Molecular Cloning And Functional Characterization Of Ethylene-responsive Transcription Factor Gene MdEIL1in Apple

The plant gas hormone ethylene can regulate multiple aspects of plant growth, development and responses to environmental stress. ETHYLENE INSENSITIVE3(EIN3) is a very important transcription factor take part in the ethylene signal transduction pathway in Arabidopsis and it is acting downstream of EIN2and upstream of ERF. To have a better understanding of how the ethylene signal transduction pathway work in MalusxDomestica, we have identified an EIN3-like gene named MdEIL1in MalusxDomestica. Subsenquently, their gene expression profiles and fuctions were analized characterized. The main results were shown as follows.1. The full length of cDNAs of MdEIL1were obtained by using RT-PCR, and the full length of cDNA of ORF is1980bp, it encodes a polypeptide including559amino acid residues. The predicted protein is4.99in PI and the weight of protein is74.4kDa.2. The analysis of RT-PCR of MdEIL1and its homologous genes showed that the4genes were expressed in fruit and pericarp at the same time, but they were different in root, stem and leaf and the4genes weren’t detected in blossom. We also found the4genes’ expression can be induced by ACC, CTK, IAA, but were not obvious by Me-JA.3. By the protokaryon induction of MdEIL1, found its location was identical with theoretical value, further prove the veracity of clone.4. Ectopic expression of MdEILl reveal it can enhance the ethylene response in ranscriptional Arabidopsis, and regulate the length of hypocoty1by regulate the gene in dowmstream. In the dark, it can enhance the expression of AtERF1, inhibition of hypocotyl elongation; in the light, it can enhance the expression of AtPIFS, promote of hypocotyl elongation.The above data shows that the MdEIL1is take a part-in ethylene signal transduction pathway and can enhance ethylene response.