Banca de QUALIFICAÇÃO: KELLYA FRANCISCA MENDONÇA BARRETO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : KELLYA FRANCISCA MENDONÇA BARRETO
DATA : 18/05/2018
HORA: 14:00
LOCAL: sala SS1
TÍTULO:

The role of Calmodulin gene in sugarcane

PALAVRAS-CHAVES:

Early flowering, Anatomy, protein interaction network, Saccharum spp.

PÁGINAS: 121
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
SUBÁREA: Biologia Molecular
RESUMO:

Sugarcane is one of the most important monocultures in Brazil, producing ethanol, sugar and biomass. The climatic conditions of the Northeast (high temperature, drought and soil conditions) may be bad for plant for sugarcane developing and then it may promotes an abiotic stress and consequently an early flowering. This may have a negative impact on production by reducing or losing its products. In this study, the aim of this work is to understand the role of a ScCAM sequence (Calmodulin sequence from sugarcane) using different approaches. This sequence was idendify previously bo other work and it was suggested to be related to the early flowering process. Bioinformatics analyzes allowed to observe a conservation in the nucleotide sequence when comparing the ScCAM sequence to Arabidopsis sequences with 99% identity. The phylogenetic tree allowed to observe the conservation of this sequence in plants. Based on these results, a protein model was proposed for ScCAM. It was observed an overlap of the sugarcane model to the existing 4AQR crystal from AtCAM7 (a homologous to ScCAM). Next, a protein interaction network was constructed using the AtCAM7 sequence generated by Cytoscape. Clusters were enriched through the Gene Ontology (GO) program for the interaction network. Some proteins of the network may act as inducers of flowering and control of homeostasis during the oxidation / reduction process. The data from the interaction network also suggest that AtCAM7 may be involved in signaling response to stress. Furthermore, two hybrids approach allowed us to identify two clones that had 77.6% identity for A. thaliana ribosomal proteins L31-1 and L19-1. Moreover, the other approach was functional characterization using transgenic tobacco plants. For this, a construct with overexpression cassette in antisense orientation was used. This construction might reduce or block the presence of endogenous mRNA from CAM. The morphological analysis of these plants allowed visualizing the structural changes in the root tissue with an increase of the lateral capillary roots. Furthermore, it was observed an increased in number of branches, inflorescence and fruits in transgenic plants when compared to the control (transgenic plants containing the empty plasmid). No morphological changes were observed in leaf tissue, as well as plant height. At the same time, a histological analysis was done for the apical meristematic tissue of early and late cultivar from sugarcane plants grown in production fields. The histological analyzes showed that in the early flowering cultivar showed morphological change that may be associated to flowering process. Moreover, these changes were not observed in late-flowering cultivar. Then, the results obtained with this work showed that the CAM sequence in plants may be associated to flowering as well as to signaling pathways by promoting modifications in physiological processes, remodeling of root and apical meristematic and consequently modifying flowering process. Therefore, it also appears to be associated with a wide-ranging regulatory protein and can act in the nuclear pore complex (NPC) by participating in the transport of ribosomal 60S protein and participation in the formation of ribosomal subunits.

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Externo ao Programa - 2294466 - CRISTIANE ELIZABETH COSTA DE MACEDO
Externo à Instituição - DAIANE CRISTINA FERREIRA GOLBERT - UFRN