Abstract:

According to the genome database of Chinese white pear（Pyrus bretschneideri Rehd.），a 1 566 bp length gene was cloned from the tender stem of pear dwarfing rootstock‘Zhongai 1’. This gene is predicted to encode a 57.2 kD protein，pI 8.11，comprising 521 amino acids. The deduced amino acid sequences has high homology（about 78.01%–98.66% identity）to Katanin protein family，thus we named it PcLUE1. Real-time quantitative polymerase chain reaction（qRT-PCR）analysis showed that PcLUE1 expressed significantly higher in pear shoots in slowly growing dwarf cultivars than that in fast growing cultivars during rapid growing period. Paraffin sections of pear shoots showed that the cell arrangement and size had significant differences among dwarf，semi-dwarf and vigorous cultivars. The PcLUE1 over-expressed transgenic tobacco lines showed smaller and darker leaves than the controls，which is consistent with the phenotype of‘Zhongai 1’. Taken together，these results suggested that PcLUE1 may contribute to the dwarf phenotype of‘Zhongai 1’.

Key words: pear, Katanin Protein family, PcLUE1 gene, dwarf