AUTHOR=Rasool Brwa , Karpinska Barbara , Konert Grzegorz , Durian Guido , Denessiouk Konstantin , Kangasjärvi Saijaliisa , Foyer Christine H. 

TITLE=Effects of light and the regulatory B-subunit composition of protein phosphatase 2A on the susceptibility of Arabidopsis thaliana to aphid (Myzus persicae) infestation

JOURNAL=Frontiers in Plant Science

VOLUME=5

YEAR=2014

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2014.00405

DOI=10.3389/fpls.2014.00405

ISSN=1664-462X

ABSTRACT=<p>The interactions between biotic and abiotic stress signaling pathways are complex and poorly understood but protein kinase/phosphatase cascades are potentially important components. Aphid fecundity and susceptibility to <italic>Pseudomonas syringae</italic> infection were determined in the low light-grown <italic>Arabidopsis thaliana</italic> wild type and in mutant lines defective in either the protein phosphatase (PP)2A regulatory subunit B'γ (<italic>gamma</italic>; <italic>pp2a-b'γ</italic>) or B'ζ (<italic>zeta</italic>; <italic>pp2a-b'ζ1-1</italic> and <italic>pp2a-b'ζ 1-2</italic>) and in <italic>gamma zeta</italic> double mutants (<italic>pp2a-b'γζ</italic>) lacking both subunits. All the mutants except for <italic>pp2a-b'ζ 1-1</italic> had significantly lower leaf areas than the wild type. Susceptibility to <italic>P. syringae</italic> was similar in all genotypes. In contrast, aphid fecundity was significantly decreased in the <italic>pp2a-b'γ</italic> mutant relative to the wild type but not in the <italic>pp2a-b'γζ</italic> double mutant. A high light pre-treatment, which led to a significant increase in rosette growth in all mutant lines but not in the wild type, led to a significant decrease in aphid fecundity in all genotypes. The high light pre-treatment abolished the differences in aphid resistance observed in the <italic>pp2a-b'γ</italic> mutant relative to the wild type. The light and CO<sub>2</sub> response curves for photosynthesis were changed in response to the high light pre-treatment, but the high light effects were similar in all genotypes. These data demonstrate that a pre-exposure to high light and the composition of B-subunits on the trimeric PP2A holoenzymes are important in regulating plant resistance to aphids. The functional specificity for the individual regulatory B-subunits may therefore limit aphid colonization, depending on the prevailing abiotic stress environment.</p>