Spatial patterns of senescence and development-dependent distribution of reactive oxygen species in tobacco (Nicotiana tabacum) leaves.
J Plant Physiol
; 166(10): 1057-68, 2009 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-19261356
ABSTRACT
Senescence of tobacco leaves is distributed non-uniformly over a leaf blade. While photosynthetic competence and expression of photosynthesis-associated genes decline in interveinal areas of the leaf lamina with advancing age of the leaf, they are maintained at high levels in the tissue surrounding the veins. In contrast, expression of senescence-associated genes (SAG) was enhanced in both areas of the leaf blade. Accumulation of hydrogen peroxide was shown to precede the phase of senescence initiation in the veinal tissue. In the interveinal tissue, the level of hydrogen peroxide was increased with senescence progression and paralleled by an increase in the level of superoxide anions. It is hypothesized that the spatial differences in superoxide anions are important for the non-uniform down-regulation of photosynthesis-associated genes (PAG), while hydrogen peroxide is responsible for up-regulation of SAG.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nicotiana
/
Senescência Celular
/
Espécies Reativas de Oxigênio
/
Folhas de Planta
Idioma:
En
Revista:
J Plant Physiol
Assunto da revista:
BOTANICA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Polônia