INVESTIGADORES
GONZALEZ SCHAIN Nahuel Damian
artículos
Título:
Ectopic expression of mitochondrial gamma carbonic anhydrase 2 causes male sterility by anther indehiscence.
Autor/es:
VILLARREAL F; MARTÍN V; COLANERI A; GONZÁLEZ SCHAIN N; PERALES M; MARTÍN M; LOMBARDO C; BRAUN HP; BARTOLI C; ZABALETA E
Revista:
PLANT MOLECULAR BIOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2009 vol. 70 p. 471 - 485
ISSN:
0167-4412
Resumen:
Plant mitochondria include gamma-type carbonic anhydrases (gammaCAs) of
unknown function. In Arabidopsis, the gammaCAs form a gene family of
five members which all are attached to the NADH dehydrogenase complex
(complex I) of the respiratory chain. Here we report a functional
analysis of gamma carbonic anhydrase 2 (CA2). The gene encoding CA2 is
constitutively expressed in all plant organs investigated but it is ten
fold induced in flowers, particularly in tapetal tissue. Ectopic
expression of CA2 in Arabidopsis causes male sterility in transgenic
plants. In normal anther development, secondary thickenings of the
endothecial cell wall cause anthers to open upon dehydration.
Histological analyses revealed that abnormal secondary thickening
prevents anther opening in 35S::CA2 transgenic plants. CA2 abundance in
transgenic plants is increased 2-3 fold compared to wild-type plants as
revealed by Western blotting analyses. Moreover, abundance of other
members of the CA family, termed CA3 and CAL2, is increased in
transgenic plants. Oxygen uptake measurements revealed that respiration
in transgenic plants is mainly based on NADH reduction by the
alternative NADH dehydrogenases present in plant mitochondria.
Furthermore, the formation of reactive oxygen species (ROS) is very low
in transgenic plants. We propose that reduction in ROS inhibits H(2)O(2)
dependent lignin polymerization in CA2 over-expressing plants, thereby
causing male sterility.