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| Author(s): |
Eduardo Leal Oliveira Camargo
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2013-02-19 |
| Examining board members: |
Gonçalo Amarante Guimarães Pereira;
Helaine Carrer;
Carlos Alberto Labate;
José Antônio Bressiani;
Marcelo Menossi
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| Advisor: | Gonçalo Amarante Guimarães Pereira |
| Abstract | |
The nitrogen (N) is the main macronutrient required for plants development and biomass accumulation. The genus Eucalyptus is the principal source of biomass to forest industries, mainly to the pulp and paper. Their fast growth, valuable wood properties and ease of management have great potential to generate biofuel and chemicals. In this scenario, the projections lead to a high demand of biomass, resulting in the need to associate new strategies of genetic improvement programs, which results in a higher productivity with a better wood quality. The wood quality depends from many properties of secondary xylem that are influenced by genetics and environment factors, like water and nutrients availability. In this study, we demonstrate in Eucalyptus that N fertilization promotes changes on secondary xylem formation and quality. Plants from a commercial clone of Eucalyptus urophylla x E. grandis were submit to contrasting N fertilizations. The histological analyses from stem regions demonstrate that lignin deposition were reduced by high N fertilization, whereas a consistent increased were observed on those cultivate at N deficient treatment. These results were corroborate by chemical analyses. By the RNA sequencing analyses, it was identified 1,469 differently expressed genes, exhibiting an N-dependent expression pattern. Between those are genes related to N and phenylpropanoid metabolisms. The results allowed us to understand the mechanism involved on the maintenance of the high rates of lignifications under N depletion, and also to point some possible candidates genes involve on Eucalyptus wood quality (AU) | |