Identification of an ETR1-homologue from mango fruit expressing during fruit ripening and wounding

We have isolated a mango (Mangifera indica L.) cDNA homologue of the ethyle ne receptor gene ETR-1, referred to as METR1, which codes for a polypeptide of 802 amino acids with a predicted molecular weight of 89 kDa. The amino acid sequence is highly homologous lover 80%) to ETRs from other fruits. Ge nomic Southern blot analysis indicates that two or more ETR homologues exis t in mango. RNA blot analysis revealed that the level of METR1 mRNA in the mesocarp increased during fruit ripening. in addition, it was round that th e METR1 mRNA increases transiently during wounding of the tissue. This is t he first report of an ETR homologue showing an induction during fruit ripen ing and wounding.