AUTHOR=Liu Qiuping , Liu Ying , Tang Yuanman , Chen Juanni , Ding Wei 

TITLE=Overexpression of NtWRKY50 Increases Resistance to Ralstonia solanacearum and Alters Salicylic Acid and Jasmonic Acid Production in Tobacco

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.01710

DOI=10.3389/fpls.2017.01710

ISSN=1664-462X

ABSTRACT=<p>WRKY transcription factors (TFs) modulate plant responses to biotic and abiotic stresses. Here, we characterized a WRKY IIc TF, NtWRKY50, isolated from tobacco (<italic>Nicotiana tabacum</italic>) plants. The results showed that NtWRKY50 is a nuclear-localized protein and that its gene transcript is induced in tobacco when inoculated with the pathogenic bacterium <italic>Ralstonia solanacearum</italic>. Overexpression of <italic>NtWRKY50</italic> enhanced bacterial resistance, which correlated with enhanced SA and JA/ET signaling genes. However, silencing of the <italic>NtWRKY50</italic> gene had no obvious effects on plant disease resistance, implying functional redundancy of NtWRKY50 with other TFs. In addition, it was found that <italic>NtWRKY50</italic> can be induced by various biotic or abiotic stresses, such as Potato virus Y, <italic>Rhizoctonia solani, Phytophthora parasitica</italic>, hydrogen peroxide, heat, cold, and wounding as well as the hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). Importantly, additional analysis suggests that <italic>NtWRKY50</italic> overexpression markedly promotes SA levels but prevents pathogen-induced JA production. These data indicate that <italic>NtWRKY50</italic> overexpression leads to altered SA and JA content, increased expression of defense-related genes and enhanced plant resistance to <italic>R. solanacearum.</italic> These probably due to increased activity of endogenous <italic>NtWRKY50</italic> gene or could be gain-of-function phenotypes by altering the profile of genes affected by <italic>NtWRKY50</italic>.</p>