RT Journal Article SR Electronic(1) A1 Hirata, Hisae A1 Lu, Xiaoyun A1 Yamaji, Yasuyuki A1 Kagiwada, Satoshi A1 Ugaki, Masashi A1 Namba, ShigetouYR 2003 T1 A single silent substitution in the genome of Apple stem grooving virus causes symptom attenuation JF Journal of General Virology, VO 84 IS 9 SP 2579 OP 2583 DO https://doi.org/10.1099/vir.0.19179-0 PB Microbiology Society, SN 1465-2099, AB Among randomly mutagenized clones derived from an infectious cDNA copy of genomic RNA of Apple stem grooving virus (ASGV), we previously identified a clone, pRM21, whose in vitro transcript (ASGV-RM21) does not induce any symptoms characteristic of the original (wild-type) cDNA clone (ASGV-wt) in several host plants. Interestingly, ASGV-RM21 has only a single, translationally silent nucleotide substitution, U to C, at nucleotide 4646 of the viral genome within open reading frame (ORF) 1. Here, we characterize and verify this unprecedented silent-mutation-induced attenuation of symptoms in infected plants. Northern and Western blot analyses showed that less ASGV-RM21 accumulates in host plants than ASGV-wt. In addition, two more silent substitutions, U to A and U to G, constructed by site-directed mutagenesis at the same nucleotide (4646), also induced attenuated symptoms. This is the first report that a single silent substitution attenuates virus-infection symptoms and implicates a novel determinant of disease symptom severity., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.19179-0