Open AccessP epino mosaic virus triple gene block protein 1 ( TGBp1 ) interacts with and increases tomato catalase 1 activity to enhance virus accumulation
Author(s) -
Mathioudakis Matthaios M.,
Veiga Rita S. L.,
Canto Tomas,
Medina Vicente,
Mossialos Dimitris,
Makris Antonios M.,
Livieratos Ioannis
Publication year - 2013
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12034
Subject(s) - bimolecular fluorescence complementation , biology , potexvirus , subgenomic mrna , plant virus , virology , tobacco mosaic virus , virus , viral replication , catalase , microbiology and biotechnology , rna , gene , enzyme , biochemistry , coat protein
Summary Various plant factors are co‐opted by virus elements ( RNA , proteins) and have been shown to act in pathways affecting virus accumulation and plant defence. Here, an interaction between P epino mosaic virus ( PepMV ) triple gene block protein 1 ( TGBp1 ; p26) and tomato catalase 1 ( CAT1 ), a crucial enzyme in the decomposition of toxic hydrogen peroxide ( H 2 O 2 ), was identified using the yeast two‐hybrid assay, and confirmed via an in vitro pull‐down assay and bimolecular fluorescent complementation ( BiFC ) in planta . Each protein was independently localized within loci in the cytoplasm and nuclei, sites at which their interaction had been visualized by BiFC . Following PepMV inoculation, CAT mRNA and protein levels in leaves were unaltered at 0, 3 and 6 days (locally) and 8 days (systemically) post‐inoculation; however, leaf extracts from the last two time points contained increased CAT activity and lower H 2 O 2 levels. Overexpression of PepMV p26 in vitro and in planta conferred the same effect, suggesting an additional involvement of TGBp1 in potexvirus pathogenesis. The accumulation of PepMV genomic and subgenomic RNA s and the expression of viral coat protein in noninoculated (systemic) leaves were reduced significantly in CAT ‐silenced plants. It is postulated that, during PepMV infection, a p26– CAT1 interaction increases H 2 O 2 scavenging, thus acting as a negative regulator of plant defence mechanisms to promote PepMV infections.