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Dennis Gonsalves - One of the best experts on this subject based on the ideXlab platform.
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Transgenic Papaya in Hawaii and Beyond
2020Co-Authors: Dennis GonsalvesAbstract:Papaya ringspot virus (PRSV) is often a limiting factor in the production of Papaya worldwide. In 1992, PRSV was discovered in the district of Puna on Hawaii island, where 95% of Hawaii's Papaya was grown. Within two years, PRSV was widespread and causing severe damage to the Papaya in that area. Coincidentally, a field trial to test a PRSV-resistant transgenic Papaya had started in 1992, and by 1995 the 'Rainbow' and 'SunUp' transgenic cultivars had been developed. These cultivars were commercialized in 1998. 'Rainbow' is now widely planted and has helped to save the Papaya industry from devastation by PRSV. Transgenic Papaya have also been developed for other countries, such as Thailand, Jamaica, Brazil, and Venezuela. Efforts to have these Papaya deregulated in these countries are ongoing.
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sequence similarity between the viral cp gene and the transgene in transgenic Papayas
Pesquisa Agropecuaria Brasileira, 2005Co-Authors: Manoel Teixeira Souza, Dennis GonsalvesAbstract:The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' Papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in 'SunUp'. The objective of this work was to evaluate the degree of sequence similarity between the cp gene in the challenge isolate and the cp transgene in transgenic Papayas resistant to PRSV. The production of a hybrid virus containing the genome backbone of PRSV HA up to the Apa I site in the NIb gene, and downstream from there, the sequence of PRSV TH was undertaken. This hybrid virus, PRSV HA/TH, was obtained and used to challenge 'Rainbow', 'SunUp', and an R2 population derived from line 63-1, all resistant to PRSV HA. PRSV HA/TH broke down the resistance in both Papaya varieties and in the 63-1 population, demonstrating that sequence similarity is a major factor in the mechanism of resistance used by transgenic Papayas expressing the cp gene. A comparative analysis of the cp gene present in line 55-1 and 63-1-derived transgenic plants and in PRSV HA, BR, and TH was also performed.
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comparative development and impact of transgenic Papayas in hawaii jamaica and venezuela
Methods of Molecular Biology, 2005Co-Authors: Gustavo Fermin, Paula Tennant, C Gonsalves, Dennis GonsalvesAbstract:We present data concerning the creation of transgenic Papayas resistant to Papaya ringspot virus (PRSV) and their adoption by three different countries: the United States (e.g., Hawaii), Jamaica, and Venezuela. Although the three sets of transgenic Papayas showed effective resistance to PRSV, the adoption rate in each country has varied from full utilization in Hawaii to aggressive testing but delay in deregulating of the product in Jamaica to rejection at an early stage in Venezuela. Factors that contributed to the rapid adoption in Hawaii include a timely development of the transgenic product, PRSV causing severe damage to the Papaya industry, close collaboration between researchers and the industry, and the existence of procedures for deregulating a transgenic product. In Jamaica, the technology for developing the initial field-testing of the product progressed rather rapidly, but the process of deregulation has been slowed down owing to the lack of sustained governmental efforts to complete the regulatory procedures for transgenic crops. In Venezuela, the technology to develop and greenhouse test the transgenic Papaya has moved abreast with the Jamaica project, but the field testing of the transgenic Papaya within the country was stopped very early on by actions by people opposed to transgenic products. The three cases are discussed in an effort to provide information on factors, other than technology, that can influence the adoption of a transgenic product.
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sequence similarity between the cp gene and the transgene in transgenic Papayas similaridade de sequencia entre o gene cp do virus e do transgene presente em mamoeiros transgenicos
Pesquisa Agropecuaria Brasileira, 2005Co-Authors: Manoel Teixeira Souza, M Teixeira, Dennis GonsalvesAbstract:The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' Papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in 'SunUp'. The objective of this work was to evaluate the degree of sequence similarity between the cp gene in the challenge isolate and the cp transgene in transgenic Papayas resistant to PRSV. The production of a hybrid virus containing the genome backbone of PRSV HA up to the Apa I site in the NIb gene, and downstream from there, the sequence of PRSV TH was undertaken. This hybrid virus, PRSV HA/TH, was obtained and used to challenge 'Rainbow', 'SunUp', and an R2 population derived from line 63-1, all resistant to PRSV HA. PRSV HA/TH broke down the resistance in both Papaya varieties and in the 63-1 population, demonstrating that sequence similarity is a major factor in the mechanism of resistance used by transgenic Papayas expressing the cp gene. A comparative analysis of the cp gene present in line 55-1 and 63-1-derived transgenic plants and in PRSV HA, BR, and TH was also performed
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engineered resistance against Papaya ringspot virus in venezuelan transgenic Papayas
Plant Disease, 2004Co-Authors: Gustavo Fermin, Valentina Inglessis, Cesar Garboza, Sairo Rangel, Manuel Dagert, Dennis GonsalvesAbstract:Fermin, G., Inglessis, V., Garboza, C., Rangel, S., Dagert, M., and Gonsalves, D. 2004. Engineered resistance against Papaya ringspot virus in Venezuelan transgenic Papayas. Plant Dis. 88:516-522. Local varieties of Papaya grown in the Andean foothills of Merida, Venezuela, were transformed independently with the coat protein (CP) gene from two different geographical Papaya ringspot virus (PRSV) isolates, designated VE and LA, via Agrobacterium tumefaciens. The CP genes of both PRSV isolates show 92 and 96% nucleotide and amino acid sequence similarity, respectively. Four PRSV-resistant R0 plants were intercrossed or selfed, and the progenies were tested for resistance against the homologous isolates VE and LA, and the heterologous isolates HA (Hawaii) and TH (Thailand) in greenhouse conditions. Resistance was affected by sequence similarity between the transgenes and the challenge viruses: resistance values were higher for plants challenged with the homologous isolates (92 to 100% similarity) than with the Hawaiian (94% similarity) and, lastly, Thailand isolates (88 to 89% similarity). Our results show that PRSV CP gene effectively protects local varieties of Papaya against homologous and heterologous isolates of PRSV.
Joao Paulo Fabi - One of the best experts on this subject based on the ideXlab platform.
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pectin interaction with immune receptors is modulated by ripening process in Papayas
Scientific Reports, 2020Co-Authors: Samira Bernardino Ramos Do Prado, Martin Beukema, Eva Jermendi, Hendrik Arie Schols, Joao Paulo FabiAbstract:Dietary fibers have been shown to exert immune effects via interaction with pattern recognition receptors (PRR) such as toll-like receptors (TLR) and nucleotide-binding oligomerization domain (NOD)-like receptors. Pectin is a dietary fiber that interacts with PRR depending on its chemical structure. Papaya pectin retains different chemical structures at different ripening stages. How this influence PRR signaling is unknown. The aim of this work was to determine how ripening influences pectin structures and their ability to interact with TLR2, 3, 4, 5 and 9, and NOD1 and 2. It was evaluated the interaction of the water-soluble fractions rich in pectin extracted from unripe to ripe Papayas. The pectin extracted from ripe Papayas activated all the TLR and, to a lesser extent, the NOD receptors. The pectin extracted from unripe Papayas also activated TLR2, 4 and 5 but inhibited the activation of TLR3 and 9. The differences in pectin structures are the higher methyl esterification and smaller galacturonan chains of pectin from ripe Papayas. Our finding might lead to selection of ripening stages for tailored modulation of PRR to support or attenuate immunity.
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metabolome and proteome of ethylene treated Papayas reveal different pathways to volatile compounds biosynthesis
Food Research International, 2020Co-Authors: Roberta Ghedini Der Agopian, Joao Paulo Fabi, Beatriz Rosana CordenunsilysenkoAbstract:Abstract Papayas undergo fast postharvest changes triggered by the plant hormone ethylene. Some important pathways have been analyzed in limited studies (transcriptomics and targeted metabolomics); however, broad use of proteomics or untargeted metabolomics have not yet been used in Papayas. In this study, two groups of green Papayas (150 days after anthesis—physiological maturity for Papayas) were treated with ethylene at different times (6 and 12 h) and their metabolic changes in fruit pulp were evaluated with untargeted metabolomics (general metabolites and volatile compounds) and proteomics. Polar metabolites exhibited distinct patterns, especially with regard to some amino and fatty acids during stimulated ripening. In particular, glutamate increased through a possible gamma aminobutyric acid (GABA) shunt and/or proteases activity. Moreover, the stimulated ripening altered the volatile compounds and the protein profiles. The results suggest that changes in membrane breakdown and the resulting oxidative processes could be responsible for volatile compound production, altering some sensorial qualities of Papayas, such as pulp softening and the specific Papaya linalool volatile compound increment. Thus, GABA levels could also be a strong biological marker for Papaya development and ripening stages. This study applied two “omic” techniques that provided insight into how the plant hormone ethylene could influence Papaya postharvest quality.
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changes in cell wall composition associated to the softening of ripening Papaya evidence of extensive solubilization of large molecular mass galactouronides
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Tania Misuzu Shiga, Joao Paulo Fabi, Joao Roberto Oliveira Do Nascimento, Lucia Cristina Vriesmann, Franco Maria Lajolo, Carmen Lucia De Oliveira Petkowicz, Beatriz Rosana CordenunsiAbstract:Papaya (Carica Papaya) is a climacteric fruit that undergoes dramatic pulp softening. Fruits sampled at three different conditions (natural ripening or after exposition to ethylene or 1-methylcyclopropene) were used for the isolation of cell wall polymers to find changes in their degradation pattern. Polymers were separated according to their solubility in water, CDTA, and 4 M alkali, and their monosaccharide compositions were determined. Water-soluble polymers were further characterized, and their increased yields in control and ethylene-treated fruit, in contrast to those that were treated with 1-MCP, indicated a strong association between fruit softening and changes in the cell wall water-soluble polysaccharide fraction. The results indicate that the extensive softening in the pulp of ripening Papayas is a consequence of solubilization of large molecular mass galacturonans from the pectin fraction of the cell wall. This process seems to be dependent on the levels of ethylene, and it is likely that the ...
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Papaya fruit ripening response to ethylene and 1 methylcyclopropene 1 mcp
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Joao Paulo Fabi, Franco Maria Lajolo, Beatriz Rosana Cordenunsi, Gisela Pizarro De Mattos Barreto, Adriana Zerlotti Mercadante, Joao Roberto Oliveira Do NascimentoAbstract:Ripening affects the quality and nutritional contents of fleshy fruits, and Papayas are climacteric fruits very susceptible to postharvest losses due to the fast softening caused by ethylene. This paper reports the changes in respiration, ethylene production, and pulp color and firmness, along with the contents of soluble sugars and major carotenoids, during ripening of ‘Golden' Papaya, an important Brazilian cultivar that has been exported to North American and European markets. The results obtained for nontreated and ethylene- or 1-MCP-treated Papaya suggest that 1-MCP can decrease the quality of treated fruit and that even the use of ethylene for triggering or inducing homogeneous ripening can result in lower quality when compared to that of fruit allowed to ripe naturally. Keywords: Papaya; ethylene; 1-methylcyclopropene; climacteric; soluble sugars; carotenoids; fruit ripening
X Scheldeman - One of the best experts on this subject based on the ideXlab platform.
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distribution diversity and environmental adaptation of highland Papayas vasconcellea spp in tropical and subtropical america
Biodiversity and Conservation, 2007Co-Authors: X Scheldeman, Romero J Motoche, Coppens G Deeckenbrugge, E Romeijnpeeters, Maria Teresa Restrepo, Daniel Jimenez, C I Medina, Louise Willemen, M. Lobo, C ReyesAbstract:Vasconcellea species, often referred to as highland Papayas, consist of a group of fruit species that are closely related to the common Papaya (Carica Papaya). The genus deserves special attention as a number of species show potential as raw material in the tropical fruit industry, fresh or in processed products, or as genetic resources in Papaya breeding programs. Some species show a very restricted distribution and are included in the IUCN Red List. This study on Vasconcellea distribution and diversity compiled collection data from five Vasconcellea projects and retrieved data from 62 herbaria, resulting in a total of 1,553 georeferenced collection sites, in 16 countries, including all 21 currently known Vasconcellea species. Spatial analysis of species richness clearly shows that Ecuador, Colombia and Peru are areas of high Vasconcellea diversity. Combination of species occurrence data with climatic data delimitates the potential distribution of each species and allows the modeling of potential richness at continent level. Based on these modeled richness maps, Ecuador appears to be the country with the highest potential Vasconcellea diversity. Despite differences in sampling densities, its neighboring countries, Peru and Colombia, possess high modeled species richness as well. A combination of observed richness maps and modeled potential richness maps makes it possible to identify important collection gaps. A Principal Component Analysis (PCA) of climate data at the collection sites allows us to define climatic preferences and adaptability of the different Vasconcellea species and to compare them with those of the common Papaya.
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potential of highland Papayas vasconcella spp in southern ecuador potencial de Papayas de altura vasconcella spp en el sur del ecuador
2003Co-Authors: X Scheldeman, Jose Parcemon Romero Motoche, Veerle Van Damme, Veerle Heyens, Patrick Van Damme, J J PenaAbstract:Southern Ecuador is considered to be a centre of biodiversity of the so-called highland Papayas, Andean species of the recently rehabilitated Vasconcella genus, Caricaceae family. Vasconcella species in southern Ecuador grow mostly in the wild, above 1000 masl, and consist of Vasconcella cundinamarcensis V.M. Badillo, V. stipulata (V.M. Badillo) V.M. Badillo, V. × heilbornii (V.M. Badillo) V.M. Badillo, V. candicans (A. Gray) A.DC. , V. weberbaueri (Harms) V.M. Badillo, V. monoica (Desf.) V.M. Badillo, V. microcarpa (Jacq.) A.DC., V. parviflora A.DC. and the new endemic species V. palandensis (V.M. Badillo et al.) V.M. Badillo. At this moment only the natural hybrid V. × heilbornii ‘Babaco’, commercially known as babaco, is getting attention on the continuously expanding subtropical fruit market and is grown at commercial level in Ecuador. Natural hybridisation and presence of accessions of which taxonomical position (at the species level) remains unclear, combined with a limited number of botanical studies suggest that taxonomy of Vasconcella in southern Ecuador is still not completely explained. Nevertheless, local collections and characterization studies show that, from an agronomical point of view, these highland Papayas show a big potential for the future. Organoleptic characteristics of some accessions and species are very promising, especially for use in juices and marmalades. Making use of natural or artificial hybridisation can even expand this potential. Analyses of the activity of the proteolytic enzyme complex (papain) of these local accessions and species shows that latex of unripe fruits possesses up to 15 times more proteolytic activity than Papaya (Carica Papaya L.) cultivars selected and grown for their high enzyme content. Some Vasconcella species, especially V. weberbaueri and V. monoica, show resistance against some important babaco root diseases as Fusarium oxysporum and Meloidogyne incognita, and could be used as a rootstock for babaco grafting. The potential of Vasconcella species, which needs further detailed study, is increasingly under threat as population is growing, putting pressure on fallow and forest land and concentrating on food and cash crops consequently neglecting little known native fruit crops and reducing the natural vegetation in which they occur.
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highland Papayas in southern ecuador need for conservation actions
International symposium on Tropical and Subtropical Fruits, 2002Co-Authors: X Scheldeman, Patrick Van Damme, Romero J MotocheAbstract:Southern Ecuador is considered to be a centre of biodiversity of the so-called highland Papayas. In Southern Ecuador, this group, which comprises lesser-known Andean Caricaccae that grow, mostly in the wild, above 1000 mas1, consists of Carica pubescens (A. DC.) Solms-Laub., C. stipulata Badillo, C. x heilbornii Badillo, C. candicans A. Gray, C. weberbaueri Harms., C. parviflora (A. DC.) Solms-Laub., C. microcarpa Jacq, C. monoica Desf. and the new endemic species C. palandensis Badillo, Van den Eynden & Van Damme. At this moment only the natural hybrid C. x heilbornii nm. pentagona Badillo, commercially known as babaco, is getting attention on the continuously expanding subtropical fruit market. Natural hybridisation and presence of accessions of which taxonomical position (at the species level) remains unclear, combined with a limited number of botanical studies, suggest that the taxonomy of the Caricaceae in Southern Ecuador is still not completely explained. Nevertheless, local collections and characterisation studies show that, from an agronomical point of view, these highland Papayas show a big potential for the future. Organoleptic characteristics of some accessions and species are very promising, especially for use as juices and marmalades. Making use of natural or artificial hybridisation can even expand this potential. Analyses of the activity of the proteolytic enzyme complex (papain) of these local accessions and species showed that the latex of the unripe fruit possessed up to 15 times more activity than Papaya (Carica Papaya L.) cultivars selected and grown for their high enzyme activity. This potential, which needs further detailed study, is increasingly under threat as population is increasing, putting pressure on fallow and forest land and concentrating agricultural systems on food and cash crops, consequently neglecting little known native fruit crops and reducing the natural vegetation in which they occur. A survey on local knowledge of these highland Papayas showed that younger people have significantly less knowledge on them than older people proving the urgent need for further studies and conservation strategies.
Beatriz Rosana Cordenunsi - One of the best experts on this subject based on the ideXlab platform.
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changes in cell wall composition associated to the softening of ripening Papaya evidence of extensive solubilization of large molecular mass galactouronides
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Tania Misuzu Shiga, Joao Paulo Fabi, Joao Roberto Oliveira Do Nascimento, Lucia Cristina Vriesmann, Franco Maria Lajolo, Carmen Lucia De Oliveira Petkowicz, Beatriz Rosana CordenunsiAbstract:Papaya (Carica Papaya) is a climacteric fruit that undergoes dramatic pulp softening. Fruits sampled at three different conditions (natural ripening or after exposition to ethylene or 1-methylcyclopropene) were used for the isolation of cell wall polymers to find changes in their degradation pattern. Polymers were separated according to their solubility in water, CDTA, and 4 M alkali, and their monosaccharide compositions were determined. Water-soluble polymers were further characterized, and their increased yields in control and ethylene-treated fruit, in contrast to those that were treated with 1-MCP, indicated a strong association between fruit softening and changes in the cell wall water-soluble polysaccharide fraction. The results indicate that the extensive softening in the pulp of ripening Papayas is a consequence of solubilization of large molecular mass galacturonans from the pectin fraction of the cell wall. This process seems to be dependent on the levels of ethylene, and it is likely that the ...
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Papaya fruit ripening response to ethylene and 1 methylcyclopropene 1 mcp
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Joao Paulo Fabi, Franco Maria Lajolo, Beatriz Rosana Cordenunsi, Gisela Pizarro De Mattos Barreto, Adriana Zerlotti Mercadante, Joao Roberto Oliveira Do NascimentoAbstract:Ripening affects the quality and nutritional contents of fleshy fruits, and Papayas are climacteric fruits very susceptible to postharvest losses due to the fast softening caused by ethylene. This paper reports the changes in respiration, ethylene production, and pulp color and firmness, along with the contents of soluble sugars and major carotenoids, during ripening of ‘Golden' Papaya, an important Brazilian cultivar that has been exported to North American and European markets. The results obtained for nontreated and ethylene- or 1-MCP-treated Papaya suggest that 1-MCP can decrease the quality of treated fruit and that even the use of ethylene for triggering or inducing homogeneous ripening can result in lower quality when compared to that of fruit allowed to ripe naturally. Keywords: Papaya; ethylene; 1-methylcyclopropene; climacteric; soluble sugars; carotenoids; fruit ripening
Ricardo Pereira Louro - One of the best experts on this subject based on the ideXlab platform.
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streptopodium caricae sp nov with a discussion of powdery mildews on Papaya and emended descriptions of the genus streptopodium and oidium caricae
Fungal Biology, 2004Co-Authors: Jennifer R. Liberato, Robert W Barreto, Ricardo Pereira LouroAbstract:A new powdery mildew infecting Papaya (Carica Papaya) in Brazil, Streptopodium caricae sp. nov., is described. The species is compared with other anamorphic Erysiphales known to infect Papaya: Oidiopsis sicula, Ovulariopsis Papayae, Oidium caricae, O. Papayae, O. caricicola, O. indicum, O. caricae-Papayae, Podosphaera (syn. Sphaerotheca) spp., and Erysiphe spp. An emended description Streptopodium and a key to the anamorphs of powdery mildews on Papaya are also presented. A re-examination of the type material of Phyllactinia caricaefolia showed that conidia in this material are dimorphic, indicating that its anamorph does not belong to Ovulariopsis and that the teleomorph is not conspecific with Phyllactinia guttata. Oidium caricae, the common powdery mildew of Papaya, was re-examined, recognized as a member of subgenus Pseudoidium, an emended description was prepared, and a new type was indicated. O. Papayae was recognized as a synonym of O. caricae, and many of the records of this fungus are considered to be doubtful or incorrect, either omitting a description of the fungus or including a description or illustration of an euodium conidiophore morphology.
