Salt stress affects glutamine synthetase activity and mRNA accumulation on potato plants in an organ-dependent manner

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Jorge Teixeira (Autor) FCUP; Fernanda Fidalgo (Autor) FCUP

Revista

Título: Plant Physiology and Biochemistry

Vol. 47

Páginas: 807-813

ISSN: 0981-9428

Editora: Elsevier

Indexação

ISI Web of Knowledge - 38 Citações

Scopus - 51 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Ciências biológicas

Outras Informações

ID Authenticus: P-003-GG2

DOI: 10.1016/j.plaphy.2009.05.002

Abstract (EN): Ammonium assimilation into glutamine and glutamate is vital for plant growth as these are precursors for almost all nitrogenous compounds. Ammonium can be assimilated onto nitrogenous organic compounds by the concerted action of two enzymes that compose the glutamine synthetase (GS, EC 6.3.1.2) - glutamate synthase (Fd-GOGAT EC 1.4.7.1; NADH-GOGAT, EC 1.4.1.14) cycle. Ammonium may also be directly incorporated into glutamate by the glutamate dehydrogenase (GDH, EC 1.4.1.2) aminating reaction. However, as GDH reversibly deaminates glutamate, its physiological role in vivo remains controversial. Potato has been classified as moderately tolerant to salinity. Potato GS is encoded by a small multigene family which is differentially regulated in an organ and age-dependent way. In this study, the effect of increasing concentrations of salinity in the soil in GS activity and gene-specific mRNA accumulation levels were studied on potato leaves and roots, as well as the biochemical parameters protein, chlorophyll, lipid peroxidation and proline levels, in order to evaluate the severity of the imposed stress. The data obtained suggests that when potato plants are subjected to salt stress, increased ammonium assimilation occurs in roots, due to an increased GS accumulation, along with a decreased assimilation in leaves. Regarding GS gene-specific mRNA accumulation, an organ-dependent response was also observed that contributes for the detected alteration in the ammonium assimilatory metabolism. This response may be a key feature for future genetic manipulations in order to increase crop productivity in salty soils. The possible contribution of GDH for ammonia assimilation was also investigated.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7