Submitted to: American Phytopathological Society Potomac Division Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2005
Publication Date: 5/1/2005
Citation: Abraitiene, A., Zhao, Y., Hammond, R. 2005. Variant plant response in the whole plant nuclear targeting assay. Phytopathology. 95:S158.
Technical Abstract: The whole plant nuclear targeting assay, an experimental system that utilizes a vector derived from the cytoplasmic virus Potato virus X (PVX) to study and ultimately identify the nuclear targeting signals of Potato spindle tuber viroid (PSTVd), was developed by Zhao et al. (MPMI 82: 1911-1497, 2001). In that system, the coding region of the green fluorescence protein (GFP) was interrupted by insertion of an intron derived from the intervening sequence 2 of the potato ST-LS1 gene. In our study, four fragments representing different portions of the PSTVd upper RNA strand (1-180 bp) were embedded within the intron and the reporter RNAs were delivered into Nicotiana benthamiana plants via transient expression from a Potato virus X-based vector. High similarities between different organisms at the molecular level enables genes originally isolated from potato (such as the ST-LS1 gene intervening sequence) or even from the jellyfish Aequorea victoria (such as GFP) to function in N. benthamiana plants. However differences in the plant response among individuals to the same construct occurred, including the time of appearance and the pattern of GFP lesions and the splice sites and efficiency of RNA splicing. This study demonstrated significant effects of the plant genome upon such conservative molecular mechanisms as RNA trafficking, splicing, and protein expression. In addition to the correctly spliced RNA, alternative splicing or RNA recombination occurred in individual plants, as revealed by RT-PCR and sequence analysis of products derived from the same construct containing certain small PSTVd fragments.