Surface electric charge of thylakoid membranes from genetically modified tobacco plants under freezing stress.
J Photochem Photobiol B
; 119: 22-30, 2013 Feb 05.
Article
em En
| MEDLINE
| ID: mdl-23298695
ABSTRACT
In the present study we characterize for the first time electrokinetic and light scattering properties of thylakoids from freezing-tolerant tobacco plants, transformed to accumulate osmoprotectants (proline AtP5Cs, VacP5Cs; fructan SacB; glycine betaine codA). Tobacco plants of wild type (WT) and transformed variants were cultivated at 2°C (cold acclimated) and -2°C (freezing stressed). "Lower salt" thylakoids (I=0.0006) of WT and SacB plants exhibited a decrease in electrophoretic mobility (EPM) after (2°C) treatment. AtP5Cs thylakoids (22°C) show a substantial increase in negative electrical charge (σ) upon illumination. We observed that "low salt"SacB thylakoids at 22°C and 2°C increased the σ on their membrane surfaces during the process of acclimation. WT (22°C) and AtP5Cs thylakoids (2°C) in "low salt" media (I=0.0156) showed a substantial increase in surface electrical charge upon illumination. Cold acclimation on WT and freezing stress on transformed plants resulted in a decrease in aggregation of thylakoids at both ionic strengths. There was a large enhancement in the relaxation capacity of reverse photosynthetic reactions in codA and SacB tobacco after freezing stress. Maximal intensity of the delayed light emission following low temperature stimuli was decreased, revealing a path for tobacco transformants to improve their cold stress tolerance. Here, we suggest the EPM value as an indicator for stability of thylakoids undergone genetic transformation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Estresse Fisiológico
/
Nicotiana
/
Tilacoides
Idioma:
En
Revista:
J Photochem Photobiol B
Assunto da revista:
BIOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Bulgária