Multiple determinants in the coding region of Pea seed-borne mosaic virus P3 are involved in virulence against sbm-2 resistance.
Viral determinants for overcoming Pisum sativum recessive resistance, sbm-2, against the potyvirus Pea seed-borne mosaic virus (PSbMV) were identified in the region encoding the N-terminal part of the P3 protein. Codons conserved between sbm-2 virulent isolates in this region: Q21, K30 and H122 were found to specifically impair sbm-2 virulence when mutated in selected genetic backgrounds. The corresponding amino acids, Gln21 and Lys30, are neighbored by P3 residues strongly conserved among potyviruses and His122 is conserved particularly in potyviral species infecting legumes. The strongest selective inhibition of sbm-2 virulence, however, was observed by elimination of isolate specific length polymorphisms also located in the N-terminal part of the P3 protein. Length variation in N-terminal P3 is common between potyviral species. However, intra-species length polymorphism in this region was found only among PSbMV isolates. Our findings comply with a model for PSbMV pathotypes having evolved by a diversification of the P3 protein likely to extend to the level of function.
Hjulsager
Charlotte Kristiane
CK
Department of Genetics and Biotechnology, Danish Institute of Agricultural Sciences, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark. ckh@dfvf.dk
Olsen
Birgit Schlichter
BS
Jensen
Ditte Marie Kjaer
DM
Cordea
Mirela Irina
MI
Krath
Britta N
BN
Johansen
I Elisabeth
IE
Lund
Ole Søgaard
OS
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D003062:Codon / Q000235:genetics; D017124:Conserved Sequence; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000821:virology*; D010935:Plant Diseases / Q000821:virology*; D011110:Polymorphism, Genetic; D017800:Potyvirus / Q000235:genetics / Q000472:pathogenicity*; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014774:Virulence / Q000235:genetics*
D003062:Codon; D014764:Viral Proteins