Virus-induced cell death in plants expressing the mammalian 2',5' oligoadenylate system.
The major components of the 2-5A system, responsible for the mammalian interferon-induced antiviral response, are the 2',5' oligoadenylate synthetase (2-5Aase) and 2',5' oligoadenylate (2-5A) dependent ribonuclease (RNase L). Transgenic tobacco plants expressing these two enzyme activities were produced by crossing the transgenic plants expressing RNase L with those expressing 2-5Aase. The double transgenic plants showed complete resistance against cucumber mosaic virus (CMV), infection with necrotic spots only forming on the virus-inoculated leaf. On the other hand, although plants inoculated with potato virus Y (PVY) formed necrotic spots on the inoculated leaf and virus amplification could not be detected, all plants died within 20 days of inoculation. The transgenic tobacco plants expressing either 2-5Aase or RNase L activity showed typical disease symptoms with CMV- or PVY-inoculation. These results suggest that the introduced 2-5A system is activated in tobacco cells by dsRNA, the replicating intermediates of RNA viruses, leading to death of the host cells, which has not been observed in mammalian cells.
Ogawa
T
T
Central Laboratories for Key Technology, Kanagawa, Japan.
Hori
T
T
Ishida
I
I
D000227:Adenine Nucleotides / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D016923:Cell Death / Q000235:genetics; D017799:Cucumovirus; D004722:Endoribonucleases / Q000096:biosynthesis / Q000235:genetics*; D009843:Oligoribonucleotides / Q000096:biosynthesis* / Q000235:genetics; D010942:Plant Viruses / Q000235:genetics*; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D017800:Potyvirus; D014026:Nicotiana / Q000821:virology; D014779:Virus Replication / Q000235:genetics
D000227:Adenine Nucleotides; D009843:Oligoribonucleotides; C023505:2',5'-oligoadenylate; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease