Banca de DEFESA: DAYANE GOMES DOS SANTOS RIBEIRO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: DAYANE GOMES DOS SANTOS RIBEIRO
DATA: 17/07/2018
HORA: 15:00
LOCAL: Auditório do Campus de Paragominas
TÍTULO:

Brassinosteroids induces tolerance to water deficit in soybean seedlings: Contributions linked to root anatomy and antioxidant enzymes

PALAVRAS-CHAVES:

Antioxidant metabolism. Drought. Glycine max. Root anatomy. 24- epibrassinolide.

PÁGINAS: 41
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Fisiologia de Plantas Cultivadas
RESUMO:

Water deficit is an abiotic stress that often limits seed germination, causing oxidative stress, cellular damages and reduction of the physiological quality. In other hand, the brassinosteroids (EBR) regulates several biochemical and physiological processes in plants, reducing the oxidative stress caused by the abiotic stresses, such as water deficit. This research had the aim to evaluate the EBR contributions on the root anatomy and antioxidant enzymes, and possible interferences on the oxidative stress, germination and biomass of soybean seedlings submitted to the water deficit. The experiment was a factorial design with the factors completely randomised, being two osmotic potentials (0.0 and -0.3 MPa, being describe as control and water deficit, respectively) and three levels of brassinosteroids (0, 50 and 100 nM EBR). Soybean seedlings submitted to water deficit presented reductions of root epidermis (RET), root endodermis (RDT) and root cortex (RCT) vascular cylinder (VCD) and root metaxylem (RMD), however the application of 100 nM brassinosteroids promoted the increases of these values by 21%, 12%, 15%, 38% and 15%, respectively, when compared to water deficit + 0 nM brassinosteroids. In relation to antioxidant enzymes, the treatment with 100 nM brassinosteroids induced increases all enzymes evaluated. This research revealed that brassinosteroids promoted increases in germination, length and dry matter of soybean seedlings and these results are explained by the increments in root anatomy, more specifically on RET, RDT, RCT, VCD and RMD. Reductions in concentrations of oxygen reactive species (superoxide and hydrogen peroxide) and membrane damages (malondialdehyde and electrolyte leakage) are intrinsically related to the higher activities of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase), confirming the benefits of brassinosteroids on antioxidant system. In addition, the concentration of 100 nM of brassinosteroids resulted in a better dose response in soybean seedlings exposed to water deficit.

MEMBROS DA BANCA:
Presidente - 1803899 - ALLAN KLYNGER DA SILVA LOBATO
Externo ao Programa - 2935509 - ANDERSON GONCALVES DA SILVA
Externo à Instituição - JOÃO RODRIGO COIMBRA NOBRE - UEPA
Externo ao Programa - 2412324 - RAFAEL SILVA GUEDES