Unique Glycine-Rich Motif at the N-terminal Region of Bamboo mosaic virus Coat Protein Is Required for Symptom Expression

• Published in: Molecular plant-microbe interactions Vol. 23; no. 7; pp. 903 - 914
• Main Authors: Lan, Ping, Yeh, Wen-Bin, Tsai, Chih-Wei, Lin, Na-Sheng
• Format: Journal Article
• Language: English
• Published: St. Paul, MN APS Press 01.07.2010; The American Phytopathological Society
• Subjects: active transport; Amino Acid Motifs; amino acid sequences; Bamboo mosaic virus; Biological and medical sciences; Capsid Proteins - genetics; Capsid Proteins - metabolism; Chenopodium quinoa; Chenopodium quinoa - microbiology; chlorosis; coat proteins; deletion mutational analysis; disease course; DNA, Complementary - genetics; DNA, Complementary - metabolism; Fundamental and applied biological sciences. Psychology; glycine (amino acid); host plants; mass spectrometry; microbial genetics; Molecular Sequence Data; mutagenesis; Mutation; necrosis; Nicotiana; Nicotiana - microbiology; Nicotiana benthamiana; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - microbiology; Plant Leaves - microbiology; plant viruses; Plant Viruses - genetics; Plant Viruses - metabolism; Plant viruses and viroids; signs and symptoms (plants); site-directed mutagenesis; virion; virulence; virus replication; Virus; Plant; Plant pathogen; Flexiviridae; Potexvirus; Bamboo mosaic virus; Protein
• ISSN: 0894-0282; 1943-7706
• DOI: 10.1094/mpmi-23-7-0903

The coat proteins (CP) of many plant viruses are multifunctional proteins. We used N-terminal sequencing and mass spectrometry/mass spectrometry analysis to identify a truncated form of the Bamboo mosaic virus (BaMV) CP missing the N-terminal 35 amino acids (N35). The N35 region is unique in the potexviruses by its containing a glycine-rich motif (GRM) not present in databases but highly conserved among BaMV isolates. Results from site-directed mutagenesis and deletion mutational analysis showed that loss of this region converted necrotic local lesions to chlorotic local lesions on Chenopodium quinoa leaves. Furthermore, this region is required for successful development of mosaic symptoms on Nicotiana benthamiana leaves but is dispensable for BaMV replication and cell-to-cell and long-distance movement as well as virion assembly. This unique GRM-containing region of BaMV CP may be a symptom determinant in specific hosts.