Banca de DEFESA: CAMILLE FERREIRA MAIA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: CAMILLE FERREIRA MAIA
DATA: 21/02/2018
HORA: 09:00
LOCAL: Auditório do Campus de Paragominas
TÍTULO:

Brassinosteroids positively modulate growth: Physiological, biochemical and anatomical evidences
using two tomato genotypes contrasting to dwarfism

PALAVRAS-CHAVES:

Chlorophyll fluorescence. Dwarf. Gas exchange. Leaf anatomy. Solanum lycopersicum. 24-epibrassinolide

PÁGINAS: 49
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Fisiologia de Plantas Cultivadas
RESUMO:

Our hypothesis considered that the utilization of genotypes with different levels of
biosynthesis to BR can explain the roles of this steroid in relation to growth and
metabolic behavior. The aim of this research was to investigate the possible
interferences occasioned by the exogenous application of BR on growth and
metabolism, using two genotypes contrasting to the Dwarf gene (MT-d and MT-D), that
are BR-deficient and BR-efficient, respectively. The experiment had four treatments,
being two genotypes (BR-efficient and BR-deficient) and two levels of brassinosteroids
(0 and 100 nM BR, here after described as – BR and + BR, respectively). This research
revealed that the exogenous application of BR promoted improvement on growth,
inducing increases in BR-deficient plants of 120%, 469%, 219%, and 203% in LDM,
RDM, SDM and TDM, respectively. The positive effects on gas exchange and
chlorophyll fluorescence confirm the benefits of this steroid on photosynthetic
apparatus. The changes in the anatomical characteristics of the leaf are related to
contribution of the BR on influx and consequent fixation of CO2. In addition,
modifications related to root anatomy occurred by the BR action with objective to
increase the barrier against biotic and abiotic stresses and the efficiency in the
absorption of water and nutrients. The improvements in photosynthetic pigments,
observed in the increases of 16%, 35%, 20% and 67% in Chl a, Chl b, Total Chl and
Car, respectively, to BR-deficient plants, suggested that the role of BR must be linked to
the chlorophyll biosynthesis route and maintenance of chloroplast integrity, this result
being intrinsically associated with the increments found in the activities of antioxidant
enzymes that modulate the accumulation of ROS.

MEMBROS DA BANCA:
Presidente - 1803899 - ALLAN KLYNGER DA SILVA LOBATO
Externo ao Programa - 2896115 - ELAINE MARIA SILVA GUEDES LOBATO
Externo ao Programa - 2412324 - RAFAEL SILVA GUEDES
Externo à Instituição - JOÃO RODRIGO COIMBRA NOBRE - UEPA