Characterization of two putative ethylene receptor genes expressed during peach fruit development and abscission.
Two peach genes homologous to the Arabidopsis ethylene receptor genes ETR1 and ERS1, named Pp-ETR1 and Pp-ERS1 respectively, have been isolated and characterized. Pp-ETR1 and Pp-ERS1 are conserved in terms of exon numbers and intron positions, although the first and fifth introns of Pp-ETR1 have an unusual length. In addition, two putative polyadenylation sites, that may cause an incomplete splicing at the 3' terminus, are present in the fifth intron. A motif of 28 nt, which shows high homology with ethylene responsive elements found in promoters of genes up-regulated by ethylene, is present in the promoter region of Pp-ERS1. Expression analysis, carried out by quantitative RT-PCR, was performed during fruit development and ripening, and leaf and fruitlet abscission. The level of Pp-ETR1 transcripts remained unchanged in all the tissues and developmental stages examined, whereas Pp-ERS1 mRNA abundance increased in ripening mesocarp, in leaf and fruitlet activated abscission zones, and following propylene application. 1-methylcyclopropene (1-MCP), an inhibitor of ethylene action, did not affect Pp-ETR1 transcription, while it down-regulated Pp-ERS1. A rise in ethylene evolution, accompanied by an increase of Pp-ERS1 transcript accumulation occurred within 24 h from the end of 1-MCP treatment. These results indicate that Pp-ERS1 might play a role in abscission and ripening.
Rasori
Angela
A
Department of Environmental Agronomy and Crop Science, University of Padova, Via Romea, 16-Agripolis, Legnaro (Padova), 35020 Italy.
Ruperti
Benedetto
B
Bonghi
Claudio
C
Tonutti
Pietro
P
Ramina
Angelo
A
D001483:Base Sequence; D015139:Blotting, Southern; D017931:DNA Primers; D018745:Genome, Plant; D010940:Plant Proteins / Q000235:genetics*; D027861:Prunus / Q000235:genetics / Q000254:growth & development*; D011956:Receptors, Cell Surface / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C083750:ethylene receptors, plant