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Spatial division of PEPC and NR enzymes activity and its regulation by cytokinins in CAM induced leaves of Guzmania monostachia.

Grant number: 10/04273-3
Support type:Scholarships in Brazil - Master
Effective date (Start): August 01, 2010
Effective date (End): February 29, 2012
Field of knowledge:Biological Sciences - Botany - Pant Physiology
Principal researcher:Helenice Mercier
Grantee:Paula Natália Pereira
Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil


Previous research group showed that when plants Guzmania monostachia, a facultative C3-CAM specie, are subjected to water shortage, formed a gradient of acidity and activity of the enzyme phosphoenolpyruvate carboxylase (PEPCase) along the leaf length, and the apex portion that expressed more strongly the CAM. Regarding the activity of redutase do nitrato (NR), it was observed that for another tank epiphytic bromeliad (Vriesea gigantea) the activity of this enzyme is found almost exclusively in the basal leaf portion. Furthermore, we showed the importance of signaling fitormônio cytokinin for induction of gene expression and in activation of NR in seedlings of pineapple (Ananas comosus) facultative C3-CAM, cultivated in vitro. Based on these results, the following questions arise: there would be changes in the activity of the enzyme NR in leaf portions of that work as C3 or CAM? The greater availability of carbon skeletons evening (accumulation of acidity) would positively influence the enzymatic activity, shifting its peak of activity for the evening? Changes in endogenous levels of cytokinins accompany the possible changes in NR activity, thereby indicating the participation of this class of hormonal signaling in NR? Thus, this project will aims to evaluate the enzyme activity of NR in different portions of leaves (basal and apical) Guzmania monostachia when detached leaves of mature plants are subjected to a water shortage, causing a sharp increase in the expression of CAM photosynthesis . Search will also know and relate the changes in the levels of endogenous cytokinins in those portions of leaf with the activities of NR. It is expected, therefore, a deeper understanding of the relationship between behavior and photosynthetic nitrogen metabolism in bromeliads.

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Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
PEREIRA, PAULA NATALIA; PURGATTO, EDUARDO; MERCIER, HELENICE. Spatial division of phosphoenolpyruvate carboxylase and nitrate reductase activity and its regulation by cytokinins in CAM-induced leaves of Guzmania monostachia (Bromeliaceae). Journal of Plant Physiology, v. 170, n. 12, p. 1067-1074, . (11/50637-0, 10/04273-3)
Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
PEREIRA, Paula Natália. Spatial division of PEPC and NR enzymes activity and its regulation by cytokinins in CAM induced leaves of Guzmania monostachia. 2012. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) São Paulo.

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