AUTHOR=Sibisi Phumzile , Venter Eduard 

TITLE=Wheat Argonaute 5 Functions in Aphid–Plant Interaction

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00641

DOI=10.3389/fpls.2020.00641

ISSN=1664-462X

ABSTRACT=<p>Aphids feeding on plants experience similar responses to pathogens due to the prolonged and intimate contact with the plant. <italic>Diuraphis noxia</italic> is an economically important aphid pest on wheat that exhibits such an interaction. Studies on small RNA (sRNA) that regulate genes imparting resistance to wheat against <italic>D. noxia</italic> have predicted an <italic>Argonaute 5</italic> (<italic>TaAGO5</italic>) gene as possible role player in the resistance response. Functional characterization revealed that <italic>TaAGO5</italic> is crucial in regulating the response to infestation by <italic>D. noxia</italic>. Knockdown of <italic>TaAGO5</italic> by 22% in <italic>D. noxia</italic> resistant wheat resulted in a completely susceptible phenotype. The fecundity and stress levels of <italic>D. noxia</italic> feeding on these silenced plants were similar to aphids feeding on the susceptible controls. Thus, <italic>TaAGO5</italic> is crucial in the defense response by wheat plants during aphid feeding and this is similar to <italic>Nicotiana benthaminia</italic> plants experiencing arthropod herbivory. Additionally, <italic>TaAGO5</italic> was differentially regulated by the Barley mosaic virus (BMV) used in the functional characterization. This provides evidence that <italic>TaAGO5</italic> could play a role during virus infection of wheat. The role of AGO5 proteins in plant responses to arthropod herbivory and virus infection is known for dicotyledonous plants. Here, we present data that indicate that this role of <italic>TaAGO5</italic> is conserved in wheat and possibly for monocotyledonous plants. These observations extend our knowledge on the roles of AGO proteins in plant resistance.</p>