Banca de DEFESA: FLÁVIA RAPHAELA CARVALHO MIRANDA GUEDES
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : FLÁVIA RAPHAELA CARVALHO MIRANDA GUEDES
DATA : 27/04/2021
HORA: 14:00
LOCAL: On line
TÍTULO:
Exogenous 24-Epibrassinolide stimulates root protection, and leaf antioxidant enzymes in lead stressed rice plants: Central roles to minimize Pb content and oxidative stress
PALAVRAS-CHAVES:
Brassinosteroids; Environmental pollutant; Oryza sativa L.; Redox status; Root structures
PÁGINAS: 44
RESUMO:
Lead (Pb) is an environmental pollutant that negatively affects rice plants, causing damage to the root system and chloroplast structures, as well as reducing growth. 24-Epibrasnolide (EBR) is a plant growth regulator with a high capacity to modulate antioxidant metabolism. The objective of this research was to investigate whether exogenous EBR application can mitigate oxidative damage in Pb-stressed rice plants, measure anatomical structures and evaluate physiological and biochemical responses connected with redox metabolism. The experiment was randomized with four treatments, including two lead treatments (0 and 200 mM PbCl2, described as - Pb and þ Pb, respectively) and two treatments with brassinosteroid (0 and 100 nM EBR, described as - EBR and þ EBR, respectively). The results revealed that plants exposed to Pb suffered significant disturbances, but the EBR alleviated the negative interferences, as confirmed by the improvements in the root structures and antioxidant system. This steroid stimulated the root structures, increasing the epidermis thickness (26%) and aerenchyma area (50%), resulting in higher protection of this tissue against Pb2þ ions. Additionally, EBR promoted significant increases in superoxide dismutase (26%), catalase (24%), ascorbate peroxidase (54%) and peroxidase (63%) enzymes, reducing oxidative stress on the photosynthetic machinery in Pb-stressed plants. This research proved that EBR mitigates the toxic effects generated by Pb in rice plants.
MEMBROS DA BANCA:
Presidente - 1803899 - ALLAN KLYNGER DA SILVA LOBATO
Interno - 030.493.086-56 - SILVIO JUNIO RAMOS - ITV
Externo à Instituição - FLÁVIO JOSÉ RODRIGUES CRUZ - UFRPE
Externo à Instituição - RODRIGO MOREIRA DA SILVA - USP