Physiological performance of transplastomic tobacco plants overexpressing aquaporin AQP1 in chloroplast membranes
Fecha
2018Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
|
10.1093/jxb/ery148
Resumen
The leaf mesophyll CO2 conductance and the concentration of CO2 within the chloroplast are major factors affecting photosynthetic performance. Previous studies have shown that the aquaporin NtAQP1 (which localizes to the plasma membrane and chloroplast inner envelope membrane) is involved in CO2 permeability in the chloroplast. Levels of NtAQP1 in plants genetically engineered to overexpress the ...
[++]
The leaf mesophyll CO2 conductance and the concentration of CO2 within the chloroplast are major factors affecting photosynthetic performance. Previous studies have shown that the aquaporin NtAQP1 (which localizes to the plasma membrane and chloroplast inner envelope membrane) is involved in CO2 permeability in the chloroplast. Levels of NtAQP1 in plants genetically engineered to overexpress the protein correlated positively with leaf mesophyll CO2 conductance and photosynthetic rate. In these studies, the nuclear transformation method used led to changes in NtAQP1 levels in the plasma membrane and the chloroplast inner envelope membrane. In the present work, NtAQP1 levels were increased up to 16-fold in the chloroplast membranes alone by the overexpression of NtAQP1 from the plastid genome. Despite the high NtAQP1 levels achieved, transplastomic plants showed lower photosynthetic rates than wild-type plants. This result was associated with lower Rubisco maximum carboxylation rate and ribulose 1,5-bisphosphate regeneration. Transplastomic plants showed reduced mesophyll CO2 conductance but no changes in chloroplast CO2 concentration. The absence of differences in chloroplast CO2 concentration was associated with the lower CO2 fixation activity of the transplastomic plants. These findings suggest that non-functional pores of recombinant NtAQP1 may be produced in the chloroplast inner envelope membrane. [--]
Materias
Aquaporin,
Chloroplast envelope,
CO2 permeability,
Plastid transformation,
Protein targeting,
Tobacco
Editor
Oxford University Press
Publicado en
Journal of Experimental Botany, 2018, 69(15), 3661-3673
Departamento
Universidad Pública de Navarra. Departamento de Agronomía, Biotecnología y Alimentación /
Nafarroako Unibertsitate Publikoa. Agronomia, Bioteknologia eta Elikadura Saila /
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Versión del editor
Entidades Financiadoras
MA is a recipient of a Formación de Profesorado Universitario fellowship from the Ministerio de Educación, Cultura y Deporte, Spain. MN was supported by a predoctoral fellowship BES2015-072578 from the Ministerio de Economía y Competitividad (MINECO), Spain, co-financed by the European Science Foundation.