Papers by Alexandre Levi Rodrigues Chaves
Virus Diseases of Ornamental Plants, 2021
Journal of Seed Science, Dec 11, 2012
O Lettuce mosaic virus espécie mais importante na cultura de alface (Lactuca sativa L.) no Brasil... more O Lettuce mosaic virus espécie mais importante na cultura de alface (Lactuca sativa L.) no Brasil, causando sintomas de mosaico, clareamento das nervuras, necrose, distorção foliar e redução do crescimento da planta, pode ser transmitido por sementes com uma taxa de 1% a 16%, dependendo da interação dos genótipos de alface com os isolados LMV-Most ou LMV-Common. Neste trabalho, avaliou-se a detecção do LMV por PTA-ELISA, em sementes e plântulas de oito genótipos de alface: 'Vanessa Roxa', 'Baba de Verão', 'Verdinha', 'Maravilha das 4 Estações', 'Evely', 'Marcela', 687 ('Sapore' x 'Vera' ), 784 ('Sapore' x 'Vera'), utilizando anti-soro policlonal específico. O vírus não foi detectado em sementes do genótipo 'Verdinha' e, em plântulas dos genótipos 687, 'Marcela' e 'Evely', após a germinação em papel e 687, 784 e 'Marcela' com gene mo1¹, após a germinação em substrato. A avaliação individual do número de sementes infectadas foi de 100% para 'Vanessa Roxa' e 'Baba de Verão', 87,7% para 'Verdinha', 46,6% para 'Maravilha das 4 Estações' e 16,6% para 'Evely'. Nos genótipos com gene de resistência o percentual foi de 15,6%, 26,6%, 90% em 'Marcela', 687 e 784, respectivamente. A detecção do LMV por PTA-ELISA foi eficiente tanto em sementes quanto em plântulas.
Summa Phytopathologica, Jun 1, 2012
International Journal of Green Economics
Sustainability and innovation are two inseparable concepts. This study aims to integrate new tech... more Sustainability and innovation are two inseparable concepts. This study aims to integrate new technologies with the development of energy trading projects grounded on environmental sustainability and energetic efficiency. These projects, based on peer-to-peer (P2P) energy trading systems, may significantly change the paradigm of energy distribution management, while also introducing stronger renewable energy sources. As such, in this study an extensive literature review is conducted with the objective of introducing and explaining P2P systems, and a review of existing projects is made to show the benefits these systems may have. Also, a survey is conducted to understand how several factors influence the implementation value of P2P
Animal : an international journal of animal bioscience, Jan 20, 2015
In vitro batch cultures were used to screen four fibrolytic enzyme mixtures at two dosages added ... more In vitro batch cultures were used to screen four fibrolytic enzyme mixtures at two dosages added to a 60 : 40 silage : concentrate diet containing the C4 tropical grass Andropogon gayanus grass ensiled at two maturities - vegetative stage (VS) and flowering stage (FS). Based on these studies, one enzyme mixture was selected to treat the same diets and evaluate its impact on fermentation using an artificial rumen (Rusitec). In vitro batch cultures were conducted as a completely randomized design with two runs, four replicates per run and 12 treatments in a factorial arrangement (four enzyme mixtures×three doses). Enzyme additives (E1, E2, E3 and E4) were commercial products and contained a range of endoglucanase, exoglucanase and xylanase activities. Enzymes were added to the complete diet 2 h before incubation at 0, 2 and 4 μl/g of dry matter (DM). Gas production (GP) was measured after 3, 6, 12, 24 and 48 h of incubation. Disappearance of DM (DMD), NDF (NDFD) and ADF (ADFD) were de...
Boletim de Botânica, Dec 1, 2014
Plant Science, 2020
pathway played by salicylic acid, gentisic acid, nitric oxide, polyamines and non-enzymatic antio... more pathway played by salicylic acid, gentisic acid, nitric oxide, polyamines and non-enzymatic antioxidants in compatible and incompatible Solanum-tomato mottle mosaic virus interactions,
Ornamental Horticulture
Ornamental plants, which were originally grown for magical or esthetic reasons, have gained indus... more Ornamental plants, which were originally grown for magical or esthetic reasons, have gained industrial status in recent decades, contributing economically to the development of several countries. The presence of pathogens, especially viruses, can interfere in production by causing symptoms in leaves and flowers, thereby depreciating the product and affecting normal plant growth. Furthermore, perennial species can act as a natural reservoir for other crops. Depending on the species, viruses can be transmitted by vegetative propagation, contact, insect vectors, pollen and seeds. As such, knowledge of the genetic diversity, geographic distribution and biological properties of viruses may contribute to preventing future infections. In this review, a number of tropical species infected by viruses reported in Brazil are presented, highlighting the first occurrences of new viral species. Aspects related to virus control and management in ornamental plants are also discussed.
Revista Mexicana de Fitopatología, Mexican Journal of Phytopathology
Xantosoma riedelianum, also called “mangarito” in Brazil, is an unconventional food plant (UFP) o... more Xantosoma riedelianum, also called “mangarito” in Brazil, is an unconventional food plant (UFP) of the Araceae family native to tropical America. Foliar samples of the X. riedelianum showing mosaic, mottle and vein clearing symptoms were collected in the municipality of Monte Alegre (São Paulo State). Transmission electron microscope observations, mechanical transmission to experimental plants, serological (DAS-ELISA) and RT-PCR analyzes indicated that the symptoms could be associated with the presence of dasheen mosaic virus (DsMV, Potyvirus). This is the first report of DsMV in X. riedelianum in Brazil.
Revisao anual de patologia de plantas, Mar 5, 2023
RESUMO Durante a evolução, as plantas desenvolveram um conjunto complexo de mecanismos de defesa ... more RESUMO Durante a evolução, as plantas desenvolveram um conjunto complexo de mecanismos de defesa morfológicos, bioquímicos e moleculares, pré-formados e induzíveis, que lhes permitiram conviver em condições estressantes. Além disso, a capacidade das plantas em sintetizar compostos orgânicos (metabólitos primários, secundários e hormônios vegetais), tem garantido sucesso na colonização de ambientes desafiadores. Com a prática da monocultura intensiva, visando a alimentar uma população cada vez mais numerosa, a incidência das fitoviroses tem aumentado quase que na mesma proporção. Assim, práticas de controle agressivas ao ambiente e à saúde humana, como a utilização de agrotóxicos, passaram a ser recomendadas de forma descontrolada, o que vem incentivando a busca de uma agricultura mais sustentável. A compreensão dos mecanismos utilizados pelos vírus para interferir no metabolismo em interações compatíveis e incompatíveis, bem como aqueles utilizados pelas plantas para suplantar ou não a infecção, é fundamental e pode ajudar a esclarecer pontos importantes nas interações planta-vírus, viabilizando a recomendação e utilização de um manejo ecologicamente amigável. Nesta revisão, serão abordados os aspectos moleculares das interações planta-vírus, as alterações metabólicas induzidas pelos vírus, a utilização de produtos naturais visando ao controle das fitoviroses e aplicação dessas substâncias na agricultura sustentável.
Archives of Virology
A putative new virus with sequence similarity to members of the genus Cavemovirus in the family C... more A putative new virus with sequence similarity to members of the genus Cavemovirus in the family Caulimoviridae was identified in wild chicory (Cichorium intybus) by next-generation sequencing (NGS). The putative new virus was tentatively named "chicory mosaic cavemovirus" (ChiMV), and its genome was determined to be 7,775 nucleotides (nt) long with the typical genome organization of cavemoviruses. ORF1 encodes a putative coat protein/movement polyprotein (1,278 aa), ORF2 encodes a putative replicase (650 aa), and ORF3 encodes a putative transactivator factor (384 aa). The first two putative proteins have 46.2% and 68.7% amino acid sequence identity to the CP/MP protein (YP_004347414) and replicase (YP_004347415), respectively, of sweet potato collusive virus (SPCV). ORF3 encodes a protein with 38.5% amino acid sequence identity to the putative transactivator factor (NP_056849) of cassava vein mosaic virus (CsVMV). The new putative viral genome and those of three cavemoviruses (epiphyllum virus 4 [EpV-4], SPCV, and CsVMV) differ by 24-27% in the nt sequence of the replicase gene, which exceeds the species demarcation cutoff (>20%) for the family.
Summa Phytopathologica, 2000
Journal of Plant Pathology, 2016
Brazil is the world’s main passion fruit (Passiflora edulis Sims) producer. The high incidence of... more Brazil is the world’s main passion fruit (Passiflora edulis Sims) producer. The high incidence of passion fruit woodiness (PFW) induced by Cowpea aphid-borne mosaic virus (CABMV) from the genus Potyvirus, which is transmitted non-persistently by several aphid species, has caused constant and significant production losses, prompting producers to abandon or renew orchards once a year. The present study evaluated the effects of agricultural and ecological conditions on the abundance and composition of aphid populations and the influence thereof on CABMV spread in a passion fruit orchard established with young (30 cm tall) and advanced (80 cm tall) seedlings. The ecological and agricultural characteristics of the region negatively influenced the local aphid population, while aphid swarms and population dynamic were not affected by rainfall, temperature and season. However, when considered together these factors negatively influenced the local aphid population, manifested as low abundanc...
Summa Phytopathologica, 2001
Journal of Plant Pathology, 2014
Tropaeolum majus (Tropaeolaceae), popularly known as garden nasturtium and often confused with Na... more Tropaeolum majus (Tropaeolaceae), popularly known as garden nasturtium and often confused with Nasturtium officinale (Brassicaceae), is widely cultivated in southern and southeastern regions of Brazil as ornamental, medicinal and food plant. T. majus plants from Sao Paulo state showing symptoms of mosaic, blistering and leaf distortion were subjected to biological, serological and molecular tests for virus diagnosis. Inoculations on Chenopodium species induced local lesions and reproduced the original symptoms on T. majus. Naturally and experimentally infected T. majus reacted positively to an antiserum raised against a potyvirus group in DAS-ELISA and against a Turnip mosaic virus (TuMV) antiserum in indirect ELISA. Total RNA was extracted from infected T. majus leaf, and RT-PCR carried out using primers designed on the sequence of part of the cytoplasmic inclusion region of the potyviral genome (Ha et al., 2008), produced a fragment ca. 700 bp in size The fragment was directly seq...
New Disease Reports, 2021
Archives of Virology, 2020
Morphological, biological, serological, and molecular tests underpin the description of costus st... more Morphological, biological, serological, and molecular tests underpin the description of costus stripe mosaic virus (CoSMV) as a new member of the genus Potyvirus, family Potyviridae. Found affecting the native ornamental Costus spiralis in Brazil, the pathogen showed a severely restricted natural and experimental host range. Excluding the poly(A) tail, the CoSMV genome contains a large open reading frame (ORF) of 9,446 nucleotides that encodes a polyprotein with 3,046 amino acids, which is potentially cleaved into ten products, and a small ORF (77 amino acids) knows as PIPO. Genome analysis demonstrated the highest CoSMV nucleotide sequence identity to onion yellow dwarf virus (51.79%). No evidence of recombination was detected in the CoSMV genome, and phylogenetic analysis revealed its basal position in a group formed by members of the genus Potyvirus, along with Cyrtanthus elatus virus A (Vallota speciosa virus) and canna yellow streak virus. CoSMV was not transmitted by aphids of the species Aphis solanella, Myzus persicae or Uroleucon sonchi, which could be due to mutations in the HC-Pro motifs required for aphid transmission. A divergence in the P1 protein cleavage site was found when compared to other members of the family Potyviridae. Based on its unique biological and molecular characteristics and the current species demarcation criteria, we propose CoSMV to be a new tentative member of the genus Potyvirus.
European Journal of Plant Pathology, 2019
Tomato is an important crop, which can be infected by a wide range of pathogens. Among plant viru... more Tomato is an important crop, which can be infected by a wide range of pathogens. Among plant viruses, tomato mosaic virus (ToMV) had been described as the most troublesome to tomato crops. Recently, tomato mottle mosaic virus (ToMMV) has gained attention. ToMV and ToMMV are now considered as major threats to tomato. Therefore, the study of some aspects of these viral species would be an advance for the understanding of the disease in the field. In this context, our work aimed: i) to look for possible recombination events in the emergence of ToMMV, ii) to verify the involvement of Tm-2 2 in the resistance against ToMMV, and iii) to evaluate the behavior of ToMV and ToMMV in tomato cultivars and hybrid lines. Our results revealed no recombination events involving ToMMV. Also, our results suggested that Tm-2 2 confers resistance to ToMMV. Brazilian commercial cultivars and hybrid lines 'Alambra', 'Débora Max', 'Santa Clara', 'Santa Cruz', 'Bubble Candy', 'Kada' and 'Salada' were evaluated with ToMMV and ToMV. Only 'Alambra' showed partial resistance to ToMMV and ToMV and 'Debora Max' to ToMV. Finally, it should be noted that these commercial tomato cultivars and hybrids tested were more susceptible to the Brazilian ToMMV isolate when compared to ToMV since the symptoms were much more drastic. The results presented here have important implications for breeding virusresistant tomatoes. Keywords Recombination. Tm-2 2. Tomato; ToMMV. ToMV Tomato (Solanum lycopersicum L.) is one of the most important crops in the world, with an annual production of around 192.2 million tons of fresh weight (FW) which is equivalent to rice, another crop consumed by billions of people (FAO 2014). Besides this large production, this edible fruit is a source of carotenoids and presents limited caloric supply, high fiber content, minerals, vitamins (mainly vitamin A) and phenols, like flavonoids. From all these reasons, this fruit has been pointed out as a functional food, providing physiological benefits and basic nutritional requirements (Dorais et al. 2008). Cultivars, hybrids and wild species related to tomato are susceptible to a large number of pathogens (Ambrós
Tropical Plant Pathology, 2018
In 2016, a virus causing foliar mosaic and color break in flowers was isolated from Gloriosa supe... more In 2016, a virus causing foliar mosaic and color break in flowers was isolated from Gloriosa superba plants (gloriosa lily) purchased at four different flower markets in the city of São Paulo (São Paulo state, Brazil). Gloriosa lily leaf and flower extracts were inoculated on indicator plants from the families Amaranthaceae, Cucurbitaceae, and Solanaceae, and processed for observations under transmission electron microscope. Following serological tests (ELISA) with potyvirus group and cucumber mosaic virus antisera, the extracts were also submitted to RT-PCR, sequencing, and sequence analyses. The virus was not mechanically transmitted and ELISA results were negative. However, several flexuous particles were observed in negatively stained leaf extract, as well as pinwheel and lamellar inclusions typical of potyvirus infections in ultrathin sections of infected parenchymal leaf tissue. Analysis of the sequences corresponding to the coat protein region obtained after RT-PCR and sequencing indicated nucleotide identity ranging from 84 to 99% with Gloriosa stripe mosaic virus (GSMV, genus Potyvirus). A survey of GSMV occurrence in gloriosa lily producing regions in São Paulo state revealed 100% infection in all of the crops assessed.
Genome announcements, Jan 10, 2018
The complete nucleotide sequence of an isolate of tomato mottle mosaic virus (ToMMV) was determin... more The complete nucleotide sequence of an isolate of tomato mottle mosaic virus (ToMMV) was determined. The virus, originally isolated from symptomatic tomato plants found in a county near the city of São Paulo, Brazil, has a genome with 99% nucleotide sequence identity with ToMMV from Mexico, China, Spain, and the United States.
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Papers by Alexandre Levi Rodrigues Chaves