Articles
CHANGES IN THE EXPRESSION OF GENES INVOLVED IN ETHYLENE SIGNALLING IN PEACH FRUIT WITH DIFFERENT FLESH TEXTURE AND SOFTENING PATTERNS
Article number
884_13
Pages
125 – 131
Language
English
Abstract
Melting flesh (MF) and non-melting flesh (NMF) peaches show different texture and firmness and different ethylene evolution.
The MF phenotype is linked to the presence of high levels of an active ripening-related endopolygalacturonase (endoPG). In Oro A the predicted amino acidic sequence of endoPG protein is very similar to that of MF Bolero but the levels of the active endoPG protein and Pp-endoPG transcripts are very low, suggesting that expression of the Pp-endoPG gene could be transcriptionally regulated.
Regulation of Pp-endoPG gene expression could be related to possible differences in ethylene perception/transduction in fruit flesh tissues.
Fruit of two NMF (Oro A and Andross) and two MF (Bolero and Springcrest) peach cultivars were analyzed for ethylene evolution and levels of transcripts of a few genes involved in ethylene signalling.
Ethylene emission were lower in MF than in NMF fruit; the levels of Pp-ERS1, Pp-ETR2 and Pp-CTR1 transcripts were lower in MF fruit, consistent with their suggested role of negative regulators of the ethylene response.
The levels of transcripts of Pp-ERF1, which is involved in response induction, were higher in MF fruit and well related to higher levels of Pp-endoPG transcripts.
The Pp-endoPG gene is present as one allele (m) in Oro A and as two alleles (m and M) in Bolero; sequence analysis of a 1970 bp sequence upstream of ATG of the Pp-endoPG-m allele showed presence of potential regulatory sequences associated with hormone responses.
Preliminary results obtained by partial isolation and sequencing of the 124 bp sequence upstream of ATG of the Pp-endoPG-M allele of Bolero showed deep differences compared to the Pp-endoPG-m allele.
Work is now in progress to complete sequencing of this region of the Bolero Pp-endoPG-M allele.
The MF phenotype is linked to the presence of high levels of an active ripening-related endopolygalacturonase (endoPG). In Oro A the predicted amino acidic sequence of endoPG protein is very similar to that of MF Bolero but the levels of the active endoPG protein and Pp-endoPG transcripts are very low, suggesting that expression of the Pp-endoPG gene could be transcriptionally regulated.
Regulation of Pp-endoPG gene expression could be related to possible differences in ethylene perception/transduction in fruit flesh tissues.
Fruit of two NMF (Oro A and Andross) and two MF (Bolero and Springcrest) peach cultivars were analyzed for ethylene evolution and levels of transcripts of a few genes involved in ethylene signalling.
Ethylene emission were lower in MF than in NMF fruit; the levels of Pp-ERS1, Pp-ETR2 and Pp-CTR1 transcripts were lower in MF fruit, consistent with their suggested role of negative regulators of the ethylene response.
The levels of transcripts of Pp-ERF1, which is involved in response induction, were higher in MF fruit and well related to higher levels of Pp-endoPG transcripts.
The Pp-endoPG gene is present as one allele (m) in Oro A and as two alleles (m and M) in Bolero; sequence analysis of a 1970 bp sequence upstream of ATG of the Pp-endoPG-m allele showed presence of potential regulatory sequences associated with hormone responses.
Preliminary results obtained by partial isolation and sequencing of the 124 bp sequence upstream of ATG of the Pp-endoPG-M allele of Bolero showed deep differences compared to the Pp-endoPG-m allele.
Work is now in progress to complete sequencing of this region of the Bolero Pp-endoPG-M allele.
Authors
A. Ghiani, F. Baldin, S. Morgutti, N. Negrini, F.F. Nocito, I. Mignani, D. Bassi, M. Cocucci
Keywords
: Prunus persica, fruit softening, ethylene receptors, Pp-endo-PG gene, transcript levels
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