Expression and regulation of the ethylene receptor PpERS gene during pear fruit development and following salicylic acid treatment

A gene encoding an ethylene receptor protein was isolated from pear (Pyrus pyrifolia). This gene, designated PpERS (GenBank accession No. KC517482), was 1,918 bp in length with an open reading frame encoding a protein of 638 amino acids that shared high similarity with another pear ethylene receptor protein PpERS1, and two apple ethylene receptor proteins MdERS and MdERS1. The PpERS was grouped into the ETR1 subfamily of ethylene receptor based on its conserved domain and phylogenetic status. The PpERS gene contained five exons interrupted by four introns. Quantitative RT-PCR indicated that PpERS was differentially expressed in pear tissues and predominantly expressed in petals, shoots, anthers, and 160 days after full bloom fruit. The PpERS expression was regulated during fruit development. In addition, the PpERS gene expression was regulated by salicylic acid (SA) and ethylene in fruit. The results indicated that PpERS might participate in ethylene and SA signaling transduction during pear fruit development.