Improved silencing suppression and enhanced heterologous protein expression are achieved using an engineered viral helper component proteinase.
RNA silencing limits transient expression of heterologous proteins in plants. Co-expression of viral silencing suppressor proteins can increase and prolong protein expression, but highly efficient silencing suppressors may stress plant tissue and be detrimental to protein yields. Little is known whether silencing suppression could be improved without harm to plant tissues. This study reports development of enhanced silencing suppressors by engineering the helper component proteinase (HCpro) of Potato virus A (PVA). Mutations were introduced to a short region of HCpro (positions 330-335 in PVA HCpro), which is hypervariable among potyviruses. Three out of the four HCpro mutants suppressed RNA silencing more efficiently and sustained expression of co-expressed jellyfish green fluorescent protein for a longer time than wild-type HCpro in agroinfiltrated leaves of Nicotiana benthamiana. Leaf tissues remained healthy-looking without any visible signs of stress.
Department of Agricultural Sciences, P.O. Box 27, University of Helsinki, FIN-00014 Helsinki, Finland.
T
T
Haikonen
M-L
ML
Rajamäki
J P T
JP
Valkonen
D001709:Biotechnology / Q000379:methods; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D017800:Potyvirus / Q000235:genetics / Q000254:growth & development* / Q000276:immunology; D034622:RNA Interference; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014026:Nicotiana / Q000235:genetics / Q000276:immunology / Q000821:virology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014773:Virology / Q000379:methods
D050505:Mutant Proteins; D011994:Recombinant Proteins; D014764:Viral Proteins; D049452:Green Fluorescent Proteins; D003546:Cysteine Endopeptidases; C072775:HC-Pro protein, potyvirus
Agroinfiltration; Helper component proteinase; Potyvirus; RNA silencing; Transient protein expression