Turnip mosaic potyvirus resistance in Nicotiana benthamiana derived by post-transcriptional gene silencing.
The coat protein (CP) gene of turnip mosaic potyvirus isolate ESC8 (TuMV-ESC8) was cloned and sequenced. Comparisons of the 867-nucleotide (nt) CP region with those of 11 TuMV isolates showed 86.7-89.3% nucleotide identity and 92.4-95.5% amino acid identity. The CP gene was cloned into a plant expression vector and transformed into Nicotiana benthamiana plants via Agrobacterium tumefaciens-mediated leaf disk transformation. Progeny from R0 lines was screened for resistance to TuMV-ESC8. Five of 29 tested lines showed TuMV protection in more than 50% of their progeny. Interestingly, some of the resistant plants transformed with the CP gene of TuMV displayed mild mosaicism in the new growing leaves at the later stages of evaluation; but these mosaic symptoms disappeared when the leaves were fully expanded. Collective data from steady-state RNA analysis and nuclear run-on assay of a line showed that the resistance was RNA-mediated through the post-transcriptional gene silencing mechanism.
Jan
F J
FJ
Department of Plant Pathology, Cornell University, NYSAES, Geneva, NY 14456, USA.
Pang
S Z
SZ
Fagoaga
C
C
Gonsalves
D
D
D000595:Amino Acid Sequence; D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology; D030821:Plants, Genetically Modified / Q000821:virology*; D010947:Plants, Toxic; D017800:Potyvirus / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development* / Q000821:virology*; D014158:Transcription, Genetic; D014170:Transformation, Genetic; D019076:Transgenes