O Cancro citrico e uma das principais doencas dos citros e causa grandes prejuizos economicos a c... more O Cancro citrico e uma das principais doencas dos citros e causa grandes prejuizos economicos a citricultura mundial. A bacteria Xanthomonas citri subsp. citri (Xac), agente causal da doenca, pode infectar uma ampla variedade de citros atraves da abertura natural dos estomatos ou aberturas causadas por ferimentos. A Xac possui dois genes que codificam uma proteina auxiliar do Sistema de Secrecao do Tipo III (SSTT), denominada transglicosilase litica de mureina, que desempenha um papel importante no processo de infeccao do hospedeiro. Um destes genes, denominado mltB, esta localizado no cromossomo da Xac e o outro, denominado mlt, esta em um dos dois plasmideos presentes na bacteria, o pXAC64. A identidade de sequencia da proteina codificada por estes dois genes e de 99,6%. O gene mltB, quando inativado pela insercao de um transposon, produz uma Xac mutante (XacΔmltB) que apresenta fenotipo menos virulento do que a Xac selvagem. Nao se sabe que papel o gene mlt plasmidial desempenha na patogenese e/ou virulencia de Xac, ou se ha diferencas no nivel de expressao entre mlt e mltB. O objetivo deste projeto foi avaliar o papel dos genes mlt e mltB na virulencia e/ou patogenicidade de Xac, utilizando-se para tanto da mutagenese sitio dirigida, seguida por testes de patogenicidade no hospedeiro laranja Pera, curvas de crescimento in vitro e in planta, ensaios de formacao de biofilme e producao de goma xantana.
Resumo A produção de citros é uma das atividades agroindustriais mais importantes em nosso País, ... more Resumo A produção de citros é uma das atividades agroindustriais mais importantes em nosso País, a qual vem sendo constantemente ameaçada pela doença do cancro-cítrico, causada pela bactéria Gram negativa Xanthomonas axonopodis pv. citri (Xac-A). Esta bactéria, ...
Xanthomonascitri subsp. citri (Xcc) causes citrus canker, a worldwide disease found mainly in swe... more Xanthomonascitri subsp. citri (Xcc) causes citrus canker, a worldwide disease found mainly in sweet oranges (Citrus sinensis (L.) Osbeck). The expression of nine candidate internal reference genes was analyzed in Xcc grown alone and during C. sinensis infection to identify genes most suitable for comparative expression studies in Xcc using reverse transcription quantitative PCR (qRT-PCR). The stability of these genes was determined using the programs geNorm, NormFinder and BestKeeper. The genes most suitable for data normalization during C. sinensis infection were atpD, rpoB, gyrA and gyrB. The use of at least three reference genes is essential for accurate data normalization in Xcc.
Selection of endogenous genes for gene expression studies in Eucalyptus under biotic (Puccinia ps... more Selection of endogenous genes for gene expression studies in Eucalyptus under biotic (Puccinia psidii) and abiotic (acibenzolar-S-methyl) stresses using RT-qPCR
Huanglongbing is a highly destructive citrus disease associated with “Candidatus Liberibacter asi... more Huanglongbing is a highly destructive citrus disease associated with “Candidatus Liberibacter asiaticus” (Las), a phloem−limited and non-culturable bacterium, naturally transmitted by the psyllid Diaphorina citri. Although diverse approaches have been used to understand the molecular mechanisms involved in the pathogen–host interaction, such approaches have focused on already infected and/or symptomatic plants, missing early events in the initial days post-inoculation. This study aimed to identify the time course of Las multiplication and whole-plant colonization immediately following inoculation by infected psyllids feeding for 2 days. Thus, the experimental approach was to track Las titers after psyllid inoculation in new shoots (NS) of Citrus × sinensis (susceptible), Murraya paniculata (partially resistant), and Bergera koenigii (fully resistant). Soon after psyllid removal, Las titers dropped until the 10–12th days in all three species. Following this, Las titers increased expo...
Despite several studies on genetic markers and differently expressed genes related to ribeye area... more Despite several studies on genetic markers and differently expressed genes related to ribeye area (REA) and tenderness traits in beef cattle, there is divergence in the results regarding the genes associated with these traits. Thirteen genes that had been associated or have biological functions that may influence such phenotypes were included in this study. A total of five genes for REA (IGF-1, IGF-2, MSTN, NEDD4, and UBE4A) and eight genes for meat tenderness (CAPN1, CAPN2, CAST, HSPB1, DNAJA1, FABP4, SCD, and PRKAG3) were selected from previously studies in beef cattle. Genes and its respective proteins expression were validated in a commercial population of Nellore cattle using quantitative real-time PCR (RT-qPCR) and advanced mass spectrometry (LC / MS-MS) techniques, respectively. MSTN gene was upregulated in animals with low REA. CAPN1, CAPN2, CAST, HSPB1, and DNAJA1 genes were upregulated in animals with tougher meat. The proteins translated by these genes were not differenti...
O Cancro citrico e uma das principais doencas dos citros e causa grandes prejuizos economicos a c... more O Cancro citrico e uma das principais doencas dos citros e causa grandes prejuizos economicos a citricultura mundial. A bacteria Xanthomonas citri subsp. citri (Xac), agente causal da doenca, pode infectar uma ampla variedade de citros atraves da abertura natural dos estomatos ou aberturas causadas por ferimentos. A Xac possui dois genes que codificam uma proteina auxiliar do Sistema de Secrecao do Tipo III (SSTT), denominada transglicosilase litica de mureina, que desempenha um papel importante no processo de infeccao do hospedeiro. Um destes genes, denominado mltB, esta localizado no cromossomo da Xac e o outro, denominado mlt, esta em um dos dois plasmideos presentes na bacteria, o pXAC64. A identidade de sequencia da proteina codificada por estes dois genes e de 99,6%. O gene mltB, quando inativado pela insercao de um transposon, produz uma Xac mutante (XacΔmltB) que apresenta fenotipo menos virulento do que a Xac selvagem. Nao se sabe que papel o gene mlt plasmidial desempenha na patogenese e/ou virulencia de Xac, ou se ha diferencas no nivel de expressao entre mlt e mltB. O objetivo deste projeto foi avaliar o papel dos genes mlt e mltB na virulencia e/ou patogenicidade de Xac, utilizando-se para tanto da mutagenese sitio dirigida, seguida por testes de patogenicidade no hospedeiro laranja Pera, curvas de crescimento in vitro e in planta, ensaios de formacao de biofilme e producao de goma xantana.
Resumo A produção de citros é uma das atividades agroindustriais mais importantes em nosso País, ... more Resumo A produção de citros é uma das atividades agroindustriais mais importantes em nosso País, a qual vem sendo constantemente ameaçada pela doença do cancro-cítrico, causada pela bactéria Gram negativa Xanthomonas axonopodis pv. citri (Xac-A). Esta bactéria, ...
Xanthomonascitri subsp. citri (Xcc) causes citrus canker, a worldwide disease found mainly in swe... more Xanthomonascitri subsp. citri (Xcc) causes citrus canker, a worldwide disease found mainly in sweet oranges (Citrus sinensis (L.) Osbeck). The expression of nine candidate internal reference genes was analyzed in Xcc grown alone and during C. sinensis infection to identify genes most suitable for comparative expression studies in Xcc using reverse transcription quantitative PCR (qRT-PCR). The stability of these genes was determined using the programs geNorm, NormFinder and BestKeeper. The genes most suitable for data normalization during C. sinensis infection were atpD, rpoB, gyrA and gyrB. The use of at least three reference genes is essential for accurate data normalization in Xcc.
Selection of endogenous genes for gene expression studies in Eucalyptus under biotic (Puccinia ps... more Selection of endogenous genes for gene expression studies in Eucalyptus under biotic (Puccinia psidii) and abiotic (acibenzolar-S-methyl) stresses using RT-qPCR
Huanglongbing is a highly destructive citrus disease associated with “Candidatus Liberibacter asi... more Huanglongbing is a highly destructive citrus disease associated with “Candidatus Liberibacter asiaticus” (Las), a phloem−limited and non-culturable bacterium, naturally transmitted by the psyllid Diaphorina citri. Although diverse approaches have been used to understand the molecular mechanisms involved in the pathogen–host interaction, such approaches have focused on already infected and/or symptomatic plants, missing early events in the initial days post-inoculation. This study aimed to identify the time course of Las multiplication and whole-plant colonization immediately following inoculation by infected psyllids feeding for 2 days. Thus, the experimental approach was to track Las titers after psyllid inoculation in new shoots (NS) of Citrus × sinensis (susceptible), Murraya paniculata (partially resistant), and Bergera koenigii (fully resistant). Soon after psyllid removal, Las titers dropped until the 10–12th days in all three species. Following this, Las titers increased expo...
Despite several studies on genetic markers and differently expressed genes related to ribeye area... more Despite several studies on genetic markers and differently expressed genes related to ribeye area (REA) and tenderness traits in beef cattle, there is divergence in the results regarding the genes associated with these traits. Thirteen genes that had been associated or have biological functions that may influence such phenotypes were included in this study. A total of five genes for REA (IGF-1, IGF-2, MSTN, NEDD4, and UBE4A) and eight genes for meat tenderness (CAPN1, CAPN2, CAST, HSPB1, DNAJA1, FABP4, SCD, and PRKAG3) were selected from previously studies in beef cattle. Genes and its respective proteins expression were validated in a commercial population of Nellore cattle using quantitative real-time PCR (RT-qPCR) and advanced mass spectrometry (LC / MS-MS) techniques, respectively. MSTN gene was upregulated in animals with low REA. CAPN1, CAPN2, CAST, HSPB1, and DNAJA1 genes were upregulated in animals with tougher meat. The proteins translated by these genes were not differenti...
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