Data/hora: 14/06/2024 02:36:45

Biblioteca(s): 	Embrapa Arroz e Feijão; Embrapa Solos.	
Data corrente: 	22/04/1997	
Data da última atualização: 	06/03/2024	
Autoria: 	PEREIRA, P. A. A.; BALDANI, J. I.; DOBEREINER, J.; NEYRA, C. A.	
Afiliação: 	PEDRO ANTONIO ARRAES PEREIRA, CNPAF; JOSE IVO BALDANI, CNPAB; JOHANNA DOBEREINER, CNPAB; CARLOS A. NEYRA.	
Título: 	Nitrate reduction and nitrogenase activity in excised corn roots.	
Ano de publicação: 	1981	
Fonte/Imprenta: 	Canadian Journal of Botany, v. 59, n. 12, p. 2445-2449, Dec. 1981.	
DOI: 	https://doi.org/10.1139/b81-295	
Idioma: 	Inglês	
Conteúdo: 	Root segments obtained from field-grown corn plants were divided into small sections and assayed for acetylene (C2H2) reduction. After overnight preincubation, C2H2 reduction started immediately and linear rates were observed for several hours. Addition of NO3-(1 mM) delayed the start of C2H2 reduction but linear rates followed thereafter. A similar pattern was observed with excised roots inoculated with Azospirillum lipoferum. Addition of malate did not eliminate the NO3- effect. Inoculation with A. lipoferum resulted in relatively large rates of C2H2 reduction and a shorter lag than normal (4 to 8 h). A transient accumulation of NO2- accompanied the disappearance of NO3- and C2H2 reduction started only after all the NO2- had been reduced. A very sizable fraction of the reduced NO3- and NO2- was accounted for as N2O accumulation. Thus, the results provided support for the in situ operation of both N2 fixation and denitrification in A. lipoferum - corn root associations and it is proposed that mature corn roots are able to provide sufficient carbon to support both processes.	
Palavras-Chave: 	Denitrificacao; Reducao de acetileno.	
Thesagro: 	Fixação de Nitrogênio; Milho.	
Thesaurus Nal: 	acetylene reduction; Azospirillum; denitrification.	
Categoria do assunto: 	F Plantas e Produtos de Origem Vegetal	
Registro original: 	Embrapa Arroz e Feijão (CNPAF)	
Exemplares: 	CNPAF - (12635-1) - UPC - AP - DD - 1981 -  - 1981 - DIS
CNPS - (20818-1) - UPC - AP - DD -  -  -  - DIS