INVESTIGADORES
LODEYRO Anabella Fernanda
congresos y reuniones científicas
Título:
Chloroplast-generated reactive oxygen species play a role in leaf development and senescence
Autor/es:
MARTÍN MAYTA; NÉSTOR CARRILLO; ANABELLA F. LODEYRO
Lugar:
Rosario
Reunión:
Congreso; L Reunión Anual de SAIB; 2014
Institución organizadora:
Socieda Argentina de Investigacipon en Bioquímica y Biología Molecular
Resumen:
Leaf development
can be divided in several processes: i) initiation of primordia,
ii) cell proliferation, iii) cell expansion, and iv) senescence. Reactive
oxygen species (ROS) are involved in both the early steps of leaf development, and
leaf senescence. Noteworthy,
the onsets of cell expansion and senescence represent extreme stages of leaf
development with a feature in common, an imperfectly assembled photosynthetic
electron transport (PET) chain, which is in the process of full assembly in the
first case and of collapse in the second. Non-functional PET leads to runaway
ROS production. A plastid-targeted flavodoxin (Fld) can
increase tolerance to multiple stresses in plants by acting as a general
antioxidant specific for chloroplasts preventing ROS accumulation in these
organelles. Therefore Fld-expressing lines can be used as tools to probe the
role played by chloroplast-generated ROS in different processes undergone by
plants. In plants grown under controlled conditions, leaves of
the Fld transformants showed a decrease in leaf size caused by a repression of
cell expansion. Likewise, Fld expression significantly delayed senescence. The
?stay-green? phenotype was reflected
by extended preservation of leaf pigments and photosynthetic activity. Taken
together, the results indicate that chloroplast-generated ROS are involved in
leaf development and senescence.