Cloning and sequence analysis of ethylene receptor ETR1 and ERS1 genes from mango(Mangnifera indica L.)

ObjectiveEthylene receptor ETR1 and ERS1 genes(MiETR1 and MiERS1)from mango(Mangnifera in-dica L.)were cloned,and bioinformatics analysis was conducted in order to provide theoretical reference for further study of functional mechanism of the ethylene receptors in mango ripening and senescencing.MethodUsing mango fruit as material,full-length cDNA sequences of MiETR1 and MiERS1 by RACE technology was amplified,and the encoded ami-no acid sequences were predicted by bioinformatics method.ResultThe full-length cDNA sequence of cloned gene Mi-ETR1 was 2570 bp,an open reading frame(ORF)of 2220 bp,encoding 739 amino acids. The full-length cDNA sequence of cloned gene MiERS1 was 2171 bp,and it was consisted of an ORF of 1890 bp,encoding 629 amino acids. The Gen-Bank accession numbers for the two were KY002681 and KY002682. Bioinformatic analysis showed that the MiETR1 and MiERS1 proteins were non secreted hydrophobic protein with transmembrane domain,belonging to the ETR1 family member of ethylene receptor with Ser-based,Thr-assisted phosphorylation-modulatory. MiETR1 and MiERS1 proteins contained three typical modules,namely GAF domain,HisKA domain and HATPase_c domain. MiERS1 protein lacked REC domain compared with MiETR1. The amino acid sequences of ETR1 and ERS1 proteins in different species were highly conserved. MiETR1 and MiERS1 had high homologous with the ETR1 and ERS1 proteins of Citrus sinensis and Citrus clementina. However,the two clustered on two different branches,indicating that there was genetic differentiation between the two proteins at certain extents.ConclusionEthylene receptor gene plays a regulatory role in mango fruit maturation and senescence.