Open AccessTransgenic Tobacco Plants Expressing the Potato virus X Open Reading Frame 3 Gene Develop Specific Resistance and Necrotic Ring Symptoms After Infection with the Homologous Virus
Author(s) -
Ken Kobayashi,
Silvia Cabral,
Gabriela Calamante,
Sara Maldonado,
Alejandro Mentaberry
Publication year - 2001
Publication title -
molecular plant-microbe interactions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.565
H-Index - 153
eISSN - 1943-7706
pISSN - 0894-0282
DOI - 10.1094/mpmi.2001.14.11.1274
Subject(s) - potato virus x , transgene , virus , biology , virology , open reading frame , tobacco mosaic virus , genetically modified crops , potato virus y , gene , inoculation , plant virus , genetics , horticulture , peptide sequence
Tobacco plants were transformed with the open reading frame 3 gene from Potato virus X (PVX) coding for the p12 protein. Although the transgenic plants exhibited a normal morphological aspect, microscopic examination revealed extensive alterations in leaf tissue structure. After being challenged with PVX, the transgenic plants showed resistance to PVX infection and formation of specific leaf symptoms consisting of concentric rings encircled by necrotic borders. These novel symptoms were accompanied by biochemical changes normally associated with the hypersensitive response (HR) and were absent in noninfected transgenic plants or in PVX-infected nontransgenic plants. No equivalent virus resistance was observed after inoculation with Tobacco mosaic virus or Potato virus Y, suggesting the presence of a specific resistance mechanism. Despite development of HR-like symptoms, systemic acquired resistance was not induced in PVX-infected p12 transgenic plants. No evidence of an RNA-mediated resistance mechanism was found.