Identification of four Eucalyptus genes potentially involved in cell wall biosynthesis and evolutionarily related to SHINE transcription factors

Recently, a new Arabidopsis thaliana master regulator of plant cell wall biosynthesis was characterized. It was named SHINE transcription factor (SHINE TF). This work searched for homologous genes in Eucalyptus grandis genome draft. RNAseq data, phylogeny analysis and qRT-PCR experiments were performed to complement SHINE gene analysis. By similarity searches using A. thaliana SHINE genes, four sequences were identified in Eucalyptus. Two of them contain all conserved motifs and characteristic features of this family, being assumed as true SHINE TFs and named EgrSHN1 and EgrSHN2. The other two sequences contain an incomplete 'mm' motif and were not considered true SHINE TFs, being further referred as Egr33m and Egr40m. Expression analysis revealed that EgrSHN1 is more expressed in flowers than in leaves and immature xylem, and both EgrSHN1 and EgrSHN2 are absent from adult xylem RNAseq libraries. This expression profile is similar to A. thaliana orthologues. On the other hand, Egr33m and Egr40m expression was detected in adult xylems. The phylogenetic studies indicate that both EgrSHNs were originated by gene duplication events which, together with gene loss, are hypothesized as common events in SHINE evolution. In conclusion, it is possible that the overexpression of SHINE genes in Eucalyptus xylem can generate information about wood formation processes, allowing an effective increase in forest plantation productivity.692203208International Paper do Brazil Ltda

Flavonoid Supplementation Reduces the Extractive Content and Increases the Syringyl/Guaiacyl Ratio in Eucalyptus grandis x Eucalyptus urophylla Hybrid Trees

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The Eucalyptus genus plays an important role in the worldwide forest industry, with highly productive plantations supplying high-quality raw material for pulp and paper, wood, and biomass that would otherwise come from native forests. Lignin and extractives are important components for wood structure and protection but they are disruptive elements with respect to some industrial processes involving paper, pulp, and biomass production. This work evaluated effects of supplementation of flavonoids on the wood composition of Eucalyptus grandis x Eucalyptus urophylla (E. urograndis), a commercial hybrid. The wood samples were analyzed for extractives and lignin contents by wet chemical analysis, and the composition of lignin monomers and the carbohydrate hexosan/pentosan ratio were determined by analytical pyrolysis. The results showed that supplementation with the flavonoids naringenin and naringenin-chalcone led to an overall reduction of the extractive content and altered the monomeric composition of lignins towards a higher syringyl content. Thus, the treatment of Eucalyptus with flavonoids results in the improvement of wood quality for technological purposes.8217471757Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacaopara a Ciencia e Tecnologia (Portugal) [P-KBBE/AGR-GPL/0001/2010, PTDC/AGR-GPL/098179/2008]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacaopara a Ciencia e Tecnologia (Portugal) [P-KBBE/AGR-GPL/0001/2010, PTDC/AGR-GPL/098179/2008

Reference Genes for High-Throughput Quantitative Reverse Transcription-PCR Analysis of Gene Expression in Organs and Tissues of Eucalyptus Grown in Various Environmental Conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Interest in the genomics of Eucalyptus has skyrocketed thanks to the recent sequencing of the genome of Eucalyptus grandis and to a growing number of large-scale transcriptomic studies. Quantitative reverse transcription-PCR (RT-PCR) is the method of choice for gene expression analysis and can now also be used as a high-throughput method. The selection of appropriate internal controls is becoming of utmost importance to ensure accurate expression results in Eucalyptus. To this end, we selected 21 candidate reference genes and used high-throughput microfluidic dynamic arrays to assess their expression among a large panel of developmental and environmental conditions with a special focus on wood-forming tissues. We analyzed the expression stability of these genes by using three distinct statistical algorithms (geNorm, NormFinder and delta Ct), and used principal component analysis to compare methods and rankings. We showed that the most stable genes identified depended not only on the panel of biological samples considered but also on the statistical method used. We then developed a comprehensive integration of the rankings generated by the three methods and identified the optimal reference genes for 17 distinct experimental sets covering 13 organs and tissues, as well as various developmental and environmental conditions. The expression patterns of Eucalyptus master genes EgMYB1 and EgMYB2 experimentally validated our selection. Our findings provide an important resource for the selection of appropriate reference genes for accurate and reliable normalization of gene expression data in the organs and tissues of Eucalyptus trees grown in a range of conditions including abiotic stresses.531221012116Agence Nationale pour la Recherche (ANR) [ANR-2010-KBBE-007-01]Centre National pour la Recherche Scientifique (CNRS)University Paul Sabatier Toulouse III (UPS)Fundacao para a Ciencia e Tecnologia (FCT) [P-KBBE/AGR_GPL/0001/2010, PTDC/AGR-GPL/098179/2008, PEst-OE/EQB/LA0004/2011]INTEREG IVB SudoE project InterbioLaboratoire d'Excellence (LABEX) project entitled TULIP [ANR-10-LABX-41]China Scholarship CouncilFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FCT [SFRH/BD/72982/2010]Departament d'Universitats, Recerca i Societat de la Informacio de la Generalitat de CatalunyaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Agence Nationale pour la Recherche (ANR) [ANR-2010-KBBE-007-01]Fundacao para a Ciencia e Tecnologia (FCT) [P-KBBE/AGR_GPL/0001/2010, PTDC/AGR-GPL/098179/2008, PEst-OE/EQB/LA0004/2011]Laboratoire d'Excellence (LABEX) project entitled TULIP [ANR-10-LABX-41]FAPESP [FAPESP]FCT [SFRH/BD/72982/2010