RESUMO
BACKGROUND: C4 plants have been classified into three subtypes based on the enzymes used to decarboxylate C4 acids in the bundle sheath cells (NADP-ME, NAD-ME and PEPCK pathways). Evidences indicate that, depending on environmental factors, C4 plants may exhibit a certain degree of flexibility in the use of the decarboxylation mechanisms. In this context, the objective was to extend the knowledge on the degree of flexibility between the pathways of decarboxylation in sugarcane, a NADP-ME species, at different levels of water deficit. RESULTS: An experiment was carried out with two cultivars - RB92579 (tolerant to water deficit) and SP80-3280 (susceptible to water deficit) subjected to moderate level (- 1.5 to - 1.8 MPa), severe level (below - 2.0 MPa) and recovery (48 h after rehydration) and changes in the activities of the enzymes involved in the three C4 mechanisms and in gene expression were investigated. Our results showed that sugarcane uses the PEPCK pathway as a decarboxylation mechanism in addition to the NADP-ME, which was more evident under water deficit conditions for both cultivars. CONCLUSIONS: The results obtained here, show that sugarcane increases the use of the PEPCK pathway as a decarboxylation mechanism, in addition to the NADP-ME pathway, under conditions of water deficit, particularly in the tolerant cultivar.
Assuntos
Carbono/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Fotossíntese , Proteínas de Plantas/metabolismo , Saccharum/enzimologia , Saccharum/fisiologia , Água , Adaptação Fisiológica , Biomassa , Descarboxilação , Gases/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Saccharum/genéticaRESUMO
O aumento da eficiência de uso do nitrogênio nas plantas cultivadas é resultado da melhoria nos mecanismos envolvidos na absorção, translocação, assimilação e remobilização do nitrogênio. Nesse estudo, plantas de tabaco com alto acúmulo de prolina causado pela inserção do gene mutante VaP5CSF129A sob controle do promotor constitutivo CaMV35S foram utilizadas como modelo para investigar o efeito da superexpressão do transgene na absorção e utilização de nitrogênio. Para tanto, foi conduzido um experimento em casa de vegetação, em delineamento inteiramente casualizado, em arranjo fatorial 2x5, formado por dois genótipos (evento transgênico e controle não transformado) e cinco doses de adubação nitrogenada (25, 50, 100, 200 e 400 kgha-¹ de nitrogênio). As plantas foram avaliadas quanto à altura, número de folhas, massa seca, teor de prolina livre, teores de nitrogênio e de proteína total; além das eficiências de absorção (EAbs), utilização (EUtil) e uso (EUN) do nitrogênio aplicado. As plantas do evento transgênico com alto acúmulo de prolina foram menos eficientes que as plantas controle em termos de absorção de nitrogênio, apresentando menores teores de nitrogênio nas folhas, raiz e na planta inteira, o que resultou em menor EAbs nessas plantas. Não houve diferença na eficiência de utilização de nitrogênio entre os genótipos transgênico e o controle. No entanto, as plantas transgênicas apresentaram menor EUN em comparação às plantas controle. Concluiu-se que plantas de tabaco transgênicas com alto acúmulo de prolina não apresentam potencial de utilização direta em sistemas agrícolas, uma vez que a alteração do balanço bioquímico entre os metabolismos de nitrogênio e carbono não resultou em plantas com maior eficiência de uso do nitrogênio.
Increasing the nitrogen use efficiency of crop plants is a result of the improvement in the mechanisms involved in nitrogen uptake, translocation, assimilation and remobilization. In this study, tobacco plants with high accumulation of proline caused by the insertion of the VaP5CSF129A mutant gene under control of the constitutive promoter CaMV35S was used as a model to investigate the effect of overexpression of the transgene in the uptake and utilization of N. For this, an experiment was carried out in a completely randomized design, in a 2x5 factorial arrangement, with two genotypes (transgenic event and untransformed control) and five levels of nitrogen fertilization (25, 50, 100, 200 and 400 kg N ha-¹), cultivated under greenhouse conditions. Plants were evaluated for height, number of leaves, dry mass, free proline content, nitrogen content, total protein content and use of the applied N (efficiency of absorption -EAbs, efficiency of leaf utilization EUtil and efficiency of plant use -EUN). The transgenic plants with high proline accumulation were less efficient than the control plants in terms of nitrogen absorption (with lower N levels in root, leaves and whole plant), which resulted in lower EAbs. There was no difference between the transgenic and control genotypes for EUtil. However, the transgenic plants presented lower EUN in comparison to the control plants. Our data showed that transgenic tobacco plants with high proline accumulation do not have potential for direct use in agricultural systems, since the alteration of the biochemical balance between the metabolisms of nitrogen and carbon did not result in plants with higher EUN.
RESUMO
The Dof family (DNA-binding with One Finger) is a group of transcription factors that are involved in a variety of functions of importance for different biological processes in plants, such as plant growth, development and response to biotic and abiotic stresses. The Dof genes have been identified and characterized in many plant species, but so far there is no information about these genes in coffee species. In the present study, we identified 24 Dof members in Coffea canephora using the Coffee Genome Hub database. Systematic bioinformatics analyses were performed to characterize all CcDof genes, including complete genome sequence, conserved protein domains, subcellular locations, phylogenetic relationships and gene expression profiles in different tissues. The results obtained here provide new insights into the CcDof gene family, allowing the design of future experiments for the molecular characterization of these genes in coffee plants.
A família Dof (DNA-binding with One Finger) é um grupo de fatores de transcrição que desempenham papéis importantes no crescimento, desenvolvimento e na resposta das plantas aos estresses bióticos e abióticos. Os genes Dof foram identificados e caracterizados em várias espécies de plantas; entretanto até o presente momento não há informações sobre esses genes em café. No presente estudo foram identificados 24 membros da família Dof no genoma de C. canephora depositados no banco de dados Coffee Genome Hub. Análises sistemáticas de bioinformática foram realizadas para caracterizar os genes Dof em C. canephora, incluindo a análise de sequências genômicas, domínios proteicos conservados, localizações subcelulares, relações filogenéticas e perfis de expressão gênica em diferentes tecidos. Os resultados obtidos fornecem uma melhor compreensão sobre a família dos genes CcDof permitindo projetar experimentos futuros para caracterização molecular desses genes no cafeeiro.
RESUMO
The Dof family (DNA-binding with One Finger) is a group of transcription factors that are involved in a variety of functions of importance for different biological processes in plants, such as plant growth, development and response to biotic and abiotic stresses. The Dof genes have been identified and characterized in many plant species, but so far there is no information about these genes in coffee species. In the present study, we identified 24 Dof members in Coffea canephora using the Coffee Genome Hub database. Systematic bioinformatics analyses were performed to characterize all CcDof genes, including complete genome sequence, conserved protein domains, subcellular locations, phylogenetic relationships and gene expression profiles in different tissues. The results obtained here provide new insights into the CcDof gene family, allowing the design of future experiments for the molecular characterization of these genes in coffee plants.(AU)
A família Dof (DNA-binding with One Finger) é um grupo de fatores de transcrição que desempenham papéis importantes no crescimento, desenvolvimento e na resposta das plantas aos estresses bióticos e abióticos. Os genes Dof foram identificados e caracterizados em várias espécies de plantas; entretanto até o presente momento não há informações sobre esses genes em café. No presente estudo foram identificados 24 membros da família Dof no genoma de C. canephora depositados no banco de dados Coffee Genome Hub. Análises sistemáticas de bioinformática foram realizadas para caracterizar os genes Dof em C. canephora, incluindo a análise de sequências genômicas, domínios proteicos conservados, localizações subcelulares, relações filogenéticas e perfis de expressão gênica em diferentes tecidos. Os resultados obtidos fornecem uma melhor compreensão sobre a família dos genes CcDof permitindo projetar experimentos futuros para caracterização molecular desses genes no cafeeiro.(AU)
RESUMO
O aumento da eficiência de uso do nitrogênio nas plantas cultivadas é resultado da melhoria nos mecanismos envolvidos na absorção, translocação, assimilação e remobilização do nitrogênio. Nesse estudo, plantas de tabaco com alto acúmulo de prolina causado pela inserção do gene mutante VaP5CSF129A sob controle do promotor constitutivo CaMV35S foram utilizadas como modelo para investigar o efeito da superexpressão do transgene na absorção e utilização de nitrogênio. Para tanto, foi conduzido um experimento em casa de vegetação, em delineamento inteiramente casualizado, em arranjo fatorial 2x5, formado por dois genótipos (evento transgênico e controle não transformado) e cinco doses de adubação nitrogenada (25, 50, 100, 200 e 400 kgha-¹ de nitrogênio). As plantas foram avaliadas quanto à altura, número de folhas, massa seca, teor de prolina livre, teores de nitrogênio e de proteína total; além das eficiências de absorção (EAbs), utilização (EUtil) e uso (EUN) do nitrogênio aplicado. As plantas do evento transgênico com alto acúmulo de prolina foram menos eficientes que as plantas controle em termos de absorção de nitrogênio, apresentando menores teores de nitrogênio nas folhas, raiz e na planta inteira, o que resultou em menor EAbs nessas plantas. Não houve diferença na eficiência de utilização de nitrogênio entre os genótipos transgênico e o controle. No entanto, as plantas transgênicas apresentaram menor EUN em comparação às plantas controle. Concluiu-se que plantas de tabaco transgênicas com alto acúmulo de prolina não apresentam potencial de utilização direta em sistemas agrícolas, uma vez que a alteração do balanço bioquímico entre os metabolismos de nitrogênio e carbono não resultou em plantas com maior eficiência de uso do nitrogênio.(AU)
Increasing the nitrogen use efficiency of crop plants is a result of the improvement in the mechanisms involved in nitrogen uptake, translocation, assimilation and remobilization. In this study, tobacco plants with high accumulation of proline caused by the insertion of the VaP5CSF129A mutant gene under control of the constitutive promoter CaMV35S was used as a model to investigate the effect of overexpression of the transgene in the uptake and utilization of N. For this, an experiment was carried out in a completely randomized design, in a 2x5 factorial arrangement, with two genotypes (transgenic event and untransformed control) and five levels of nitrogen fertilization (25, 50, 100, 200 and 400 kg N ha-¹), cultivated under greenhouse conditions. Plants were evaluated for height, number of leaves, dry mass, free proline content, nitrogen content, total protein content and use of the applied N (efficiency of absorption -EAbs, efficiency of leaf utilization EUtil and efficiency of plant use -EUN). The transgenic plants with high proline accumulation were less efficient than the control plants in terms of nitrogen absorption (with lower N levels in root, leaves and whole plant), which resulted in lower EAbs. There was no difference between the transgenic and control genotypes for EUtil. However, the transgenic plants presented lower EUN in comparison to the control plants. Our data showed that transgenic tobacco plants with high proline accumulation do not have potential for direct use in agricultural systems, since the alteration of the biochemical balance between the metabolisms of nitrogen and carbon did not result in plants with higher EUN.(AU)
RESUMO
Galactinol synthase (GolS) is the enzyme that catalyzes the first step of the biosynthesis of the raffinose family oligosaccharides (RFOs), and is involved in many biological processes in plants. In the present study, four putative GolS genes were identified in the Musa acuminate genome. We further characterized these MaGolS genes in terms of protein length, molecular weight, theoretical isoelectric point and 3D protein structure. Genomic organization revealed that most MaGolS genes have four exons. The conserved motifs were identified, demonstrating high group-specificity of all MaGolS proteins. Multiple sequence alignment showed that the APSAA typical domain is present in all GolS proteins. Comparative phylogenetic analysis of the MaGolS proteins revealed three distinct groups. These data provide insight to support new studies a dressing the role of GolS genes in this important fruit species.
A galactinol sintase (GolS) é a enzima que catalisa o primeiro passo da biossíntese dos oligossacarídeos da família da rafinose (OFRs) e está envolvida em muitos processos biológicos nas plantas. No presente estudo, quatro genes GolS foram identificados no genoma de Musa acuminata. Esses genes MaGolS foram caracterizados em termos de comprimento de proteína, peso molecular, ponto isoelétrico teórico e estrutura 3D de proteína. A organização genômica revelou que a maioria dos genes MaGolS possui quatro éxons. Os motivos conservados foram identificados, demonstrando alta especificidade de grupo de todas as proteínas MaGolS. O alinhamento múltiplo das sequências mostrou que o domínio típico de APSAA está presente em todas as proteínas GolS. A análise filogenética comparativa das proteínas MaGolS revelou três grupos distintos. Estes dados fornecem insights para apoiar novos estudos sobre o papel dos genes GolS nesta importante espécie frutífera.
RESUMO
Galactinol synthase (GolS) is the enzyme that catalyzes the first step of the biosynthesis of the raffinose family oligosaccharides (RFOs), and is involved in many biological processes in plants. In the present study, four putative GolS genes were identified in the Musa acuminate genome. We further characterized these MaGolS genes in terms of protein length, molecular weight, theoretical isoelectric point and 3D protein structure. Genomic organization revealed that most MaGolS genes have four exons. The conserved motifs were identified, demonstrating high group-specificity of all MaGolS proteins. Multiple sequence alignment showed that the APSAA typical domain is present in all GolS proteins. Comparative phylogenetic analysis of the MaGolS proteins revealed three distinct groups. These data provide insight to support new studies a dressing the role of GolS genes in this important fruit species.(AU)
A galactinol sintase (GolS) é a enzima que catalisa o primeiro passo da biossíntese dos oligossacarídeos da família da rafinose (OFRs) e está envolvida em muitos processos biológicos nas plantas. No presente estudo, quatro genes GolS foram identificados no genoma de Musa acuminata. Esses genes MaGolS foram caracterizados em termos de comprimento de proteína, peso molecular, ponto isoelétrico teórico e estrutura 3D de proteína. A organização genômica revelou que a maioria dos genes MaGolS possui quatro éxons. Os motivos conservados foram identificados, demonstrando alta especificidade de grupo de todas as proteínas MaGolS. O alinhamento múltiplo das sequências mostrou que o domínio típico de APSAA está presente em todas as proteínas GolS. A análise filogenética comparativa das proteínas MaGolS revelou três grupos distintos. Estes dados fornecem insights para apoiar novos estudos sobre o papel dos genes GolS nesta importante espécie frutífera.(AU)
RESUMO
Urochloa brizantha is one of the most important warm season forage grasses in tropical countries. Despite its importance, there are few studies on gene expression in this species under stressful conditions. Real-time (RT-qPCR) is an accurate technique for gene quantification analysis, but reference genes must be validated under the same conditions used to assess the expression of the target genes. Here, we evaluated the stability of nine reference genes: Actin 12, Eukaryotic initiation factor 4 A, Elongation factor-1 alpha, FTSH protease 4, U2 auxiliary fator, Succinol Co-enzyme A, Tubulin alfa-5, Tubulin beta-6, Ubiquitin conjugating enzyme. Total RNA was extract from leaf tissues of U. brizantha subjected to 6, 12 and 24 h of cold and heat stresses (10 and 45 °C, respectively), and drought, including moderate (-0.5 to -0.7 MPa), severe (-1.1 to -1.8 MPa) and recovery after re-watering. The RefFinder web-based tool was used to rank the most stable reference genes for each stress. Elongation factor-1 alpha, Elongation factor-1 alpha or Ubiquitin conjugating enzyme, and Eukaryotic initiation factor 4 A were the most stable genes for heat, cold and drought stress, respectively. The expression of Rubisco large subunit gene was normalized against the most stable gene selected by ReFfinder for each stress.
Assuntos
Perfilação da Expressão Gênica/normas , Genes de Plantas , Poaceae/fisiologia , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência , Estresse Fisiológico , Secas , Folhas de Planta/genética , Folhas de Planta/fisiologia , Poaceae/genética , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Fatores de TempoRESUMO
Global interest in sugarcane has increased significantly in recent years because of its economic impact on sustainable energy production. The purpose of the present study was to evaluate changes in the concentrations of total sugars, amino acids, free proline, and total proteins by colorimetric analyses and nuclear magnetic resonance (NMR) to perform a metabolic profiling of a water-soluble fraction of symplastic sap in response to the constitutive expression of a mutant Δ1-pyrroline-5-carboxylate synthetase (P5CS) gene from Vigna aconitifolia. However, there was not a significant increase in the free proline content in the sap of transgenic plants compared to the non-transformed control plants. The most noticeable difference between the two genotypes was an almost two-fold increase in the accumulation of sucrose in the stem internodes of P5CS transgenic sugarcane plants. The results presented in this work showed that transgenic sugarcane plants with increased levels of free proline accumulates high soluble sugar content and, therefore, may represent a novel genotype for improving sugarcane cultivars.
Assuntos
Prolina/biossíntese , Saccharum/genética , Saccharum/metabolismo , 1-Pirrolina-5-Carboxilato Desidrogenase/genética , 1-Pirrolina-5-Carboxilato Desidrogenase/metabolismo , Biomassa , Etanol/metabolismo , Genótipo , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/metabolismo , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas , Prolina/metabolismo , Saccharum/enzimologia , Sacarose/metabolismo , Vigna/enzimologia , Vigna/genética , Água/químicaRESUMO
Coffea arabica L. is an important crop in several developing countries. Despite its economic importance, minimal transcriptome data are available for fruit tissues, especially during fruit development where several compounds related to coffee quality are produced. To understand the molecular aspects related to coffee fruit and grain development, we report a large-scale transcriptome analysis of leaf, flower and perisperm fruit tissue development. Illumina sequencing yielded 41,881,572 high-quality filtered reads. De novo assembly generated 65,364 unigenes with an average length of 1,264 bp. A total of 24,548 unigenes were annotated as protein coding genes, including 12,560 full-length sequences. In the annotation process, we identified nine candidate genes related to the biosynthesis of raffinose family oligossacarides (RFOs). These sugars confer osmoprotection and are accumulated during initial fruit development. Four genes from this pathway had their transcriptional pattern validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, we identified ~24,000 putative target sites for microRNAs (miRNAs) and 134 putative transcriptionally active transposable elements (TE) sequences in our dataset. This C. arabica transcriptomic atlas provides an important step for identifying candidate genes related to several coffee metabolic pathways, especially those related to fruit chemical composition and therefore beverage quality. Our results are the starting point for enhancing our knowledge about the coffee genes that are transcribed during the flowering and initial fruit development stages.