Data/hora: 16/06/2024 19:13:02

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