INVESTIGADORES
BUSTAMANTE Claudia Anabel
artículos
Título:
Fruit specific plasma membrane aquaporins subtype PIP1 are strongly regulated during fruit ripening in Fragaria x ananassa
Autor/es:
MUT P, BUSTAMANTE C, MARTÍNEZ G, ALLEVA K, SUTKA M, CIVELLO M, AMODEO G
Revista:
PHYSIOLOGIA PLANTARUM
Editorial:
Blackwell Publishing
Referencias:
Lugar: Lund; Año: 2008 vol. 132 p. 538 - 551
ISSN:
0031-9317
Resumen:
Despite the advances in the physiology of fruit ripening, the role and
contribution of water pathways are still barely considered. Our aim was
therefore to characterize aquaporins, proteins that render the molecular basis
for putative regulatory mechanisms in water transport.We focused our work on
strawberry (Fragariaananassa) fruit, a non-climacteric fruit of special interest
because of its forced brief commercial shelf life. A full-length cDNA was
isolated with high homology with plasma membrane (PM) intrinsic proteins
(named FaPIP1;1), showing a profile with high expression in fruit, less in
ovaries and no detection at all in other parts. Its cellular localization was
confirmed at the PM. As reported in other plasma membrane intrinsic proteins
subtype 1 (PIP1s), when expressing the protein in Xenopus leavis oocytes,
FaPIP1;1 shows low water permeability values that only increased when it is
coexpressed with a plasma membrane intrinsic protein subtype 2. Northern
blotting using total RNA shows that its expression increases during fruit
ripening. Moreover, functional characterization of isolated PM vesicles from
red stage fruit unequivocally demonstrates the presence of active water
channels, i.e. high water permeability values and a low Arrhenius activation
energy, both evidences of water transport mediated by proteins. Interestingly,
as many ripening-related strawberry genes, the expression pattern of FaPIP1;1Fragariaananassa) fruit, a non-climacteric fruit of special interest
because of its forced brief commercial shelf life. A full-length cDNA was
isolated with high homology with plasma membrane (PM) intrinsic proteins
(named FaPIP1;1), showing a profile with high expression in fruit, less in
ovaries and no detection at all in other parts. Its cellular localization was
confirmed at the PM. As reported in other plasma membrane intrinsic proteins
subtype 1 (PIP1s), when expressing the protein in Xenopus leavis oocytes,
FaPIP1;1 shows low water permeability values that only increased when it is
coexpressed with a plasma membrane intrinsic protein subtype 2. Northern
blotting using total RNA shows that its expression increases during fruit
ripening. Moreover, functional characterization of isolated PM vesicles from
red stage fruit unequivocally demonstrates the presence of active water
channels, i.e. high water permeability values and a low Arrhenius activation
energy, both evidences of water transport mediated by proteins. Interestingly,
as many ripening-related strawberry genes, the expression pattern of FaPIP1;1Xenopus leavis oocytes,
FaPIP1;1 shows low water permeability values that only increased when it is
coexpressed with a plasma membrane intrinsic protein subtype 2. Northern
blotting using total RNA shows that its expression increases during fruit
ripening. Moreover, functional characterization of isolated PM vesicles from
red stage fruit unequivocally demonstrates the presence of active water
channels, i.e. high water permeability values and a low Arrhenius activation
energy, both evidences of water transport mediated by proteins. Interestingly,
as many ripening-related strawberry genes, the expression pattern of FaPIP1;1FaPIP1;1
was also repressed by the presence of auxins. We therefore report a fruit
specific PIP1 aquaporin with an accumulation pattern tightly associated to
auxins and to the ripening process that might be responsible for increasing
water permeability at the level of the PM in ripe fruit.