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| Author(s): |
Mariana Faulin Foresto
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2012-06-28 |
| Examining board members: |
Eduardo Purgatto;
Luciano Freschi;
João Roberto Oliveira do Nascimento
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| Advisor: | Eduardo Purgatto |
| Abstract | |
The literature indicates that the starch degradation in bananas is probably regulated by ethylene and auxins, among other factors. To understand the mechanisms involved, we followed the ripening of banana slices infiltrated with indole-3-acetic acid (AIA). We measured the evolution of endogenous AIA levels and starch degradation, as well as shifts in transcription and activity of β-amilase and DPE2 and their possible correlation with alterations in the ethylene signal transduction path. In AIA-treated slices, results indicated delay in starch degradation and acummulation of soluble sugars; the changes in β-amilase transcripts and activity levels in control and treated groups were similar, although they were delayed for the AIA-treated group, when compared to control. DPE2 transcript levels, stronger in the earlier stages of rippening in both groups, were sustained longer in AIA-treated bananas; on the other hand, its activity seems to has been severely inhibited by the AIA treatment. The transcript profiles of ERS3 and ETR1 ethylene receptors indicate that they were both strongly affected by the treatment. In this way, the results sugest that modifications in the ethylene signaling pathway may be part of the mechanism by which high level of AIA affects the profile of transcripts and activities of β-amilase and DPE2, inducing the delay in the mobilization of the starch reserve of the bananas, as well as the sugar synthesis. (AU) | |
| FAPESP's process: | 09/11751-1 - Influence of the indole-3-acetic acid levels on expression of the ethylene receptors and the correlation with the expression of the starch metabolizing enzymes in bananas |
| Grantee: | Mariana Faulin Foresto |
| Support Opportunities: | Scholarships in Brazil - Master |