Abstract:

Up-regulated expression NAC transcription factor was selected from transcriptome
sequencing data of Pyrus calleryana Decne infected by Pear black spot. Full length gene was polymerized
and entitled as PcNAC1. The open reading frame（ORF）consists on 792 bp nucleotides encoding 263
amino acids polypeptide. Comparison of PcNAC1 with peptide sequences of NAC transcription factors
protein family and phylogenetic analysis revealed the highest homology of PcNAC1 with TaNAC4 in
Triticum aestivu and ATAF1 in Arabidopsis thaliana. It revealed by Quantitative Real-time PCR that the expression of PcNAC1 was high in stem，leaf and root of Pyrus calleryana Decne but very low expression
in flower and fruit. We synthesized a sub-cellular localization vector to get the transient expression in
Nicotiana benthamiana. By confocal laser scanning microscopy it was observed that the fusion protein was
localized in nucleus. Furthermore，we infected transgenic Nicotiana benthamiana with Phytophthora
parasitica，it was obvious that PcNAC1 enhanced the disease resistance in plant by triggering the
expression of pathways of defense response plant hormone genes.

Key words: Pyrus calleryana, Pear black spot, NAC transcription factor, sub-cellular localization, defense response