INVESTIGADORES
CIVELLO Pedro Marcos
artículos
Título:
Polygalacturonase activity and expression of related genes during ripening of strawberry cultivars with contrasting fruit firmness.
Autor/es:
NATALIA M. VILLARREAL; HERNÁN G. ROSLI; PEDRO MARCOS CIVELLO; GUSTAVO A. MARTÍNEZ
Revista:
POSTHARVEST BIOLOGY AND TECHNOLOGY
Editorial:
Elsevier
Referencias:
Lugar: Holanda; Año: 2008 vol. 47 p. 141 - 150
ISSN:
0925-5214
Resumen:
Fleshy fruits soften during ripening mainly as a consequence of the
catabolism of cell wall components. In strawberry (Fragaria×ananassa Duch), the
depolymerization and solubilization of pectins increase during ripening and
contribute to fruit softening. In the present paper, we report the cloning and expression analysis of two polygalacturonase (PG)
putative cDNAs: FaPG1 and T-PG. The former seems to be the same sequence of
previously reported PG in strawberry, while T-PG cDNA has a deletion of 85 bp
that cause a frame shift and would produce an inactive protein. Measurement of total PG activity and expression of FaPG1 and T-PG were
performed in strawberry cultivars with contrasting softening rates. The softest
cultivar (Toyonaka)
showed the higher total PG activity in all ripening stages analyzed. The
analysis by RT-PCR revealed that both genes express in the three cultivars, though the expression pattern was
different. In the firmer cultivars (Selva and Camarosa) the expression of T-PG
was considerably higher than the expression of FaPG1, while the opposite
occurred in the softest cultivar (Toyonaka).
Therefore, the higher PG activity detected in Toyonaka correlates with the enhanced
expression of FaPG1 gene, while the low PG activity found in the firm cultivars
correlates with a higher expression of T-PG, a gene that could encode a
truncated protein without PG activity. The influence of auxins on both the
xpression of PG genes and the total PG activity during strawberry fruit
ripening was also analyzed.