Papers by Eduardo Purgatto
Aluminum (Al) toxicity is a major worldwide agricultural problem. At low pH, Al speciates into th... more Aluminum (Al) toxicity is a major worldwide agricultural problem. At low pH, Al speciates into the soluble and phyto-toxic form Al3+, inhibiting the root growth and affecting plant development. In Brazil, agriculture in acidic soils with elevated concentration of Al has significantly increased in the last decades. Therefore, in order to achieve efficient agriculture practices, the selection of plant cultivars with improved Al resistance has become crucial in this type of soils. In this work we have evaluated the Al resistance of six genotypes of grapevine rootstocks. The grapevine hardwood cuttings were grown in nutrient solution in the absence and presence of 250 and 500 μM Al at pH 4.2. The phenotypic indexes of relative root growth, fresh and dry root weight, root area, hematoxylin staining profile, and Al content were evaluated for all six genotypes. These phenotypic indexes allowed us to identify the 'Kober 5BB', 'Gravesac', 'Paulsen 1103', and 'IAC ...
Current Agricultural Science and Technology, 2013
This paper reviews the recent advances in the understanding of the fruit ripening process and des... more This paper reviews the recent advances in the understanding of the fruit ripening process and describes future challenges. Fruit ripening is a complex developmental process which is orchestrated by the expression of ripening-related genes under the control of a network of signaling pathways. In climacteric fruit components responsible for the production of climacteric ethylene have been identified. Less progress has been made on non-climacteric fruit. Great advances have been made in the characterization of transcription factors (ERFs, RIN, etc…) that induce gene expression through the binding to their promoters. Genetic resources, genome sequencing and “omics” tools have been developed bringing a huge amount of data that will help to draw an integrative network of regulatory and signaling pathways responsible for triggering and coordinating the ripening process. The discovery that some ripening events are controlled at the epigenetic level and not in relation with the DNA sequences...
Food Chemistry, 2019
This study analyzed six uvaia (Eugenia pyriformis Cambess) accessions ('Comum', 'Rugosa', 'Doce d... more This study analyzed six uvaia (Eugenia pyriformis Cambess) accessions ('Comum', 'Rugosa', 'Doce de Patos de Minas', 'Pêra', 'Rugosa Doce' and 'Dura') with respect to chemical composition, nutritional value, bioactive compounds and antioxidant capacity. The 'Rugosa Doce' and 'Doce de Patos de Minas' accessions were sweeter (20.18 g 100 g-1 and 18.88 g 100 g-1 , respectively), while the 'Rugosa' and 'Pêra' accessions were less acid (0.28 g 100 g-1 and 0.33 g 100 g-1 , respectively). Terpenes were the major volatile compounds (46.75%) identified by SPME-GC/MS. The 'Rugosa' accession contained high levels of fibers (43.81 g 100 g-1) and minerals (2235.10 mg 100 g-1). The 'Rugosa Doce' and 'Rugosa' accessions were distinguished by total flavonoids and phenolic compounds. 'Rugosa Doce' and 'Rugosa' may potentially serve as a raw material for food, while 'Doce de Patos de Minas' and 'Pêra' can be used for cosmetic and pharmaceutical industries purposes.
BMC Plant Biology, 2015
Background: Ethylene is a phytohormone known for inducing a triple response in seedlings, leaf ab... more Background: Ethylene is a phytohormone known for inducing a triple response in seedlings, leaf abscission and other responses to various stresses. Several studies in model plants have evaluated the importance of this hormone in crosstalk signaling with different metabolic pathways, in addition to responses to biotic stresses. However, the mechanism of action in plants of agricultural interest, such as soybean, and its participation in abiotic stresses remain unclear. Results: The studies presented in this work allowed for the identification of 176 soybean genes described elsewhere for ethylene biosynthesis (108 genes) and signal transduction (68 genes). A model to predict these routes in soybean was proposed, and it had great representability compared to those described for Arabidopsis thaliana and Oryza sativa. Furthermore, analysis of putative gene promoters from soybean gene orthologs permitted the identification of 29 families of cis-acting elements. These elements are essential for ethylenemediated regulation and its possible crosstalk with other signaling pathways mediated by other plant hormones. From genes that are differentially expressed in the transcriptome database, we analyzed the relative expression of some selected genes in resistant and tolerant soybean plants subjected to water deficit. The differential expression of a set of five soybean ethylene-related genes (MAT, ACS, ACO, ETR and CTR) was validated with RT-qPCR experiments, which confirmed variations in the expression of these soybean target genes, as identified in the transcriptome database. In particular, two families of ethylene biosynthesis genes (ACS and ACO) were upregulated under these experimental conditions, whereas CTR (involved in ethylene signal transduction) was downregulated. In the same samples, high levels of ethylene production were detected and were directly correlated with the free fraction levels of ethylene's precursor. Thus, the combination of these data indicated the involvement of ethylene biosynthesis and signaling in soybean responses to water stress.
Annals of botany, Jan 28, 2015
Chrysolaena obovata, an Asteraceae of the Brazilian Cerrado, presents seasonal growth, marked by ... more Chrysolaena obovata, an Asteraceae of the Brazilian Cerrado, presents seasonal growth, marked by senescence of aerial organs in winter and subsequent regrowth at the end of this season. The underground reserve organs, the rhizophores, accumulate inulin-type fructans, which are known to confer tolerance to drought and low temperature. Fructans and fructan-metabolizing enzymes show a characteristic spatial and temporal distribution in the rhizophores during the developmental cycle. Previous studies have shown correlations between abscisic acid (ABA) or indole acetic acid (IAA), fructans, dormancy and tolerance to drought and cold, but the signalling mechanism for the beginning of dormancy and sprouting in this species is still unknown. Adult plants were sampled from the field across phenological phases including dormancy, sprouting and vegetative growth. Endogenous concentrations of ABA and IAA were determined by GC-MS-SIM (gas chromatography-mass spectrometry-selected ion monitoring)...
Annals of Botany, 2010
† Background and Aims Endospermic legumes are abundant in tropical forests and their establishmen... more † Background and Aims Endospermic legumes are abundant in tropical forests and their establishment is closely related to the mobilization of cell-wall storage polysaccharides. Endosperm cells also store large numbers of protein bodies that play an important role as a nitrogen reserve in this seed. In this work, a systems approach was adopted to evaluate some of the changes in carbohydrates and hormones during the development of seedlings of the rain forest tree Sesbania virgata during the period of establishment. † Methods Seeds imbibed abscisic acid (ABA), glucose and sucrose in an atmosphere of ethylene, and the effects of these compounds on the protein contents, a-galactosidase activity and endogenous production of ABA and ethylene by the seeds were observed. † Key Results The presence of exogenous ABA retarded the degradation of storage protein in the endosperm and decreased a-galactosidase activity in the same tissue during galactomannan degradation, suggesting that ABA represses enzyme action. On the other hand, exogenous ethylene increased a-galactosidase activity in both the endosperm and testa during galactomannan degradation, suggesting an inducing effect of this hormone on the hydrolytic enzymes. Furthermore, the detection of endogenous ABA and ethylene production during the period of storage mobilization and the changes observed in the production of these endogenous hormones in the presence of glucose and sucrose, suggested a correlation between the signalling pathway of these hormones and the sugars. † Conclusions These findings suggest that ABA, ethylene and sugars play a role in the control of the hydrolytic enzyme activities in seeds of S. virgata, controlling the process of storage degradation. This is thought to ensure a balanced flow of the carbon and nitrogen for seedling development.
Brazilian Journal of Medical and Biological Research, 2011
β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promis... more β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO, or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm 2) compared to control (0.91 ± 0.07 apoptotic cells/mm 2) in the distal colon. The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcinogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.
Revista Brasileira de Fruticultura, 2010
Este trabalho teve como objetivo avaliar o potencial de maturação das cultivares Pinot Noir, Temp... more Este trabalho teve como objetivo avaliar o potencial de maturação das cultivares Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay e Sauvignon Blanc submetidas ao regime de dupla poda, em Cordislândia, região cafeeira do sul de Minas Gerais. As plantas foram submetidas a dois ciclos de produção, um de primavera-verão, compreendido entre agosto e janeiro, e outro ciclo de outono-inverno, entre janeiro e julho. Como parâmetros de qualidade, foram avaliados os diâmetros transversal e longitudinal da baga, acidez, ácidos tartárico e málico, pH, sólidos solúveis, antocianinas, fenólicos totais e os teores de glicose, frutose e sacarose. Todas as variedades apresentaram maiores teores de pH, sólidos solúveis, açúcares, antocianinas e fenólicos totais, e redução nos diâmetros transversal e longitudinal na safra de inverno. A cultivar Syrah destacou-se das demais no conteúdo de antocianinas e fenólicos totais tanto no verão quanto no inverno, entretanto apresentou o men...
Toxicon : official journal of the International Society on Toxinology, 2008
The effects of myotoxin III (MT-III), a phospholipase A(2) (sPLA2) from Bothrops asper snake veno... more The effects of myotoxin III (MT-III), a phospholipase A(2) (sPLA2) from Bothrops asper snake venom, and crotoxin B (CB), a neurotoxic and myotoxic sPLA2 from the venom of Crotalus durissus terrificus, on cyclooxygenases (COXs) expression and biosynthesis of prostaglandins (PGs) were evaluated, together with the mechanisms involved in these effects. Upon intraperitoneal injection in mice, both sPLA(2)s promoted the synthesis of PGD2 and PGE2, with a different time-course. MT-III, but not CB, induced COX-2 expression by peritoneal leukocytes without modification on COX-1 constitutive expression, whereas CB increased the constitutive activity of COX-1. MT-III increased the enzymatic activity of COX-1 and COX-2. Similar effects were observed when these sPLA(2)s were incubated with isolated macrophages, evidencing a direct effect on these inflammatory cells. Moreover, both toxins elicited the release of arachidonic acid from macrophages in vitro. Inhibition of cPLA2 by AACOCF3, but not o...
Revista Brasileira de Fruticultura, 2010
RESUMO Este trabalho teve como objetivo avaliar a influência do sistema de condução na qualidade ... more RESUMO Este trabalho teve como objetivo avaliar a influência do sistema de condução na qualidade de bagas de uvas 'Niágara Rosada' e 'Folha-de-Figo' cultivadas em Caldas-MG. Foram avaliados a produção por planta, o diâmetro, a massa, o teor de potássio e a temperatura das bagas, pH, teor de sólidos solúveis, açúcares redutores, acidez total e ácidos orgânicos do mosto, compostos fenólicos nas cascas e sementes, e antocianinas. As plantas foram conduzidas em espaldeira, lira, latada ou cordão simples, e os frutos, avaliados nas safras de 2006 e 2007. As videiras de…
Pesquisa Agropecuária Brasileira, 2012
O objetivo deste trabalho foi avaliar a influência de porta-enxertos sobre as características agr... more O objetivo deste trabalho foi avaliar a influência de porta-enxertos sobre as características agronômicas, ecofisiológicas e qualitativas da videira 'Syrah' manejada por meio da técnica da dupla poda. As videiras foram enxertadas nos porta-enxertos 'SO4', '110 Richter' e '1103 Paulsen', e sustentadas em sistema espaldeira sem irrigação. Foram avaliadas as características ecofisiológicas, de produção e de composição físico-química das bagas maduras em três safras (2007, 2008 e 2010). Os porta-enxertos não exerceram influência sobre o potencial hídrico de base, que apresentou valores próximos a -0,2 MPa, o que indica que não houve restrição hídrica no solo ao final da maturação (junho). Também não houve diferença significativa quanto à produção. O porta-enxerto '1103 Paulsen' conferiu menor vigor, menor taxa fotossintética e melhores resultados de maturação, para as safras com menores precipitações. Os porta-enxertos '110 Richter' e '...
Radiation Physics and Chemistry, 2011
Tea is the second most widely consumed beverages in the world and is processed from two and a bud... more Tea is the second most widely consumed beverages in the world and is processed from two and a bud of Camellia sinensis (L.). Depending on the processing may give rise to four mainly teas (green, black, oolong and white tea). The white tea is the one that has recently awakened interest in scientific community due the fact that this tea has more antioxidant property and activity than green tea. A further industrialization and commercialization of these plants become a problem of public health. The presence of potentially toxigenic fungi can be found in these products, indicating a great potential for the presence of mycotoxins that can cause acute and chronic effects in different organs and systems of the human body. Ionizing radiation is one of the most effective means disinfecting dry food ingredients. This treatment can inhibit cellular life division, like microorganisms, promoting a molecular structural modification. The aim of this study was evaluate the effects of radiation on volatile formation in white tea. Samples were irradiated in room temperature at 60 Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20kGy. The volatiles organic compound was extracted by hydrodestilation and the extract was separated and identified by gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the quantities of volatiles formations are directly proportional to the increase of radiation dose. About 37.86% of the compounds were stable at all radiation doses and 47.53% of new compounds were identified after irradiation.
Planta, 2001
Page 1. Abstract. In order to observe the effect of indole-3-acetic acid (IAA) on carbohydrate me... more Page 1. Abstract. In order to observe the effect of indole-3-acetic acid (IAA) on carbohydrate metabolism, unripe banana (Musa acuminata AAA, cv. NanicaÄo) slices were infiltrated with the hormone and left to ripen under controlled conditions. ...
Plant Physiology, 2012
A comparative proteomic approach was performed to identify differentially expressed proteins in p... more A comparative proteomic approach was performed to identify differentially expressed proteins in plastids at three stages of tomato (Solanum lycopersicum) fruit ripening (mature-green, breaker, red). Stringent curation and processing of the data from three independent replicates identified 1,932 proteins among which 1,529 were quantified by spectral counting. The quantification procedures have been subsequently validated by immunoblot analysis of six proteins representative of distinct metabolic or regulatory pathways. Among the main features of the chloroplast-to-chromoplast transition revealed by the study, chromoplastogenesis appears to be associated with major metabolic shifts: (1) strong decrease in abundance of proteins of light reactions (photosynthesis, Calvin cycle, photorespiration) and carbohydrate metabolism (starch synthesis/degradation), mostly between breaker and red stages and (2) increase in terpenoid biosynthesis (including carotenoids) and stress-response proteins ...
Plant Physiology, 2004
Hymenaea courbaril is a leguminous tree species from the neotropical rain forests. Its cotyledons... more Hymenaea courbaril is a leguminous tree species from the neotropical rain forests. Its cotyledons are largely enriched with a storage cell wall polysaccharide (xyloglucan). Studies of cell wall storage polymers have been focused mostly on the mechanisms of their disassembly, whereas the control of their mobilization and the relationship between their metabolism and seedling development is not well understood. Here, we show that xyloglucan mobilization is strictly controlled by the development of first leaves of the seedling, with the start of its degradation occurring after the beginning of eophyll (first leaves) expansion. During the period of storage mobilization, an increase in the levels of xyloglucan hydrolases, starch, and free sugars were observed in the cotyledons. Xyloglucan mobilization was inhibited by shoot excision, darkness, and by treatment with the auxin-transport inhibitor N-1-naphthylphthalamic acid. Analyses of endogenous indole-3-acetic acid in the cotyledons rev...
Plant and Cell Physiology, 2010
Chromoplasts are carotenoid-accumulating plastids conferring color to many fl owers and fruits as... more Chromoplasts are carotenoid-accumulating plastids conferring color to many fl owers and fruits as well as to some tubers and roots. Chromoplast differentiation proceeds from preexisting plastids, most often chloroplasts. One of the most prominent changes is remodeling of the internal membrane system associated with the formation of carotenoidaccumulating structures. During the differentiation process the plastid genome is essentially stable and transcriptional activity is restricted. The buildup of the chromoplast for specifi c metabolic characteristics is essentially dependent upon the transcriptional activity of the nucleus. Important progress has been made in terms of mediation of the chloroplast-to-chromoplast transition with the discovery of the crucial role of the Or gene. In this article we review recent developments in the structural, biochemical and molecular aspects of chromoplast differentiation and also consider the reverse differentiation of chromoplasts into chloroplast-like structures during the regreening process occurring in some fruit. Future perspectives toward a full understanding of chromoplast differentiation include in-depth knowledge of the changes occurring in the plastidial proteome during chromoplastogenesis, elucidation of the role of hormones and the search for signals that govern the dialog between the nuclear and the chromoplastic genome.
Parasitology, 2014
SUMMARYPreviously we have characterized the complete gene encoding a pyruvate decarboxylase (PDC)... more SUMMARYPreviously we have characterized the complete gene encoding a pyruvate decarboxylase (PDC)/indolepyruvate decarboxylase (IPDC) ofPhytomonas serpens, a trypanosomatid highly abundant in tomato fruits. Phylogenetic analyses indicated that the clade that contains the trypanosomatid protein behaves as a sister group of IPDCs ofγ-proteobacteria. Since IPDCs are key enzymes in the biosynthesis of the plant hormone indole-3-acetic acid (IAA), the ability for IAA production byP. serpenswas investigated. Similar to many microorganisms, the production of IAA and related indolic compounds, quantified by high performance liquid chromatography, increased inP. serpensmedia in response to amounts of tryptophan. The auxin functionality was confirmed in the hypocotyl elongation assay. In tomato fruits inoculated withP. serpensthe concentration of free IAA had no significant variation, whereas increased levels of IAA-amide and IAA-ester conjugates were observed. The data suggest that the auxin...
Nutrition and Cancer, 2013
Dietary isoprenic derivatives such as β-ionone (βI) are a promising class of chemopreventive agen... more Dietary isoprenic derivatives such as β-ionone (βI) are a promising class of chemopreventive agents. In this study, cellular aspects of βI protective activities during early hepatocarcinogenesis were evaluated. Male Wistar rats were submitted to "resistant hepatocyte" model and then received daily 16 mg/100 g body weight (b.w.) of βI (βI group) or only 0.25 mL/100 g b.w. of corn oil (vehicle, control group [CO]) during 4 wk, specifically during early promotion phase. Compared to controls, βI inhibited (P < 0.05) the development of persistent preneoplastic lesions (pPNL), considered to be potential hepatocellular carcinoma (HCC) progression sites, and increased remodeling PNL (rPNL) (P < 0.05) that tend to regress to a normal phenotype. Increased βI hepatic levels (P < 0.05), in the βI group, were associated with its chemopreventive actions. Compared to control rats, βI reduced the frequency of both pPNL and rPNL positive for tumor growth factor (TGF)-α (P < 0.05), reduced the frequency of pPNL stained for p65 (nuclear factor-kappaB; NF-κB) (P…
Uploads
Papers by Eduardo Purgatto