title: TMV mutants with poly(A) tracts of different lengths demonstrate structural variations in 3'UTR affecting viral RNAs accumulation and symptom expression.
abstract: The upstream pseudoknots domain (UPD) of Tobacco mosaic virus (TMV) is located at the 3'-untranslated region (UTR). It plays an important role in virus replication and translation. To determine the importance of UPD and 3'-UTR, and the effects of introduced RNA elements in TMV 3'-UTR, a series of TMV mutants with internal poly(A) tract upstream of UPD was constructed for structural analysis by selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). TMV(24A+UPD) and TMV(42A+UPD) formed a similar structure as that of TMV 3'-UTR, but TMV(62A+UPD) structures altered by the introduced poly(A) tract. In addition, TMV(24A+UPD) had a higher viral RNAs accumulation than TMV in N. benthamiana protoplasts, and induced lethal symptoms in the infected plants. TMV(62A+UPD) showed a drastically reduced accumulation, its coat protein was undetectable in protoplasts, and the inoculated plants remained symptomless. This study analyzed the structures of 3'-UTR of TMV and found that the longer poly(A) tract introduced upstream of UPD reduced viral RNAs accumulation and induced milder symptoms in N. benthamiana. In conclusion, different lengths of the internal poly(A) tract introduced into the TMV 3'UTR lead to structural variations that affect virus accumulation and symptom expression.
authors.affiliation: Department of Biological Sciences, National University of Singapore, Republic of Singapore.
authors.forename: Song
authors.initials: S
authors.lastname: Guo
authors.affiliation: Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego 12/14, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Kierzek
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, PRC.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Zhou
authors.affiliation: Department of Biological Sciences, National University of Singapore, Republic of Singapore.|Temasek Life Sciences Laboratory, Singapore, Republic of Singapore.|National University of Singapore Research Institute in Suzhou, Jiangsu, PRC.
authors.forename: Sek-Man
authors.initials: SM
authors.lastname: Wong
mesh_terms: D020413:3' Untranslated Regions; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000737:chemistry / Q000235:genetics; D011523:Protoplasts / Q000378:metabolism / Q000821:virology; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*; D014026:Nicotiana / Q000378:metabolism / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000737:chemistry / Q000235:genetics*; D014779:Virus Replication
chemical_list: D020413:3' Untranslated Regions; D012367:RNA, Viral; D011061:Poly A