Express?o g?nica diferencial em h?bridos de Eucalyptus grandis x Eucalyptus urophylla afetados por dist?rbio fisiol?gico

O presente trabalho foi realizado com apoio da Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - Brasil (CAPES) - C?digo de Financiamento 001.Estresses abi?ticos como baixa ou elevada temperatura, d?ficit ou excesso de ?gua, alta salinidade, metais pesados e radia??o ultravioleta podem limitar o crescimento e desenvolvimento de esp?cies florestais. A depender da constitui??o gen?tica da planta e da capacidade em oferecer resposta adaptativa, fatores externos podem ser um desafio para diferentes esp?cies. Combina??es de estresses podem ocasionar efeitos ?nicos que n?o podem ser previstos a partir de estressores individuais, nisso, uma multiplicidade de intera??es fisiol?gicas pode ser esperada. Plantios florestais brasileiros de Eucalyptus grandis x Eucalyptus urophylla localizados no sul do estado da Bahia apresentaram dist?rbio fisiol?gico em seu crescimento em maio de 2007. Foi verificado que a intera??o entre o fator gen?tico e as condi??es do meio (fatores ed?ficos, nutricionais e clim?ticos) poderia ter desencadeado altera??es quanto a express?o g?nica dos indiv?duos. Para identificar poss?veis genes responsivos pelo dist?rbio a t?cnica de RT-qPCR ? grande aliada. Diante do exposto, o primeiro artigo deste estudo busca definir genes de refer?ncia apropriados para serem utilizados como normalizadores nas an?lises de express?o g?nica por meio da RT-qPCR. J? o segundo artigo tem o intuito de detectar altera??es na express?o g?nica de seis genes envolvidos em diversos estresses abi?ticos de plantas que podem estar relacionados ao dist?rbio fisiol?gico nos clones.Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2021.Abiotic stresses such as low or high temperature, deficit or excess of water, high salinity, heavy metals and ultraviolet radiation can limit the growth and development of forest species. Depending on the genetic makeup of the plant and its ability to offer an adaptive response, external factors can be challenging for different species. Combinations of stresses can cause unique effects that cannot be due to individual stressors, so that a multiplicity of physiological interactions can be expected. Brazilian forest plantations of Eucalyptus grandis x Eucalyptus urophylla located in the south of the state of Bahia showed a physiological disturbance in its growth in May 2007. It was found that the interaction between the genetic factor and the conditions of the environment (edaphic, nutritional and climatic factors) may have triggered changes in the individuals' gene expression. To identify possible genes responsive to the disorder, the RT-qPCR technique is a great ally. Given the above, the first article of this study seeks to define reference genes to be used as normalizers in the analysis of gene expression by RT-qPCR. The second article aims to detect changes in the gene expression of six genes involved in several abiotic plant stresses that may be related to the physiological disturbance in the clones

Gene expression analysis identifies hypothetical genes that may be critical during the infection process of Xanthomonas citri subsp. citri.

Background: Gene expression analysis via microarray is widely used in phytobacteria to validate differential gene expression associated with virulence or to compare biological profiles of wild type and mutant strains. Here, we employed DNA microarrays to study the early stages of the infection process (24, 72 and 120 h post-inoculation) of Xanthomonas citri subsp. citri (Xac) infecting Citrus sinensis to interrogate the expression profiles of hypothetical genes. Results: Under infective conditions, 446 genes were up- and 306 downregulated. Outstanding among genes upregulated during infection were those involved in synthesizing the Type 3 Secretion System and effectors, xanthan gum and quorum-sensing induction, and flagellum synthesis and regulation. Additionally, 161 hypothetical genes were up- and 100 were downregulated, 49 of which are known to have a significant biological role. To understand hypothetical gene co-regulation or -expression, nine expression profiles including 158 genes were identified during the three infection phases. Of these, 47 hypothetical genes were identified as having expression profiles associated with at least one connected to a gene associated with adaptation and virulence. Conclusions: Expression patterns of six differentially expressed genes were validated by quantitative reverse transcription polymerase chain reaction, thus demonstrating the effectiveness of this tool in global gene expression analysis in Xac