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| Author(s): |
Carolina Cassano Monte Bello
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2018-08-08 |
| Examining board members: |
Camila Caldana;
Michel Georges Albert Vincentz;
Marcelo Menossi;
Sandra Martha Gomes Dias;
Willian Tadeu Lara Festuccia
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| Advisor: | Camila Caldana; Marina Câmara Mattos Martins |
| Abstract | |
Plant growth and development are maintained by a complex network controlled by environmental factors including the availability of nutrients, water and light, and by several signaling pathways that interact with each other. One of the most important pathways that plays a key role in regulating cell growth in eukaryotes is the kinase "Target of Rapamycin" (TOR). In plants, several lines of evidence point out that TOR has a crucial function in carbon and nitrogen balance, acting as a regulator of central metabolism controlling growth and biomass production. However, knowledge about its mode of action is limited in plants. To investigate the contribution of TOR to the control of metabolism, seedlings of Arabidopsis thaliana in the early-stage of development were treated with the chemical inhibitor of TOR, AZD-8055, and analyzed using large-scale MS-based metabolite profiling (GC-TOF-MS and LC-MS/MS) in combination with enzymatic assays during the diurnal cycle. Short-term metabolic responses to the inhibition of this pathway have provided further evidences for a strong regulation of primary metabolism. TOR repression in specific periods of the diel cycle made it possible to elucidate that the starch excess phenotype occurs due to reduced starch degradation in particular periods of the day (first and last hours of light). On the other hand, the low levels of sucrose could not confirm that inhibition of TOR complex leads simply to a reduction in carbon demand for growth. Conversely, repression of this pathway uncouples sugar sensing and signaling, indicating that TOR complex is not only affected by the levels of these metabolites, but also play a role on their regulation. One example is the breakage of the solid correlation between sucrose and the signal molecule trehalose-6-phosphate (Tre6P) by an unknown mechanism. The results obtained in this thesis expose for the first time the interaction between TOR and Tre6P pointing out an important role of this pathway to sense nutrient levels in order to adjust plant growth (AU) | |
| FAPESP's process: | 14/10407-3 - Cross-talk between the Target of Rapamycin (TOR) pathway and energetic metabolism in plants |
| Grantee: | Carolina Cassano Monte Bello |
| Support Opportunities: | Scholarships in Brazil - Doctorate |