Identification of an Apple NBS-LRR1 Gene and Its Expression Analysis

NBS-LRR proteins are one protein family which contains Nucleotide-binding site(NBS) and leucine-rich repeat(LRR),and play an important role in defending plants from various pathogens. A new NBS-LRR gene was identified from‘Gala’apple and named MdNBS-LRR1(JX126858). The full cDNA was 3 116 bp in length with an open reading frame(ORF)of 2 826 bp and encoded a protein of 941 amino acids. The putative amino acid sequence contains an NB-ARC domain. The BLAST analysis exhibited high identity(60%)to NBS-LRR resistant protein(ACM89637)from Glycine max. Real time quantitative PCR analysis showed that the expression of MdNBS-LRR1 was observed in all tissues tested here including young leaves,shoot,functional leaves,bud,bark and flower,and the highest expression level was found in younger leaves. The expression of MdNBS-LRR1 was up-regulated by infection with Botryosphaeria dothide and reached the peak value at 24 d(10.6-fold higher than that in control)after inoculation. In addition,SA,MeJA and ACC could induce the expression of MdNBS-LRR1 gene in leaves,indicating that MdNBS-LRR1 could be regulated by the disease-resistant related signaling pathway.