Data/hora: 27/05/2024 06:41:47

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	17/12/2014	
Data da última atualização: 	17/12/2014	
Autoria: 	ALVAREZ-PIZARRO, J. C.; GOMES FILHO, E.; PRISCO, J. T.; GROSSI DE SA, M. F.; OLIVEIRA NETO, O. B. de; FRAGOSO, R. da R.	
Afiliação: 	MARIA FATIMA GROSSI DE SA, CENARGEN; RODRIGO DA ROCHA FRAGOSO, CPAC.	
Título: 	Plasma membrane H+-ATPase in sorghum roots as affected by potassium deficiency and nitrogen sources.	
Ano de publicação: 	2014	
Fonte/Imprenta: 	Biologia Plantarum, v. 58, n. 3, p. 507-514, 2014.	
Idioma: 	Inglês	
Conteúdo: 	Abstract: We studied the influence of inorganic nitrogen sources (NO3- or NH4+) and potassium deficiency on expression and activity of plasma membrane (PM) H+-ATPase in sorghum roots. After 15 d of cultivation at 0.2 mM K+, the plants were transferred to solutions lacking K+ for 2 d. Then, K+ depletion assays were performed in the presence or absence of vanadate. Further, PMs from K+-starved roots were extracted and used for the kinetic characterization of ATP hydrolytic activity and the immunodetection of PM H+-ATPase. Two major genes coding PM H+-ATPase (SBA1 and SBA2) were analyzed by real-time PCR. PM H+-ATPase exhibited a higher Vmax and Km in NH4+-fed roots compared with NO3--fed roots. The optimum pH of the enzyme was slightly lower in NO3- -fed roots than in NH4+ -fed roots. The vanadate sensitivity was similar. The expressions of SBA1 and SBA2 were increased in roots grown under NH4+. Concomitantly, an increased content of the enzyme in PM was observed. The initial rate of K+ uptake did not differ between plants grown with NO3- or NH4+, but it was significantly reduced by vanadate in NH4+-grown plants.	
Palavras-Chave: 	Nitrato de Amonia.	
Thesagro: 	Fertilizante nitrogenado; Potássio; Sorghum Bicolor; Sorgo.	
Thesaurus Nal: 	Ammonium nitrate; Nitrate fertilizers; Potassium.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (34278-1) - UPC - AP - PP - S1774 -  - S1774 - DIS