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Express?o g?nica relacionada ? produ??o de ?leo essencial e avalia??o do metabolismo de Mentha arvensis L. sob diferentes condi??es de cultivo / Gene expression related to production of essential oil and evaluation of Mentha arvensis metabolism under different conditions of cultivationSouza, Marco Andre Alves de 18 January 2010 (has links)
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Previous issue date: 2010-01-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The cultivation of aromatic specimens for obtaining essential oils have great economic
importance, mainly by increasing demand in the food, cosmetic and pharmaceutical industry.
Brazil is the largest producer of essential oil, however, is what earns less in money value,
because, its production is mainly of orange essential oil, with low added value. The essential
oil of M. arvensis is rich in menthol (70-80%), a natural products with higher demand in daily
life of modern man. Currently, Brazil has become a major importer of menthol which has
contributed negatively to the brazilian trade balance. Thus, for the development of this work
was chosen to be a specimens of economic interest and social demand, the Mentha arvensis.
The purpose of study was to evaluate whether changes in light intensities and different levels
of phosphorus promote changes in biomass production and nutrition, with consequences for
the biosynthesis of essential oils. We also analyzed the influence of leaf age on the quality of
essential oil. To this end, the plant of M. arvensis was grown under the effect of different
conditions, which allowed the analysis of the levels of soluble fractions, of photosynthetic
pigments, the activities of enzymes related to nitrogen assimilation and the anatomical and
histochemical study of trichomes, morphological structure where it is produce the essential
oil. The study also included analysis of the expression of genes related to the route of menthol
synthesis. The essential oil was obtained by extraction with hydrodestillation in modified
Clevenger and the chemical analysis of substances obtained by GC-MS. The Kovats index
was used to collaborate in identification of the main substances in essential oil. The results
showed that the essential oil quality is determined by physiological conditions and leaf age
and that the production is dependent on the synthesis efficiency and density of trichomes on
the leaves. In addition, it was found that different concentrations of phosphorus affected some
aspects of plant metabolism, which reflected the production of biomass in the soluble fraction,
with consequences on production and quality of essential oils. Also showed that variations in
light levels affected the expression of six of the eight genes involved in the route of synthesis
of menthol, in plants of M. arvensis and that changes in gene expression are probably
associated with a transcription factor, which could be acting on the whole pathway. All of this
information showed that environmental conditions and / or nutritional affected some aspects
of plant metabolism, which reflected the production of biomass, of trichomes and on the
expression of genes related to the route of menthol, which reflect on the quality and the
production of essential oils / O cultivo de esp?cies arom?ticas para a obten??o de ?leos essenciais tem grande import?ncia
econ?mica, principalmente, pela crescente demanda nas ind?strias de alimentos, de
cosm?ticos e a farmac?utica. O Brasil ? o maior produtor de ?leo essencial, entretanto, ? o que
menos arrecada em valores monet?rios, pois, sua produ??o ? basicamente de ?leo essencial de
laranja, com baixo valor agregado. O ?leo essencial de Mentha arvensis L. ? rico em mentol
(70-80%), uma dos produtos naturais com maior demanda no dia-a-dia do homem moderno.
Atualmente, o Brasil tornou-se um grande importador de mentol o que tem contribu?do
negativamente para a balan?a comercial brasileira. Deste modo, para o desenvolvimento deste
trabalho escolheu-se a planta M. arvensis. O objetivo do estudo foi avaliar se varia??es nas
intensidades luminosas e diferentes concentra??es de f?sforo promovem altera??es na
produ??o de biomassa e em aspectos nutricionais, com reflexos na bioss?ntese de ?leos
essenciais. Tamb?m foi avaliada a influ?ncia da idade da folha sobre a qualidade do ?leo
essencial. Com esta finalidade, a planta de M. arvensis foi cultivada sob o efeito de diferentes
condi??es, o que permitiu a an?lise dos teores das fra??es sol?veis, dos pigmentos
fotossint?ticos, das atividades das enzimas relacionadas com a assimila??o do nitrog?nio e o
estudo histoqu?mico e anat?mico dos tricomas secretores, estrutura morfol?gica onde ?
produzido o ?leo essencial. Tamb?m foram realizadas analises da express?o dos genes
relacionados com a rota de s?ntese do mentol. O ?leo essencial foi obtido por hidrodestila??o
em Clevenger modificado e as analises qu?micas das subst?ncias realizadas por CG/EM. A
utiliza??o do ?ndice de Kovats auxiliou na identific??o das principais subst?ncias no ?leo
essencial. Os resultados permitiram concluir que a qualidade do ?leo essencial ? determinada
pelas condi??es fisiol?gicas e a idade das folhas e que a produ??o ? dependente da efici?ncia
de s?ntese e a densidade de tricomas secretores nas folhas. Al?m disso, foi constatado que as
diferentes concentra??es de f?sforo afetaram alguns aspectos do metabolismo vegetal, os
quais refletiram na produ??o de biomassa, nas fra??es sol?veis, com conseq??ncias na
produ??o e qualidade dos ?leos essenciais. Tamb?m, mostraram que varia??es nos n?veis de
luminosidade afetaram a express?o de seis entre os oito genes envolvidos com a rota de
s?ntese do mentol, em plantas de M. arvensis e que as altera??es na express?o dos genes
provavelmente est?o associados a um fator de transcri??o, o qual deve estar atuando sobre
toda a rota metab?lica
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