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Temporal coordination of the source sink relationship in jatobá seedings (Hymenaea courbaryl L.)

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Author(s):
Ivan Salles Santos
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
Defense date:
Examining board members:
Marcos Silveira Buckeridge; Gisele Akemi Oda; Marco Aurélio Silva Tiné
Advisor: Marcos Silveira Buckeridge
Abstract

Jatobá seedlings have large amounts of carbon reserves in the form of wall constituent polysaccharides, present in their cotyledons. These reserves are initially used in the expansion of the eophylls. After this stage, the seedlings have two sources of carbon, the reserves (which are not fully degraded yet) and autotrophic (understood as photosynthesis) (Santos and Buckeridge, 2004). The constant conditions allowed us to conclude that most of the parameters involved in the photosynthesis process are circadian controlled. This control mechanism has at least two independent oscillatory systems, which are coupled when under the influence of an environmental cycle. The nature of the temporal control of the reserves degradation is yet unclear. Although, evidences are that it\'s being controlled by an endogenous component. We were able to identify, in some cases, a strong influence of the environment, acting directly on the expression of some variables (such as chlorophyll concentration). Finally, we draw a general picture of the temporal control mechanism involved in the source-sink balance (during the establishment phase of this species), in which we were able to integrate all our data and therefore, identify some important control mechanisms involved (AU)

FAPESP's process: 09/03988-1 - Influence of Chronobiology in the Cotiledon Reserves Mobilization in Jatoba (Hymenaea courbaril L.)
Grantee:Ivan Salles Santos
Support Opportunities: Scholarships in Brazil - Master