Papers by Arthur Fett-neto
Journal of Plant Physiology, Nov 1, 1992
ABSTRACT
Nature Biotechnology, Jun 1, 1993
Plant Physiology and Biochemistry, Feb 1, 2019
Mimosine is a non-protein amino acid of Fabaceae, such as Leucaena spp. and Mimosa spp. Several r... more Mimosine is a non-protein amino acid of Fabaceae, such as Leucaena spp. and Mimosa spp. Several relevant biological activities have been described for this molecule, including cell cycle blocker, anticancer, antifungal, antimicrobial, herbivore deterrent and allelopathic activities, raising increased economic interest in its production. In addition, information on mimosine dynamics in planta remains limited. In order to address this topic and propose strategies to increase mimosine production aiming at economic uses, the effects of several stressrelated elicitors of secondary metabolism and UV acute exposure were examined on mimosine accumulation in growth room-cultivated seedlings of Leucaena leucocephala spp. glabrata. Mimosine concentration was not significantly affected by 10 ppm salicylic acid (SA) treatment, but increased in roots and shoots of seedlings treated with 84 ppm jasmonic acid (JA) and 10 ppm Ethephon (an ethylene-releasing compound), and in shoots treated with UV-C radiation. Quantification of mimosine amidohydrolase (mimosinase) gene expression showed that ethephon yielded variable effect over time, whereas JA and UV-C did not show significant impact. Considering the strong induction of mimosine accumulation by acute UV-C exposure, additional in situ ROS localization, as well as in vitro antioxidant assays were performed, suggesting that, akin to several secondary metabolites, mimosine may be involved in general oxidative stress modulation, acting as a hydrogen peroxide and superoxide anion quencher.
Tree Physiology, Feb 1, 2005
Psychotria umbellata Vell. (Rubiaceae), a Brazilian coastal woody species, produces umbellatine (... more Psychotria umbellata Vell. (Rubiaceae), a Brazilian coastal woody species, produces umbellatine (also known as psychollatine), an analgesic indole alkaloid. An in vitro embryogenic regeneration protocol capable of yielding alkaloid-accumulating plants was developed. Rhizogenic calli, which were obtained from stem segments derived from rooted apical cuttings, were cultured on Murashige and Skoog's (MS) medium containing either 1 mg l-1 NAA (naphthalene acetic acid) and no kinetin, or 5 mg l-1 NAA + 1 mg l-1 kinetin. Calli did not accumulate umbellatine. Segments of rhizogenic callus were cultured on complete MS medium with various concentrations of kinetin and sucrose. Plant regeneration was best in the light with 0.25 mg l-1 of kinetin and 1.5% sucrose. After 3 months of acclimatization in soil mixture, plant survival was 81%. Leaves of 10-month-old regenerated plants yielded umbellatine concentrations equivalent to those of adult forestgrown plants.
Plant Science, 2020
Adventitious roots (ARs) form from above-ground organs, and auxins are major regulators of AR dev... more Adventitious roots (ARs) form from above-ground organs, and auxins are major regulators of AR development. TIR1/AFB F-box proteins act as well-established auxin receptors. Auxin transport involves the PINFORMED (PIN) auxin efflux carriers and AUXIN RESISTANT 1/LIKE AUX1 (AUX1/LAX1) influx carriers. To further elucidate the basis of AR development, we investigated the participation of these proteins and phosphorylation of PINs during adventitious rooting in hypocotyls of pre-etiolated flooded Arabidopsis thaliana seedlings. Mutant and GUS localization studies indicated that AFB2 is important in AR development. AUX1 loss-of-function reduced AR numbers, which could not be reversed by exogenous auxin. Single mutations in LAX1, LAX2 and LAX3 had no negative impact on AR development and the first and last mutations even promoted it. Double and triple mutants of AUX1, LAX1, LAX2 and LAX3 significantly reduced rooting, which was reversed by exogenous auxin. AUX1 was essential in AR establishment, with LAX3 apparently acting in conjunction. Proper phosphorylation of PINs by PID, WAG1 and WAG2 and auxin transport direction were equally essential for AR establishment. PIN1, AUX1 and AFB2 (overexpression) and LAX1, LAX3, PIN4 and PIN7 (downregulation) emerged as potential targets for genetic manipulation aiming at improving AR development.
Natural Product Research, Mar 1, 2013
Introduction: N,β-D-glucopyranosyl vincosamide (GPV), a major alkaloid of Psychotria leiocarpa, c... more Introduction: N,β-D-glucopyranosyl vincosamide (GPV), a major alkaloid of Psychotria leiocarpa, constitutes up to 2.5 % of the dry weight in leaves; alkaloids are often reported as toxic compounds playing direct herbivore protection. Here we evaluate the dynamics of accumulation and possible function to this alkaloid for P. leiocarpa. Experimental: Field-grown P. leiocarpa leaves were submitted to UV-B, wounding or jasmonate stresses and GPV content analyzed by HPLC after 48h/ 96h of exposure; relevant parameters related to each stress condition or to evaluate plant physiological status were also taken. Isolated GPV was tested for deterrent activity in three different models and antioxidant assays were performed to measure quenching of reactive oxygen species (ROS). All assays were performed in biological quadruplicates and repeated at least twice independently. The results were analyzed by ANOVA followed by Tukey (P ≤ 0.05). Results/Discussion: Alkaloid content was not elicited by wounding or jasmonate. GPV did not inhibit herbivory in two unrelated generalist models (Helix aspersa and Spodoptera frugiperda) or in a specific interaction model (Heliconius erato fed with Passiflora suberosa). In situ staining assay showed quenching activity of hydrogen peroxide by GPV. Exposure of P. leiocarpa to acute UV-B stress did not change GPV or chlorophyll content, indicating high tolerance to this stress by the species. In vitro antioxidant tests against singlet oxygen, superoxide anions and hydroxyl radicals showed efficient quenching activity of the alkaloid. Conclusion: GPV was not effective as antifeedant in tested models, and, due to its broad antioxidant activity, it may act indirectly in P. leiocarpa protection against oxidative stress generated upon herbivory, wounding, UV exposure, and perhaps other environmental stresses.
Theoretical and Experimental Plant Physiology, 2013
Oleoresin is a key defense strategy of advanced gymnosperms, based on the combination of a comple... more Oleoresin is a key defense strategy of advanced gymnosperms, based on the combination of a complex anatomical structure of resin ducts and elaborate terpene biochemistry. Given the vast array of oleoresin economic applications in the chemical, pharmaceutical, agrochemical, and biofuel industries, translating factors that regulate terpene biosynthesis into higher oleoresin yield is a challenge for the forestry industry. Field tests with approximately 3,500 28-year-old slash pine (Pinus elliottii Engelm. var. elliottii) trees were carried out from 2005 to 2008, under the subtropical climate of Southern Brazil, in order to examine the seasonal profile of oleoresin production stimulation in response to different chemical adjuvants, after mechanical injury. Yields of trees treated with oleoresin-inducing pastes containing alternative adjuvants were compared to the standard commercial one used on an industrial scale (based on the ethylene-releasing compound-2-chloroethylphosphonic acid-CEPA). Significant increases in pine oleoresin yield were observed by modulating its biosynthesis and using chemical stimulants affecting defense responses (benzoic acid, used in addition to CEPA) and biosynthetic enzymes (metal cofactors of terpene synthases, iron or potassium, used as replacements for CEPA). Oleoresin stimulation was consistent over at least four consecutive years. Overall effectiveness of oleoresin yield adjuvant stimulation was higher in the faster growth seasons, although potassium was effective in all of them. Combining metal cofactors did not show synergistic or additive interactions. The results suggest that higher oleoresin yields can be obtained by using individual adjuvants of the same signaling pathway in a season-specific fashion.
Industrial Crops and Products, May 1, 2008
The production of oleoresin from Pinus trees is a relevant economic activity in developing countr... more The production of oleoresin from Pinus trees is a relevant economic activity in developing countries, since it provides terpenes used in the chemical industry. The oleoresin production by trees of Pinus elliottii in southern Brazil was investigated. Trees of approximately 28 years of age were individually analyzed for oleoresin yield using the bark streak method of wounding for resin tapping. Plain wounding and wounding followed by application of commercial resin stimulant paste, composed of an ethylene precursor (CEPA) and sulphuric acid, were used as reference treatments. The optimum concentrations of CEPA and sulphuric acid in the stimulant paste were investigated in relation to oleoresin yield, as well as the shape of wound and tree diameter. The replacement of CEPA with auxin in the resin stimulant paste was also evaluated. The results showed that both horizontal and V-shaped streaks are equivalent for oleoresin yield. Trees with larger diameter at breast height, defined as the trunk diameter 1.4 m above the ground (22-23.5 cm) yielded more oleoresin than their smaller counterparts (18-19.5 cm). Oleoresin yield was equivalent with stimulant pastes containing between 1.5 and 4.5% CEPA. Trees exposed to stimulant pastes containing from 3 to 4.5% CEPA had average year oleoresin yield above 5 kg. The use of 20% sulphuric acid in the stimulant paste resulted in higher oleoresin yields. Auxin (2,4-D at 1 mM) was effective in replacing CEPA in the stimulant paste, particularly in smaller DBH trees or after 1 year of application in larger DBH individuals. In conclusion, cost reductions on resin tapping can be achieved by adjusting stimulant paste components and managing subsets of trees in specific fashion based on DBH ranges.
Phytochemistry Letters, Jun 1, 2021
Planta Medica, Nov 11, 2020
Tropane alkaloids are specialized plant metabolites mostly found in the Erythroxylaceae and Solan... more Tropane alkaloids are specialized plant metabolites mostly found in the Erythroxylaceae and Solanaceae families. Although tropane alkaloids have a high degree of structural similarity because of the tropane ring, their pharmacological actions are quite distinct. Brazil is one of the main hotspots of Erythroxylum spp. diversity with 123 species (almost 66% of the species catalogued in tropical America). Erythroxylum pungens occurs in the Caatinga, a promising biome that provides bioactive compounds, including tropane alkaloids. As part of our efforts to investigate this species, 15 alkaloids in specimens harvested under different environmental conditions are presented herein. The occurrence of 3-(2-methylbutyryloxy)tropan-6,7-diol in the stem bark of plants growing in their natural habitat, greenhouse controlled conditions, and after a period of water restriction, suggests that it is a potential chemical marker for the species. This alkaloid was evaluated for several parameters in zebrafish (Danio rerio) as a model organism. Regarding toxicity, teratogenic effects were observed at 19.5 µM and the lethal dose for embryos was 18.4 µM. No mortality was observed in adults, but a behavioral screen showed psychostimulatory action at 116.7 µM. Overall, the alkaloid was able to cause zebrafish behavioral changes, prompting further investigation of its potential as a new molecule in the treatment of depression-like symptoms. In silico, targets involved in antidepressant pathways were identified by docking.
Biology, Feb 16, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Planta Medica, Dec 9, 2020
Selaginella convoluta is a desiccation tolerant plant native to the Brazilian semiarid region (Ca... more Selaginella convoluta is a desiccation tolerant plant native to the Brazilian semiarid region (Caatinga), endowed with an effective drought resistance mechanism. As part of our research efforts to understand the chemical diversity of S. convoluta, dehydrated (harvested in their natural habitat in the dry season) and hydrated (plant acclimated in a laboratory after rehydration) specimens were analyzed by HR-LC-ESI-MS/MS followed by a structural annotation on the Global Natural Products Social Molecular Networking Web platform. The molecular networking approach allowed for putative annotation of 39 metabolites, mainly selaginellins and flavonoids. Based on MS/MS data, three unprecedented selaginellins were annotated: 29-hydroxy selaginellin O, 29-hydroxy selaginellin A, and 4-{[2-(4-hydrophenyl)-6-[2-(4-hydroxyphenyl)ethynyl]phenyl](4-oxocyclohexa-2,5-dien-1-ylidene)methyl}benzaldehyde. Th results pointed out that valuable scientific knowledge can be obtained from studies conducted with plants in their natural habitat by allowing a more realistic profile of chemical diversity. The present study adds new information on specialized metabolites of S. convoluta, mainly flavonoids and selaginellins, and highlights the species as an untapped source of chemobiodiversity from Caatinga.
Biochemical Systematics and Ecology, Dec 1, 2009
Psychollatine is an unusual indole alkaloid produced by Psychotria umbellata Vell, an Atlantic Fo... more Psychollatine is an unusual indole alkaloid produced by Psychotria umbellata Vell, an Atlantic Forest understorey tree. Leaves, young inflorescences and fruit pulp displayed high amounts of psychollatine (from 2.5 to 4.5% dry wt). Seeds accumulated lower quantities (0.2% dry wt), and roots, trace amounts (0.06% dry wt). Alkaloid accumulation was not seasonally affected and leaf content was not significantly enhanced by wounding, exposure to salicylic acid, hydrogen peroxide, or UV. The alkaloid content in leaves decreased upon cutting exposure to auxin. Under strong UV, the amount of chlorophylls did not decrease compared to control contents at 48 and 72 h. Post-harvest psychollatine content in leaves was stable in different temperatures, except at 65 C. Psychollatine was an effective singlet oxygen, superoxide, and peroxide quencher. These antioxidant properties and the constitutively high amount of psychollatine indicate a role for the alkaloid in oxidative stress responses.
Journal of Natural Products, Feb 21, 2008
A monoterpene indole alkaloid, psychollatine ( 1), was isolated from Psychotria umbellata leaves.... more A monoterpene indole alkaloid, psychollatine ( 1), was isolated from Psychotria umbellata leaves. Its structure was characterized by interpretation of spectroscopic data and by comparison of its NMR data with those of croceaine A ( 2) from Palicourea crocea. The configuration of psychollatine ( 1) was established by NOE difference and circular dichroism (CD) techniques, while its conformation was evaluated through molecular modeling studies and NMR coupling constants.
Biotechnology and Bioengineering, Jun 20, 1994
Cell culture of Taxus cuspidata may represent an alternative to extraction of bark as a source of... more Cell culture of Taxus cuspidata may represent an alternative to extraction of bark as a source of taxol and related taxanes. Cell suspensions of a cell line of T. cuspidata were grown for 44 days in shake flasks containing B5C2 medium. Throughout the growth cycle, fresh and dry weight accumulation, taxol yield on a dry weight basis, taxol accumulation in the medium, pH and pigmentation variation in the medium, as well as the uptake of sucrose, glucose, fructose, nitrate, and inorganic phosphate from the culture medium were examined. The results showed that the growth was relatively slow (doubling times of 17 and 20 days for fresh and dry weight, respectively), and taxol accumulation in the cells was non-growth related (higher in the stationary phase) and at relatively low levels (up to 4 mug/g of the extracted dry weight). Taxol concentration in the medium had two peaks: one during the early (0.4mug/mL) and another during the late (0.1-mug/mL) parts of the growth cycle. On a volumetric basis, the average total amount of taxol produced during the stationary phase (day 38) was 0.15 mug/mL, of which approximately 66% was in the medium and 34% was in the cells. Total carbohydrate uptake was closely associated with the increase in dry biomass. Sucrose was apparently extracellularly hydrolyzed after the first 6 days of culture; glucose was used before fructose. Nitrate was assimilated throughout the growth cycle, but phosphate was absorbed within the first week of culture. The pH variation showed an initial drop followed by a trend toward alkalinization for most of the growth period. Dark pigmentation in the medium increased progressively, particularly during the stationary phase. (c) 1994 John Wiley &amp;amp;amp; Sons, Inc.
Nature Biotechnology, Dec 1, 1992
1. Plant Secondary Metabolism and Challenges in Modifying Its Operation: An Overview Naila Cannes... more 1. Plant Secondary Metabolism and Challenges in Modifying Its Operation: An Overview Naila Cannes do Nascimento and Arthur Germano Fett-Neto 2. Suppression Subtractive Hybridization as a Tool to Identify Anthocyanin Metabolism-Related Genes in Apple Skin Yusuke Ban and Takaya Moriguchi 3. Identification of Regulatory Protein Genes Involved in Alkaloid Biosynthesis Using a Transient RNAi System Yasuyuki Yamada, Nobuhiko Kato, Yasuhisa Kokabu, Qingyun Luo, Joseph Gogo Dubouzet, and Fumihiko Sato 4. Site-Directed Mutagenesis and Saturation Mutagenesis for the Functional Study of Transcription Factors Involved in Plant Secondary Metabolite Biosynthesis Sitakanta Pattanaik, Joshua R. Werkman, Que Kong, and Ling Yuan 5. Isolation of Proteins Binding to Promoter Elements of Alkaloid Metabolism-Related Genes Using Yeast One-Hybrid Debora Vom Endt and Giancarlo Pasquali 6. Modulation of Carotenoid Accumulation in Transgenic Potato by Inducing Chromoplast Formation with Enhanced Sink Strength Joyce Van Eck, Xiangjun Zhou, Shan Lu, and Li Li 7. Overexpression of Rate-Limiting Enzymes to Improve Alkaloid Productivity Tomoya Takemura, Yit-lai Chow, Takehiko Todokoro, Takuya Okamoto, and Fumihiko Sato 8. Microbial Expression of Alkaloid Biosynthetic Enzymes for Characterization of Their Properties Hiromichi Minami, Nobuhiro Ikezawa, and Fumihiko Sato 9. Producing a Recombinant Flavin-Containing Monooxygenase from Coffea arabica in Escherichia coli for Screening of Potential Natural Substrates Igor Cesarino and Paulo Mazzafera 10. Efficient Production of Active Form Recombinant Cassava Hydroxynitrile Lyase Using Escherichia coli in Low-Temperature-Culture Hisashi Semba, Eita Ichige, Tadayuki Imanaka, Haruyuki Atomi, and Hideki Aoyagi 11. Introduction of theEarly Pathway to Taxol Biosynthesis in Yeast by Means of Biosynthetic Gene Cluster Construction Using SOE-PCR and Homologous Recombination Pia Dahm and Stefan Jennewein 12. Biocatalytic Synthesis of Tritium (3H) Labelled Taxa-4(5),11(12)-diene, the Pathway Committing Precursor of the Taxoid Diterpenoids Hans Schmeer and Stefan Jennewein 13. USER Cloning and USER Fusion: The Ideal Cloning Techniques for Small and Big Laboratories Hussam H. Nour-Eldin, Fernando Geu-Flores, and Barbara A. Halkier 14. Enrichment of Carotenoids in Flaxseed by Introducing a Bacterial Phytoene Synthase Gene Masaki Fujisawa and Norihiko Misawa 15. Metabolic Engineering by Plastid Transformation as a Strategy to Modulate Isoprenoid Yield in Plants Tomohisa Hasunuma, Akihiko Kondo, and Chikahiro Miyake 16. Engineering High Yields of Secondary Metabolites in Rubia Cell Cultures through Transformation with Rol Genes Victor P. Bulgakov, Yuri N. Shkryl, and Galina N. Veremeichik 17. Flow Cytometric Methods to Investigate Culture Heterogeneities for Plant Metabolic Engineering Vishal Gaurav, Martin E. Kolewe, and Susan C. Roberts 18. Phenylpropanoid Biosynthesis in Leaves and Glandular Trichomes of Basil (Ocimum basilicum L.) Cicero Deschamps and James E. Simon 19. Fusion with Fluorescent Proteins for Subcellular Localization of Enzymes Involved in Plant Alkaloid Biosynthesis Patricia Duarte, Johan Memelink, and Mariana Sottomayor 20. Immunohistochemical Localization of a Putative Flavonoid Transporter in Grape Berries Elisa Petrussa, Enrico Braidot, Marco Zancani, Carlo Peresson, Alberto Bertolini, Sonia Patui, Valentino Casolo, Sabina Passamonti, Francesco Macri, and Angelo Vianello 21. Electrogenic Bromosulfalein Transport in Isolated Membrane Vesicles:
Industrial Crops and Products, Feb 1, 2018
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Papers by Arthur Fett-neto