Full text
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| Author(s): |
Ingrid Andrade Rocha
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2023-03-28 |
| Examining board members: |
Nubia Barbosa Eloy;
Francisco Scaglia Linhares;
Hana Paula Masuda
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| Advisor: | Nubia Barbosa Eloy |
| Abstract | |
Plant development is regulated by conserved molecular mechanisms of cell division, differentiation and expansion. Cell division ensures cell duplication and maintenance of genetic information for daughter cells, and this process is controlled by phase changes mediated by proteolysis of ubiquitinated substrates, allowing unidirectional progression of the cell cycle. The exit from mitosis and the G2/M transition is accomplished through the E3 ubiquitin ligase, APC/C. APC/C is composed of specific modules, including catalytic (APC2 and APC11), structural (TPR subunits) and connector (APC4, APC5 and APC1). This study investigated the role of subunits 4 (APC4) and 11 (APC11) during growth and development of Arabidopsis thaliana, through the generation of APC4 overexpression plants driven by the constitutive promoter CaMV 35S, and APC11 knockdown mutant plants. Our results showed that APC4 overexpression can have a positive effect on Arabidopsis development, such as increased cotyledons and leaf primordia size. In addition, the APC4OE364 line showed significant increase in leaf area and root length. The expression profile of cell cycle marker genes in APC4OE plants showed high levels of CYCD3;1 mRNA, suggesting a possible impact of APC4 in the control of S-phase cyclins level. However, we did not observe any difference in the degradation of the G2/M regulatory protein, CYCB1;1. APC11 knockdown mutants showed a significant reduction in their mRNA levels and alteration in the expression pattern of G2/M marker genes throughout development. In addition, they exhibited smaller roots due to a reduction in root meristem, and increased lateral root density. Furthermore, we observed the presence of starch granules in the cell layer below the QC (Quiescent Center), suggesting premature columella cell differentiation. (AU) | |
| FAPESP's process: | 20/02353-1 - Use of anaphase promoter complex genes to increase biomass |
| Grantee: | Ingrid Andrade Rocha |
| Support Opportunities: | Scholarships in Brazil - Master |