Abstract
To elucidate the defense mechanisms of tobacco plant to Ralstonia solanacealum(Rs), we used differential display to isolate gene that were induced by nonpathogenic Rs mutant MINE inoculation. We focused on a cDNA, which have asparagine-rich structure (Nicotiana tabacum Asparagine-rich protein;NtARP and its ortholog from N.benthamiana Asparagine-rich protein;NbARP). Deduced amino acid sequence of NtARP and NbARP showed similarity to a rolB responsive gene (ROX1) and arabinogalactan protein (AGP). The expression of NtARP was induced by H2O2 treatment. The appearance of wilt symptoms was accelerated in the NbARP-silenced N.benthamiana challenged with pathogenic Rs. Expression of PR-4 was compromised, but appearance of HR was not affected in the silenced plant. ROX1 and AGP were reportedly to involved in bundle formation and signal transduction, respectively. Therefore NtARP and NbARP might have a role in regulation of disease development by bundle formation or signal transduction leading to defense response.
