AUTHOR=Wang Bing , Song Na , Zhang Qiong , Wang Ning , Kang Zhensheng 

TITLE=TaMAPK4 Acts as a Positive Regulator in Defense of Wheat Stripe-Rust Infection

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00152

DOI=10.3389/fpls.2018.00152

ISSN=1664-462X

ABSTRACT=<p>Highly conserved mitogen-activated protein kinase (MAPK) cascades regulate numerous plant processes, including hormonal responses, stress, and innate immunity. In this research, <italic>TaMAPK4</italic> was predicted to be a target of tae-miR164. We verified the binding and suppression of <italic>TaMAPK4</italic> by co-expression in <italic>Nicotiana benthamiana</italic>. Moreover, we found <italic>TaMAPK4</italic> was localized in the cytoplasm and nucleus using transient expression analyses. <italic>TaMAPK4</italic> transcripts increased following salicylic acid (SA) treatment and when host plants were infected with an avirulent race of the stripe-rust pathogen. Silencing of <italic>TaMAPK4</italic> by virus-induced gene silencing permitted increased colonization by the avirulent pathogen race. Detailed histological results showed increased <italic>Puccinia striiformis</italic> (<italic>Pst</italic>) hyphal length, hyphal branches, and infection uredinial size compared to the non-silenced control. SA accumulation and the transcript levels of <italic>TaPR1, TaPR2</italic>, and <italic>TaPR5</italic> were significantly down-regulated in <italic>TaMAPK4</italic> knockdown plants. Overall, these results suggest that <italic>TaMAPK4</italic> plays an important role in signaling during the wheat-<italic>Pst</italic> interaction. These results present new insights into MAPK signaling in wheat defense to rust pathogen.</p>