A. The 22-nt complementary sequences of the ChlI genes
of various plants and Y-sat or Y-sat mutants. The 22-nt complementary
sequences in the ChlI genes (yellow region; YR) and in
the Y-sat (satellite yellow region; SYR) are in bold face. Site-directed
mutations were introduced in the SYR of Y-sat so that the generated
Y-sat mutants (Y-sat mut-Tom, Y-sat mut-Ara1 and Y-sat mut-Ara2) have
the 22-nt complementary sequence including G-U pairs to the host YR in
ChlI of tomato, Arabidopsis ChlI1
and ChlI2, respectively. Introduced mutations of the
Y-sat mutants are underlined. B. Yellow phenotype of pepper infected
with CMV-Y (left) or CMV-Y and Y-sat (right) at 10 dpi. Pepper has the
same YR sequence in the ChlI gene as that of tobacco.
C. Yellow phenotype of tomato infected with CMV-Y and Y-sat mutant,
Y-sat mut-Tom at 10 dpi. Left, tomato plant infected with CMV-Y and
Y-sat mut-Tom; right, tomato plant infected with CMV-Y and Y-sat. D.
Green mosaic on N. benthamiana
infected with CMV-Y and Y-sat mut-Tom at 14 dpi. Left,
N. benthamiana infected with CMV-Y
and Y-sat mut-Tom; right, N.
benthamiana infected with CMV-Y and Y-sat. E.
Yellow phenotype of Arabidopsis infected with CMV-Y and
Y-sat mut-Ara1 at 10 dpi. F. Green mosaic symptoms on
N. benthamiana infected with CMV-Y and
Y-sat mut-Ara1 at 14 dpi. Left, N.
benthamiana infected with CMV-Y; middle,
N. benthamiana infected with CMV-Y
and Y-sat; right, N. benthamiana
infected with CMV-Y and Y-sat mut-Ara1. G. The mRNA levels of
ChlI in Y-sat mutant-infected N.
benthamiana determined by quantitative real-time
RT-PCR. RNAs were extracted from equivalent systemic leaves infected
with CMV, CMV+Y-sat or CMV+Y-sat mutant, and equivalent leaves
of healthy N. benthamiana. ChlI mRNA
levels relative to the actin mRNA level are shown (mean
± SE; n = 3). H. SatRNAs
accumulation in Y-sat- and Y-sat mut-Ara1-infected N.
benthamiana. Total RNAs were extracted from the N.
benthamiana leaves shown in panel F. An ethidium
bromide-stained 1.2% agarose gel is shown. I. CMV accumulation at
14 dpi in systemic leaves of N.
benthamiana inoculated with CMV-Y and Y-sat
mut-Ara1, which was determined by conventional ELISA using antibodies
raised against CMV CP. Samples are those shown in panel F.