Banca de QUALIFICAÇÃO: MARCIO YUKIHIRO KOHATSU

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : MARCIO YUKIHIRO KOHATSU
DATA : 28/09/2020
HORA: 14:00
LOCAL: WEBCONFERÊNCIA
TÍTULO:

Study of the application of biogenic copper oxide nanoparticles in in vitro and in vivo bioassays with lettuce (Lactuca sativa L.)

PÁGINAS: 65
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

Copper oxide nanoparticles (CuO NPs) have been used in agriculture as fertilizers, pesticides, herbicides and insecticides, which has contributed to the increase in agricultural production. However, NPs can cause several phytotoxic effects, which depend on several factors, such as: dose, synthesis, size and composition of NPs and the sensitivity of the seed / plant. Thus, it is extremely important to evaluate the safe conditions for the application of NPs in agricultural use. Considering this context, the present study aimed to evaluate and compare the effects of applying different concentrations (0 to 300 mg L^-1) of biogenic CuO NPs (synthesized with green tea extract) on lettuce (Lactuca sativa L.) using bioassays in vitro (Petri dishes) and in vivo (cultivable soil), with n = 4. For the in vivo assay, CuSO₄ was used for comparison with the NPs. Elongation and oxidative stress in the rootlets of lettuce seeds were evaluated in in vitro bioassays. In in vivo bioassays, in addition to oxidative stress, the concentrations of macro and microelements present in lettuce and soil will be determined; also, pigments (chlorophyll and carotenoids) and primary metabolites (total phenolics and flavonoids) will be evaluated. Data will be analyzed using ANOVA one way (in vitro bioassays) and two way (in vivo bioassays), Pearson correlation and linear regression tests (in vitro bioassays). Among the main results obtained so far, in vitro bioassays showed that, at concentrations ≤ 40 mg L^-1, CuO NPs did not negatively affect and even improved seed germination. There was less production of nitric oxide, which plays a role of signaling and acclimatizing to stress to protect the plant against potentially toxic elements; in concentrations ≥ 80 mg L^-1, the growth of radicles decreased between 35 to 75%. With the increase in the concentrations of CuO NPs, the level of nitric oxide (nitrite and S-nitrosothiols) in the radicles increased. However, the total antioxidant activity, catalase, peroxidase and ascorbate peroxidase had no significant difference (p <0.05) and there was the reduction of superoxide dismutase. The study represents advances in understanding the effects of the application of CuO NPs on the absorption of micronutrients with great potential for agricultural applications.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1809833 - TATIANE ARAUJO DE JESUS
Membro Titular - Examinador(a) Interno ao Programa - 3047358 - RICARDO HIDEO TANIWAKI
Membro Titular - Examinador(a) Externo ao Programa - 219.120.588-71 - CAMILA NEVES LANGE - UFABC
Membro Titular - Examinador(a) Externo ao Programa - 206.339.958-19 - LEONARDO FERNANDES FRACETO - UNICAMP
Membro Suplente - Examinador(a) Interno ao Programa - 1814655 - LUCIA HELENA GOMES COELHO
Membro Suplente - Examinador(a) Externo ao Programa - 839.822.640-49 - RODRIGO MENDES PEREIRA - UFABC