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Viral protein suppresses oxidative burst and salicylic acid‐dependent autophagy and facilitates bacterial growth on virus‐infected plants
Author(s) -
Zvereva Anna S.,
Golyaev Victor,
Turco Silvia,
Gubaeva Ekaterina G.,
Rajeswaran Rajendran,
Schepetilnikov Mikhail V.,
Srour Ola,
Ryabova Lyubov A.,
Boller Thomas,
Pooggin Mikhail M.
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13967
Subject(s) - biology , pseudomonas syringae , innate immune system , effector , autophagy , gene silencing , cucumber mosaic virus , microbiology and biotechnology , arabidopsis , virus , cauliflower mosaic virus , plant immunity , respiratory burst , virology , plant virus , transgene , pathogen , immune system , genetically modified crops , biochemistry , mutant , genetics , gene , apoptosis
Summary Virus interactions with plant silencing and innate immunity pathways can potentially alter the susceptibility of virus‐infected plants to secondary infections with nonviral pathogens. We found that Arabidopsis plants infected with Cauliflower mosaic virus (CaMV) or transgenic for CaMV silencing suppressor P6 exhibit increased susceptibility to Pseudomonas syringae pv. tomato ( Pst ) and allow robust growth of the Pst mutant hrcC‐ , which cannot deploy effectors to suppress innate immunity. The impaired antibacterial defense correlated with the suppressed oxidative burst, reduced accumulation of the defense hormone salicylic acid (SA) and diminished SA‐dependent autophagy. The viral protein domain required for suppression of these plant defense responses is dispensable for silencing suppression but essential for binding and activation of the plant target‐of‐rapamycin (TOR) kinase which, in its active state, blocks cellular autophagy and promotes CaMV translation. Our findings imply that CaMV P6 is a versatile viral effector suppressing both silencing and innate immunity. P6‐mediated suppression of oxidative burst and SA‐dependent autophagy may predispose CaMV‐infected plants to bacterial infection.