Inverse correlation between mRNA levels in GFP-silenced transgenicNicotiana benthamianaand resistance toPotato virus Xengineered to contain GFP sequence.

Shimono, Masaki; Ino, Makoto; Sonoda, Shoji; Fujimura, Tatsuhito; Nishiguchi, Masamichi

Nicotiana benthamianawas transformed with a green fluorescent protein (GFP) gene driven by cauliflower mosaic virus 35S promoter. A GFP-silenced line and a nonsilenced line were selected after ultraviolet irradiation. GFP short-interfering RNAs (siRNAs) were detected in the silenced line but not in the nonsilenced line. T1 progeny of the silenced line varied in GFP suppression patterns and were grouped into three types (I, II, III) based on the GFP suppression pattern. With Northern blot analysis, different levels of GFP mRNA accumulated, from a very low level in type I and II to an intermediate level in type III, in contrast to a much higher level in the nonsilenced line. Plants were also inoculated withPotato virus Xengineered to contain the GFP sequence to evaluate the levels of virus resistance. None to a few GFP spots were observed on inoculated leaves in types I and II, whereas numerous spots and systemic infection appeared in type III. These results showed that virus resistance was inversely correlated with the levels of mRNA, suggesting that the strength of RNA silencing determines the extent of virus resistance.

PLANT diseases; NICOTIANA; POTATOES; PROTEINS; PLANTS

Journal of General Plant Pathology, 2005, Vol 71, Issue 2, p147

1345-2630

Academic Journal

10.1007/s10327-004-0177-9