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Polyploidy is an event that culminates with the condition of having two or more pairs of homologous chromosomes. Here we used proteomics to unveil the differential gene expression in Eucalyptus urophylla x Eucalyptus grandis polyploids, and its isogenic diploid, when plants were challenged against high temperature and elevated CO2 concentration. Growth under high temperature induced an increase in the leaf area, a phenotypic pattern further increased when plants were cultivated in both high temperature and elevated CO2, but inversely for stem branching. Global proteome analysis indicated the absence of a clear pattern of proteome similarities between genotypes, suggesting a unique differential genome regulation would only occur upon environmental stimulus. We concluded that the polyploidy effects in Eucalyptus genotypes are mostly revealed when influenced by environment, that the proteome responses are genotype dependent and that the changes in the gene expression are more pronounced when plants are cultivated in high temperature. RESUMO: Poliploidia é um evento que culmina na condição de ter dois ou mais pares de cromossomos homólogos. Aqui, usamos a proteômica para revelar a expressão gênica diferencial em poliploides de Eucalyptus urophylla x Eucalyptus grandis e seu diploide isogênico, quando as plantas foram desafiadas contra altas temperaturas e concentrações elevadas de CO2. O crescimento sob altas temperaturas induziu um aumento na área foliar, um padrão fenotípico ainda mais acentuado quando as plantas foram cultivadas tanto em altas temperaturas quanto em CO2 elevado, mas inversamente para a ramificação do caule. A análise global do proteoma indicou a ausência de um padrão claro de semelhanças no proteoma entre genótipos, sugerindo que uma regulação gênica diferencial única ocorreria apenas sob estímulo ambiental. Concluímos que os efeitos da poliploidia em genótipos de Eucalyptus são mais revelados quando influenciados pelo ambiente, que as respostas proteômicas são dependentes do genótipo e que as mudanças na expressão gênica são mais pronunciadas quando as plantas são cultivadas em altas temperaturas.

Genomic selection in Eucalyptus enables the identification of superior genotypes, thereby reducing breeding cycles and increasing selection intensity. However, its efficiency may be compromised due to the complex structures of breeding populations, which arise from the use of multiple parents from different species. In this context, partial inbred lines have emerged as a viable alternative to enhance efficiency and generate productive clones. This study aimed to apply genomic selection to a self-fertilized population of different Eucalyptus spp. Our objective was to predict the genomic breeding values (GEBVs) of individuals lacking phenotypic information, with a particular focus on inbred line development. The studied population comprised 662 individuals, of which 600 were phenotyped for diameter at breast height (DBH) at 36 months in a field experiment. The remaining 62 individuals were located in a hybridization orchard and lacked phenotypic data. All individuals, including progeny and parents, were genotyped using 10,132 SNP markers. Genomic prediction was conducted using four frequentist models—GBLUP, GBLUP dominant additive, HBLUP, and ABLUP—and five Bayesian models—BRR, BayesA, BayesB, BayesC, and Bayes LASSO—using k-fold cross-validation. Among the GS models, GBLUP exhibited the best overall performance, with a predictive ability of 0.48 and an R2 of 0.21. For mean squared error, the Bayes LASSO presented the lowest error (3.72), and for the other models, the MSE ranged from 3.72 to 15.50. However, GBLUP stood out as it presented better precision in predicting individual performance and balanced performance in the studied parameter. These results highlight the potential of genomic selection for use in the genetic improvement of Eucalyptus through inbred lines. In addition, our model facilitates the identification of promising individuals and the acceleration of breeding cycles, one of the major challenges in Eucalyptus breeding programs. Consequently, it can reduce breeding program production costs, as it eliminates the need to implement experiments in large planted areas while also enhancing the reliability in selection of genotypes.

Various parameterizations of nonlinear models are common in the literature.In addition to complicating the understanding of these models, these parameterizations affect the nonlinearity measures and subsequently the inferences about the parameters. Bates and Watts (1980) quantified model nonlinearity using the geometric concept of curvature. Here we aimed to evaluate the three most common parameterizations of the Logistic and Gompertz nonlinear models with a focus on their nonlinearity and how this might affect inferences, and to establish relations between the parameters under the various expressions of the models. All parameterizations were adjusted to the growth data from pequi fruit. The intrinsic and parametric curvature described by Bates and Watts were calculated for each parameter. The choice of parameterization affects the nonlinearity measures, thus influencing the reliability and inferences about the estimated parameters. The most used methodologies presented the highest distance from linearity, showing the importance of analyzing these measures in any growth curve study. We propose that the parameterization in which the estimate of B is the abscissa of the inflection point should be used because of the lower deviations from linearity and direct biological interpretation for all parameters.

Polyploidy is an event that culminates with the condition of having two or more pairs of homologous chromosomes. Here we used proteomics to unveil the differential gene expression in Eucalyptus urophylla x Eucalyptus grandis polyploids, and its isogenic diploid, when plants were challenged against high temperature and elevated C[O.sub.2] concentration. Growth under high temperature induced an increase in the leaf area, a phenotypic pattern further increased when plants were cultivated in both high temperature and elevated C[O.sub.2], but inversely for stem branching. Global proteome analysis indicated the absence of a clear pattern of proteome similarities between genotypes, suggesting a unique differential genome regulation would only occur upon environmental stimulus. We concluded that the polyploidy effects in Eucalyptus genotypes are mostly revealed when influenced by environment, that the proteome responses are genotype dependent and that the changes in the gene expression are more pronounced when plants are cultivated in high temperature. Key words: climate change, genome duplication, genotype-phenotype relationship, plant-environment interaction. Poliploidia é um evento que culmina na condição de ter dois ou mais pares de cromossomos homólogos. Aqui, usamos a proteômica para revelar a expressão gênica diferencial em poliploides de Eucalyptus urophylla x Eucalyptus grandis e seu diploide isogênico, quando as plantas foram desafiadas contra altas temperaturas e concentrações elevadas de C[O.sub.2]. O crescimento sob altas temperaturas induziu um aumento na área foliar, um padrão fenotípico ainda mais acentuado quando as plantas foram cultivadas tanto em altas temperaturas quanto em C[O.sub.2] elevado, mas inversamente para a ramificação do caule. A análise global do proteoma indicou a ausência de um padrão claro de semelhanças no proteoma entre genótipos, sugerindo que uma regulação gênica diferencial única ocorreria apenas sob estímulo ambiental. Concluímos que os efeitos da poliploidia em genótipos de Eucalyptus são mais revelados quando influenciados pelo ambiente, que as respostas proteômicas são dependentes do genótipo e que as mudanças na expressão gênica são mais pronunciadas quando as plantas são cultivadas em altas temperaturas. Palavras-chave: mudança climática, duplicação do genoma, relação genótipo-fenótipo, interação planta-ambiente.

We have produced a number of 'Carrizo' citrange ( Citrus sinensis x Poncirus trifoliata) transformed with the Arabidopsis thaliana NPR1, a transcriptional co-activator that is key in the regulation of systemic acquired resistance (SAR) and the expression of pathogenesis related (PR) genes. Over-expression of this gene has been shown to induce broad spectrum disease resistance in several species. One of the limitations in obtaining genetically resistant citrus plants to HLB is how lengthy it is to propagate and evaluate the transgenic plants. Using grafting with infected budwood takes several months, is labor intensive and normally requires specialized greenhouse space which can be limited. We have developed a system to quickly screen AtNPR1 transgenic lines and determine if they exhibit an enhanced defense response to Candidatus Liberibacter asiaticus PAMPs. First, we used a synthetic peptide of L-flg22 (22 amino acid flagellin epitope derived from CLas) capable of triggering immunity in citrus. Second, using real time PCR, we determined changes in the expression levels of a battery of genes associated with defense in citrus in a time course of up to 72 hours after infiltration with L-flg22 and compared it with the expression in wild type plants. Certain lines consistently showed an enhanced defense response when exposed to L-flg22 thus identifying the ones with the most potential. The advantage of this method as a first step in the screening process is that is quick, controlled and does not require specialized greenhouse space. The selected lines are being further evaluated through graft inoculation for their tolerance to HLB.

Various parameterizations of nonlinear models are common in the literature.In addition to complicating the understanding of these models, these parameterizations affect the nonlinearity measures and subsequently the inferences about the parameters. Bates and Watts (1980) quantified model nonlinearity using the geometric concept of curvature. Here we aimed to evaluate the three most common parameterizations of the Logistic and Gompertz nonlinear models with a focus on their nonlinearity and how this might affect inferences, and to establish relations between the parameters under the various expressions of the models. All parameterizations were adjusted to the growth data from pequi fruit. The intrinsic and parametric curvature described by Bates and Watts were calculated for each parameter. The choice of parameterization affects the nonlinearity measures, thus influencing the reliability and inferences about the estimated parameters. The most used methodologies presented the highest distance from linearity, showing the importance of analyzing these measures in any growth curve study. We propose that the parameterization in which the estimate of B is the abscissa of the inflection point should be used because of the lower deviations from linearity and direct biological interpretation for all parameters.

Various parameterizations of nonlinear models are common in the literature.In addition to complicating the understanding of these models, these parameterizations affect the nonlinearity measures and subsequently the inferences about the parameters. Bates and Watts (1980) quantified model nonlinearity using the geometric concept of curvature. Here we aimed to evaluate the three most common parameterizations of the Logistic and Gompertz nonlinear models with a focus on their nonlinearity and how this might affect inferences, and to establish relations between the parameters under the various expressions of the models. All parameterizations were adjusted to the growth data from pequi fruit. The intrinsic and parametric curvature described by Bates and Watts were calculated for each parameter. The choice of parameterization affects the nonlinearity measures, thus influencing the reliability and inferences about the estimated parameters. The most used methodologies presented the highest distance from linearity, showing the importance of analyzing these measures in any growth curve study. We propose that the parameterization in which the estimate of B is the abscissa of the inflection point should be used because of the lower deviations from linearity and direct biological interpretation for all parameters.

Em função da interferência do milho em outras plantas, objetivou-se verificar a presença e a concentração de benzoxazolinona no milho por meio de extração aquosa obtida de material vegetal das cultivares AG-1051, C-333 e C-435. A massa fresca das amostras foi colocada em água destilada e deixada em repouso durante quatro horas. O extrato foi filtrado e particionado em solventes com diferentes polaridades. O extrato etéreo desidratado foi filtrado, concentrado em evaporador rotatório e levado à estufa. Este foi purificado por cromatografia de camada delgada. Recristalizou-se em hexano, e os cristais obtidos foram submetidos à análise em espectrometria no Infravermelho. As bandas presentes no produto padrão também foram caracterizadas nas amostras das cultivares de milho testadas. As amostras dos extratos foram qualificadas e quantificadas por espectrofotometria de ultravioleta. Pelos resultados, infere-se que a planta de milho possui em seu metabolismo a benzoxazolinona, na seguinte ordem decrescente: AG-1051 29 µg g-1, C-333 24 µg g-1 e C-435 21 µg g-1 de BOA.

Transgenic Citrus sinensis ‘Hamlin’ and ‘Valencia’ plants containing Citrus tristeza virus (CTV)-derived sequences were propagated and inoculated with CTV. For propagation, selected buds from transgenic and non-transgenic control plants were grafted onto C. aurantium and C. limonia rootstock plants. CTV inoculation was performed via viruliferous aphids (Toxoptera citricida), and viral detection post-inoculation was performed through DASI-ELISA or RT-qPCR. After four inoculations, none of the transgenic lines tested showed complete resistance. However, viral multiplication was undetectable in some of the propagated clones. These resistant clones mainly came from transgenic ‘Valencia’ sweet orange plants grafted onto C. limonia rootstock containing the pCTV-CS gene construct. Although the tested viral inoculation method represents natural field infection conditions, the results did not differ significantly from those previously reported when the same transgenic lines were bud-graft inoculated. This finding indicates that the difficulties in producing CTV-resistant transgenic citrus lines may be unrelated to the inoculation method. Transgene expression level was quantified by RT-qPCR analysis and it was not possible to relate transgene mRNA level with resistance to the pathogen.