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Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Seed germination and seedling establishment are critical processes for commercial plantation and depend directly on reserve mobilization as a source of cellular fuels and biosynthetic precursors. In this way, we investigated the coordination among reserve mobilization, metabolite partitioning, and mobilizing enzyme activities in Moringa oleifera Lam (moringa) an oil-seeded species employed in biofuel production. Seeds were germinated under controlled conditions and seedlings were grown hydroponically at a greenhouse. Samples were harvested at 0, 4, 8, 10, 12, 16, and 20 days after imbibition (DAI). The contents of dry mass (DM), neutral lipids (NL), soluble proteins (SP), starch, total soluble sugars (TSS), non-reducing sugars (NRS), and total free amino acids (TFAA) as the activity of isocitrate lyase (ICL), acid proteases, and amylases were determined. The mobilization of storage proteins was initiated during seed germination whereas the mobilization of storage lipids and starch was triggered throughout seedling establishment although all reserves have been depleted until 20 DAI. The partitioning of DM and metabolites to the roots and the shoots was uneven during seedling establishment. Low shoot/root ratio on the basis of DM could be related to the natural occurrence of moringa in drought climates. In the roots, TSS, NRS, and TFAA were accumulated from 12 to 16 DAI and then were consumed until the end of the experiment. In the shoots, TSS and TFAA were consumed in parallel with NRS accumulation from 12 to 20 DAI. The activity of ICL, acid proteases, and amylases was coordinated with the mobilization of lipids, proteins and starch respectively. Thus, we propose that the patterns of reserve mobilization and metabolite partitioning verified in moringa seem distinct from those found to other tree species and may be involved in metabolic strategies to enable environment colonization / A germina??o da semente e o estabelecimento da pl?ntula s?o processos cr?ticos para o cultivo comercial. Assim, este trabalho tem como objetivo caracterizar a mobiliza??o das reservas e a parti??o dos produtos durante estes processos em moringa, uma esp?cie promissora para a produ??o de biodiesel no Nordeste Brasileiro. Para tanto, as sementes foram germinadas em sistema de rolo sob condi??es controladas (80 ?mol/m2/s, fotoper?odo de 12h e 27?2 ?C) e as pl?ntulas foram transferidas para ?gua destilada em vasos pl?sticos de 1 L de capacidade e mantidas em condi??es de casa de vegeta??o por mais 10 dias. As coletas foram realizadas aos 0, 4, 8, 10, 12, 16 e 20 dias ap?s a embebi??o (DAE), dividindo as pl?ntulas em cotil?dones, parte a?rea e sistema radicular. Foram determinados os conte?dos de massa seca (MS), lip?deos neutros (LN), prote?nas sol?veis (PS), amido, a??cares sol?veis totais (AST), a??cares n?o redutores (ANR) e amino?cidos livres totais (AALT) e as atividades de isocitrato liase (ICL), proteases ?cidas e amilases. A parti??o dos produtos, em termos de MS, ocorreu de forma diferencial, resultando em baixa raz?o parte a?rea/sistema radicular, indicativa de um poss?vel mecanismo de resist?ncia ao d?ficit h?drico. A mobiliza??o das PS foi iniciada na germina??o, enquanto que a mobiliza??o dos LN e do amido foi desencadeada no estabelecimento da pl?ntula, embora todas as reservas tenham sido exauridas at? o 20? DAE, culminando com a expans?o das primeiras folhas. No sistema radicular, houve acumula??o de AST, ANR e AALT do 12? ao 16? DAE e consumo destes metab?litos at? o 20? DAE, enquanto que na parte a?rea, ocorreu diminui??o de AST e AALT em paralelo com o aumento de ANR do 12? ao 20? DAE. As atividades de ICL, proteases ?cidas e amilases ocorreram de forma coordenada com a mobiliza??o de LN, PS e amido, respectivamente. Estes padr?es de mobiliza??o das reservas e parti??o dos metab?litos em moringa se mostraram distintos daqueles verificados para outras esp?cies arb?reas estudadas. ? poss?vel que estes padr?es estejam relacionados com estrat?gias metab?licas utilizadas por esta esp?cie para alcan?ar sucesso durante o estabelecimento da pl?ntula
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/13513 |
| Date | 31 March 2014 |
| Creators | Furtado, Adna La?s de Oliveira Leoc?dio |
| Contributors | CPF:93216717991, http://lattes.cnpq.br/2455621187263790, Pacheco, Mauro Vasconcelos, CPF:04606379677, http://lattes.cnpq.br/1488351961014416, Silva, S?rgio Luiz Ferreira da, CPF:70981027334, http://lattes.cnpq.br/0173411400092352, Voigt, Eduardo Luiz |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncias Florestais, UFRN, BR, Ci?ncias Florestais; Manejo e Utiliza??o dos Recursos Florestais |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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