AUTHOR=Vo Kieu T. X. , Kim Chi-Yeol , Hoang Trung V. , Lee Sang-Kyu , Shirsekar Gautam , Seo Young-Su , Lee Sang-Won , Wang Guo-Liang , Jeon Jong-Seong 

TITLE=OsWRKY67 Plays a Positive Role in Basal and XA21-Mediated Resistance in Rice

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.02220

DOI=10.3389/fpls.2017.02220

ISSN=1664-462X

ABSTRACT=<p>WRKY proteins play important roles in transcriptional reprogramming in plants in response to various stresses including pathogen attack. In this study, we functionally characterized a rice WRKY gene, <italic>OsWRKY67</italic>, whose expression is upregulated against pathogen challenges. Activation of <italic>OsWRKY67</italic> by T-DNA tagging significantly improved the resistance against two rice pathogens, <italic>Magnaporthe oryzae</italic> and <italic>Xanthomonas oryzae</italic> pv. <italic>oryzae</italic> (<italic>Xoo</italic>). Reactive oxygen species (ROS) rapidly accumulated in <italic>OsWRKY67</italic> activation mutant lines in response to elicitor treatment, compared with the controls. Overexpression of <italic>OsWRKY67</italic> in rice confirmed enhanced disease resistance, but led to a restriction of plant growth in transgenic lines with high levels of OsWRKY67 protein. <italic>OsWRKY67</italic> RNAi lines significantly reduced resistance to <italic>M. oryzae</italic> and <italic>Xoo</italic> isolates tested, and abolished XA21-mediated resistance, implying the possibility of broad-spectrum resistance from OsWRKY67. Transcriptional activity and subcellular localization assays indicated that OsWRKY67 is present in the nucleus where it functions as a transcriptional activator. Quantitative PCR revealed that the pathogenesis-related genes, <italic>PR1a, PR1b, PR4, PR10a</italic>, and <italic>PR10b</italic>, are upregulated in <italic>OsWRKY67</italic> overexpression lines. Therefore, these results suggest that OsWRKY67 positively regulates basal and XA21-mediated resistance, and is a promising candidate for genetic improvement of disease resistance in rice.</p>