Abstract

In response to pathogen attacks, plant produces a wide range of pathogenesis-related (PR) proteins. PR-1 genes represent the first identified PR gene family. Most members of PR-1 gene family are not inducible by pathogen attacks. In this study, we identified a pathogen-responsive PR-1 gene designated as VqPR-1 (GenBank accession no. JN256202), in a subtractive suppression hybridization (SSH) cDNA-library from Elsinoe ampelina-inoculated young leaves of Chinese wild Vitis quinquangularis clone ‘shang-24’. VqPR-1 protein contained the requisite signal sequence at the N-terminus, a conserved three-dimensional structure called ‘PR-1 fold’ and a highly conserved six-cysteine motif. Expression level of VqPR-1 rose rapidly in response to E. ampelina infection. The three tested plant defence signaling molecules, salicylic acid (SA), ethephon (Eth) and methyl jasmonate (MeJA) all triggered an induction of VqPR-1. However, the induction by addition of MeJA was weaker than that induced by SA and Eth. In addition, the response to inoculation withE. ampelina or treatment with signaling molecules, was sometimes a suppression ofVqPR-1 gene expression. The highest expression of VqPR-1 was observed in flowers, stems and leaves, while low-level or no obvious transcripts were detected in pericarps and tendrils, respectively.

Key words: Vitis quinquangularis, PR-1 gene, Elsinoe ampelina, expression analysis.

Abbreviation

SSH, Subtractive suppression hybridization; qRT-PCR, quantitative reverse transcription-polymerase chain reaction; sqRT-PCR, semi-quantitative reverse transcription-polymerase chain reaction; SAR, systemic acquired resistance;PR, pathogenesis-related; SA, salicylic acid; MeJA, methyl jasmonate; Eth,ethephon; Hpi, hours post inoculation; Hpt, hours post treatment.