Acclimatization of micropropagated plantlets induces an antioxidative burst: a case study with Ulmus minor Mill.

• Tipo: Artigo em Revista Científica Internacional
• Data: 2011

Autores

Dias, MC (Autor) Outra; Pinto, G (Autor) Outra; Santos, C (Autor) Outra

Revista

Título: Photosynthetica

Vol. 49

Páginas: 259-266

ISSN: 0300-3604

Editora: Akademie Ved Ceske Republiky

Indexação

ISI Web of Knowledge - 30 Citações

Scopus - 34 Citações

Outras Informações

ID Authenticus: P-002-R5Q

DOI: 10.1007/s11099-011-0028-9

Abstract (EN): In this article, the effects of increased light intensities on antioxidant metabolism during ex vitro establishment of Ulmus minor micropropagated plants are investigated. Three month old in vitro plants were acclimatized to ex vitro conditions in a climate chamber with two different light intensities, 200 mu mol m(-2) s(-1) (high light, HL) and 100 mu mol m(-2) s(-1) (low light, LL) during 40 days. Immediately after ex vitro transfer, the increase of both malondialdehyde (MDA) and electrolyte leakage in persistent leaves is indicative of oxidative stress. As the acclimatization continues, an upregulation of the superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) enzyme activities were also observed. Simultaneously, MDA content and membrane permeability stabilized, suggesting that the antioxidant enzymes decrease the deleterious effects of reactive oxygen species (ROS) generation. Unexpectedly, newly formed leaves presented a different pattern of antioxidative profile, with high levels of MDA and membrane leakage and low antioxidant enzyme activity. Despite these differences, both leaf types looked healthy (e.g. greenish, with no necrotic spots) during the whole acclimatization period. The results indicate that micropropagated U. minor plantlets develop an antioxidant enzyme system after ex vitro transfer and that, in general, LL treatment leads to lower oxidative stress. Moreover, new leaves tolerate higher levels of ROS without the need to activate the antioxidative pathway, which suggests that the environment at which leaves are exposed during its formation determinate their ability to tolerate ROS.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8