto com a comunidade internacional e os ex-guerrilheiros reintegrados à sociedade para promover um país livre de minas.


Assuntos
Humanos , Terrorismo , Violência , Colômbia , Conflitos Armados , Substâncias Explosivas , Armas , Jurisprudência
5.
Plants (Basel) ; 10(12)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34961133

RESUMO

Wounding stress is an effective strategy to induce glucosinolate (GS) biosynthesis in broccoli. However, there is insufficient knowledge on the physiological and molecular mechanisms underlying this stress response. Herein, a chemical-genetic approach was applied to elucidate the role of jasmonic acid (JA), ethylene (ET), and reactive oxygen species (ROS) on the wound-induced biosynthesis of GS. Broccoli was processed into chops to induce wounding stress. Broccoli chops were treated with phenidone (PHEN) and diphenyleneiodonium chloride (DPI) as inhibitors of JA and ROS biosynthesis, respectively, whereas 1-methylcyclopropene (1-MCP) was applied as an inhibitor of ET action. Wounding stress induced the expression of genes related to the biosynthesis of indolic and aliphatic GS, which was correlated with the accumulation of GS and modulated by the inhibitors of signaling molecules applied. Results of gene expression analysis indicated that JA played a key role in the activation of most genes, followed by ROS. Furthermore, except for the CYP79B2 gene, PHEN and 1-MCP synergistically downregulated the expression of GS biosynthetic genes evaluated, showing that the interaction between JA and ET was fundamental to modulate GS biosynthesis. Results presented herein increased our knowledge of the physiological and molecular mechanisms governing the wound-induced biosynthesis of GS in broccoli.

6.
J Morphol ; 282(12): 1765-1771, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34609011

RESUMO

Traumatic mating, that is, copulation that involves wounding the partner's body, is a widespread phenomenon that is particularly prevalent in hermaphroditic animals. Traumatic mating is generally a collateral side effect of diverse strategies (from physical anchorage to injection of substances to manipulate the partner), but the trauma could also be adaptive by itself if it delays remating by the injured partner. In the Tricladida (the clade of planarian flatworms), reciprocal sperm transfer is often assumed to occur by means of a 'regular' nontraumatic copulation, that is, insertion of the penis through the partner's gonopore and deposition of the ejaculate into its genital atrium, with subsequent sperm migration to the oviducts. However, while studying the anatomy of Brazilian land planarians for taxonomic purposes, we found foreign bodies, reminiscent of spermatophores, implanted within the parenchyma of Choeradoplana albonigra (Riester, 1938). Herein, we describe and illustrate several lines of morphological evidence indicating that these foreign bodies likely represent a novel case of intragenital copulatory wounding (e.g., structural and histochemical similarity to land planarians spermatophores; implantation at the level of the gonopore; vestiges of rupture of the genital atrium's wall), corroborating that traumatic mating is pervasive and underreported in Metazoa. We also propose two different hypotheses to explain such copulatory wounding, viz., that it concerns (1) a regular mating strategy or (2) an accidental effect of the copulation. In any event, this land planarian may prove useful as a novel, noninsect terrestrial model organism to investigate the evolution of traumatic mating.


Assuntos
Corpos Estranhos , Planárias , Animais , Copulação , Masculino , Reprodução , Comportamento Sexual Animal
7.
J Sci Food Agric ; 100(13): 4995-4998, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32478414

RESUMO

BACKGROUND: During the production of fresh-cut products, crops are exposed to wounding stress, and as a stress response, phenolic antioxidants are synthesized. This stress response is elicited by extracellular adenosine triphosphate, released from wounded cells and recognized by receptors of unwounded cells. The phenolic antioxidants produced as a stress response are beneficial for human health. However, a common practice in the fresh-cut industry is the application of washing/sanitizing procedures after cutting. These procedures could be highly detrimental, since they partially remove the wound signal that elicits the biosynthesis of phenolics in plants. In this study, the impact of different washing/sanitizing treatments post-shredding on the wound-induced accumulation of chlorogenic acid (CHA) in carrot was evaluated. Peeled carrots were shredded and dipped in aqueous solutions containing chlorine (100 ppm, 2 min), hydrogen peroxide (1.5%, 2 min) or water (2 min). The content of CHA in treated carrots was evaluated before and after 48 h of storage (19 ± 2 °C). RESULTS: The control carrots sanitized only before peeling and shredding showed 4000% higher content of CHA as compared with time 0 h samples. However, carrots treated with washing/sanitizing procedures post-shredding including water, chlorine and hydrogen peroxide showed a decrease in the accumulation of CHA by 46.9%, 53.6% and 89.9%, respectively. CONCLUSIONS: The results demonstrated that washing/sanitizing procedures applied after fresh-cutting are potentially detrimental to the wound-induced accumulation of health-promoting compounds during storage of fresh produce. Thus, the fresh-cut industry could consider avoiding washing procedures after cutting and implement alternative sanitizing procedures that avoid the partial removal of the wound signal, such as sanitizing only before cutting. © 2020 Society of Chemical Industry.


Assuntos
Antioxidantes/química , Daucus carota/química , Desinfetantes/farmacologia , Desinfecção/métodos , Manipulação de Alimentos/métodos , Fenóis/química , Antioxidantes/metabolismo , Cloro/farmacologia , Ácido Clorogênico/farmacologia , Daucus carota/efeitos dos fármacos , Daucus carota/metabolismo , Fenóis/metabolismo , Tubérculos/química , Tubérculos/metabolismo
8.
Food Chem ; 307: 125551, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648173

RESUMO

Postharvest wounding stress in carrots induces the accumulation of phenolics, whereas extrusion generates modifications in the nutritional profiles of food matrixes. In the present study, the sequential application of wounding stress and extrusion on total free and bound phenolics as well as on carotenoid profiles of carrots was evaluated. Wounding was applied by shredding carrots and storing the tissue (48 h, 15 °C). The stressed-tissue was dehydrated and extruded at 63 °C or 109 °C and at continuous or expansion screw configurations. Extrudates were milled and sieved before phytochemical analysis. Wounding increased total free (288.1%) and bound (407.6%) phenolic content, whereas the carotenoid content was unaltered. The free and bound phenolics that showed the highest increase due to wounding were the chlorogenic (579.8%) and p-coumaric (390.9%) acids. Extrusion, at 109 °C under expansion screw configuration, further increased the wound-induced accumulation of total free (296.6%) and bound (22.1%) phenolics and induced trans-cis isomerization of ß-carotene.


Assuntos
Daucus carota/química , Fenóis/análise , Carotenoides/análise , Compostos Fitoquímicos/análise , Estresse Fisiológico
9.
Front Plant Sci ; 11: 620832, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33584761

RESUMO

Adventitious root (AR) development takes place in an intricate cellular environment. Reactive oxygen species (ROS) and antioxidant defenses, triggered by wounding in cuttings, can modulate this process. A comparative assessment of biochemical and anatomical parameters at critical rooting stages in hard- (Eucalyptus globulus Labill.) and easy- (Eucalyptus grandis W.Hill ex Maiden) to-root species was carried out. Microcuttings from seedlings were inoculated in auxin-free AR induction medium and, after 96 h, transferred to AR formation medium for a period of 24 h. Samples were collected upon excision (Texc) and at the 5th day post excision (Tform). Delayed xylem development, with less lignification, was recorded in E. globulus, when compared to E. grandis, suggesting lower activity of the cambium layer, an important site for AR development. Superoxide was more densely present around the vascular cylinder at both sampled times, and in greater quantity in E. globulus than E. grandis, declining with time in the former. Hydrogen peroxide was localized primarily along cell walls, more intensely in the primary xylem and phloem, and increased significantly at Tform in E. globulus. Ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT) activities were generally higher in E. grandis and varied as a function of time in E. globulus. Soluble guaiacol peroxidase (GPRX) activity increased from Texc to Tform in both species, whereas cell wall-bound GPRX activity increased with time in E. grandis, surpassing E. globulus. Flavonoid content increased with time in E. grandis and was higher than E. globulus at Tform. Principal component analysis showed that species- and time-derived differences contributed to almost 80% of the variance. Overall, data indicate that E. grandis shows higher cambium activity and tighter modulation of redox conditions than E. globulus. These features may influence ROS-based signaling and phytohormone homeostasis of cuttings, thereby impacting on AR development. Besides being players in the realm of AR developmental differences, the specific features herein identified could become potential tools for early clone selection and AR modulation aiming at improved clonal propagation of this forest crop.

10.
Int J Mol Sci ; 20(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31731568

RESUMO

The present study evaluated the effects of ultraviolet B (UVB) radiation and wounding stress, applied alone or combined, on the biosynthesis of phenolic compounds and ascorbic acid in the peel and pulp of red prickly pear (Opuntia ficus-indica cv. Rojo Vigor). Whole and wounded-fruit samples were treated with UVB radiation (6.4 W·m-2) for 0 and 15 min, and stored for 24 h at 16 °C. Phytochemical analyses were performed separately in the peel and pulp. The highest phenolic accumulation occurred after storage of the whole tissue treated with UVB, where the main phenolic compounds accumulated in the peel and pulp were quercetin, sinapic acid, kaempferol, rosmarinic acid, and sinapoyl malate, showing increases of 709.8%, 570.2%, 442.8%, 439.9%, and 186.2%, respectively, as compared with the control before storage. Phenylalanine ammonia-lyase (PAL) activity was increased after storage of the whole and wounded tissue treated with UVB light, and this increase in PAL activity was associated to phenolic accumulation. On the other hand, l-galactono-γ-lactone dehydrogenase (GalLDH) activity and ascorbic acid biosynthesis was enhanced due to UVB radiation, and the effect was increased when UVB was applied in the wounded tissue showing 125.1% and 94.1% higher vitamin C content after storage when compared with the control. Respiration rate was increased due to wounding stress, whereas ethylene production was increased by wounding and UVB radiation in prickly pears. Results allowed the generation of a physiological model explaining the UVB and wound-induced accumulation of phenolic compounds and ascorbic acid in prickly pears, where wounding facilitates UVB to access the underlying tissue and enhances an apparent synergistic response.


Assuntos
Modelos Biológicos , Opuntia/metabolismo , Fenóis/metabolismo , Proteínas de Plantas/metabolismo , Raios Ultravioleta
11.
J Food Sci ; 84(5): 1151-1161, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30994933

RESUMO

Phenolic compounds have potential to prevent and treat chronic degenerative diseases (CDDs). A phenolic-rich carrot juice was produced by the application of wounding stress. The effects of wounding intensity, storage, peeling, blanching, filtration, and pasteurization over physicochemical, nutritional, nutraceutical, and sensory properties of carrot juice were evaluated. Juices from unpeeled carrots had 7% to 40% more minerals, 0.46 to 1.6 less °Brix, and 1.16× more titratable acidity. The carrot juice with the highest phenolic content was obtained by cutting unpeeled carrots into slices, storing them (48 hr, 15 °C), and blanching them thereafter (80 °C, 6 min; stressed unpeeled carrot juice, SUCJ). SUCJ had 3,600% more chlorogenic acid, 195% more total phenolics, and similar carotenoid content than conventional carrot juice. Sensory evaluation of SUCJ was acceptable and willingness to pay increased by providing information about health benefits. SUCJ has potential as a functional beverage that could aid in the prevention and treatment of CDDs. PRACTICAL APPLICATION: Consumers are increasingly demanding foods and beverages that are healthier, natural, safe, and GMO-free. Abiotic stresses can enhance greatly the nutraceutical content of crops without the need of genetic engineering or dangerous chemicals. These crops could be used as raw materials to produce foods and beverages of higher nutraceutical quality. An easy-to-control abiotic stress is wounding stress, which consists of mechanically damaging the plant tissue (for example, cutting). We applied wounding stress to carrot to produce a phenolic-rich carrot juice. This juice could aid in the prevention or treatment of chronic degenerative diseases.


Assuntos
Daucus carota , Suplementos Nutricionais/análise , Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Alimento Funcional/análise , Ácido Clorogênico/análise , Fenóis/análise
12.
J Plant Physiol ; 218: 94-99, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28802186

RESUMO

Combination of biotic and abiotic stress is a major challenge for crop and fruit production. Thus, identification of genes involved in cross-response to abiotic and biotic stress is of great importance for breeding superior genotypes. Lectins are glycan-binding proteins with a functions in the developmental processes as well as in the response to biotic and abiotic stress. In this work, a lectin like gene, namely ClLectin1, was characterized in Volkamer lemon and its expression was studied in plants exposed to either water stress, hormonal elicitors (JA, SA, ABA) or wounding to understand whether this gene may have a function in the response to multiple stress combination. Results showed that ClLectin1 has 100% homology with a L-type lectin gene from C. sinensis and the in silico study of the 5'UTR region showed the presence of cis-responsive elements to SA, DRE2 and ABA. ClLectin1 was rapidly induced by hormonal treatments and wounding, at local and systemic levels, suggesting an involvement in defence signalling pathways and a possible role as fast detection biomarker of biotic stress. On the other hand, the induction of ClLectin1 by water stress pointed out a role of the gene in the response to drought. The simultaneous response of ClLectin1 expression to water stress and SA treatment could be further investigated to assess whether a moderate drought stress may be useful to improve citrus performance by stimulating the SA-dependent response to biotic stress.


Assuntos
Citrus/fisiologia , Regulação da Expressão Gênica de Plantas , Lectinas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Água/metabolismo , Ácido Abscísico/metabolismo , Citrus/genética , Ciclopentanos/metabolismo , Secas , Lectinas/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Ácido Salicílico/metabolismo
13.
Molecules ; 22(4)2017 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-28420123

RESUMO

Broccoli contains bioactive molecules and thus its consumption is related with the prevention of chronic and degenerative diseases. The application of wounding stress to horticultural crops is a common practice, since it is the basis for the fresh-cut produce industry. In this study, the effect of four different cutting styles (CSs) (florets (CS1), florets cut into two even pieces (CS2), florets cut into four even pieces (CS3), and florets processed into chops (CS4)) and storage time (0 and 24 h at 20 °C) on the content of bioactive compounds in broccoli was evaluated. Immediately after cutting, 5-O-caffeoylquinic acid and caffeic acid content increased by 122.4% and 41.6% in CS4 and CS2, respectively. Likewise, after storage, 3-O-caffeoylquinic acid and 5-O-caffeoylquinic acid increased by 46.7% and 98.2%, respectively in CS1. Glucoerucin and gluconasturtiin content decreased by 62% and 50%, respectively in CS3; whereas after storage most glucosinolates increased in CS1. Total isothiocyanates, increased by 133% immediately in CS4, and after storage CS1 showed 65% higher levels of sulforaphane. Total ascorbic acid increased 35% after cutting in CS2, and remained stable after storage. Results presented herein would allow broccoli producers to select proper cutting styles that preserve or increase the content of bioactive molecules.


Assuntos
Brassica/química , Compostos Fitoquímicos/química , Ácido Ascórbico/química , Manipulação de Alimentos , Armazenamento de Alimentos , Glucosinolatos/química , Isotiocianatos/química , Fenóis/química , Fatores de Tempo
14.
Methods Mol Biol ; 1405: 19-26, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26843161

RESUMO

Tapping technique comprises the extraction of pine oleoresin, a non-wood forest product consisting of a complex mixture of mono, sesqui, and diterpenes biosynthesized and exuded as a defense response to wounding. Oleoresin is used to produce gum rosin, turpentine, and their multiple derivatives. Oleoresin yield and quality are objects of interest in pine tree biotechnology, both in terms of environmental and genetic control. Monitoring these parameters in individual trees grown in the field provides a means to examine the control of terpene production in resin canals, as well as the identification of genetic-based differences in resinosis. A typical method of tapping involves the removal of bark and application of a chemical stimulant on the wounded area. Here we describe the methods for preparing the resin-stimulant paste with different adjuvants, as well as the bark streaking process in adult pine trees.


Assuntos
Fracionamento Químico/métodos , Pinus/química , Casca de Planta/química , Extratos Vegetais/química
15.
Front Plant Sci ; 7: 45, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26904036

RESUMO

Broccoli contains high levels of bioactive molecules and is considered a functional food. In this study, postharvest treatments to enhance the concentration of glucosinolates and phenolic compounds were evaluated. Broccoli whole heads were wounded to obtain florets and wounded florets (florets cut into four even pieces) and stored for 24 h at 20 °C with or without exogenous ethylene (ET, 1000 ppm) or methyl jasmonate (MeJA, 250 ppm). Whole heads were used as a control for wounding treatments. Regarding glucosinolate accumulation, ET selectively induced the 4-hydroxylation of glucobrassicin in whole heads, resulting in ∼223% higher 4-hydroxyglucobrassicin than time 0 h samples. Additionally, glucoraphanin was increased by ∼53% in whole heads treated with ET, while neoglucobrassicin was greatly accumulated in wounded florets treated with ET or MeJA, showing increases of ∼193 and ∼286%, respectively. On the other hand, although only whole heads stored without phytohormones showed higher concentrations of phenolic compounds, which was reflected in ∼33, ∼30, and ∼46% higher levels of 1,2,2-trisinapoylgentiobose, 1,2-diferulolylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose, respectively; broccoli florets stored under air control conditions showed enhanced concentrations of 3-O-caffeoylquinic acid, 1,2-disinapoylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose (∼22, ∼185, and ∼65% more, respectively). Furthermore, exogenous ET and MeJA impeded individual phenolics accumulation. Results allowed the elucidation of simple and effective postharvest treatment to enhance the content of individual glucosinolates and phenolic compounds in broccoli. The stressed-broccoli tissue could be subjected to downstream processing in order to extract and purify bioactive molecules with applications in the dietary supplements, agrochemical and cosmetics markets.

16.
Front Plant Sci ; 6: 837, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26528305

RESUMO

The application of postharvest abiotic stresses is an effective strategy to activate the primary and secondary metabolism of plants inducing the accumulation of antioxidant phenolic compounds. In the present study, the effect of water stress applied alone and in combination with wounding stress on the activation of primary (shikimic acid) and secondary (phenylpropanoid) metabolic pathways related with the accumulation of phenolic compound in plants was evaluated. Carrot (Daucus carota) was used as model system for this study, and the effect of abiotic stresses was evaluated at the gene expression level and on the accumulation of metabolites. As control of the study, whole carrots were stored under the same conditions. Results demonstrated that water stress activated the primary and secondary metabolism of carrots, favoring the lignification process. Likewise, wounding stress induced higher activation of the primary and secondary metabolism of carrots as compared to water stress alone, leading to higher accumulation of shikimic acid, phenolic compounds, and lignin. Additional water stress applied on wounded carrots exerted a synergistic effect on the wound-response at the gene expression level. For instance, when wounded carrots were treated with water stress, the tissue showed 20- and 14-fold increases in the relative expression of 3-deoxy-D-arabino-heptulosanate synthase and phenylalanine ammonia-lyase genes, respectively. However, since lignification was increased, lower accumulation of phenolic compounds was detected. Indicatively, at 48 h of storage, wounded carrots treated with water stress showed ~31% lower levels of phenolic compounds and ~23% higher lignin content as compared with wounded controls. In the present study, it was demonstrated that water stress is one of the pivotal mechanism of the wound-response in carrot. Results allowed the elucidation of strategies to induce the accumulation of specific primary or secondary metabolites when plants are treated with water stress alone or when additional water stress is applied on wounded tissue. If the accumulation of a specific primary or secondary metabolite were desirable, it would be recommended to apply both stresses to accelerate their biosynthesis. However, strategies such as the use of enzymatic inhibitors to block the carbon flux and enhance the accumulation of specific compounds should be designed.

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