Papers by Eduardo Purgatto
Application of exogenous jasmonate can stimulate the production of ethylene, carotenoids and arom... more Application of exogenous jasmonate can stimulate the production of ethylene, carotenoids and aroma compounds, resulting in the acceleration of fruit ripening. These alterations improve fruit quality and make fruit desirable for human consumption, but overripening of a fruit results in large losses of fruit crops. In order to overcome this problem, 1-methylcyclopropene was ap-plied to the fruits due to its capacity to block the receptors of ethylene, resulting in the sup-pressed of fruit ripening. In this study, treatments only with 1-methylcyclopropene, and with both 1-methylcyclopropene and methyl jasmonate was conducted to observe if an exogenous methyl jasmonate can improve the levels of metabolites in their fruits with ethylene receptors blocked. Fruits were analyzed at 4, 10 and 21 day after harvest (DAH) and compared with the no treated fruits. The postharvest treatments affected primary metabolites (sugars, organic acids, amino acids and fatty acids) and secondary metabolites...
In silico Characterization of Ethylene Soybean Genes. Detailed description of characterization, ... more In silico Characterization of Ethylene Soybean Genes. Detailed description of characterization, gene localization and gene onthology (GO) of ethylene soybean genes. (PDF 12 kb)
Figure S1. Soybean Chromosomal Ideogram; Figure S2. Gene Ontology Classification; Figure S3. Pro... more Figure S1. Soybean Chromosomal Ideogram; Figure S2. Gene Ontology Classification; Figure S3. Protein Orthology by Best Bidirectional Hit (BBH) Analysis; Figure S4. ACSs Classification; Figure S5. Differential Expression of Genes Related to Soybean Ethylene Biosynthesis in Transcriptomes Under Drought Stress Conditions; Figure S6. Differential Expression of Genes Related to Soybean Ethylene Signal Transduction in Transcriptomes Under Drought Stress Conditions; Figure S7. Comparison of Ethylene Biosynthesis and Signaling Differential Gene Expression Among Similar Tissues in Soybean Cultivars Under Drought Stress Conditions; Figure S8. Expression of Ethylene-Related Genes in Soybean Under Drought Stress Conditions; Figure S9. Evaluation of Physiological Parameters in Soybean Cultivars Under Drought Stress Conditions; Figure S10. Levels of Ethylene Production and Free ACC in Soybean Under Drought Stress Conditions. (PDF 3938 kb)
Plants, 2022
Methyl jasmonate hormone can stimulate the production of several metabolites responsible for impr... more Methyl jasmonate hormone can stimulate the production of several metabolites responsible for improving fruit quality and nutritional attributes related to human health. In this context, efforts to manipulate tomatoes, such as using hormonal treatment to increase metabolite levels essential to plant growth and human nutrition, have received considerable attention. The aim of this study was to show the impact of metabolic profile on fruit quality and nutritional properties under exogenous methyl jasmonate during fruit ripening. The treatments were performed using 100 ppm of methyl jasmonate and 100 ppm of gaseous ethylene over 24 h. Ethylene emission, fruit surface color and metabolomics analysis were measured at 4, 10, and 21 days after harvest, considering the untreated fruits as control group. Methyl jasmonate induced the production of amino acids—mainly glutamine, glutamic acid and γ-aminobutyric acid (at least 14-fold higher)—and fatty acids—mainly oleic, linoleic, and linolenic ...
Foods, 2021
The application of exogenous jasmonate can stimulate the production of ethylene, carotenoids, and... more The application of exogenous jasmonate can stimulate the production of ethylene, carotenoids, and aroma compounds and accelerate fruit ripening. These alterations improve fruit quality and make fruit desirable for human consumption. However, fruit over-ripening results in large losses of fruit crops. This problem is overcome by applying 1-methylcyclopropene to the fruits, due to its capacity to block the ethylene receptors, suppressing fruit ripening. In this study, treatments with only 1-methylcyclopropene and both 1-methylcyclopropene and methyl jasmonate were administered to observe whether exogenous methyl jasmonate can improve the metabolite levels in fruits with blocked ethylene receptors. Fruit pericarps were analyzed at 4, 10, and 21 days after harvest (DAH) and compared with untreated fruits. The post-harvest treatments affected primary metabolites (sugars, organic acids, amino acids, and fatty acids) and secondary metabolites (carotenoids, tocopherols, and phytosterols). H...
Our knowledge of the factors mediating ethylene-dependent and-independent ripening of climacteric... more Our knowledge of the factors mediating ethylene-dependent and-independent ripening of climacteric fruit remains limited. Besides the known importance of ethylene roles, auxin has also been emerged as crucial to regulating ripening. Furthermore, the crosstalk between ethylene and auxin in tomato fruit ripening still awaits clarification. ERFs (Ethylene Responsive Factors) are transcription factors belonging to a large family acting downstream on ethylene signaling that direclty regulate ripening-related metabolisms, but their specific roles are still lacking. We present here a comprehensive expression profiling of tomato ERFs in wild-type and tomato ripening-impaired tomato mutants (Nr, rin and nor) indicating that out of the 77 ERFs present in the tomato genome, 27 show enhanced expression at the onset of ripening, while 28 display a ripening-associated decrease in expression, suggesting that different ERFs may have contrasting roles in fruit ripening. Members of subclass E, ERF.E1, ERF.E2 and ERF.E4, show dramatic down-regulation in the ripening mutants suggesting their expression might be instrumental to fruit ripening. The study illustrates the high complexity of the regulatory network interconnecting RIN and ERFs and identifies subclass E members as the most active ERFs in ethylene-and RIN/NOR-dependent ripening. Additionally, with the aim to shed more light into ethylene and auxin interplay, hormonal treatments were applied to tomato fruits and several ripening aspects were then evaluated such as the volatile profile. Overall, results elicited that auxin delay the onset of ripening further showing epistatic effects over the influence of ethylene. Several ripening-related genes, including components of the ethylene signaling, were affected by auxin suggesting potential crosstalk points between the two hormones. Moreover, ethylene appears as potentially part of the auxin regulation through inducing its conjugation. The modulation of hormone levels in tomato fruit throughout ripening can be useful to help designing approaches that both improve fruit quality and extend shelf life.
Frontiers in Plant Science, 2018
Scientific Reports, 2017
Phytochomes and plant hormones have been emerging as important regulators of fleshy fruit biology... more Phytochomes and plant hormones have been emerging as important regulators of fleshy fruit biology and quality traits; however, the relevance of phytochrome-hormonal signaling crosstalk in controlling fruit development and metabolism remains elusive. Here, we show that the deficiency in phytochrome chromophore phytochromobilin (PΦB) biosynthesis inhibits sugar accumulation in tomato (Solanum lycopersicum) fruits by transcriptionally downregulating sink-and starch biosynthesis-related enzymes, such as cell-wall invertases, sucrose transporters and ADP-glucose pyrophosphorylases. PΦB deficiency was also shown to repress fruit chloroplast biogenesis, which implicates more limited production of photoassimilates via fruit photosynthesis. Genetic and physiological data revealed the involvement of auxins and cytokinins in mediating the negative impact of PΦB deficiency on fruit sink strength and chloroplast formation. PΦB deficiency was shown to transcriptionally repress type-A TOMATO RESPONSE REGULATORs and AUXIN RESPONSE FACTORs both in pericarp and columella, suggesting active phytochrome-hormonal signaling crosstalk in these tissues. Data also revealed that PΦB deficiency influences fruit ripening by delaying the climacteric rise in ethylene production and signaling. Altogether, the data uncover the impact of phytochromobilin deficiency in fine-tuning sugar metabolism, chloroplast formation and the timing of fruit ripening and also reveal a link between auxins, cytokinins and phytochromes in regulating sugar import and accumulation in fruits. Photoreceptor-mediated light perception and signaling have long been described to regulate the development and metabolism of fleshy fruits, ultimately affecting their final composition 1, 2. In tomato (Solanum lycopersicum), the model species for fleshy fruit physiology 3 , red/far-red light perception via phytochromes has emerged as a relevant source of environmental information controlling fruit ripening and carotenogenesis 4-6. Phytochromes (PHYs) are part of a multigene family, which in tomato encompasses five members: SlPHYA, SlPHYB1, SlPHYB2, SlPHYE and SlPHYF 7. Functional PHYs are homodimers associated with a conserved chromophore known as phytochromobilin (PΦB), which upon red light exposure undergoes a conformational alteration that triggers light signaling 8. Hence, tomato chromophore-deficient mutants, such as yellow-green-2 (yg-2) and aurea (au), are deficient in functional phytochromes, resulting in phenotypic changes such as increased stem and petiole elongation as well as pale-green leaves and fruits 3. Once activated by light, phytochromes are transported to the nucleus 8 , where they inhibit the PHYTOCHROME INTERACTION FACTORs (PIFs), negative regulators of light response, and promote photomorphogenesis-promoting factors such as LONG HYPOCOTYL 5 (HY5) by downregulating the protein complexes formed by CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1), DETIOLATED1 (DET1), DAMAGE DNA BINDING1 (DDB1) and CULLIN4 (CUL4) 8-11. In accordance with their key functions in light signal transduction, overexpression or knockout/knockdown of tomato genes encoding PIF,
Acta Physiologiae Plantarum, 2017
The plant fruiting process requires more energy and availability of soil water. Consequently, ide... more The plant fruiting process requires more energy and availability of soil water. Consequently, identifying the appropriate time for additional water supplying for cultivation of mango is an important part of successful crop handling for production of fruit with high quality. Therefore, we studied effects of additional water supplied by irrigation on chlorophyll fluorescence parameters in a field experiment during phenological stages of Mangifera indica L. cv. Ubá. Our results showed that the irrigation at specific periods of plant development improved fluorescence parameters (resulting in high values of the performance index), preventing damage of the photosynthetic apparatus, which positively influenced the supply of photoassimilates to fruit load. Furthermore, the results suggest that the additional water supply by irrigation in rainfed mango trees is recommended for maintaining high photosynthetic performance just during fruit development and fruit maturation.
Plant physiology, Jan 14, 2017
Senescence is the process that marks the end of leaves lifespan. As it progresses, the massive ma... more Senescence is the process that marks the end of leaves lifespan. As it progresses, the massive macromolecular catabolism dismantles the chloroplasts and, consequently, decreases the photosynthetic capacity of these organs. Thus, senescence manipulation is a strategy to improve plant yield by extending the leaf photosynthetically active window of time. However, it remains to be addressed if this approach can improve fleshy fruit production and nutritional quality. One way to delay senescence initiation is by regulating key transcription factors (TFs) involved in triggering this process, such as the NAC TF ORESARA1 (ORE1). Here, three senescence-related NAC TFs from Solanum lycopersicum were identified, namely SlORE1S02, SlORE1S03 and SlORE1S06. All three genes showed to be responsive to senescence-inducing stimuli and post-transcriptionally regulated by the microRNA miR164. Moreover, the encoded proteins physically interacted with the chloroplast maintenance related TF SlGLKs. This c...
Plant & cell physiology, Jan 14, 2016
Although chlorophyll (Chl) degradation is an essential biochemical pathway for plant physiology, ... more Although chlorophyll (Chl) degradation is an essential biochemical pathway for plant physiology, our knowledge regarding this process retains unfilled gaps. Pheophytinase (PPH) was shown to be essential for Chl breakdown in dark-induced senescent leaves. However, the catalyzing enzymes involved in pigment turnover and fruit ripening-associated degreening are still controversial. Chl metabolism is closely linked to the biosynthesis of other isoprenoid-derived compounds, such as carotenoids and tocopherols, which are also components of the photosynthetic machinery. Chls, carotenoids and tocopherols share a common precursor, geranylgeranyl diphosphate, produced by the plastidial methylerythritol 4-phosphate (MEP) pathway. Additionally, the Chl degradation-derived phytol can be incorporated into tocopherol biosynthesis. In this context, tomato turns out as an interesting model to address isoprenoid-metabolic crosstalk since fruit ripening combines degreening and an intensely active MEP ...
beta-ionone (beta I), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a... more beta-ionone (beta I), 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 beta I 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 beta I (16 mg/100 g body weight), GO (25 mg/100 g body weight), beta I 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 beta I (91 +/- 11 and 14 +/- 3) and beta I+GO groups (96 +/- 5 and 19 +/- 2). Apoptosis level, identified by classical apoptosis morphologi...
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.
BMC Plant Biology, 2015
Background: Tomato fruit ripening is controlled by ethylene and is characterized by a shift in co... more Background: Tomato fruit ripening is controlled by ethylene and is characterized by a shift in color from green to red, a strong accumulation of lycopene, and a decrease in β-xanthophylls and chlorophylls. The role of other hormones, such as auxin, has been less studied. Auxin is retarding the fruit ripening. In tomato, there is no study of the carotenoid content and related transcript after treatment with auxin. Results: We followed the effects of application of various hormone-like substances to "Mature-Green" fruits. Application of an ethylene precursor (ACC) or of an auxin antagonist (PCIB) to tomato fruits accelerated the color shift, the accumulation of lycopene, α-, β-, and δ-carotenes and the disappearance of β-xanthophylls and chlorophyll b. By contrast, application of auxin (IAA) delayed the color shift, the lycopene accumulation and the decrease of chlorophyll a. Combined application of IAA + ACC led to an intermediate phenotype. The levels of transcripts coding for carotenoid biosynthesis enzymes, for the ripening regulator Rin, for chlorophyllase, and the levels of ethylene and abscisic acid (ABA) were monitored in the treated fruits. Correlation network analyses suggest that ABA, may also be a key regulator of several responses to auxin and ethylene treatments. Conclusions: The results suggest that IAA retards tomato ripening by affecting a set of (i) key regulators, such as Rin, ethylene and ABA, and (ii) key effectors, such as genes for lycopene and β-xanthophyll biosynthesis and for chlorophyll degradation.
Journal of Botany, 2011
Chromoplasts are nonphotosynthetic plastids that accumulate carotenoids. They derive from other p... more Chromoplasts are nonphotosynthetic plastids that accumulate carotenoids. They derive from other plastid forms, mostly chloroplasts. The biochemical events responsible for the interconversion of one plastid form into another are poorly documented. However, thanks to transcriptomics and proteomics approaches, novel information is now available. Data of proteomic and biochemical analysis revealed the importance of lipid metabolism and carotenoids biosynthetic activities. The loss of photosynthetic activity was associated with the absence of the chlorophyll biosynthesis branch and the presence of proteins involved in chlorophyll degradation. Surprisingly, the entire set of Calvin cycle and of the oxidative pentose phosphate pathway persisted after the transition from chloroplast to chromoplast. The role of plastoglobules in the formation and organisation of carotenoid-containing structures and that of theOrgene in the control of chromoplastogenesis are reviewed. Finally, using transcrip...
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.
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 ...
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Papers by Eduardo Purgatto