masterThesis
Mobilização de reservas e perfil preliminar de metabólitos secundários durante e após a germinação em Erythrina velutina
Fecha
2020-08-27Registro en:
SILVA, Diêgo Augusto Azevedo da. Mobilização de reservas e perfil preliminar de metabólitos secundários durante e após a germinação em Erythrina velutina. 2020. 54f. Dissertação (Mestrado em Ciências Florestais) - Escola Agrícola de Jundiaí, Universidade Federal do Rio Grande do Norte, Natal, 2020.
Autor
Silva, Diêgo Augusto Azevedo da
Resumen
Considering the medicinal potential of Erythrina velutina Willd., a woody species native to the
Caatinga, the aim of this work was to characterize the mobilization of reserves in parallel with
the content secondary metabolites during seed germination and seedling establishment.
Hence, seeds were scarified, surface-sterilized, planted between towel paper sheets and
cultivated under controlled conditions. Then, seedlings were transferred to distilled water in
hydroponics and cultivated in a greenhouse. In a time-course experiment, seedling growth,
reserve mobilization and the content of soluble sugars and free amino acids, as well as the
preliminary profile of secondary metabolites were assessed in the cotyledons during and
after germination. Germination included the stages of imbibed seed and radicle protrusion,
whereas establishment encompassed hypocotyl emergence, plumule hook opening, and the
expansion of cordiform leaves, first trifoliate leaf and second trifoliate leaf. Seeds contained
20% starch, 14,5% storage proteins, 11,6% neutral lipids and 5,7% non-reducing sugars in
dry weight basis. The major reserves were synchronically and intensely mobilized from apical
hook opening, while non-reducing sugars were utilized from hypocotyl emergence. The
activity of amylases, lipases and acid proteases increased from cordiform leaf emergence,
coinciding with the mobilization of starch, lipids and proteins, respectively. By thin layer
chromatography, it was possible to verify the presence of terpenes and phenolic acids during
the experiment. The results indicate the occurrence of flavonoids from seed germination and
at the expansion of cordiform leaves. Throughout the experiment, it was evidenced the
presence of alkaloids, mainly in the imbibed seed. The elucidation of these processes may
help in understanding the strategies used by E. velutina to colonize the environment as a
Caatinga pioneer species.