Data/hora: 19/06/2024 02:06:24

Biblioteca(s): 	Embrapa Agrobiologia.	
Data corrente: 	19/07/2019	
Data da última atualização: 	11/09/2020	
Autoria: 	SANTOS, S. G. dos; RIBEIRO, F. da S.; ALVES, G. C.; SANTOS, L. A.; REIS, V. M.	
Afiliação: 	Silvana Gomes dos Santos, Universidade Federal Rural do Rio de Janeiro; Flaviane da Silva Ribeiro, Instituto Federal do Pará, Campus Bragança; Gabriela Cavalcanti Alves, UFRRJ; Leandro Azevedo Santos, UFRRJ; VERONICA MASSENA REIS, CNPAB.	
Título: 	Inoculation with five diazotrophs alters nitrogen metabolism during the initial growth of sugarcane varieties with contrasting responses to added nitrogen	
Ano de publicação: 	2019	
Fonte/Imprenta: 	Plant and Soil, First Online, 08 May, 2019	
Idioma: 	Inglês	
Notas: 	Publicado na Plant and Soil, v. 451, 25-44, 2020.	
Conteúdo: 	We examined the influence of inoculation with five species/strains of diazotrophic bacteria on the modulation of two enzymes involved in the assimilation of N and on the soluble N fractions in the sugarcane varieties RB867515 (adapted for low fertility soils) and IACSP95-5000 (adapted for medium to high fertility soils) under high- (3 mM) and low (0.3 mM)-N conditions in hydroponic cultivation for 59 days.The sugarcane plants were produced in three steps to obtain the hydroponic cultivation: the supply of 3 mM N for 30 days (first harvest), N depletion for 72 h (second harvest), and cultivation in high- and low-N conditions over 26 days (final harvest). Inoculation was performed by immersion of the minisetts in a diluted solution of five diazotrophic bacteria. After the final harvest, plants were divided into roots and shoots to assess their dry weight and N, P, and K accumulation.The variety played an important role in the interaction with diazotrophs, each showing distinct behavior in the activity of their N-assimilation enzymes. The nitrate reductase activity (NRa?EC 1.7.1.1) was increased in var. RB867515 by 26% in the shoots and by 48% in the roots after 72 h under N depletion, while var. IACSP95-5000 showed a reduced enzymatic activity in the roots (by 62%) but not in the shoots. Under high-N conditions, the inoculated IACSP95-5000 plants showed 31% higher glutamine synthetase activity (GSa?EC 6.31.2) compared with 19% in RB867515. Under low-N conditions, the GSas were 21% and 16% higher in the inoculated RB867515 and IACSP95-5000 plants, respectively, compared with that of the control. The content of nitrogen in the form of nitrate (N-nitrate) confirmed these varietal differences, but the soluble sugar content did not.	
Palavras-Chave: 	Diazotrophic bacteria; Enzymatic activity; Saccharum sp.	
Thesaurus Nal: 	Nitrogen.	
Categoria do assunto: 	S Ciências Biológicas	
Registro original: 	Embrapa Agrobiologia (CNPAB)	
Exemplares: 	CNPAB - (41196-1) - UPC - AP - DD -  -  -  - DIS