INVESTIGADORES
FRANKEL Nicolas
congresos y reuniones científicas
Título:
Asr1 is involved in sugar signaling in tobacco plants
Autor/es:
DOMINGUEZ PG; FRANKEL N; IUSEM ND; CARRARI F
Lugar:
San Luis
Reunión:
Congreso; XLVII Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular (SAIB); 2011
Institución organizadora:
SAIB
Resumen:
Asr (ABA, stress, ripening) genes belong to the group 7 of LEA
proteins. Grape ASR1 protein has been proposed to regulate the
transcription of the hexose transporter VvHt. Silenced Asr1 tobacco
plants were characterized in detail at vegetative phase. Transgenic
lines showed higher glucose levels in leaves, diminished CO2
assimilation, higher sugar contents in phloem sap, altered total
protein pattern and foliar necrosis. This phenotype mimics tobacco
leaf senescence. In agreement with this observation, the relative
amount of ASR1 protein increases along with leaf age in wild-type
plants. These results might indicate that ASR1 is involved in foliar
senescence. Moreover, alterations in ABA and gibberellin levels and
in sensitivity to GA3 were detected in the silenced lines, probably as
a consequence of the interactions between sugar and hormone
signalling. Expression analyses of a hexose transporter, NtHt, and a
sucrose transporter-like, NtSut2, showed that their levels are
reduced. These results suggest that Asr1 is involved in sugar
signalling by a mechanism involving the regulation of sugar
transporters gene expression and that the same mechanism
contributes to modulate foliar senescence.