Banca de DEFESA: ALBIANE CARVALHO DIAS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALBIANE CARVALHO DIAS
DATE: 30/11/2021
TIME: 13:00
LOCAL: videoconferência
TITLE:

Metabolismo in maize modified by inoculation of diazotrophic bacteria

KEY WORDS:

Plant growth-promoting bacteria. Azospirillum baldaniorum. Herbaspirillum seropedicae. Nitrate. Zea mays L.

PAGES: 149
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

Maize (Zea mays L) is one of the world’s leading produced cereals. Its inoculation with diazotrophic bacteria described as plant growth-promoters can reduce the demand for nitrogen fertilizers and at the same time the costs associated with this practice. This study investigated how inoculation of the diazotrophic bacteria Azospirillum brasilense, Azospirillum baldaniorum and Herbaspirillum seropedicae in maize plants would influence the modulation of root architecture and the parameters associated with the absorption rate of nutrients, especially nitrogen (N), under different conditions of availability of N. Experiments were developed in a hydroponic system and sterile substrate (sand+vermiculite) in a greenhouse, in order to verify the metabolism and expression of genes involved in the absorption and assimilation of N. For this purpose, nitrogen fractions, the activity of the enzymes nitrate reductase and glutamine synthetase, the gene expression of proton pump isoforms, high-affinity nitrate transporters (NO₃^-) and N-reduction and assimilation enzymes were evaluated. Parameters such as biomass accumulation, total N, N use efficiency (EUN), leaf area and chlorophyll index were also evaluated. The inoculation with A. baldaniorum (Ab)-Sp245 and H. seropedicae (Hs)-ZAE94 strains promoted the greatest changes in root architecture, with improvement in all parameters evaluated, which was in agreement with the increase in dry mass and accumulation of N, but they were dependent on the date of sampling and experiment. The parameters improved due to greater availability of N. The Ab-Sp245 was more effective in the greater absorption of macronutrients, with higher speed of absorption of NO₃^-. The changes caused by inoculation in the gene expression profile were less consistent, but those found in the content of soluble metabolites and enzymatic activity indicated an improvement in the N assimilation process. The shift in root architecture and the maintenance of N uptake per unit of root area through inoculation with Ab-Sp245 was probably the main effect.

BANKING MEMBERS:
Interno - 681.282.827-00 - BRUNO JOSÉ RODRIGUES ALVES - EMBRAPA
Externo à Instituição - GABRIELA CAVALCANTI ALVES - EMBRAPA
Interna - 1815763 - IRENE DA SILVA COELHO
Externa à Instituição - MARCIA SOARES VIDAL - EMBRAPA
Presidente - 631.052.847-53 - VERONICA MASSENA REIS - EMBRAPA