AUTHOR=Qi Tuo , Wang Juan , Sun Qixiong , Day Brad , Guo Jun , Ma Qing 

TITLE=TaARPC3, Contributes to Wheat Resistance against the Stripe Rust Fungus

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.01245

DOI=10.3389/fpls.2017.01245

ISSN=1664-462X

ABSTRACT=<p>The actin cytoskeleton participates in numerous cellular processes, including less-characterized processes, such as nuclear organization, chromatin remodeling, transcription, and signal transduction. As a key regulator of actin cytoskeletal dynamics, the actin related protein 2/3 complex (Arp2/3 complex) controls multiple developmental processes in a variety of tissues and cell types. To date, the role of the Arp2/3 complex in plant disease resistance signaling is largely unknown. Herein, we identified and characterized wheat ARPC3, <italic>TaARPC3</italic>, which encodes the C3 subunit of the Arp2/3 complex. Expression of <italic>TaARPC3</italic> in the <italic>arc18</italic> mutant of <italic>Saccharomyces cerevisiae</italic> Δ<italic>arc18</italic> resulted in complementation of stress-induced phenotypes in <italic>S. cerevisiae</italic>, as well as restore wild-type cell shape malformations. TaARPC3 was found predominantly to be localized in the nucleus and cytoplasm when expressed transiently in wheat protoplast. <italic>TaARPC3</italic> was significantly induced in response to avirulent race of <italic>Puccinia striiformis</italic> f. sp. <italic>tritici</italic> (<italic>Pst</italic>). Knock-down of <italic>TaARPC3</italic> by virus-induced gene silencing resulted in a reduction of resistance against <italic>Pst</italic> through a specific reduction in actin cytoskeletal organization. Interestingly, this reduction was found to coincide with a block in reactive oxygen species (ROS) accumulation, the hypersensitive response (HR), an increase in <italic>TaCAT1</italic> mRNA accumulation, and the growth of <italic>Pst</italic>. Taken together, these findings suggest that <italic>TaARPC3</italic> is a key subunit of the Arp2/3 complex which is required for wheat resistance against <italic>Pst</italic>, a process that is associated with the regulation of the actin cytoskeleton.</p>